Luminous Landscape Forum
Equipment & Techniques => Digital Cameras & Shooting Techniques => Topic started by: elliot_n on November 05, 2010, 09:29:13 am
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Hi
I've recently started exploring the world of stitching. I'm attempting to achieve the resolution and image quality of a medium format digital back and/or large format film with my humble Nikon D700.
I'm interested to hear the experiences of others who have gone down this road.
My subject matter is urban - interiors and exteriors.
I like moderately wide angle views (90mm lens on 4"x5", 24mm lens on single frame Nikon). (I've no interest in wide-aspect ratio panoramas, 360VR tours, or distant landscapes.)
To achieve this I've been shooting multi-row stitches (3 rows of 6) with D700 + 50mm prime + Manfrotto 303 Pano Head + PTGui Pro.
The pano head (borrowed from a friend - I've just ordered a Nodal Ninja 5) made the world of difference - totally seamless stitches from PTGui Pro in easy (automated) mode.
I've had some problems with the geometry of the final stitch, and at the moment I'm finding it essential to take a preliminary single frame wide-angle reference shot of the whole view, framed to my liking, so that I can locate my intended centre point in the final stitch. (Anyone else do this?)
I'm interested to know how closely this technique can emulate a single medium format or large format capture?
Seems to me that one essential difference is that with stitching the plane of focus is spherical (there's no way you can get a sharp picture of a brick wall at f5.6). I like deep focus, and have found that shooting at f16 is the best compromise (f22 is too mushy).
Any thoughts
Elliot
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I went through this process a couple of years ago Elliot using a D3x and Phase P-45+ (on controlled landscapes). I tried every way I could think of to make the Nikon stitches look as good, but it never did and I ended up selling the Nikon and keeping the Phase. I'm sure many others have come to the opposite conclusion though (especially with the X) - it really is what you want to see and believe and you could go either way...
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I'm interested in what ways the D3X, stitched, failed against the P45. I'm thinking it would only take 3 vertical frames from the D3X to match the P45's resolution, so a simple stitching operation (compared to the multi rows I'm stitching).
I'll soon be digging out my 4"x5" camera to do a direct comparison of stitched D700 against a sheet of large format film. Both techniques seem about equally fiddly (if you include the hassle of scanning and retouching the film).
(I should have mentioned in my original post, that this is for big (minimum 30"x40") exhibition prints.)
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There is a lot more to it than just resolution (discussed to death here and elsewhere), otherwise you probably already answered your own question, know what you are going to do, and don't need any more info. Like I said, it really has a lot to do with what you want to see...
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There is a lot more to it than just resolution
Yes, that's what I'm interested in discussing here.
(discussed to death here and elsewhere)
So far, I've found relatively little about using stitching to emulate a large format film workflow. This article goes into some detail: http://www.scotthendershot.com/Example01.aspx
otherwise you probably already answered your own question, know what you are going to do, and don't need any more info
Hmm, I'm new to this. Whilst I've got some things resolved - e.g the necessity of using a spherical panorama head and good stitching software - there are other issues that I'm only just learning about. For example:
- The focal plane in a stitched shot is spherical.
- As you increase resolution (by adding more images to the stitch), you lose depth of field. No problem if your shooting a giga-pixel view of the city from your balcony, but limiting if you're photographing an interior. By my calculations (allowing for a 30% overlap between frames), a 3x3 vertical frame stitch from a D700 has an effective sensor size of 56mm x 84mm, and a 5x5 stitch has a sensor size of 88mm x 132mm (about the same as 4"x5" film).
- Geometry. I've been overlaying my stitched shot on an uprezzed single frame capture. There are geometrical differences that I haven't fully understood. Some are good - no vignetting or barrel/pincushion distortion - but sometimes horizontal or vertical dimensions seem squashed. (This is using PTGui at its default settings - except for setting a centre point of the image. PTGui is obviously capable of infinite variations in rendering, but I'm wary of tinkering too much. I just want the straightforward (?) view of a single frame capture.)
- Dust. A 5x5 stitch means 25 times more dust from a dirty sensor.
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Hmm, I'm new to this. Whilst I've got some things resolved - e.g the necessity of using a spherical panorama head and good stitching software - there are other issues that I'm only just learning about. For example:
- The focal plane in a stitched shot is spherical.
Ah, a grand disclaimer, which isn't necessarily true. As a relative newbie, you're forgiven ;)
You mentioned "good stitching software" (the spherical panorama head is only needed to avoid parallax issues). Good stitching software knowns how to deal with the effects of re-focusing. By checking the "focal length" parameter in a "good stitching software" as a part of the optimization, the magnification differences due to re-focucisng will be reduced.
- As you increase resolution (by adding more images to the stitch), you lose depth of field. No problem if your shooting a giga-pixel view of the city from your balcony, but limiting if you're photographing an interior. By my calculations (allowing for a 30% overlap between frames), a 3x3 vertical frame stitch from a D700 has an effective sensor size of 56mm x 84mm, and a 5x5 stitch has a sensor size of 88mm x 132mm (about the same as 4"x5" film).
In fact, the DOF of a larger format "sensor" is also 'limited'. The general explanation is the larger maginification by the longer focal length.
- Geometry. I've been overlaying my stitched shot on an uprezzed single frame capture. There are geometrical differences that I haven't fully understood. Some are good - no vignetting or barrel/pincushion distortion - but sometimes horizontal or vertical dimensions seem squashed. (This is using PTGui at its default settings - except for setting a centre point of the image. PTGui is obviously capable of infinite variations in rendering, but I'm wary of tinkering too much. I just want the straightforward (?) view of a single frame capture.)
This is related to the "projection" one chooses for the final stitch. The current champion of projection methods is PTAssembler (for Windows only).
- Dust. A 5x5 stitch means 25 times more dust from a dirty sensor.
A decent Raw converter allows to duplicate the "spot" corrections (which are the same for a number of images).
Cheers,
Bart
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Ah, a grand disclaimer, which isn't necessarily true. As a relative newbie, you're forgiven ;)
You mentioned "good stitching software" (the spherical panorama head is only needed to avoid parallax issues). Good stitching software knowns how to deal with the effects of re-focusing. By checking the "focal length" parameter in a "good stitching software" as a part of the optimization, the magnification differences due to re-focucisng will be reduced.
Thanks for the reply.
I've been doing my tests with a demo version of PTGui Pro.
I've been following what I think is the orthodox method of not changing focus between shots. I'm using old Nikkor A-iS primes, so I don't think PTGui Pro would have any focus information to read if I decide to change focus between shots. But it's a technique I should look into.
I guess another option would be to focus stack and then use Helicon Focus - but I think number of images would become unwieldly.
Actually I did another test shot of an interior earlier today - 3x3 grid with a 50mm lens to emulate the view of a 24mm lens - and with the 50mm set at f16, with the focus set a third of the way into the room, the overall depth of focus was quite acceptable.
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I've been following what I think is the orthodox method of not changing focus between shots. I'm using old Nikkor A-iS primes, so I don't think PTGui Pro would have any focus information to read if I decide to change focus between shots. But it's a technique I should look into.
PTGUI or PTAssembler or Hugin don't need focus information, it's automatically derived from the parameter optimization. By allowing the optimizer to also optimize focal length, differences in image magnification can be resolved. That way one can keep the focus on a plane.
I guess another option would be to focus stack and then use Helicon Focus - but I think number of images would become unwieldly.
Focus stacking is also possible, and there as well one needs to allow the focal length parameter to be optimized. The number of images does grow, and then one can also add HDR exposure bracketing. Programs like PTAssembler can do it all, stack, fuse exposures and focus layers, and stitch it all together.
Cheers,
Bart
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Look for Bernard Languillier's posts. He does a lot of stitching with a Nikon.
Kumar
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Look for Bernard Languillier's posts. He does a lot of stitching with a Nikon.
Kumar
Yes, his posts here and elsewhere put me on to the idea of stitching Nikon files for high res images.
I've been doing test stitches for the last few days and I'm finally getting the hang of it.
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I do stitching with a D700, Zeiss 50 Makro combination. Works great. You do end up with some quite large files, though.
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hi
i use a D3X with the 24 45 and 85 PCE lenses, using the shift makes stiching quite easy, i use a linhof multiview finder on top from my 4x5 which i have set up to show 3 frames stitched on the 45 and 85 (3 frames on the 24 goes too wide for the finder).
the quality is very good (even without stiching...), i didn't go down the MFDF route so i can't compare but i've made exhibition prints up to 2,66 meters wide using this technique and if properly treated they are really very good.
adrian
http://adriantyler.net/
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Yes the D3X sounds like the ultimate stitching camera. On a D700, shifting the lens won't give me the resolution I'm after, so I'm stuck with multi row panos. Pre-visualising the shot is important for me. I'm shooting standard aspect ratios (2:3, 4:5), so I use a 20-35/2.8 on my D700 to find my frame, and then either a 50/1.8 or an 85/1.8 to shoot the stitch.
