Luminous Landscape Forum
Equipment & Techniques => Digital Cameras & Shooting Techniques => Topic started by: EinstStein on December 25, 2015, 11:05:13 am
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My widest and most frequent used travel lens is 25mm. I like to shoot interior architecture such as place, cathedral, etc. Even shooting the exterior used a lot of wide angle. But I feel I want it wide, such as 17mm or 15mm.
But this is about the plain lens.
Now I want to get a Canon TS lens, but not sure 17mm or 24mm.
How do you choose between TS 17 or TS 24? if you have experience on both.
I know I want plain 17mm over plain 25mm, does this implies I should get the TS of the same length? or get the TS one step up (24mm)?
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Hi,
It depends on how you use the lens. T&S capability just gives you the option to shoot the camera level. But you can also stitch with a T&S lens.
This is a vertical stitch from two images from the 24/3.5 TSE LII:
(https://photos.smugmug.com/Travel/LuxemburgTrip/i-dz8Pb5m/0/X2/20150725-_D4A0893-Pano-2-X2.jpg)
Best regards
Erik
My widest and most frequent used travel lens is 25mm. I like to shoot interior architecture such as place, cathedral, etc. Even shooting the exterior used a lot of wide angle. But I feel I want it wide, such as 17mm or 15mm.
But this is about the plain lens.
Now I want to get a Canon TS lens, but not sure 17mm or 24mm.
How do you choose between TS 17 or TS 24? if you have experience on both.
I know I want plain 17mm over plain 25mm, does this implies I should get the TS of the same length? or get the TS one step up (24mm)?
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If you very often need to stitch 24mm, then I think 17mm would be a better choice.
I am curious, why the top of the tower is wider than the bottom? Perspect adjust in PS?
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I used to shoot a lot with a 10-22 on APS for interiors (eq. 16-35) and I enjoyed the low end very often. However when I decided to purchase a TS for FF I preferrerd the 24mm because even if it forces you to think harder about how to shoot it is a guarantee that it will end with pleasant looking images. 17mm has to be used more carefully because it makes it easy to fall in the "frame it all" mistake that can end in images where the focal length is perceived before the subject itself.
About Erik's image, I guess he was not facing the building orthogonally so the top of the tower suffers from an extra vanishing point that makes it longer there than in the basement. Linear projection plays these tricks.
Regards
Enviado desde mi GT-I9195 mediante Tapatalk
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Hi,
I think Guillermo has a good points. I used Lightroom's 'upright' on it and it does not solve the problem.
I have read that when doing perspective correction, the convergence of verticals should not be corrected fully.
Best regards
Erik
I used to shoot a lot with a 10-22 on APS for interiors (eq. 16-35) and I enjoyed the low end very often. However when I decided to purchase a TS for FF I preferrerd the 24mm because even if it forces you to think harder about how to shoot it is a guarantee that it will end with pleasant looking images. 17mm has to be used more carefully because it makes it easy to fall in the "frame it all" mistake that can end in images where the focal length is perceived before the subject itself.
About Erik's image, I guess he was not facing the building orthogonally so the top of the tower suffers from an extra vanishing point that makes it longer there than in the basement. Linear projection plays these tricks.
Regards
Enviado desde mi GT-I9195 mediante Tapatalk
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"I have read that when doing perspective correction, the convergence of verticals should not be corrected fully."
There are those who think that, but you've overcorrected here, making the top wider than the bottom. That's what you might see if you were shooting down on your subject, which is why is looks so weird here. I don't use Lightroom, but the normal way of correcting is to dupe your background layer in Ps, place vertical guides where they need to be and use Free Transform to make the building perfectly straight. There are precious few times where you don't want to fully correct and even fewer where you'd want to overcorrect.
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I have read that when doing perspective correction, the convergence of verticals should not be corrected fully.
Hi Erik,
That's often correct, because the shots that are using these extreme angles of view are often taken from a very (too?) short distance. So if shot perfectly square (or corrected by Upright and similar) the horizontal perspective plane's vanishing point is still on the horizon, but we are looking up, which confuses our mind. If we were to view the image from the proper (very short) distance and from the bottom of the image looking up, perspective would be correct.
