Luminous Landscape Forum
Equipment & Techniques => Cameras, Lenses and Shooting gear => Topic started by: aman74 on January 06, 2013, 05:08:08 am
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I've been doing a lot of reading about panorama setups and have hit a stand still. Partly because I've not yet done this type of work and I imagine it's sort of abstract for many of us to understand until we get our feet wet. The other reason I've hit a wall on this is that I'm coming across directly conflicting information.
I'm considering using a panning clamp or an Arca-Swiss P0 or other ballhead that puts the rotation on top of the ball so that the ball is doing the leveling. The other option is a leveling base for a standard ball head. I suppose a third option is combing both, but I'd like to avoid added cost and weight if possible.
The main thing I'm unsure of is which system allows you to be able to tilt the camera up or down and not always have the horizon centered? Also are multirows possible without these setups or is the standard pano head setup with both axis rails needed for that?
I've seen many posts on the web stating that you can't tilt up or down with the rotation above the head. Then I did some more digging and found people saying that about the standard ball head with leveling base setups. Both sides appear knowledgeable, but clearly one is wrong. Another thought I had was that maybe it's not possible to tilt up or down with the panning clamp, but it is if you ad a nodal rail to that setup?
Thanks so much if this can be cleared up, then I can start even more research on where to go from there. ;)
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I've been doing a lot of reading about panorama setups and have hit a stand still. Partly because I've not yet done this type of work and I imagine it's sort of abstract for many of us to understand until we get our feet wet.
Hi,
That is important. Just do it, and learn from the experience, it only costs some time. There are a few things you can do to increase the chance on successful stitching of the images.
The other reason I've hit a wall on this is that I'm coming across directly conflicting information.
That's not uncommon on the internet.
I'm considering using a panning clamp or an Arca-Swiss P0 or other ballhead that puts the rotation on top of the ball so that the ball is doing the leveling.
That is one of the most important things to maximize the field of view without having to crop excessive amounts of the composition.
The other option is a leveling base for a standard ball head. I suppose a third option is combing both, but I'd like to avoid added cost and weight if possible.
And it is very well posible to do panos without a leveling base. In fact, the pano stitcher will do its own leveling, and is much more accurate than what a simple bubble level can achieve. Also, not leveling can produce more interesting images, e.g. a landscape with a dramatic sky can concentrate on the sky. So you can save cost and weight, especially when you're starting to get your feet wet.
The main thing I'm unsure of is which system allows you to be able to tilt the camera up or down and not always have the horizon centered?
The horizon doesn't have to be dead center when you use a panning clamp on top of the Ballhead (directly attaching to the camera base). You can use the ball head to tilt up or down, and the clamp on top to rotate horizontally. However, by tilting up or down, you will introduce a vertical displacement of the entry pupil of the lens. When you don't use a 'nodal slide', then the horizontal rotation will also introduce a displacement which will create parallax issues which may be impossible to correct by blending the images together.
Also are multirows possible without these setups or is the standard pano head setup with both axis rails needed for that?
When the subject doesn't have too many geometrical features (straight lines or other predictable patterns) then you may be able to hide the parallax errors by clever blending. However, when you want to increase the success rate, especially when you can't re-shoot the scene, it is important to at least get a sliding bar or construction that allows to position the lens' entrance pupil exactly on the axis of rotation, by shifting the lens foreward and backward, to avoid parallax. When you start doing multi-row stitches, then you may get away without a tilt parallax correction, but it's safer to also correct for that which requires a more elaborate setup.
I've seen many posts on the web stating that you can't tilt up or down with the rotation above the head. Then I did some more digging and found people saying that about the standard ball head with leveling base setups. Both sides appear knowledgeable, but clearly one is wrong. Another thought I had was that maybe it's not possible to tilt up or down with the panning clamp, but it is if you ad a nodal rail to that setup?
There is a difference between what can be done, but with a risk of failure, and what is recommended, minimizing that risk. So strictly speaking, there is only one solid way that agrees with the geometrical stitching procedure. It requires alignment of the entrance pupil with the rotation axes for each axis that is used. So a fore / aft slider directly under the optical axis (which may require a sideway slider when the clamp is decentered versus the optical axis) to align the 'Yaw' rotation axis and the entrance pupil, and a vertical slider to align the 'Pitch' rotation axis with the entrance pupil.
So the complete and perfect alignment is a 3-step procedure:
1. sideways shift to align optical axis with fore / aft slider.
2. Fore / aft shift to align entrance pupil with Yaw axis.
3. Up / down shift to align entrance pupil with Pitch axis.
1+2 are needed to minimize the risk for single row pano's (even with horizons that are not centered), and 3 is only needed to reduce the risk for multi-row panos. Only when your subjects do not include foreground detail and predictable structures, you may get away with sloppy technique.
Cheers,
Bart
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Hi,
That is important. Just do it, and learn from the experience, it only costs some time. There are a few things you can do to increase the chance on successful stitching of the images.
I've not used this forum much, so bear with me. I'm trying to quote you, but my original messages that you quoted don't show up in the body of the reply. Only in the area below, a bit clunky.