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I've stitched for years and love the creative freedom and image quality that it provides.
I have recently begun stitching with an old 55mm 3.5 Nikkor macro. I had no idea that my D300 could produce images so rich in laser sharp detail. Highly recommended.
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It seems that all stitching is done taking pictures from a single vantage point, presented as some projection? Is this the only interesting way of doing things?
I imagine taking images along a line, projecting the resulting images "planar"(?) to the output. That way, "wide scenes" could be captured even when it is impractical to back up a lot, and I am curious as to what it would look like.
-h
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National Geographic Magazine did exactly that, only vertically. It's difficult to get a top-to-bottom shot of a very tall tree in the forest. By the time you get far enough away to see the entire tree, it's hidden behind other trees.
Their solution was to hoist a camera up the side of the tree, shooting successive images which were stitched in to a complete whole. Very successful, IMHO.
http://www.npr.org/blogs/pictureshow/2009/09/redwoods.html
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National Geographic Magazine did exactly that, only vertically. It's difficult to get a top-to-bottom shot of a very tall tree in the forest. By the time you get far enough away to see the entire tree, it's hidden behind other trees.
Their solution was to hoist a camera up the side of the tree, shooting successive images which were stitched in to a complete whole. Very successful, IMHO.
http://www.npr.org/blogs/pictureshow/2009/09/redwoods.html
that must have been a REALLY calm day, the first breeze will make stitching very hard...
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It seems that all stitching is done taking pictures from a single vantage point, presented as some projection? Is this the only interesting way of doing things?
I imagine taking images along a line, projecting the resulting images "planar"(?) to the output. That way, "wide scenes" could be captured even when it is impractical to back up a lot, and I am curious as to what it would look like.
-h
That's called orthographic stitching and is much harder to do well. Most software is optimized for spherical stitching.
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That's called orthographic stitching and is much harder to do well. Most software is optimized for spherical stitching.
Haven't tried yet, but the beta2 version of Autopano pro is supposed to now be able to handle these cases also.
Cheers,
Bernard
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This isn't really it, but the 140 megapixel image below was stitched handheld yesterday with a 100mm lens, I was probably standing 10m away from the store. Autopano pro 2.5 beta2 had no problem whatsoever dealing with it.
http://www.flickr.com/photos/bernardlanguillier/5213556089/sizes/o/
Cheers,
Bernard
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the quality is very good (even without stiching...), i didn't go down the MFDF route so i can't compare but i've made exhibition prints up to 2,66 meters wide using this technique and if properly treated they are really very good.
I've been using the 5dII and various t/s lenses for stitching. With a three frame stitch I get a picture that is roughly the same size as the files from the H4D-40. It seems to me that while the overall quality is good, using digital medium format is still better when the number of pixels are the similar. I think this is because with the stitch you are starting to use pixels on the far edge of the image circle and there seemed to be more degradation than with MF lenses.
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I've been using the 5dII and various t/s lenses for stitching. With a three frame stitch I get a picture that is roughly the same size as the files from the H4D-40. It seems to me that while the overall quality is good, using digital medium format is still better when the number of pixels are the similar. I think this is because with the stitch you are starting to use pixels on the far edge of the image circle and there seemed to be more degradation than with MF lenses.
Indeed, this is one of the major advantage of cylindrical stitching/planar projection compared to T/S stitching. You always use the central portion of the lens and the corners of the resulting pano are just as sharp as the center.
Some very experienced Japanese landscape photographers who had never seen large panos before couldn't believe their eyes when they saw some large prints at a show I did a few months ago at the Nikon salon in Tokyo. They had a hard time dealing with the fact that corners were just as sharp as the center portion. The reproduction of the scene was so real that it had almost lost its photographic dimension to them. It did trigger some interesting discussions though. :)
I have tried both extensively and have basically given up on shift pano, it is slower, less scalable and offers lower image quality.
Cheers,
Bernard
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Do you walk and snap? Are there some tricks to keeping the line and the plane of focus? Overlap? Are you using the 100/f2 ZF?
Very cool shot of the store front.
Thanks,
Cecelia
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Do you walk and snap? Are there some tricks to keeping the line and the plane of focus? Overlap? Are you using the 100/f2 ZF?
Those were shot from a single location, indeed with the 100 f2 ZF.
Cheers,
Bernard
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Elliot,
I'm sorry I found this thread late. I have been shooting this way for several years. I shot 4x5 for about 30 years. Stitching started out as a curiosity and now all my work is stitched mosaics. I could write about it here but my thoughts have already been captured in the pages in the links below.
All the best.
Scott
http://www.scotthendershot.com/ThoughtsOnADigitalWorkflow.html
http://www.scotthendershot.com/Example01.aspx
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Hello !
I have finally joined Luminous Landscape as I think this site best represents my photographic heartland.
I have just posted the following tutorial on stitching on my FLICKR site.
I have about 2 years experience in developing this technique so what is said below is my from my own personal experience. In terms of software I may not have tried all stitching suites but the Arcsoft package I use seems to work very well. Needless to say once you have made your final mosaic then post process as normal. With in camera dynamic range modulation and PP HDR suites such as HDR Expose, high dynamic range is not an issue.
Just so that there is no misunderstanding I am regularly attaining resolutions of 10,000 x 6,000 pixel size mosaics with the minimum of fuss and processing time.
Hope this helps and of course I welcome feedback::
STITCHING DIGITAL IMAGES. A TUTORIAL
Stitched mosaic composite images have a very high resolution attained by stitching multiple photographs together. Most photgraphers avoid stitching as a way to increase image resolution because it is thought of as too hard, just for panoramas, time consuming or "cheating''. The key is to see stiching - or more accurately digital mosaic, as a cool way of producing super resolution digital photographs.
It seems ludicrous to pay for large format film (equipment, film processing and drum scanning) when near large format quality images can be easily and readily produced by stitching small numbers of full frame digital images together.
The technology of stitching has been explored historically by the likes of Max Lyons (no relation to me) and Roger N. Clark - and the internet references are easy to Google.
However here I take the process a little further - not in terms of resolution but in terms of a practical tool.
Firstly - you can stitch any images from any camera provided the pixel dimesions are the same. The larger the sensor the greater the end resolution.
In my experience the greater the number of images stitched the greater the chances of stitching errors (seams, overlaps and ghosting) and the greater the time involved.
SHOOTING
Use a SMALL number of images.
Holding level is important. If you require perfect stitches then you must use a tripod with a leveling head. An expensive panoramic head is not really required. I have a dual head system for this work. It consists of a Manfrotto 438 ball level head with a Manfrotto 293 long lens support with a quick release plate bolted to just below the lens end (on the long lens support), rather than the camera centre. This is a poor man's version of a panoramic head, which are very costly. It works really well.
So you now have the camera on a level footing - so when the camera rotates in a horizontal arc it does not diverge from the horizontal - good !!
Oh and use a 50mm SHARP lens. Too wide angle a lens and linear distortion will screw up your mosaic, and there is no point using a soft lens when resolution is your main concern !
How many images will you need ? - 3 full frame taken in PORTRAIT orientation is all you need to give super resolution (assuming you are a full frame user). Even with APS-C sized sensors you will achieve very great resolution.
Do a test shot to meter your scene- stopped down for depth of focus. FIX the shutter speed. FIX the white balance, set the dynamic range adjsutment as required and keep it FIXED.
Shoot 3 images in a horizontal line overlapping by 15 to 20 %. That you can estimate by eye.
Thats all at the shooting stage.
POST PROCESSING
I have tried many stitching programmes. Most are heavily flawed. The only one that I recommend is Arcsoft Panrorama Maker Pro version 4. It is easy to use, intuitive, fast and yields consistently good results. It can rotate your images and compensate for exposure and some linear variations. However if you have followed the guidelines above it will not even have to do that. The better aligned your images in camera, the more sensor area you will end up with and the less chance of stiching seams.
Hey presto you will have a PERFECT high resolution image with an aspect ratio of approx 5:3.
I consistently get images now of approx 10,000 x 6000 pixels.
As a rule of thumb the 3 in a row horizontal stitch (portrait orientation) gives 2.6 to 2.75 times the area of your camera sensor.
If you believe (as I do) that a good digital sensor has 4.8 times the resolution of fine grain film (per unit area) then this is then giving about 85% of the resolution of 5"x 4" large format film.