Software like Capture One Pro (I know you are not comfortable with it) by default under-corrects the keystone correction to some 80% of the full correction (see attachement). Of course the user can adjust that to anything, between 10% and 120%, that suits the subject and the viewing conditions of the final image.
One can also use panorama stitching software on a single or composite image, and place the horizon line slightly higher by changing the pitch value.
Cheers,
Bart
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I use the 17mm a lot and it is an excellent lens (as is the 24 from what I understand). If you are shooting interiors etc then you really can't get too wide. You can always crop if required. The only downside to the 17mm is that because you can't use a lens hood you can get the occasional flair from lights etc.
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Hi Bart,
I sort of think of Capture One as an alternative (*) converter and I bought licenses for both the 7 and the 8 version. V9 was just released after I bought V8 :-(. I can of course use V9 for both Sony and P45+, by switching licenses. I see RawTherapee as another option…
Your input is most valued, as usual. Thanks for taking time to educate mostly uninterested students! :-)
I think that "upright" in LR doesn't make lines orthogonal at normal settings but leaves in some convergence, but it doesn't work on this image. Thanks for the suggestion changing the "pitch" parameter in stitching.
Best regards
Erik
(*) I am perfectly happy with LR as a workflow solution, and I try to avoid doing non parametric editing. But sometimes I need a better raw converter. So I would export to TIFF using an alternative converter, but I would still print and do whatever I do from Lightroom.
Hi Erik,
That's often correct, because the shots that are using these extreme angles of view are often taken from a very (too?) short distance. So if shot perfectly square (or corrected by Upright and similar) the horizontal perspective plane's vanishing point is still on the horizon, but we are looking up, which confuses our mind. If we were to view the image from the proper (very short) distance and from the bottom of the image looking up, perspective would be correct.
Software like Capture One Pro (I know you are not comfortable with it) by default under-corrects the keystone correction to some 80% of the full correction (see attachement). Of course the user can adjust that to anything, between 10% and 120%, that suits the subject and the viewing conditions of the final image.
One can also use panorama stitching software on a single or composite image, and place the horizon line slightly higher by changing the pitch value.
Cheers,
Bart
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I don't understand that mindset. While I agree that there is often an optical illusion of building tops diverging when they are perfectly straight... I haven't met a single professional architectural photographer that would overcompensate.
I've changed my C1 Pro Keystone Correction default to 100%.
Also, I'd agree that correcting small distortions is often best done in Photoshop with Transform>Distort. You can get absolutely exact with it, where you often can't with perspective correction.
-CB
Also, If you think the 24mm would be a decent focal length, I'd grab that. It's a much sharper lens than the 17 and far easier to filter or shade. I own both and hate having to pull the 17 out... but when you need super wide, it get's the job done.
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I don't understand that mindset. While I agree that there is often an optical illusion of building tops diverging when they are perfectly straight... I haven't met a single professional architectural photographer that would overcompensate.
Hi Chris,
Not sure I follow, there is not a mindset, just plain geometric distortion. The visual distortion starts when we look at the rectified image capture from the wrong perspective position (center of the image instead of from the bottom, and from too far away for achieving the original perspective). It's like the road signs painted on the road surface. They only look correct/legible if viewed from a shallow angle. Here (http://weburbanist.com/2008/06/29/top-10-3d-graffiti-artists-in-the-world/) and here (https://www.youtube.com/watch?v=a8tngtNgXl4) are some more exciting examples that need to be viewed from a single perspective point, or they will look very wrong.
There is no over-compensation, but rather under-compensation by using <100% correction for upward viewing directions. Percentages larger than 100% can be useful for very high vantage points, to create more realistic depth perspective.
I've changed my C1 Pro Keystone Correction default to 100%.
As would probably be more common for shots of interiors, but not necessarily for outdoor shots of facades or high structures which were taken from a very (too) close position.
Also, I'd agree that correcting small distortions is often best done in Photoshop with Transform>Distort. You can get absolutely exact with it, where you often can't with perspective correction.
I'm curious why you'd want to use Distort for perspective corrections, which does something completely different. Perspective correction changes the projection plane (a 3-dimensional change on a flat plane), distort just distorts unlike the lens projection on a flat plane does.