First off, thanks for the detailed reply. It's helpful and will probably be even moreso after I read it a couple times. ;)
There's merit to just doing it, but I also want to save money and weight by educating myself in advance.
That is one of the most important things to maximize the field of view without having to crop excessive amounts of the composition.
So that's not achieved without putting the rotation point above the head?
And it is very well posible to do panos without a leveling base. In fact, the pano stitcher will do its own leveling, and is much more accurate than what a simple bubble level can achieve. Also, not leveling can produce more interesting images, e.g. a landscape with a dramatic sky can concentrate on the sky. So you can save cost and weight, especially when you're starting to get your feet wet.
Yes, it would seem much is possible with modern software, especially considering even handheld shots can be quite effective. I just tend to get caught up in maximizing every ounce of quality. I should state that my use of panos would more likely be used to increase resolution and less for expansive vistas or other dramatic effects. I'd also like to look into being able to do them for near macro work if that's even possible. The "Brenzier"(sp.?) method is also of interest, but I understand that could largely be done handheld. I do have interest in spherical panos, etc...but not wanting to get ahead of myself.
The horizon doesn't have to be dead center when you use a panning clamp on top of the Ballhead (directly attaching to the camera base). You can use the ball head to tilt up or down, and the clamp on top to rotate horizontally. However, by tilting up or down, you will introduce a vertical displacement of the entry pupil of the lens. When you don't use a 'nodal slide', then the horizontal rotation will also introduce a displacement which will create parallax issues which may be impossible to correct by blending the images together.
This is of the most interest to me as that was the crux of my long-winded question. I saw much conflicting info on this and it was getting frustrating. I think the people saying that you couldn't tilt up or down with this setup were not mentioning or unaware that adding the Nodal slide would correct the issue.
When the subject doesn't have too many geometrical features (straight lines or other predictable patterns) then you may be able to hide the parallax errors by clever blending. However, when you want to increase the success rate, especially when you can't re-shoot the scene, it is important to at least get a sliding bar or construction that allows to position the lens' entrance pupil exactly on the axis of rotation, by shifting the lens foreward and backward, to avoid parallax. When you start doing multi-row stitches, then you may get away without a tilt parallax correction, but it's safer to also correct for that which requires a more elaborate setup.
To do the multirow stitch "ideally" would require the vertical slide right? That's basically the part of the setup I'd like to avoid for cost, size and complexity reasons. I was brainstorming last night and was wondering if raising a tripod center column would be of some use here? Since you aren't tilting the lens, maybe some complications are avoided while maintaing a smaller setup?
There is a difference between what can be done, but with a risk of failure, and what is recommended, minimizing that risk. So strictly speaking, there is only one solid way that agrees with the geometrical stitching procedure. It requires alignment of the entrance pupil with the rotation axes for each axis that is used. So a fore / aft slider directly under the optical axis (which may require a sideway slider when the clamp is decentered versus the optical axis) to align the 'Yaw' rotation axis and the entrance pupil, and a vertical slider to align the 'Pitch' rotation axis with the entrance pupil.
So the complete and perfect alignment is a 3-step procedure:
1. sideways shift to align optical axis with fore / aft slider.
2. Fore / aft shift to align entrance pupil with Yaw axis.
3. Up / down shift to align entrance pupil with Pitch axis.
1+2 are needed to minimize the risk for single row pano's (even with horizons that are not centered), and 3 is only needed to reduce the risk for multi-row panos. Only when your subjects do not include foreground detail and predictable structures, you may get away with sloppy technique.
Number 3 introduces the need for the vertical portion of the typical dual axis setup, correct?
How would I know what size nodal slide is required? I'm using a DP2M and have seen mention of using a very short slide, I believe 1.25" inches. Ideal for keep it light and small.
Thanks so much for your thoughts. Some is a bit over my head, but I think I gleaned something from it and feel more confident ordering an Araca-Swiss P0 style head or getting a pano-clamp, etc...
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The horizon doesn't have to be dead center when you use a panning clamp on top of the Ballhead (directly attaching to the camera base). You can use the ball head to tilt up or down, and the clamp on top to rotate horizontally. However, by tilting up or down, you will introduce a vertical displacement of the entry pupil of the lens. When you don't use a 'nodal slide', then the horizontal rotation will also introduce a displacement which will create parallax issues which may be impossible to correct by blending the images together.
Cheers,
Bart
I'm not sure if I understand you correctly, but when you only have a panning device on top of the ballhead (like the p0) then the horizon has to be centered, because otherwise if you start your image with the horizon not centered then after 90° the horizon is centered, then after another 90° the horizon is going to be not centered again, but now if you had more sky before, you have less sky.
of course you can take a picture, but the horizon will be curved in the picture. maybe you want that, ok but I think very often that is not what you are looking for.
however if you have the panning device below the ballhead, then you can take a picture with the horizon not centered and it will stay like that the whole 360°, but of course as you say you move the entrance pupil so you might run into parallax errors.
so if somebody says that you can't tilt the camera with a setup where the panning device is directly below the camera and somebody else says you can't when the panning device is below the head, then they are both correct and both wrong, depending on what kind of images you are trying to achieve.