((It is widely believed now that a full frame digital sensor will give the same or slightly better resolution than fine grained 7cm x 6cm film. This is of course an argument that applies to resolution only and not some of the other qualities that film fanatics argue make film so attractive. It could be said though that in the film vs digital debate the technical argument is over, so it now boils down only to personal preference, pre- existing camaras you may own and your skill set))
Experimenting with stitching is much cheaper than trying out large format film. Your outlay is a tripod and two heads and a suite of inexpensive software.
Malcolm Lyons
January 2011
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I have tried many stitching programmes. Most are heavily flawed. The only one that I recommend is Arcsoft Panrorama Maker Pro version 4. It is easy to use, intuitive, fast and yields consistently good results.
Hi Malcolm
I use PTGui. Not sure of your thoughts on that stitcher but interested if you have tested and find it flawed. I find it great and getting better all the time.
I just had a look at the Arcsoft website to find some answers to the questions I would ask, but they were not available, so I thought I would reply here. Yes I could download and try but there is little point as I am very pleased with PTGui. But specifically though, two things that are important for me. In Arcsoft (i) can you correct for perspective, i.e. get the verticals vertical and (ii) can you template a series of images for hdr?
I do a lot of what you describe but find hdr very useful to increase my dynamic range capture when needed. Stitching images first and replicating for each exposure set (template needed) then into hdr. Trying HDR Efex by Nik at the moment which I think I might prefer over my normal Photomatix. But it keeps crashing on me! That said I think the main reason is that my laptop is underpowered for the task really, trying to merge three 20000x4500px tiffs!!!
The other thing to add is correcting for vignetting before all of the above. Really important, but perhaps more so when going to HDR.
Steve
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Thanks Steve
I do not think I looked at PTGui, but if you have a suite that works well then I would stick to it.
In reference to your questions about Arcsoft ::
The suite will correct barrel and pincushion, will NOT correct perspective will but attempts to match in perspective errors anyway and does a good job. I have never had white balance, vignetting of exposure artefacts with Arcsoft as it auto-corrects all of these. My lenses have insignificant vignetting anyway.
If I have bad perspective distortion I will correct those before I load into the stitching software. It seems to make little difference to the final IQ in terms of the small loss of definition that this will cause along one image edge and helps to get a smoother stitch.
I bought Altostorm Rectlinear Plugin for Photoshop (works with newer PS Elements and Media Chance Photobrush) recently. This will completely correct the common horizontal (and vertical) curvature in mosaics and can be fine tuned. It is BRILLIANT.
In reference to HDR I try and use the appropriate dynamic range settings in camera then stitch those images. They are of course JPEGs.
If I need further HDR afterwards I do it to the final stitched image by creating a -2EV and + 2 EV version of the stitch and combining in HDR Expose which is my preferred suite. I know know its not true HDR but it works very very well.
Otherwise you are into so many shots and so much post processing time you might as well be shooting film and paying for drum scans (or buying an Epson flat bed film scanner).
In terms of lenses I am now only using an old Pentax SMC 50mm 1.8 M42 lens with an adapter on a Sony A800. The combination works well in terms of IQ. A 50mm lens like this gives to much detail and so little distortion that stitching is then a dream. Because the lens is manual there is no chance of exposure of focus variations.
Cheers Malcolm
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I'd like to comment on a couple of things that I've found make a big difference in this process.
First is that I Shoot RAW. RAW offers some significant image quality advantages over jpeg. Not the least of which is the ability to correct for lens distortions prior to stitching. I import all my RAW files into Lightroom and use the automatic lens correction built in. It's painless. I have a preset that applies the appropriate corrections based on the lens identified in the EXIF data. The image is corrected for distortion, CA and vignetting automatically. I find that when distortion is corrected for images made with short focal lengths they stitch better. Images made with longer focal lengths stitch well corrected or not.
I always bracket. Most of the time I shoot -2, -1, 0, +1, +2 even if the histogram on the camera says I'm good. I find that Shadows render much better when they are exposed longer and I very very often blend in highlight detail that would have been lost on a normal exposure.
Next is that I use Autopano Giga from Kolor (www.autopano.net). I have not used PTGui or Arcsoft so I can't comment on how well they work or how easy they are to use but I can tell you that Autopano builds magnificent mosaics whether you are stitching 2 frames or 2000. It can also handle bracketed images seamlessly. With one click Autopano will separate all the bracketed frames into separate stacks and then allow you to output a separate file for each bracket All stitched identically. This is great for combining for HDR or layering in Photoshop. Autopano also has tools for easily correcting distortions such as convergence. It's an easy program to install and learn and I believe worth a small investment in time to try out their trial version.
For HDR processing I haven't found anything that works better than Oloneo PhotoEngine. PhotoEngine can take in 7 100megapixel images and let you process them in real time without skipping a beat. I just did an image that was 5 separate 10,600 x 16,300 pixel files and Oloneo read them in as cleanly as if they were single frames. Try those file sizes with Photomatix or Nik.
I love large format film. I worked with large format for 30 plus years and can say that the view camera experience has always been thing of joy. I won't pretend for a moment that stitching is easier or replaces large format film. But it does have some very real advantages.
I can carry one camera and use it for casual spontaneous photographs or for deliberate calculated stitched mosaics. I don't need to make two trips to the lab and spend $5 for film and processing for each press of the shutter release. When I leave the location I know that I have captured the image and I don't have to worry about film being ruined going through airport security or having someone open the film box not understanding the consequences. For any focal length you can increase the field of view by stitching additional frames without changing the perspective. I no longer need to send my negs off to be drum scanned or mess with oil mounting on my flatbed scanner. I can easily capture wide subject brightness ranges by adding additional exposures. But the most compelling reason I have found is that I am able to produce stunning prints at my favorite sizes (20 x 24 and larger.)
In many ways shooting stitched mosaics exercises the same brain functions as shooting with a view camera. You really have to pay attention to the details of what you are doing. You can't see the final image through the viewfinder so you have to use your mind to visualize what you are shooting. It becomes a slow methodical experience that I truly enjoy.
One issue with using a DLSR for stitching is that many lenses don't stop down to those extreme apertures that you have on large format lenses. Along with that there are perceived diffraction issues with using apertures smaller than say f/16 on my D300. I say perceived because you have take the entire system into account when considering diffraction. That means the print size and viewing distance. When stitching images the magnification of the final print is reduced and thereby reduces the effects of diffraction.
But depth of field is a real issue. Where I could easily stop down to f/45 or smaller on a large format lens I can only stop down to f/16 on my 85mm. That makes the plane of focus critical. I used to make assumptions about actual depth of field and just stop down to cover it. Now I use a DOF application on my iPhone and a laser distance meter to measure everything. It adds more time and complexity but even changes in the plane of focus of 6 inches can sometimes mean success or failure when f/16 is your minimum aperture. A laser distance meter is an excellent tool to add to your bag.
Below is an image that is from 125 stitched frames (5 rows x 5 columns x 5 exposures.) I found that I was not able to capture the field of view I needed using my normal 3x3 matrix because I was already against the wall behind me. Adding a couple of columns and a couple of rows solved my problem. The length of time to capture all 125 frames was 38 minutes. Seems like a long time but I always found I averaged about one image per hour with the view camera.
(http://www.scotthendershot.com/images/CountyBuilding02_V5_Edit_03.png)
Sorry for the long winded post but this is a subject that is very dear to me.
All the best.
Scott
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i use a D3X with the 24 45 and 85 PCE lenses, using the shift makes stiching quite easy...
http://adriantyler.net/
I use the same material and must say the quality is very good indeed. The PCE lenses are very good even at 2.8 .
here an example of a panorama made with a shifted 45mm pce with tilt as well... I made a print of about 210 cm wide that looks gorgeous...
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Indeed, this is one of the major advantage of cylindrical stitching/planar projection compared to T/S stitching. You always use the central portion of the lens and the corners of the resulting pano are just as sharp as the center.
Cheers,
Bernard
I don't do stitching (don't own a pano head) but there's another big difference in that cylindrical projection looks really different perspective-wise. Everyone's (least?) favorite website outlines the difference pretty clearly here:
http://www.kenrockwell.com/tech/fisheye-hemi.htm
If there are a lot of horizontal lines this can be an issue. Otherwise, it mitigates a lot of the perspective distortion most people find so unpleasant and so you can go much wider than you would otherwise. Honestly, panoramic stitching offers a pretty insane number of benefits over other methods. But it's so different ontologically from shooting large format or any single image format that it's not so much emulating it as doing something entirely different (and arguably much better).