Cheers,
Bart
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I use the 17mm a lot and it is an excellent lens (as is the 24 from what I understand). If you are shooting interiors etc then you really can't get too wide. You can always crop if required. The only downside to the 17mm is that because you can't use a lens hood you can get the occasional flair from lights etc.
The flare might be a problem for interior, as often there are lightings which are hard to avoid.
like this example
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Software like Capture One Pro (I know you are not comfortable with it) by default under-corrects the keystone correction to some 80% of the full correction (see attachement). Of course the user can adjust that to anything, between 10% and 120%, that suits the subject and the viewing conditions of the final image.
One can also use panorama stitching software on a single or composite image, and place the horizon line slightly higher by changing the pitch value.
This continues to frustrate me. Why it isn't just set to 100% as default I don't know.
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Hi Bart,
I think what Chris is trying to say is professional AP's understand that Architects like straight lines.
More often than not a building is comprised of a series of horizontal and vertical lines.....they design things to be straight (generalisation as Mr Frank Gehry as an example doesn't often do this)...therefore, whether right or wrong...a vertical line of a building is preferable to our clients being straight.
The photographs we make are often used in presentations on paper and on screen with all sorts of graphics relating to them or even overlayed on them..thus from a graphical point of view...perfectly straight lines are easier for them to work with.
To my eye....also more pleasing.
What Chris said about the 24/17 relationship is very true - the 17 requires 'taming'.
AL
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...Why it isn't just set to 100% as default I don't know.
Ancient Greeks already knew why.
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Yes...I studied all of that and Bannister Fletchers bible still sit's on my desk..
Ancient Greeks already new why.
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Who do people use SW correction at all if it is TS lens?
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This continues to frustrate me. Why it isn't just set to 100% as default I don't know.
Hi Al,
Because 100% is mathematically wrong, from a perspective/projection point of view. The top of a building is much further away than the base, so it should be (imaged) smaller (both horizontally and vertically), which introduces keystoning.
If an architect wants to see a distorted* projection reality (which is fine for me, I understand that if they designed straight and not tapered), then by all means set it to 100% (and make it a default if you want/need). But for a normal observer, one expects perspective to render more distant objects smaller than the same objects closer by. The only way to come close to such an image capture is to shoot the building facade perpendicular, from a position at half its height. That way, both top and bottom will get stretched equally due to the flat plane projection (wide angle effect when viewed from the wrong distance), and no key-stoning will occur.
*) the initial uncorrected projection distortion is due to looking at the image from a different perspective point (perpendicular to the dead center of the image) than the one used to take the shot (looking up from say 1.5 metres or some 4.6 feet to say 10 metres or 30 feet at mid building height), from too close a shooting distance.
Cheers,
Bart
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The only way to come close to such an image capture is to shoot the building facade perpendicular, from a position at half its height. That way, both top and bottom will get stretched equally due to the flat plane projection (wide angle effect when viewed from the wrong distance), and no key-stoning will occur.
Even in that case you can get a vanishing perspective on both ends, as our vision really works. As long as you sacrifice the straight lines:
(http://www.buzzle.com/images/diagrams/4-point-perspective.jpg)
Enviado desde mi GT-I9195 mediante Tapatalk
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I'm curious why you'd want to use Distort for perspective corrections, which does something completely different. Perspective correction changes the projection plane (a 3-dimensional change on a flat plane), distort just distorts unlike the lens projection on a flat plane does.
Cheers,
Bart
Hi Bart,
I'm not sure what the problem is. I use Distort quite often. The Perspective control (in Free Transform) just seems to apply equal degrees of distortion on both sides of the image, but in opposite directions. Some images require a greater degree of distortion correction on one side, as Erik's image does.
In the attached, modified version of Erik's image, hope you don't mind, Erik ;) , I used Distort, Warp and Context-Aware fill, in Photoshop. It's not perfect but it looks less distorted, doesn't it?
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Hi Bart,
I'm not sure what the problem is. I use Distort quite often. The Perspective control (in Free Transform) just seems to apply equal degrees of distortion on both sides of the image, but in opposite directions. Some images require a greater degree of distortion correction on one side, as Erik's image does.
Hi Ray,
The issue may be one of adding yet another asymmetrical distortion to image elements that should be imaged square (not trapezoid), or circular (not egg) shaped. Stacking distortions upon distortions is not my idea of correcting a situation. I'd rather remove the core distortion, as much as possible or still pleasing.