I started using a panoramic setup only very recently, but before I read some articles about the topic to find out what I needed to buy, and for me the I think, what made me understand the problems (or just the things to pay attention to) with stitching was to read tutorials on how to find the no parallax point (sometimes falsely called nodalpoint) for your lens. If you do multirow panos you have to find that point (well actually you just need to find two axes, but as it turns out they cross so you have a point), if you are just doing single row panos, you only have to find one "no parallax axis"
I can recommend you this site: http://www.johnhpanos.com/epcalib.htm, when you know how to find the no parallax point, then you also know which head will work for what.
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I'm not sure if I understand you correctly, but when you only have a panning device on top of the ballhead (like the p0) then the horizon has to be centered, because otherwise if you start your image with the horizon not centered then after 90° the horizon is centered, then after another 90° the horizon is going to be not centered again, but now if you had more sky before, you have less sky.
of course you can take a picture, but the horizon will be curved in the picture. maybe you want that, ok but I think very often that is not what you are looking for.
however if you have the panning device below the ballhead, then you can take a picture with the horizon not centered and it will stay like that the whole 360°, but of course as you say you move the entrance pupil so you might run into parallax errors.
so if somebody says that you can't tilt the camera with a setup where the panning device is directly below the camera and somebody else says you can't when the panning device is below the head, then they are both correct and both wrong, depending on what kind of images you are trying to achieve.
I started using a panoramic setup only very recently, but before I read some articles about the topic to find out what I needed to buy, and for me the I think, what made me understand the problems (or just the things to pay attention to) with stitching was to read tutorials on how to find the no parallax point (sometimes falsely called nodalpoint) for your lens. If you do multirow panos you have to find that point (well actually you just need to find two axes, but as it turns out they cross so you have a point), if you are just doing single row panos, you only have to find one "no parallax axis"
I can recommend you this site: http://www.johnhpanos.com/epcalib.htm, when you know how to find the no parallax point, then you also know which head will work for what.
Uh Oh...now I've got conflicting info again...lol. I guess this won't be settled for me until I experiment for myself. I'll look into the route you took in your research to see if it clears anything up for me.
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To do the multirow stitch "ideally" would require the vertical slide right? That's basically the part of the setup I'd like to avoid for cost, size and complexity reasons. I was brainstorming last night and was wondering if raising a tripod center column would be of some use here? Since you aren't tilting the lens, maybe some complications are avoided while maintaing a smaller setup?
no the tripod center column wouldn't work, just as putting the tripod on a big rock, box, sleeping hippo or anything like that won't work. walking uphill a few steps won't work either. :)
the vertical rail (which isn't just a vertical rail it is always something like an L) is needed to get the camera in a position where you can rotate around a point inside the lens in every direction.
Number 3 introduces the need for the vertical portion of the typical dual axis setup, correct?
How would I know what size nodal slide is required? I'm using a DP2M and have seen mention of using a very short slide, I believe 1.25" inches. Ideal for keep it light and small.
Thanks so much for your thoughts. Some is a bit over my head, but I think I gleaned something from it and feel more confident ordering an Araca-Swiss P0 style head or getting a pano-clamp, etc...
ok I don't have this pano head, but for a dp2m (and probably not for any bigger camera) this system might be perfect (but be sure to measure first if it will work, because in that image with the black leica it is very badly set up and I'm not sure if that would work with this camera and nodal slide) if you are looking for an affordable and lightweight setup. this might work as an nodal slide: http://www.arca-shop.de/en/camera-plates//Lensplate-MonoballFix-100
for levellig you could use a p0 head or if you only use it for levelling just a simple levelling head plus an arca swiss clamp (the panoramic head uses the new smaller arca swiss plates there are no third party manufactures that use this standard yet.)
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A good picture is worth 1000 words, or however that cliche goes: Pano Tutorial (http://dgrin.smugmug.com/gallery/2114189)
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Nodal Ninja 5 / rotator + PTGui.
That's about all you need except a little setup time and some practice, assuming you're using nothing larger than a full frame DSLR.
Roy
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I'm not sure if I understand you correctly, but when you only have a panning device on top of the ballhead (like the p0) then the horizon has to be centered, because otherwise if you start your image with the horizon not centered then after 90° the horizon is centered, then after another 90° the horizon is going to be not centered again, but now if you had more sky before, you have less sky.
of course you can take a picture, but the horizon will be curved in the picture.
Hi Simon,
Ah, I see where the misunderstanding comes from. When you say the horizon will be curved with a tilted camera on a rotating clamp at the top of the ballhead, it's not the horizon but the segments of the virtual inside of a sphere that follow a curved path. When we stitch those segments with the correct pitch parameter, the horizon itself will be perfectly straight, but the images follow a curved path (on the inside of the 'sphere').
The same issue arises when people talk about wavy horizons on very wide angle panos. It's due to the wrong pitch setting in the stitcher when the camera was not exactly level. The wavy horizon can be fixed by using the correct pitch, but the full pano will now span an arc (with a straight horizon), which needs to be content aware filled, or cropped.
Cheers,
Bart
P.S. I've attached a simulation of the curved path from an Equirectangular projection on the inside of a virtual sphere from rotating the camera clamp on top of a tilted Ballhead. The red line is the equator. When the same is projected as a Rectilinear image (second attachement), it becomes clear that the upper corners get stretched (which also removes keystoning), but the horizontals and verticals and all other straight lines in the image will remain straight. Unfortunately I have no single ballhead image example available because I shoot my multi-row panos with a complete pano setup.