((It is widely believed now that a full frame digital sensor will give the same or slightly better resolution than fine grained 7cm x 6cm film.
Believed by whom? While I agree that the 5DII looks subjectively better than 6x7 film, it's because it has less grain and more micro-contrast, not equal resolution. Fwiw, 4x5 has equal resolution to high-end 6x7 (more-or-less) but it has less grain and more micro-contrast. I'm not sure the 5DII has 4x5 beat yet, but it's close. The huge prints I've seen from film look better from a short distance away, on par with FF digital from a normal viewing distance. But then I'd argue the difference is in approach to how you shoot more than image quality.
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5DII is maybe close to MF Film - Not even close to 4 X 5 drum scanned chrome done correctly ...the key is DONE CORRECTLY....many many ways to mess up 4 x 5 tranny
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Having read the comments about stitching suites here I decided to try a trial version of PTGui. The comments on this site are now bourne out - this is a superior suite than the Arcsoft - is capable in so many more ways - dealing with large files where Arcsoft crashes, offering superior perspective and seam control, easily dealing with larger numbers of tiles than Arcsoft is able to handle. It can also do in house exposure bracketing and HDR with the pro version.
Oh well - thats NZD 270 to find. Good jiob its my birthday soon !
Malcolm
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5DII is maybe close to MF Film - Not even close to 4 X 5 drum scanned chrome done correctly ...the key is DONE CORRECTLY....many many ways to mess up 4 x 5 tranny
I agree, but only up close. From a distance, the 5DII can look as "sharp" as anything but 8x10, then it falls apart on close inspection. Whereas 6x7 has much more resolution than the 5DII (rarely in practice because you need perfect technique, a cable release, and slow film) but it's grainy and with poorer micro-contrast. Only the rare 4x5 negative has much more resolution than 6x7 (lenses and film flatness work against you), but the tonality is much better. Looks more digital to me, actually.
While I agree 6x7 is easily replaced by full frame digital, the two are still quite different looking and have distinct technical merits.
Is there any way to stitch hand held and make it work, btw? If I could do that I would be very happy.
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Is there any way to stitch hand held and make it work, btw? If I could do that I would be very happy.
Depending on the amount of light you have and the subject matter you will have various degrees of success stitching hand held. Parallax is the problem. Even small movements will change the relationship of objects in the foreground to objects in the background. If the subject is in a single plane then stitching hand held is pretty easy. Otherwise it requires really good technique and the more your subject is in a single plane the better. It's the foreground to background relationships that mess things up.
I have rotated the camera vertically and been successful stitching 4 frames in a single row when there was a fair amount of image in the foreground but I had to brace myself against a wall and place my index finger under the barrel of the lens and use that as my point of rotation. Some people use a string as guide with one end under their foot and stretch it tight. I haven't tried it but I don't see it being effective for me.
I think it's always worth a try if you don't have a panohead with you. Do everything you can to rotate around the No Parallax Point of the lens. If you can avoid foreground objects then you will have an easier time stitching. Keep in mind that simple and effective panoheads are very easy to build. And if you purpose one for a specific camera and lens they can be really fast to use. I'm currently building a "travel" panohead out of a bamboo cutting board so I don't have to trust my heavy expensive one to the airlines.
Scott
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Having read the comments about stitching suites here I decided to try a trial version of PTGui. The comments on this site are now bourne out - this is a superior suite than the Arcsoft - is capable in so many more ways - dealing with large files where Arcsoft crashes, offering superior perspective and seam control, easily dealing with larger numbers of tiles than Arcsoft is able to handle. It can also do in house exposure bracketing and HDR with the pro version.
Oh well - thats NZD 270 to find. Good jiob its my birthday soon !
Malcolm
why spend that much when you can buy APP as noted above. even the standard program gives many features, again as noted above and iam sure does not cost that much. with out checking it was 90 euros last time around
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I have rotated the camera vertically and been successful stitching 4 frames in a single row when there was a fair amount of image in the foreground but I had to brace myself against a wall and place my index finger under the barrel of the lens and use that as my point of rotation.
Interesting...is the parallax point usually where the lens meets the body (or half way between sensor and front element or something)?
I don't have any plans to use this technique, but I've been trying to carry my t2i with me everywhere and sometimes I see something that deserves a little more resolution.
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I don't do stitching (don't own a pano head) but there's another big difference in that cylindrical projection looks really different perspective-wise. Everyone's (least?) favorite website outlines the difference pretty clearly here:
http://www.kenrockwell.com/tech/fisheye-hemi.htm
If there are a lot of horizontal lines this can be an issue. Otherwise, it mitigates a lot of the perspective distortion most people find so unpleasant and so you can go much wider than you would otherwise. Honestly, panoramic stitching offers a pretty insane number of benefits over other methods. But it's so different ontologically from shooting large format or any single image format that it's not so much emulating it as doing something entirely different (and arguably much better).
Are you aware the pano softwares like autopano pro and PTgui offer planar projection which is geometrically impossible to distinguish from a single capture? That is what most of us doing pano have been using for years.
Regards,
Bernard
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Didn't know that. Doesn't it stress the image a bit, so much restructuring? I actually prefer the look of cylindrical projection most of the time.
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Didn't know that. Doesn't it stress the image a bit, so much restructuring? I actually prefer the look of cylindrical projection most of the time.
Well, you can of course choose either depending on your needs.
There are of course limits to the field of view that can be handled by planar projection, which are the same limitations impacting wide angle lenses. The good news is that you are "stretching" pixels less and less the closer you get to the edge of the field, since you are using more original frame pictures to represent those near the edge of your resulting image.
The net outcome is perfect corner to corner very wide shots that are way superior to what can be achieved with a single wide lens or a T/S lens.
Anyway, try it for yourself and you will see. :)
Cheers,
Bernard
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Didn't know that. Doesn't it stress the image a bit, so much restructuring? I actually prefer the look of cylindrical projection most of the time.
The great thing about good stitching software is that it usually also includes a great number of projection methods (http://www.tawbaware.com/projections.htm). Some of them are 'tweakable' and there can even be a hybrid of different methods, depending on the subject.
Cheers,
Bart
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I used to stitch occasionally with a Cambo WDS and a P45+ back. With that camera body and a lateral shift, the lens stayed still and the back moved (good). A vertical shift the lens moves (a pain) so a 4 quarters shift and stitch always needed a bit of fiddling!! Rarely needed that much resolution certainly for my commercial clients.
That said I have given all that up and gone back to dslrs. The odd time I need more resolution now and also perspective correction I stitch with PTGui. I use the D3s and the D3x with precise nodal adjustment for each lens and an RRS pano head. If you think the resolution of stitched P45+ image is good when compared to the stitched dslr images those are stunning. Yes I am using the best Zeiss glass, the ones that Lloyd Chambers rates, the 25mm (OK), 35/f2 (v. good) the 50mm f/2 (v. good) and of course the 100mm (awesome). The D3x for ultimate resolution but more often than not the D3s (10 frames a second) and then HDR when needed. Rapid capture I am sure takes the ultimate edge off each image, but the quick succession certainly helps with hdr. I think even if I was to use the Alpa Max(?) which I have not tried and therefore not need the above fiddle(!) I would be surprised if it could compete quite honestly.
Post processing mmmm, I'm sure is more time consuming. But most of the time I never do it. Most images didn't warrant that attention and/or the clients didn't expect that quality. But when they or I did need the extra, the RRS pano head comes apart easily and is not too big to carry around with you. I use the L brackets anyway. So I think I have the best of both world most of the time.
Steve
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Elliot,
I'm sorry I found this thread late. I have been shooting this way for several years. I shot 4x5 for about 30 years. Stitching started out as a curiosity and now all my work is stitched mosaics. I could write about it here but my thoughts have already been captured in the pages in the links below.
All the best.
Scott
http://www.scotthendershot.com/ThoughtsOnADigitalWorkflow.html
http://www.scotthendershot.com/Example01.aspx
Hi Scott-
I see you finally found the Luminous Landscape; you will find some very knowledgeable and helpful readers here.
I would encourage anyone interested in stitching to visit Scott’s site; really beautiful work and lots of information. Unfortunately, web presentation is a great leveler and you can’t see the quality of his prints. I will say that several years ago his prints and comments convinced a dyed-in-the wool-die-hard-I-know-what-I-like Cibachrome printer to buy an Epson inkjet. You can see a better representation of his work in Lenswork
Best,
Tom
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The great thing about good stitching software is that it usually also includes a great number of projection methods (http://www.tawbaware.com/projections.htm). Some of them are 'tweakable' and there can even be a hybrid of different methods, depending on the subject.