Correct perspective correction mostly takes care of all of that with a single control. Even if under-corrected, the under-correction is uniform. Also remember that these type of shots often have a one sided shift applied, which amplifies the projection distortion which is further amplified by 100% keystone correction. That's why such high buildings can look overly stretched towards the top, but less so if somewhat under-corrected.
Cheers,
Bart
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Hi Ray,
Absolutely OK to use my image, I would not shared it if that was not the case!
Just to make it clear. It is a composite of two images. Camera was horizontal according to dual spirit levels. The two images were shot using different amount of shift and merged in Lightroom using rectangular projection. "Upright" was applied to the image after stitch. The lens used was a Canon 24/3.5 TSE LII on a Canon 5D3.
Best regards
Erik
Hi Bart,
I'm not sure what the problem is. I use Distort quite often. The Perspective control (in Free Transform) just seems to apply equal degrees of distortion on both sides of the image, but in opposite directions. Some images require a greater degree of distortion correction on one side, as Erik's image does.
In the attached, modified version of Erik's image, hope you don't mind, Erik ;) , I used Distort, Warp and Context-Aware fill, in Photoshop. It's not perfect but it looks less distorted, doesn't it?
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Hi Ray,
Absolutely OK to use my image, I would not shared it if that was not the case!
Just to make it clear. It is a composite of two images. Camera was horizontal according to dual spirit levels. The two images were shot using different amount of shift and merged in Lightroom using rectangular projection. "Upright" was applied to the image after stitch. The lens used was a Canon 24/3.5 TSE LII on a Canon 5D3.
Best regards
Erik
Hi Erik,
Yes. I understood it was a composite of 2 images. I do this sort of thing quite often, but not with a Tilt & Shift lens because I guess I'm not keen on the extra stuffing around in the field.
For wide-angle shots I use the Nikkor 14-24. If it's not wide enough, I'll take a couple of shots for stitching. However, more frequently nowadays, when I happen to have, say, my 24-120/F4 zoom attached to the camera, and I want a shot that is wider than 24mm, then instead of going to the trouble of changing lenses I'll just take a couple of shots at 24mm, and later 'Photomerge' them in Photoshop.
I understand you will be limited in Lightroom for such purposes. However, I find that stitching programs are so good nowadays, even in Photoshop, that it's very rarely that I have difficulty in not being able to get a realistic result, especially after applying to the stitched image the range of options in Free Transform, such as Distort, Warp and Content-Aware fill, when necessary.
In Photomerge there are a number of stitching options, such as Auto, Perspective, Cylindrical, Spherical etc. 'Reposition' is at the bottom of the list and I suspect it is often ignored, yet I find that Reposition often produces the best result with no requirement to apply any Distortion or Warp later.
The attached 4 images show the different results I get from 2 images stitched vertically, with camera hand-held, horizontally. I have not made any alterations to the results from the Photomerge process. I'm merely demonstrating here that one should try all the options if the first 'auto' option doesn't produce a realistic result.
In these examples, the Reposition option definitely produces the most accurate and realistic result which also requires virtually no further processing, apart from cropping or the application of Content-Aware fill, if preferred.
The top of the unusually-shaped rock in the Reposition stitch, matches very closely the upper shot before it was stitched. All the other stitches in these examples are abominable distortions that would need lots of 'distortion and warp' correction in Free Transform, before they would be acceptable.
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Auto and Reposition are the two modes I use the most. If Auto doesn't work, then Repo almost always does. Easy enough to try different modes for the best one.
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Aesthetics over mathematics :)
Hi Paul,
I agree, but that means rather a subtle under-correction instead of a mathematically perfect removal of key-stoning. :)
Cheers,
Bart
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Yesterday, I tested a lens to see to what extent, if any, it exhibits linear distortion. So I took a picture of a banal condo building. The lens is a good performer.
I used a tech camera so the building wouldn't look like it was falling backwards. The camera/lens combo did what it is supposed to do: render the building so all of the vertical lines are 90 degrees.