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Hi Simon,
Ah, I see where the misunderstanding comes from. When you say the horizon will be curved with a tilted camera on a rotating clamp at the top of the ballhead, it's not the horizon but the segments of the virtual inside of a sphere that follow a curved path. When we stitch those segments with the correct pitch parameter, the horizon itself will be perfectly straight, but the images follow a curved path (on the inside of the 'sphere').
The same issue arises when people talk about wavy horizons on very wide angle panos. It's due to the wrong pitch setting in the stitcher when the camera was not exactly level. The wavy horizon can be fixed by using the correct pitch, but the full pano will now span an arc (with a straight horizon), which needs to be content aware filled, or cropped.
Cheers,
Bart
P.S. I've attached a simulation of the curved path from an Equirectangular projection on the inside of a virtual sphere from rotating the camera clamp on top of a tilted Ballhead. The red line is the equator. When the same is projected as a Rectilinear image (second attachement), it becomes clear that the upper corners get stretched (which also removes keystoning), but the horizontals and verticals and all other straight lines in the image will remain straight. Unfortunately I have no single ballhead image example available because I shoot my multi-row panos with a complete pano setup.
hmm sorry I'm still confused by your statement, if you use this ball head ( http://www.arca-shop.de/de/Monoball/Monoball-p0-Serie/ARCA-SWISS-Monoball-p0-mit-Schnellspannvorrichtung-MonoballFix ) (or something similar) and tilt the camera upwards toward the sky so that only 10% of the image are NOT sky (in a very flat desert very big no trees) and then start to rotate the camera after 180° the camera is pointing towards the ground very much! of course you can straighten the horizon, but then you have to crop a lot of the image and the horizon is going to end in the center again right?
I'll take an image tomorrow (it's dark right no here in switzerland and very late) to show you what I mean (although not in a desert but it should still be helpful)
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... Just do it...
+1
... it is very well posible to do panos without a leveling base...
It is, of course. The downside is that you will have to deal with a staircase effect, cropping out a lot in the post. No software can compensate for that.
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hmm sorry I'm still confused by your statement, if you use this ball head ( http://www.arca-shop.de/de/Monoball/Monoball-p0-Serie/ARCA-SWISS-Monoball-p0-mit-Schnellspannvorrichtung-MonoballFix ) (or something similar) and tilt the camera upwards toward the sky so that only 10% of the image are NOT sky (in a very flat desert very big no trees) and then start to rotate the camera after 180° the camera is pointing towards the ground very much! of course you can straighten the horizon, but then you have to crop a lot of the image and the horizon is going to end in the center again right?
I'll take an image tomorrow (it's dark right no here in switzerland and very late) to show you what I mean (although not in a desert but it should still be helpful)
That's where I'm confused as well. I saw reactions to posts pointing out what you're saying while I was trying to learn about all this. There were a few people saying that that's the issue with putting the rotation above the head. They were saying to use a leveling base under the ballhead to avoid this, but I honestly don't see how that works either as I haven't had time to study the links provided in this thread yet.
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Hi,
This small article I have written may be a starting point: http://echophoto.dnsalias.net/ekr/index.php/photoarticles/panorama-and-stitching
In practice I have seen little need for a nodal slider, but I sometimes use one.
My favorite tripod head is the Arca Swiss D4m which I have on a leveling base. http://echophoto.dnsalias.net/ekr/index.php/photoarticles/53-arca-swiss-d4 (includes a short video)
Best regards
Erik
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hmm sorry I'm still confused by your statement, if you use this ball head ( http://www.arca-shop.de/de/Monoball/Monoball-p0-Serie/ARCA-SWISS-Monoball-p0-mit-Schnellspannvorrichtung-MonoballFix ) (or something similar) and tilt the camera upwards toward the sky so that only 10% of the image are NOT sky (in a very flat desert very big no trees) and then start to rotate the camera after 180° the camera is pointing towards the ground very much! of course you can straighten the horizon, but then you have to crop a lot of the image and the horizon is going to end in the center again right?
Hi Simon,
That's correct. The horizon is straight (with the correct pitch setting for stitching) but the image tiles follow a curved path.
So all I'm saying is that straight horizons have little to do with leveling the camera! Straight horizons come from setting the correct 'Pitch' parameter when stitching.
The leveling will help to avoid unnecessary cropping and/or to avoid the need to use content aware fill for turning the arc into a rectangle.
Depending on the scene and resulting FOV, using a rectilinear projection model helps. Not only does it keep all straight lines, not only the horizon, straight, but it also fills the corners of the arced path by stretching the images near the corners. It also helps to shoot in portrait orientation, because you will get more vertical FOV, which may reduce the need to do a multiple row pano.
An ideal solution is of course to use a full Multi-row Pano setup, which aligns all rotation axes in one point, the entrance pupil. The minimum to achieve a larger success rate is a fore/aft slider, to at least get zero parallax for a single row stitch. Some subjects (e.g. with non-critical foregrounds) will stitch, and more importantly blend, even without precautions to avoid parallax, but it will fail sooner or later, especially when you can least use the problems.