Cheers,
Bart
Thanks, I'm going to have to try some of that. I'm not normally a fan of ultra-wide (wider than 24mm on 135) lenses because of the distorted corners, but that looks promising.
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Interesting...is the parallax point usually where the lens meets the body (or half way between sensor and front element or something)?
I don't have any plans to use this technique, but I've been trying to carry my t2i with me everywhere and sometimes I see something that deserves a little more resolution.
The 'no parallax' point is pretty much the same as the 'entrance pupil'. It is not the same as the 'front nodal point' or 'rear nodal point', however the front nodal point and the entrance pupil can be located at the same position.
Just look in the front of the lens to find the entrance pupil. It is located at the apparent position of the diaphram. Most modern lens (especially zooms) will move the entrance pupil around when zooming and/or changing focus so they can be hard to use for stitching. The more accurately you can rotate around the entrance pupil, the less parallax will occur so you can include closer objects in the foreground.
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Hi Tom,
Thanks for the kind words. I guess you never know who you are going to run into on these forums. Interesting that you are reading about stitching. Have you started doing mosaics?
Scott
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Hi Steve
I purchased PTGui 1 week ago and now have has some experience with this suite and I have some observations to make.
Firstly may I say that PTGui is clearly the best suite developed so far. It outperforms Arcsoft and all others I have tried and so it is now my default stitcher. I need not detail its benefits here. I purchased the pro version mainly due to its ability to stitch bracketed images and apply in suite HDR and tone mapping. Thats important if you have a very high dymanic range in your required end image.
Wanting to gain the highest possible resolution I attempted an eight stitch image with 3 exposures per frame - a total of 24 vertically oriented (portrait mode) images and then applied the HDR at the end. I shoot full frame at 24 megapix per shot. To produce a good wide angle view (equivalent to a FL of about 20mm in my final stitch) I chose a 70mm FL for each frame. I have a very fast computer using Windows 7 64 bit and 12 gig of ram and a fast processor.
It took PTGui a total of about 90 minutes to complete the tasks required including creating and manipulating the HDR. I shot in JPEG and saved as a tiff - If I had shot in RAW that 90 minutes might translate to 90 hours (!!). I never tried.
The end result was fair - heaps of detail but I found the tones and colours in the final image rather bland and lacking that WOW factor. My end file was 400 megabytes and almost all my other applications could either not handle this (as they are written in 32 bits and so can only access 2 gig of ram) or took their time and in the end it became too much of a pain to enhance the images to the point I was pleased with them. I was NOT pleased with the colours or the tonal range.
I then did some maths and I recon that in terms of definition I had ended up with near 10" x 8 " film type detail.
Now the crux of the matter is this. Will this detail be visible in the end print???
That clearly depends on the size of print being created !!
I print up to 19 inch by 13 inch on an A3+ Canon printer. According to R. N Clark (whose opinion I trust) you need 600 DPI to satisfy the discerning eye in the final print. That is NOT the 300 DPI that is commonly touted (http://www.clarkvision.com/articles/printer-ppi/).
Now with the 8 stitch image printing to 19 x 13 inches I would be using a 120 megapixel image - that is then 2.5 times more than the human eye can resolve assuming my printer would detail up (and I doubt that it could, but I have not done the maths).
Now shooting 3 vertical images in a horizontal row with a 55mm FL length lens I can use the in camera dynamic range optimisation that works well here (you cannot use this with an 8 stitch and a longer FL as each piece of the mosaic is too small and the end result is images with such and exposure difference you will end up with an awful result).
Stiching 3 in a row is quick and with this software yields perfect result. With a 20 % overlap the final aspect ration is 3:2 suiting standard paper formats.
I end up with a 65 megapixel file that most of my other photoeditors handle well for the fine tuning. The in camera DRO produces far superior HDR than the software HDR in PTGui.
The image looks natural. VERY natural. WOW !!
Now is this sharp enough?? To get 600 dpi on a 19 inch by 13 inch paper you need 48 megapixels.
I have 65 megapixels from this 3 in a row stitch. There is STILL detail there that the eye will not see.
CONCLUSION
PROVIDED YOU HAVE A FULL FRAME CAMERA WITH DYNAMIC RANGE OPTIMISATION - it seems to me that this is the way to go.
Unless of course you are lucky enough to own an A2 printer. I have not done the maths on that one.
The limiter is your printer - that is my message.
And thanks for introducing PTGui to me.
Kind regards
Malcolm :o
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I used to stitch occasionally with a Cambo WDS and a P45+ back. With that camera body and a lateral shift, the lens stayed still and the back moved (good). A vertical shift the lens moves (a pain) so a 4 quarters shift and stitch always needed a bit of fiddling!! Rarely needed that much resolution certainly for my commercial clients.
That said I have given all that up and gone back to dslrs. The odd time I need more resolution now and also perspective correction I stitch with PTGui. I use the D3s and the D3x with precise nodal adjustment for each lens and an RRS pano head. If you think the resolution of stitched P45+ image is good when compared to the stitched dslr images those are stunning. Yes I am using the best Zeiss glass, the ones that Lloyd Chambers rates, the 25mm (OK), 35/f2 (v. good) the 50mm f/2 (v. good) and of course the 100mm (awesome). The D3x for ultimate resolution but more often than not the D3s (10 frames a second) and then HDR when needed. Rapid capture I am sure takes the ultimate edge off each image, but the quick succession certainly helps with hdr. I think even if I was to use the Alpa Max(?) which I have not tried and therefore not need the above fiddle(!) I would be surprised if it could compete quite honestly.
Post processing mmmm, I'm sure is more time consuming. But most of the time I never do it. Most images didn't warrant that attention and/or the clients didn't expect that quality. But when they or I did need the extra, the RRS pano head comes apart easily and is not too big to carry around with you. I use the L brackets anyway. So I think I have the best of both world most of the time.
Steve
Steve, can I ask why you switched from the P45+ to your Nikon system for landscape work?
I am looking at moving from Nikon 35mm to a P45+ so your move in the opposite direction caught my attention,
Thanks,
Aaron
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Firstly may I say that PTGui is clearly the best suite developed so far.
Have you tried Autopano Giga?
I believe that both PTgui and Autopano Giga are head and shoulder above the rest, but I would probably give APG 2.5 RC2 a slight lead over PTgui for now.
Cheers,
Bernard
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Steve, can I ask why you switched from the P45+ to your Nikon system for landscape work?
I am looking at moving from Nikon 35mm to a P45+ so your move in the opposite direction caught my attention,
Can't answer on behalf of Steve, but the reason I made a similar move a few years ago were:
- Live view
- Cold weather battery life,
- much wider range of accessible focal lenght in a reasonably compact package (especially on the long side)
- better compromise between DoF and optical quality knowing that most optics peak at around f8
- one does it all package
- support anywhere in the world in case of issue when travelling to exotic countries
Cheers,
Bernard
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Hi Aaron
I think that Bernard has beat me to answer the question but the points he has highlighted are most relevant. For me it is the one stop shop. I can do pretty much all I want to do with my dslr set up and when I need the extra I stitch. I had the P45+, a Mamiya 645II and a Cambo WDS, but ninety percent of the time I felt that set up to be cumbersome by comparison.
Sure visualising the stitched combo takes practice but maybe I have just been doing that a long time. I also like the lateral and vertical shifts that are possible in post.
I think for me now, having used both set ups for a long time, the only reason you should go with the MFDB set up above or similar, is if you need that extra quality every day of the week in one shot. My clients are very happy with the quality I produce now with the dslr and when I need that extra, even a 2 shot stitch with a D3x and a range of Zeiss glass the quality is very very impressive. Furthermore if you have the time or the subject to need more shots and then to add hdr, really you are in another league.
Steve
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Hi,
I'd just add two theoretical observations:
- A shift pano is limited by the amount of shift of the lens while a rotational pano can have any width.
- A shift pano uses the full image circle of the lens while a rotational pano would not use the corners.
Best regards
Erik
Hi Aaron
I think that Bernard has beat me to answer the question but the points he has highlighted are most relevant. For me it is the one stop shop. I can do pretty much all I want to do with my dslr set up and when I need the extra I stitch. I had the P45+, a Mamiya 645II and a Cambo WDS, but ninety percent of the time I felt that set up to be cumbersome by comparison.
Sure visualising the stitched combo takes practice but maybe I have just been doing that a long time. I also like the lateral and vertical shifts that are possible in post.
I think for me now, having used both set ups for a long time, the only reason you should go with the MFDB set up above or similar, is if you need that extra quality every day of the week in one shot. My clients are very happy with the quality I produce now with the dslr and when I need that extra, even a 2 shot stitch with a D3x and a range of Zeiss glass the quality is very very impressive. Furthermore if you have the time or the subject to need more shots and then to add hdr, really you are in another league.