I realize the photo is by no means a shining example of architecture photography. But looking at it on the screen, I notice it looks sort of unreal. Yesterday, I played around with the perspective adjustment in PS to see if a bit of distortion would make it look more real. I wasn't successful. I think I'll revisit it and try using the distort function. Without a doubt, nuance is the name of the game.
The weird thing about human vision is the way the brain constantly compensates for the raw data it is fed. As I sit in my easy chair, I look around the room and "see" how my mind works to make the floor, walls, furniture, etc. appear orthogonal. If I try this with a camera, the pictures will come out wacky.
I've already posted this picture on a few other forums (sorry for the redundancy). Being that it is longer than it is high, to what extent should it be "distorted."
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Hi BobDavid,
Nice shot, good selection of point of view and location for the tripod.
Whether it is a superb piece of Architecture or not is not the question. At this point, it describes the make up, volume and language of the building very well.
I am guessing that if you shot this in the most flattering light possible for this building (you're not far off, I think in a month or two with the sun a little further west it would be stunning) the Architect and Developer would be delighted with this image and composition if it was a building they wanted to market further as an example of their work they would get a lot of mileage out of it.
IMO
Andrew
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Hi,
This is an interesting demo of an interesting issue on which it seem opinions are very split.
Best regards
Erik
Yesterday, I tested a lens to see to what extent, if any, it exhibits linear distortion. So I took a picture of a banal condo building. The lens is a good performer.
I used a tech camera so the building wouldn't look like it was falling backwards. The camera/lens combo did what it is supposed to do: render the building so all of the vertical lines are 90 degrees.
I realize the photo is by no means a shining example of architecture photography. But looking at it on the screen, I notice it looks sort of unreal. Yesterday, I played around with the perspective adjustment in PS to see if a bit of distortion would make it look more real. I wasn't successful. I think I'll revisit it and try using the distort function. Without a doubt, nuance is the name of the game.
The weird thing about human vision is the way the brain constantly compensates for the raw data it is fed. As I sit in my easy chair, I look around the room and "see" how my mind works to make the floor, walls, furniture, etc. appear orthogonal. If I try this with a camera, the pictures will come out wacky.
I've already posted this picture on a few other forums (sorry for the redundancy). Being that it is longer than it is high, to what extent should it be "distorted."
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Of the two I prefer the 24mm for the majority of work. I do a lot of stitching with it, 4 images diagonally @ 30deg, gives around a 20mm across the long edge. The 17mm is great for tight spaces but like mentioned, you need to be careful it doesn't impose to much of a SW effect.
You could always use the 17mm with the 1.4x tc to get a 24mm when needed, results are pretty good from that combo. I use the tc with the 24mm to get a 35mm now and then.
I used to use the 17-40 at the 17mm end and crop, but when I got the 24mm tse found it was pleanty wide enough as the movements got the framing I wanted without cropping.
Hire both, plus the tc and have a play and see what you prefer.
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This is an interesting demo of an interesting issue on which it seem opinions are very split.
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Erik
you can say that.... again... :)
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My widest and most frequent used travel lens is 25mm. I like to shoot interior architecture such as place, cathedral, etc. Even shooting the exterior used a lot of wide angle. But I feel I want it wide, such as 17mm or 15mm.
But this is about the plain lens.
Now I want to get a Canon TS lens, but not sure 17mm or 24mm.
How do you choose between TS 17 or TS 24? if you have experience on both.
I know I want plain 17mm over plain 25mm, does this implies I should get the TS of the same length? or get the TS one step up (24mm)?
For the experienced user who has to choose between the two, it is a matter of personal preference. However, if the subject matter is primarily architecture, experienced architectural specialists would most likely choose the 24mm, and that is the staple focal length for architectural photographers, even when they have wider focal lengths at their disposal. If the subject matter is landscape, I think that it is possibly more open as to which one.
For the novice user, whether for landscape or architecture, I would strongly recommend the 24mm. The extreme wide angle of the 17mm presents more problems with respect to volume anamorphosis distortion (stretching effect toward the edges), which is much more pronounced at this focal length, and thus requires much more care with respect to composition.
In any case, I suspect the focal lengths your are tending to use now would be a reasonable guide, bearing in mind that, with them, you are losing field of view when making perspective corrections with software, meaning you are effectively using longer focal lengths (with a corresponding loss of some image quality) than the actual focal length of the lens when working that way.