Since the clamp rotation at the top of the ballhead, also incorporates the fore/aft slider, rotating the setup there will not create parallax. If one were to rotate at the bottom of the ballhead (to avoid a curved image path), then any non-leveled clamp will create parallax, despite the correction with a fore/aft slider on top. That's were the importance of a rotating clamp at the top of the ballhead comes from, avoiding parallax.
And take it from me, there will be issues sooner or later when the images contain parallax, so it's best to reduce the risk from the start.
Cheers,
Bart
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1I'm considering using a panning clamp or an Arca-Swiss P0 or other ballhead that puts the rotation on top of the ball so that the ball is doing the leveling.
2The other option is a leveling base for a standard ball head.
3I suppose a third option is combing both, but I'd like to avoid added cost and weight if possible.
4The main thing I'm unsure of is which system allows you to be able to tilt the camera up or down and not always have the horizon centered?
5Also are multirows possible without these setups or is the standard pano head setup with both axis rails needed for that?
6I've seen many posts on the web stating that you can't tilt up or down with the rotation above the head.
7Then I did some more digging and found people saying that about the standard ball head with leveling base setups. Both sides appear knowledgeable, but clearly one is wrong.
8Another thought I had was that maybe it's not possible to tilt up or down with the panning clamp, but it is if you ad a nodal rail to that setup?
Two things to clear up before I actually reply. This is the internet; it is filled with conflicting opinions. Some of those opinions will come from people who have no, clue as to what they blather on about, soem will have some clue, and others might actually have useful answers that relate to what you want to do.
And that brings up the second thing which is actually two questions:
A) What is the subject matter that you want to make panoramic photographs of? Roughly speaking there are landscapes where precise geometric rendering is not critical; and cityscapes and architectural studies where good geometric rendering is critical to the finished photograph's success. The hardware needs are no so critical for the first case - especially if the differences between near and far elements in the photo are slight to non-existant. The larger those near to far differences are (based on your lens focal length choice and basic subject to camera distance) the greater need you have for specialized hardware like a "nodal slide".
B) What is the intend use of the photographs?
Only you can answer those questions.
On to my answers , which are based on my experience, to your specific concerns.
1 Unless you are just looking to do quick panoramas my experience is that having rotators at the top (camera platform) and base of your tripod head makes life a whole easier. Not just for panoramic photography but anytime you use a tripod. I have four heads that I use regularly : from larger to small laods they are a Foba ASMIA (http://www.bhphotovideo.com/c/product/247458-REG/Foba_31_0118_ASMIA_Double_Pan_Tilt.html); Arca-Swiss B1 Monoball (modern equivalent = Arca-Swiss Z1sp); Arca-Swiss D4M; and Arca-Swiss p0
2 & 3For really precise architectural and product work I will use a leveling platform - A Manfrotto 338 QTVR Leveling Base (http://www.bhphotovideo.com/bnh/controller/home?O=&sku=554092&Q=&is=REG&A=details) but I put it between the top of my tripod head and the top level rotator(A Really Right Stuff PCL-1) on the ASMIA head, not underneath the head. As a tripod head is already an excellent leveling platform for my work I don't see a need to put a leveling base underneath it. But in most cases I do not use one.
4 & 5For that purpose I use a larger panoramic mounting rig, essentially it is the PG-02 Omni-Pivot Package ( http://reallyrightstuff.com/ProductDesc.aspx?code=PG-02-Pro-OPP&type=3&eq=&desc=PG-02-Pro-Omni-Pivot-Package&key=it) but withthe longer CB-18 bar instead of the shorter CB-10 bar. This has to do with the size of the camera bodies I use. I can shoot with the center row level or tilted up or down. However most of my work is either landscape or interiors, including geometrically complex industrial interiors. If you are doing landscapes, you may not need or want that degree of precise control and can do great work with a head with a panning camera platform and possibly a nodal slide.
6 & 7 The definitive answer here is simple: Whoever said those things is ignorant.
8 Using a panning clamp has nothing at all do with the angle you set your head to. rotators are just another joint and work independently. The purpose of a nodal slide is to center the entrance pupil for the lens in the axis or axes (if shooting multi-row panoramas) of rotation you'll be swing your camera around.
The reasons I like the Really Right Stuff (or similar) approach to panoramic support gear is that it is modular and I can use all of the components or just the ones that I need for a specific shot. I can also use them for other kinds of photography: still life, macro work or securely supporting the camera in positions a simple tripod and head cannot fit into. It's all about having options. Whether I choose to use them is a different matter.
I specifically like the Arca-Swiss, Foba and Really Right Stuff gear I use because it's all very well made and very, very reliable. I do my best to spend my money very carefully on these types of things.
The stitching software I rely on is PTGui Pro although the version of PhotoMerge in Adobe Photoshop CS6 is much better than it has been in earlier versions.
I hope this helps. And Bart is right: Once you start many of your questions will begin to present you with the direction you need to go in for the answers that will work for you.
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Hi Simon,
That's correct. The horizon is straight (with the correct pitch setting for stitching) but the image tiles follow a curved path.