Steve
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I took the top 10 DxOmark sensor rankings threw out the high iso ranking and multiplied the dynamic range by the color depth to see which cameras would be best for landscape work without regard to resolution:
1. D3X 338.39
2. P65+ 338
3. K5 334.7
my P45+ #7 at 312.18!
Interesting? perhaps a good DLSR stitched gives away nothing to a MFDB these days?
Marc
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Thanks Steve & Bernard :),
Can i ask about your basic set ups?
Are you using the same lens for all stitches and just increasing the number of peripheral frames to increase field of view? or do you use a wider lens to stitch a wider image? I have noted that Bernard and some others are using lenses in the 100mm range....
For example, lets say i want to emulate a single frame taken on a plate camera with a 28mm lens and a P45 back---
Do you use your D3x with 100mm and just take enough frames to cover the same field as the P45 set up?
Lets say you want to increase resolution without moving your camera position, do you use a longer lens and take more frames than the above example?
Do you always use a panoramic nodal slide system? If so, are you usually doing single or multi row stitches? Most of the multi row nodal systems look like they would be unstable under the weight of a D3x plus lens.......
Sorry for all the questions! Just trying to get my head around the alternative options before giving phase or Hassy a bag of money.....
Thanks,
Aaron
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For example, lets say i want to emulate a single frame taken on a plate camera with a 28mm lens and a P45 back---
Do you use your D3x with 100mm and just take enough frames to cover the same field as the P45 set up?
Lets say you want to increase resolution without moving your camera position, do you use a longer lens and take more frames than the above example?
Do you always use a panoramic nodal slide system? If so, are you usually doing single or multi row stitches? Most of the multi row nodal systems look like they would be unstable under the weight of a D3x plus lens.......
Sorry for all the questions! Just trying to get my head around the alternative options before giving phase or Hassy a bag of money.....
Thanks,
Aaron
why don't you want to try superresolution software instead of stitching panoramas ? http://www.photoacute.com/
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Hi Aaron
My basic set up includes a Nikon D3x and/or a D3s and lenses I use to stitch, all Zeiss 25mm, 35f2, 50mm macro and 100mm macro with Live View focus. I have L brackets on the camera bodies and use the RRS pano head (Ultimate-Pro Omni-Pivot Package), an excellent compliment when using L-brackets. The RRS pano head would be really fantastic if it had click stops which it doesn't. I have the Seitz VR Drive as well which comes into its own when mounted on a 60 foot elevated mast I also use, camera triggered using PW PlusII's.
The camera body is usually portrait but a two shot vertical stitch when the camera is landscape is straight forward with this set up and can be useful, depending on the movement within the images and the location of the join!
To be honest I stitch the least number of shots possible to achieve the resolution I require and often just two or three shots. If there is any movement you do want the least number of joins possible. The lens is selected depending on the final FOV that is required. The final images are then rendered rectilinear or cylinderical, though there are other projections I do not use.
I would not like to talk you out of the MFDB, it is just this set up works for me and the work that I do. If you need that extra resolution all of time I do not believe this solution to be cost effective.
Actually my favourite set up is the D3s (at 10fps) stitched and then with hdr. An extremely quick capture but with lengthy processing back in the studio. Try doing that with a Phase back and a pano head (I have tried!)
Steve
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Thanks Steve & Bernard :),
Can i ask about your basic set ups?
Are you using the same lens for all stitches and just increasing the number of peripheral frames to increase field of view? or do you use a wider lens to stitch a wider image? I have noted that Bernard and some others are using lenses in the 100mm range....
For example, lets say i want to emulate a single frame taken on a plate camera with a 28mm lens and a P45 back---
Do you use your D3x with 100mm and just take enough frames to cover the same field as the P45 set up?
Lets say you want to increase resolution without moving your camera position, do you use a longer lens and take more frames than the above example?
Do you always use a panoramic nodal slide system? If so, are you usually doing single or multi row stitches? Most of the multi row nodal systems look like they would be unstable under the weight of a D3x plus lens.......
Sorry for all the questions! Just trying to get my head around the alternative options before giving phase or Hassy a bag of money.....
Thanks,
Aaron
Quick answer:
- the focal lenght has to be adopted to the scene when using manual pano heads. The criteria is the ability to stitch easily, meaning the largest part of the scene without recognizable features. A nice blue sky is unstichable because the pano software has no way to recognize anything... so you'll need something on the ground below it to allow stitching, and that drives the longest focal lenght you can use,
- another criteria is time/movement, things that change fast typically need to be in one frame. It also depends on the time you can afford to spend on that image, the longer the lens, the more frames you need, the longer it takes. Time is money for pros, time is related to safety in the outdoors,
- I use 300, 100 and 60mm lenses on a regular basis. Part of that is due to the fact that the Zeiss 100mm f2.0 is the closest thing in Nikon mount to a perfect lens,
- I have been using 2 different Really Right Stuff heads with good success, but tripod stability is also critical, especially in windy conditions. Use the best you can carry/afford (Gitzo 5531s or RRS TVC when I need to be lighter) and weight it down with your pack.
Good luck.
Cheers,
Bernard
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Hi Aaron
My basic set up includes a Nikon D3x and/or a D3s and lenses I use to stitch, all Zeiss 25mm, 35f2, 50mm macro and 100mm macro with Live View focus. I have L brackets on the camera bodies and use the RRS pano head (Ultimate-Pro Omni-Pivot Package), an excellent compliment when using L-brackets. The RRS pano head would be really fantastic if it had click stops which it doesn't. I have the Seitz VR Drive as well which comes into its own when mounted on a 60 foot elevated mast I also use, camera triggered using PW PlusII's.
The camera body is usually portrait but a two shot vertical stitch when the camera is landscape is straight forward with this set up and can be useful, depending on the movement within the images and the location of the join!
To be honest I stitch the least number of shots possible to achieve the resolution I require and often just two or three shots. If there is any movement you do want the least number of joins possible. The lens is selected depending on the final FOV that is required. The final images are then rendered rectilinear or cylinderical, though there are other projections I do not use.
I would not like to talk you out of the MFDB, it is just this set up works for me and the work that I do. If you need that extra resolution all of time I do not believe this solution to be cost effective.
Actually my favourite set up is the D3s (at 10fps) stitched and then with hdr. An extremely quick capture but with lengthy processing back in the studio. Try doing that with a Phase back and a pano head (I have tried!)
Steve
Thanks Steve,
That's quite the set up, I am not sure i can get the 60 foot pole into my back pack though! I have actually looked at the Seitz Drive but wasnt convinced of its practicality over a basic RRS Pano kit, it makes more sense of course for your remote use.
I am going to test a P45 against a 3 frame Stitch on a D3x in the next couple of days, if the Nikon Stitch cuts the mustard then its a very interesting alternative.
Thanks again,
Aaron
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Quick answer:
- the focal lenght has to be adopted to the scene when using manual pano heads. The criteria is the ability to stitch easily, meaning the largest part of the scene without recognizable features. A nice blue sky is unstichable because the pano software has no way to recognize anything... so you'll need something on the ground below it to allow stitching, and that drives the longest focal lenght you can use,
- another criteria is time/movement, things that change fast typically need to be in one frame. It also depends on the time you can afford to spend on that image, the longer the lens, the more frames you need, the longer it takes. Time is money for pros, time is related to safety in the outdoors,
- I use 300, 100 and 60mm lenses on a regular basis. Part of that is due to the fact that the Zeiss 100mm f2.0 is the closest thing in Nikon mount to a perfect lens,
- I have been using 2 different Really Right Stuff heads with good success, but tripod stability is also critical, especially in windy conditions. Use the best you can carry/afford (Gitzo 5531s or RRS TVC when I need to be lighter) and weight it down with your pack.
Good luck.
Cheers,
Bernard
Appreciate the info Bernard,
I am going to run some tests this week, i guess the only way to get your head around stitching is to try it! I am just waiting on an RRS kit and i am good to go.
The different lens choices are the hardest thing to get ones head around without experience. I will try the 60 and 100mm for some test images, i have the older manual 60micro and the newer 100 vr micro, not sure how they will perform for stitching but should suffice for an initial experience.
I will bring some bricks in my bag to weigh down the tripod! Stitching workflow seems to have more in common with shooting8x10.
Thanks again,
Aaron
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why don't you want to try superresolution software instead of stitching panoramas ? http://www.photoacute.com/
Looks interesting but i would imagine the possible improvements in image quality diminish rapidly as your original single capture quality improves. I can see it working for overlaying multiple noisy images from a point and shoot but a clean low iso file from a large chip would see less gains.