Also, as some have mentioned, with some kinds of subjects, you can use shift lenses and stitching to effectively create a wider angle lens, with a corresponding increase in maximum image quality (via an increase file size and assuming proper technique).
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How do you choose between TS 17 or TS 24? if you have experience on both.
I know I want plain 17mm over plain 25mm, does this implies I should get the TS of the same length? or get the TS one step up (24mm)?
I have never owned a T&S lens though I have shot with them a little and drooled for one alot.
My recommendation would be the 24mm for full frame because it is easier to control. I might be tempted to try the 17mm though considering I shoot both FX and DX cameras.
With respect to the distortion correction discussion, sometimes the problem can be fixed or minimized behind the camera. I consider myself an amateur and can't justify the cost of every cool tool so I look for creative ways to deal with problems on scene. Recently, I shot the Cotton Candies Mardi Gras Krewe and one of the images they wanted was at the corner face of historic building with a group on the ground and groups on the 2nd and 3rd floor balconies. I knew distortion was going to be an issue so I was lucky to have a metal garbage can holder across the street. I was able to throw a piece of plywood over it and get the camera another 4 foot (9ft total) above the ground. This minimized the amount of correction required. My wife hates when she turns around and finds me hanging in the tree or on the light pole or something.
The other thing I learned is that you don't always have to have the whole damn thing in the image to tell the story. An isolated piece of the whole sometimes does the trick.
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I've changed my C1 Pro Keystone Correction default to 100%.
-CB
Hi Chiss, I asked PhaseOne Support and they told me that the default Keystone Correction setting of 80% could not be changed in Version 8. Could you please tell me how you changed this default setting?
Thank you!
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I have both lenses. Given the height of most cathedral interiors I would recommend the 17MM. I've attached three images of the National Cathedral in Washington, D.C. that I took with these lenses.
Cathedral front elevation: 17MM
Flag: 24MM
Stained light: 17MM
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It's a tough choice, the 17mm provides a unique angle of view when shifted, there really is nothing like it. However it is more difficult to get used to and create great images as you learn how use it effectively. The 24mm on the other hand does give a more natural field of view with less obvious distortion. If you use filters a lot the 24 is a better choice, however there is an adaptor for the 17mm with Lee filters. It's pricey and limits how much you can shift the lens before vignetting becomes a problem but very useful for landscapes.
Be aware that the 17 does have a few little optical characteristics caused by reflection in that big front element. The odd rainbow like artefact and flare with point light to the frame edge etc. Not as much of an issue with the 24.
In cathedral interiors it's the 24 every time. To much shift on high ceilings with the 17 makes them look like they are more like walls due to distortion. The 24 is more than wide enough for big spaces like cathedrals. The 17 can work nicely in the chapels and for exterior shots though.
For me I do find the 17 more fun to use but in practice the 24 is probably the one I really couldn't live without. I got the 24 first, the 17 followed a couple of years later. For architecture you need both in my opinion.
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I don't understand that mindset. While I agree that there is often an optical illusion of building tops diverging when they are perfectly straight... I haven't met a single professional architectural photographer that would overcompensate.
I've changed my C1 Pro Keystone Correction default to 100%.
Hi Chiss, I asked PhaseOne Support and they told me that the default Keystone Correction setting of 80% could not be changed in Version 8. Could you please tell me how you changed this default setting?
I'm running into this again - anyone know how to change this default to 100%? I understand the reasons for 80%, I have reasons for needing my verticals to be... vertical!
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yes, well you have successfully made the horizontals horizontal in addition to keeping the verticals vertical. But there is still a splinter in my brain because the two towers with the conical 'hats' should be equal height but are not.
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Even in that case you can get a vanishing perspective on both ends, as our vision really works. As long as you sacrifice the straight lines:
Guillermo ;
I agree that an rectilinear projection is something we (want to) make in our minds ( and with most lenses) but is not actually true;
Are you saying that the 'truth' is a equirectangular projection...or a cylindrical? (I believe the first)
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Also my believe is that most Architectural photographers just gamble the right proportions with transform and distort.
It took me some time to find the right way to correct it myself. It cannot be done automatically in photoshop or any other program for it depends on your position in the field.
PK