So all I'm saying is that straight horizons have little to do with leveling the camera! Straight horizons come from setting the correct 'Pitch' parameter when stitching.
The leveling will help to avoid unnecessary cropping and/or to avoid the need to use content aware fill for turning the arc into a rectangle.
ok I got it, and if you tilt only a bit that might work quite will with rectilinear stitching that makes sense.
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+1 Bart is right :)
The least expensive way to add panning is mount a ballhead upside down.
Macro panoramas just need a little more care in setting the rotation points exactly on the entrance pupil. If you want to add focus stacking, then I'd recommend using a bellows and setting the magnification and focus by moving the camera (with the lens' entrance pupil fixed at the rotation points).
Here's one of my favorite focus stacked macro panoramas: http://photosynth.net/view.aspx?cid=3c6a1c2a-7426-41d7-bbea-3f46feefa9c5
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Two things to clear up before I actually reply. This is the internet; it is filled with conflicting opinions. Some of those opinions will come from people who have no, clue as to what they blather on about, soem will have some clue, and others might actually have useful answers that relate to what you want to do.
And others will show up on this forum and in short notice pontificate in many, many threads, coinciding with their efforts to write for photo magazines.
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And others will show up on this forum and in short notice pontificate in many, many threads, coinciding with their efforts to write for photo magazines.
I hope this isn't a dig at Ellis.
Tony Jay
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Thanks for all the recent thoughts. I don't have the time to go over all of them right now, but I was thinking about this last night and think I understand what the issue is now.
Here's an extreme example. Take the camera, mounted on a tripod/ballhead and flip it over 90 degrees and aim it at the ground. Rotate it with a pano clamp and it's going to spin around to include the sky. Rotate it with the pano base of the ballhead and you'll scan the ground, which was most likely your objective.
I'm guessing this is why the people advocating that a pano base, with a leveler if you so choose, is going to come closer to achieving the results you're looking for in more varied situations, ie: tilting the camera up or down.
The pano clamp seems an excellent way to get fast results, but is more of a convenience item as it allows the ball head to become the leveler. I'm failing to see how it's superior, but that may largely be my failing, I'm not sure yet.
I certainly know a lot less than most folks about this, but this does seem to pose a good point, no?
Thoughts?
Several posters were speaking of what the stitching software can do. That's great info and the improvements nowadays are awesome, but that's not what i was driving at. Using the software more heavily may indeed, in the end, be the more practical solution, but I was more looking for what the "ideal" route was for getting as much correct at the time of the shot is.
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...Several posters were speaking of what the stitching software can do. That's great info and the improvements nowadays are awesome, but that's not what i was driving at. Using the software more heavily may indeed, in the end, be the more practical solution, but I was more looking for what the "ideal" route was for getting as much correct at the time of the shot is...
Believe me when I say this: trying to stitch poor images into a panorama must be the most frustrating and unedifying experience there is in post-processing.
With the best possible series of images you have a chance, with the best software, of getting a good result, but there is no guarantee.
So, to get any sort of result requires maximum leverage of your shooting ability and maximum facility with your stitching software.
Tony Jay
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Thanks for all the recent thoughts. I don't have the time to go over all of them right now, but I was thinking about this last night and think I understand what the issue is now.
Here's an extreme example. Take the camera, mounted on a tripod/ballhead and flip it over 90 degrees and aim it at the ground. Rotate it with a pano clamp and it's going to spin around to include the sky. Rotate it with the pano base of the ballhead and you'll scan the ground, which was most likely your objective.
I doubt it. When you spin the camera around with the pano base of the ball head, each image will have a different position of the entrance pupil of the lens in a circular path around the tripod center, which makes it impossible to avoid parallax between the image tiles, which in turn creates problems with seamlessly overlapping stitching of 3-dimensional surroundings.
Try adding a fore/aft sliding bar to your top clamp setup to eliminate the entrance pupil parallax in a single row, and you'll see the benefit of using the top clamp rotation. Only with this latter approach will overlapping tiles have zero parallax in the overlap zone, which makes reliable automatic stitching possible.
I'm guessing this is why the people advocating that a pano base, with a leveler if you so choose, is going to come closer to achieving the results you're looking for in more varied situations, ie: tilting the camera up or down.
Remember, the usual goal is being able and stitch the adjacent pano tiles, without parallax issues in the overlap zones spoiling the fun. The goal is usually not just to simply cover a given Field of View with lots of problems to make a coherent composite image out of it. If that were the objective, then hand-held shooting would suffice. Especially with demanding foreground features and predictable patterns, eliminating parallax is the key to success.
Funny enough, there is also a possible advanced use for parallax on flat surfaces, such as your thought experiment with the camera pointing down and spinning round the ballhead base, but that requires stitching software that can cope with camera position offsets and masking. With some math and masking, it is possible to eliminate the tripod (legs) from showing in the so called 'Nadir image', e.g. in a 360 degree VR pano.
Cheers,
Bart
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I hope this isn't a dig at Ellis.
Tony Jay
Of course it is. But I don't try to write for photography related publications - I've been making good money doing it for nearly ten years.