That's just my gut feeling, I have no experience of the software.
Thanks,
Aaron
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Stitching workflow seems to have more in common with shooting8x10.
Precisely so. Just like scanning backs, this isn't for everybody, but if you are demanding the best possible image quality stitching is the only option (whether you stitch with a DSLR or a back by the way).
Cheers,
Bernard
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How do you stitch several images from a single camera to most closely emulate what you could have gotten (geometrically) with a single, larger sensor/lense? tilt/shift lense and moving the camera along the image "projection plane"?
-h
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How do you stitch several images from a single camera to most closely emulate what you could have gotten (geometrically) with a single, larger sensor/lense? tilt/shift lense and moving the camera along the image "projection plane"?
Yes, stitching shifted tiles provides the closest emulation of a single larger sensor plane, and gives identical results in an untilted focus plane. For geometrical emulation, one can also use images with adequate depth of field that were rotated through the entrance pupil of the lens (one just needs to use a different projection model to recreate a flat plane).
The latter solution requires resampling of the image, which might sacrifice some resolution (unless compensated for with a longer focal length to oversample the scene, and a downsampling for same size/resolution output). A benefit of the rotation method is that one can use the higher quality part of the image circle to stitch, and it's generally faster in execution at capture time (slower in postprocessing). It also allows to use very wide (>110 degrees) angles of view.
Cheers,
Bart
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So all of these could give (principally, at least, given flawless lenses, sensors, etc) geometrically equal results, given appropriate stitching (and perhaps constraints on scene distance?)
A) Some large format sensor/lense
B) A smaller format sensor/lense tilt/shifted appropriately
C) A smaller format sensor/lense rotated "inappropriately" about the sensor centre point
Did anyone do the comparision and post example pictures? =)
-h
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So all of these could give (principally, at least, given flawless lenses, sensors, etc) geometrically equal results, given appropriate stitching (and perhaps constraints on scene distance?)
A) Some large format sensor/lense
B) A smaller format sensor/lense tilt/shifted appropriately
C) A smaller format sensor/lense rotated "inappropriately" about the sensor centre point
Did anyone do the comparision and post example pictures? =)
-h
I started this thread, and I now have a bit more experience with stitching Nikon D700 images (in a 3x3 grid) to emulate a single large format film capture.
Regarding geometry, the only difference is that the stitched image exhibits zero lens distortion (barrel/pincushion). Geometrically, it is perfect. (A 5"x4" film capture, or a single image from a medium format digital back, will always exhibit a certain amount of lens distortion.)
Likewise, the stitched image exhibits no vignetting and no corner softness.
In theory this is all good news, but in practice stitched images can look rather clinical.
I've recently been experimenting with adding a little barrel distortion, vignetting and grain to the final stitched image; knocking it back a little, to make it look more photographic.
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Good - I agree with your comments.
I did an interesting experiment with stitching a maritime dusk shot using an old pentax 55mm f1.8 smc lens on a Sony a850 FF camera. I took 3 in a row in portrait orientation and then printed up on a Canon Pixma pro printer at max resolution on A3 + size paper. That is 329 x 483 mm size.
The results were razor sharp. I then cropped out the central 50% of the stiched image and printed at the same size. Still razor sharp and detail was rendered that was not there in the uncropped print.
Message - you do not need massive stitches unless you are doing massive prints on a huge printer. If you try to do say 8 or 9 or 12 stich prints on an A3+ there will be detail you will never see.
I only do 3 in a row stiches now and it gives me more than enough.
Kind regards
Malcolm
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Elliot_n said:
I've recently been experimenting with adding a little barrel distortion, vignetting and grain to the final stitched image; knocking it back a little, to make it look more photographic.
Please reassure us that this is a joke.
Roy
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No joke (though I was hoping to get a rise from someone). As I said, an experiment. I'm talking about quite a wide angle field of view; equivalent to a 24mm lens or wider (in 35mm terms). Such a view can look especially stretched when rendered with zero lens distortion. Adding a little barrel distortion has the effect of pushing back the corners a little. I guess it's what I'm used to, shooting nikon primes from 20mm to 50mm - they all exhibit a little barrel distortion.
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...Regarding geometry, the only difference is that the stitched image exhibits zero lens distortion (barrel/pincushion). Geometrically, it is perfect. (A 5"x4" film capture, or a single image from a medium format digital back, will always exhibit a certain amount of lens distortion.)
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By "geometry" I was actually thinking about the physical effects that must be different (even using hypothetical perfect optics) when:
A)Shooting some object at a distance r1 using a "small" sensor/lense at focal length f1.
B)Shooting that same object at distance r1 using a "large" sensor/lense at focal length f2 to get the same framing.
C)Shooting that same object at some other distance, r2 using a "large" sensor/lense at focal length f1.
I was under the impression that B) and C) was sufficiently different from A) that people were willing to pay a lot (in money, weight, inconvenience) just to get that difference, even ignoring noise/dynamic range/... differences? If that really is so, I wonder if stiching can emulate that "magic factor"?
-h
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Indeed, this is one of the major advantage of cylindrical stitching/planar projection compared to T/S stitching. You always use the central portion of the lens and the corners of the resulting pano are just as sharp as the center.
Some very experienced Japanese landscape photographers who had never seen large panos before couldn't believe their eyes when they saw some large prints at a show I did a few months ago at the Nikon salon in Tokyo. They had a hard time dealing with the fact that corners were just as sharp as the center portion. The reproduction of the scene was so real that it had almost lost its photographic dimension to them. It did trigger some interesting discussions though. :)
I have tried both extensively and have basically given up on shift pano, it is slower, less scalable and offers lower image quality.
I just discovered this thread which holds some interest to me, and am most curious about your comment above Bernard.
I understand the limitations of shift stitching though this is somewhat dependent on the lens and camera system. But to my way of thinking it would seem all of the stretching, contortion, shrinking and interpolation of pixels involved with cylindrical stitching would be far more problematic than simple shifting of a lens. In the past I have used both my 85 PC lens as well as the 24 PC with very good results though the 24 is more limited at the corners of an extreme shift/rise & fall. Likewise I have used my Nikons with the Cambo Ultima conversion kit and Rodenstock digital lenses to stitch up to 9-12 frames with great success and no image degradation at the corners what so ever. Granted this is a tedious experiment not to mention the huge weight issue of carrying gear like this into the field. Not everyone has a Ultima they would lug around in the first place, and in fact even I find it more trouble than its worth.
So you are saying absolutely even with the amount of interpolation of pixels with cylindrical stitching this is still a better method than using shifts?
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By "geometry" I was actually thinking about the physical effects that must be different (even using hypothetical perfect optics) when:
A)Shooting some object at a distance r1 using a "small" sensor/lense at focal length f1.
B)Shooting that same object at distance r1 using a "large" sensor/lense at focal length f2 to get the same framing.
C)Shooting that same object at some other distance, r2 using a "large" sensor/lense at focal length f1.
I was under the impression that B) and C) was sufficiently different from A) that people were willing to pay a lot (in money, weight, inconvenience) just to get that difference, even ignoring noise/dynamic range/... differences? If that really is so, I wonder if stiching can emulate that "magic factor"?
B can be emulated by A when A uses a longer focal length (f1>= f2) and stitching to make up for the wider field of view of B.
C has a different perspective because the entrance pupil moved, so everything changes, there is no direct comparison possible.
What is important for a technical quality comparison is, that the magnification factor is the same. That might reveal differences in the MTF of the lenses used. When the camera distance is varied then the magnification factor of foreground and background features changes, also relative to eachother. The magnification factor determines where on the system MTF curve the detail and contrast are placed.
Cheers,
Bart
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By "geometry" I was actually thinking about the physical effects that must be different (even using hypothetical perfect optics) when:
A)Shooting some object at a distance r1 using a "small" sensor/lense at focal length f1.
B)Shooting that same object at distance r1 using a "large" sensor/lense at focal length f2 to get the same framing.
C)Shooting that same object at some other distance, r2 using a "large" sensor/lense at focal length f1.
I was under the impression that B) and C) was sufficiently different from A) that people were willing to pay a lot (in money, weight, inconvenience) just to get that difference, even ignoring noise/dynamic range/... differences? If that really is so, I wonder if stiching can emulate that "magic factor"?
-h
(B) and (C) are totally different. People pay for the difference between (A) and (B). Can (B) be emulated with stitching? Yes, I think it can. The geometry of the image is certainly the same. The "magic factor"? What's that? Maybe the way the depth of field falls off? I think you get the same depth of field effect with a stitched shot. You're certainly working with shallower depth of field when you're stitching.