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I doubt it. When you spin the camera around with the pano base of the ball head, each image will have a different position of the entrance pupil of the lens in a circular path around the tripod center, which makes it impossible to avoid parallax between the image tiles, which in turn creates problems with seamlessly overlapping stitching of 3-dimensional surroundings.
Try adding a fore/aft sliding bar to your top clamp setup to eliminate the entrance pupil parallax in a single row, and you'll see the benefit of using the top clamp rotation. Only with this latter approach will overlapping tiles have zero parallax in the overlap zone, which makes reliable automatic stitching possible.
Found this thread:
http://photo.net/nature-photography-forum/00OE1U?start=0
From a few posts down:
"The reason to use a leveling base for shooting stitched panos would be if you wanted to create a pano where the camera was not pointed directly at the horizon (level). For example, a pano looking downward into a canyon or pano looking slightly upward at mountains.
If you use a panning clamp (like RRS's) and tilted the camera upward the arc of the pan would curve downward the farther off center you got. If you tilted downward the inverse is true, edges of the photo curve up.
However, if you use a leveling base combined with a ballhead with built in panning base (not a panning clamp), then you can level the base of the ballhead with the leveling base and then pan left right on a perfectly horizontal axis using the ballhead's panning base. Then even if you tilt the camera down or up with the ballhead, the axis of rotation remains horizontal.
Hard to explain, but easy to see once you try it out."
That's what I'm getting at...
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If you use a panning clamp (like RRS's) and tilted the camera upward the arc of the pan would curve downward the farther off center you got. If you tilted downward the inverse is true, edges of the photo curve up.
but this way you don't get any parallax problems if you use a "nodal" slide/rail. however at some point you might not get the image you want, simply because there is too much of a curve when you stitch the images.
However, if you use a leveling base combined with a ballhead with built in panning base (not a panning clamp), then you can level the base of the ballhead with the leveling base and then pan left right on a perfectly horizontal axis using the ballhead's panning base. Then even if you tilt the camera down or up with the ballhead, the axis of rotation remains horizontal.
yes but then you get parallax errors because you move the entrance pupil of the lens. with some subjects (distant mountains) it might work perfectly but not so much with an important foreground. to avoid that you need to use a 3d pano head.
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"The reason to use a leveling base for shooting stitched panos would be if you wanted to create a pano where the camera was not pointed directly at the horizon (level). For example, a pano looking downward into a canyon or pano looking slightly upward at mountains."
Yes, and I hope that it's well understood by now that that won't affect the horizon's curvature or waviness, provided that the correct Pitch angle is used in the stitching software. As was explained (or at least hinted at) in that thread, leveling the base of the Ballhead and then allowing a joint above that with a clamp which destroys the leveling (as far as the camera is concerned) for looking down or up, doesn't help to reduce parallax. It only helps to reduce a curved image path.
That above quote only makes sense with a complete multi-row pano setup, with the entrance pupil aligned for all 3 axes, Yaw / Pitch/ Roll. With a simpler, but often good enough single row setup, there is no way to avoid both a curved image path and parallax at the same time on a 3-dimensional scene. Only with clever software and a flat plane surface can we remove parallax after the fact (http://www.tawbaware.com/ptasmblr_help_camera_position.htm).
Cheers,
Bart
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but this way you don't get any parallax problems if you use a "nodal" slide/rail. however at some point you might not get the image you want, simply because there is too much of a curve when you stitch the images.
Couldn't you use the nodal slide with the ballhead panning though?
yes but then you get parallax errors because you move the entrance pupil of the lens. with some subjects (distant mountains) it might work perfectly but not so much with an important foreground. to avoid that you need to use a 3d pano head.
Again, can't we use the nodal slide for this?
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Yes, and I hope that it's well understood by now that that won't affect the horizon's curvature or waviness, provided that the correct Pitch angle is used in the stitching software. As was explained (or at least hinted at) in that thread, leveling the base of the Ballhead and then allowing a joint above that with a clamp which destroys the leveling (as far as the camera is concerned) for looking down or up, doesn't help to reduce parallax. It only helps to reduce a curved image path.
We can't use the nodal slide for this? I'm assuming not or you guys would have mentioned it.
That above quote only makes sense with a complete multi-row pano setup, with the entrance pupil aligned for all 3 axes, Yaw / Pitch/ Roll. With a simpler, but often good enough single row setup, there is no way to avoid both a curved image path and parallax at the same time on a 3-dimensional scene. Only with clever software and a flat plane surface can we remove parallax after the fact (http://www.tawbaware.com/ptasmblr_help_camera_position.htm).
Cheers,
Bart
Ok, I'll have to re-read that thread and see what was hinted at.
I think I'm starting to get what you're driving at. Lemme see if I have this right. If we wish to stay with a single-row setup, the panning clamp makes more sense as the curved image path is easier to deal with than parallax errors?
Sorry that I'm having a hard time getting all this straight.
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...Sorry that I'm having a hard time getting all this straight.
And the hard times will continue indefinitely until you actually start doing it yourself. Otherwise, it will be like trying to become a brain surgeon by reading books, or, worse, Internet debates about it.