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Some very experienced Japanese landscape photographers who had never seen large panos before couldn't believe their eyes when they saw some large prints at a show I did a few months ago at the Nikon salon in Tokyo. They had a hard time dealing with the fact that corners were just as sharp as the center portion. The reproduction of the scene was so real that it had almost lost its photographic dimension to them. It did trigger some interesting discussions though. :)
Right - this is why I've been experimenting with subtly degrading the quality of the final stitched image.
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I just discovered this thread which holds some interest to me, and am most curious about your comment above Bernard.
I understand the limitations of shift stitching though this is somewhat dependent on the lens and camera system. But to my way of thinking it would seem all of the stretching, contortion, shrinking and interpolation of pixels involved with cylindrical stitching would be far more problematic than simple shifting of a lens. In the past I have used both my 85 PC lens as well as the 24 PC with very good results though the 24 is more limited at the corners of an extreme shift/rise & fall. Likewise I have used my Nikons with the Cambo Ultima conversion kit and Rodenstock digital lenses to stitch up to 9-12 frames with great success and no image degradation at the corners what so ever. Granted this is a tedious experiment not to mention the huge weight issue of carrying gear like this into the field. Not everyone has a Ultima they would lug around in the first place, and in fact even I find it more trouble than its worth.
So you are saying absolutely even with the amount of interpolation of pixels with cylindrical stitching this is still a better method than using shifts?
Yes, that is what I have seen. :)
It depends on the resolution though. My view is that it is much faster to rotate a lens that to shift it, so you end up being able to take more images with cylindrical than with shift to cover a single scene/crop, which means you will have more resolution if required. The effect of some interpolation on image quality isn't that large in the first place and more pixels will totally compensate for this small loss.
Besides, you will end up having loss of sharpness and light fall off in the corners even with the best T/S lenses (I still own the Nikkor 24 PCE which is excellent even if it was now overtaken a bit by the new Canon). My view is that even if interpolations were to cause issues with cylindrical panos (which again I don't find to be the case), it would be an order of magnitude less of an issue compared to soft corners.
Regards,
Bernard
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No joke (though I was hoping to get a rise from someone). As I said, an experiment. I'm talking about quite a wide angle field of view; equivalent to a 24mm lens or wider (in 35mm terms). Such a view can look especially stretched when rendered with zero lens distortion. Adding a little barrel distortion has the effect of pushing back the corners a little. I guess it's what I'm used to, shooting nikon primes from 20mm to 50mm - they all exhibit a little barrel distortion.
You might want to try PTgui. It has the ability to control the amount of lateral compression near the edges of images when using planar projections.
I only use it when dealing with images too wide for a lens to handle, but this might help you achieve the effect you are looking for.
Regards,
Bernard
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You might want to try PTgui. It has the ability to control the amount of lateral compression near the edges of images when using planar projections.
I only use it when dealing with images too wide for a lens to handle, but this might help you achieve the effect you are looking for.
Regards,
Bernard
Hi Bernard. I am using PTGui.
How do you use it to control lateral compression?
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But to my way of thinking it would seem all of the stretching, contortion, shrinking and interpolation of pixels involved with cylindrical stitching would be far more problematic than simple shifting of a lens.
I've just been comparing a stitched image (a 3x3 grid) with the 9 source images from which it is made (shot at 65mm, 25% overlap, to give an overall view representing a 24mm lens (in 35mm terms)).
The side effects of PTGui's complex interpolations are modest. The central area of the image has been downsampled slightly, and thus looks sharper than the source images, whereas the corners have been upsampled a bit, and look slightly softer than the originals.
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Hi Bernard. I am using PTGui.
How do you use it to control lateral compression?
Elliot,
In the window enabling you to tune the horizon, change projection mode,... (forgot the official name of that window), you have 2 collapsible sliders at the bottom left of the screen.
They only show when you are in flat projection mode.
Regards,
Bernard
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Elliot,
In the window enabling you to tune the horizon, change projection mode,... (forgot the official name of that window), you have 2 collapsible sliders at the bottom left of the screen.
They only show when you are in flat projection mode.
Regards,
Bernard
Many thanks, Bernard.
I had forgotten those sliders existed. When I looked at them previously I assumed they were compressing the image universally. But you're right - they compress the image more at the edges than at the centre.
This will be very useful when rendering wide-angle views.
Elliot
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I try to stay out of discussions where the standard of technical knowledge is above, if not entirely over my head, however a couple of comments.
I find the assertion that adding distortion, such as geometric distortion and vignetting as mentioned here, to an image, in order to get a more "photographic" representation, well, perverse. As far as I can recall every assessment of lenses I have ever encountered regards the absence of these attributes as a positive value; indeed most people seem prepared to pay a large premium to acquire lenses that don't exhibit these characteristics - although obviously there are also many other criteria in play. Of course adding vignetting in pp is sometimes an aesthetic decision. But adding barrel distortion? Seriously?
I was interested in the mention of PTGui's ability to compress the lateral edge distortion (volume anamorphosis?) in extreme wide angle shots. I hadn't spotted it. I've been looking for a way to achieve this for shots taken at the wide end of my Nikon 14-24. DxO is the only application I know of that incorporates the feature but I'm not prepared to buy it for this ability alone.
I'm not at a computer with PTGui right now, so has anyone used this feature successfully on single extreme wide-angle shots?
Roy
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I'm not at a computer with PTGui right now, so has anyone used this feature successfully on single extreme wide-angle shots?
I just loaded a single image into PTGui, but the compression sliders in the Panorama Editor window seem to have no effect. I guess this feature only works with stitched images (?)
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Elliot, you can download a single image in the new version of Photomatix.
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Bernard, thanks for the further clarification. I am encouraged enough to order some pano gear from RRS and give it a try myself.
Rob
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I just loaded a single image into PTGui, but the compression sliders in the Panorama Editor window seem to have no effect. I guess this feature only works with stitched images (?)
Well, I'm using PTGuiPro 9.0.3 and they definitely do compress a single image. Exactly how this compression is distributed I haven't yet had time to evaluate.
Meanwhile I'm off to add some barrel distortion on a few landscape shots to see how much improvement I can make to my amateur efforts. Maybe this is the key to where I've been falling short. Perhaps add a bit of ca for an interesting "halo" effect and a little blur to take the edge of that disturbing sharpness too...
Roy
A quick test reveals that (rectilinear projection mode) compressing the h axis stretches the v axis at the same time. Not, as far as I can see, in proportion to the amount of h compression. Although I haven't tried dialling in random amounts of V axis compression to compensate, I'd say PRGui is useless for correcting this form of distortion.
I'd love to find a solution other than DxO - although it seems that I'm the only person bothered by the volume anamorphosis effect...
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B can be emulated by A when A uses a longer focal length (f1>= f2) and stitching to make up for the wider field of view of B.
If one wishes to emulate the effects of using a large sensor with a lense of very large aperture, I am guessing that it can be difficult to find small-format lenses with sufficiently small depth of field (or can this be emulated in the stiching procedure as well?).
If one wishes to emulate the acutance (and aliasing) of typical large-format digital sensors lacking AA-filter, one would have to oversample a great deal, then use "primitive" downsampling, like boxcar filtering.
How does diffraction and diffraction-limits play out here?
-h
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If one wishes to emulate the effects of using a large sensor with a lense of very large aperture, I am guessing that it can be difficult to find small-format lenses with sufficiently small depth of field (or can this be emulated in the stiching procedure as well?).
When you're stitching you are effectively working with a large sensor - often larger than the sensors in medium format backs. For example, a 3x3 grid, shot with a full frame dSLR, with 25% overlap, will give you an effective sensor size of 6cm x 9cm. Getting shallow depth of field with a sensor that large is not a problem. Rather it is difficult to get sufficient depth of field. For a 3x3 grid you need to stop down an additional 2 and a half stops to get the same depth of field as the scene photographed as a single frame.
I shoot my stitches at f11 or f16 (D700) as I want to maximise depth of field. If you shot them at f2 or f2.8 the depth of field would be wafer thin.
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I shoot my stitches at f11 or f16 (D700) as I want to maximise depth of field. If you shot them at f2 or f2.8 the depth of field would be wafer thin.
Yep, when working with very long lenses with panos covering a wide angle you also start to have problem with focus. Unless you refocus at each frame (which can be done), you end up with a focused area that belongs to a cylinder instead of belonging to a plane. That won't show too much with a closed aperture but might be an issue in some cases at 2.8.
On the other hand most of the panos I did with my 300 f2.8 were of very distant subjects (50 to 100km) and covering a very small angle where these issues can be overlooked totally.
Cheers,
Bernard