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+1 to Slobodan! Trying to hold in your head how all of this works is very very difficult. Once you start, even without specialized panoramic stitching gear, will give you insight into the mechanics of shooting stitched panoramas
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Attached is a single row panorama with the camera level and horizontally rotated at the camera platform. The long side of the camera's sensor was oriented vertically. No pitch or other corrections were done in the stitching software. Cylindrical Projection
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Sorry that I'm having a hard time getting all this straight.
Hi,
No problem. It creates problems to envision the consequences for a lot of people, until they understand/embrace the concept of avoiding parallax as the technical goal. Actually doing it helps when that goal is kept in mind. Some subject matter may be somewhat forgiving and with proper software blending we may cover up some shortcomings, but the best chance of success comes with proper technique.
To avoid entrance pupil parallax for single row panoramas (whether tilted up, down, or on its side plays no role) we need to satisfy 2 alignments for the intersection of orthogonal rotational axes at the same time in a single point, and for multiple-row panoramas that would require alignment of 3 rotational axes in a single intersection point.
In the single row pano case, we need to make sure that the camera's Yaw axis and the optical axis (Roll axis) intersect at the entrance pupil position. That requires a lateral shift (only if the tripod socket is not aligned with the optical axis), and a fore/aft 'nodal' or rather No-Parallax Point shift, usually backwards (the amount varies with lens focal length, and perhaps a bit with focus distance). The best way to achieve this, is with a rotating clamp positioned directly under the optical axis (no lateral offset), and a fore/aft sliding bar to move the entrance pupil of the lens directly above the rotating clamp.
With that done correctly, we can happily rotate around the camera's Yaw axis, without introducing any parallax, and stitching will be easy, even with difficult subject patterns. It will not prevent a curved path of image tiles relative to a horizon when we tilt the clamp plane to a non-leveled angle, but straight lines (including the horizon) will remain straight (not level, but straight) when a rectilinear projection is used for rectilinear lenses and the correct Pitch value is set in the stitching software. When the camera is used in portrait orientation, the vertical FOV is often sufficient enough to avoid the need for a heavier, more complex, multi-row pano assembly.
When we relax our No-Parallax Point (NPP) requirement, everything becomes much harder to understand, and to stitch.
Cheers,
Bart
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Bart's explanation and analysis, is spot on.
As Bart points out, even with the camera carefully levelled, life is far easier with a rotating clamp located as close as possible to the entrance pupil (AKA"nodal point") rather then separated from it by the body of the tripod head.
Using a rotating clamp at the camera platform level isolates the camera's rotational plane from the pitch (fore/aft) and roll (lateral) angles you've set with the heads controls.
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Couldn't you use the nodal slide with the ballhead panning though?
Again, can't we use the nodal slide for this?
hmmmmmm actually I think that might work "quite well" (compared to multi row) for a single row tilted panoramas. of course you would have to reset the nodal rail when you change the tilt. but you could find an equation to help you set the nodal rail for any different tilt. it is going to be slightly different for different lenses/cameras. so theoretically it should work as well for multi row panos, but then you would have to reset the nodal rail for each row. I think that's when I would buy a real 3d pano head, actually I would buy one way earlier, because you can save the leveling base for the ballhead (or the ballhead vice versa) since you only have to level the panning base for the 3d head so you probably don't even save that much weight.
am I right or have I lost it completely?
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+1 to both!
Erik
+1 to Slobodan! Trying to hold in your head how all of this works is very very difficult. Once you start, even without specialized panoramic stitching gear, will give you insight into the mechanics of shooting stitched panoramas
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I have attempted a drawing to show why the geometry of using a rotating clamp on the head's camera platform works better. I have kept it simple and am only considered pitch (for/aft) tilt angle and not also roll (lateral) tilt angles.
While you could adjust the position of the camera forward or backward to keep it aligned with the rotational axis of a base rotator you'd have to change that position anytime to maintain parallax correction you used a different tilt angle to maintain alignment. That to me is more of a pain than just buying a rotating clamp and a slide.
If I have this wrong please correct.
two final notes:
My gut feeling is that while programs like PTGui, AutoPano Pro and the PhotoMerge script in Photoshop CS6 (although not in earlier versions of Photoshop) have gotten very good at handling parallax errors , for best results minimizing how much interpolation the stitching program must do to correct for parallax errors is a better way to work yielding fewer problems that have to corrected by hand later.
But if the final panoramic will be reproduced at a small size and/or the differences in the near/far relationships in the photo approach zero those kinds of errors may not matter.
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You forgot to list the 617 camera as an option.
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If this thread was the first thing I'd come across about pano stitching I think I'd have taken up golf instead.
You need a pano head and the software. I suppose you can do without the pano head under certain limited circumstances. You need to set up the pano head so that rotation in both axes is about the no-parallax point; there are plenty of tutorials that show you how to do this. Here's a good source:
http://www.johnhpanos.com/tuts.htm
Learning PTGui (and, I guess, AutoPano) is a bit of a challenge but it's the key to accomplishing the stitching/blending sucessfully.
Amazing how the topic of levelling before shooting comes up time after time - a total red herring.
Roy
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Concerning Ellis Vener's posted pano of the railroad tracks: it does not seem to me that there is a camera pitch, or post-processing pitch adjustment that will make both the tracks and the horizon undistortedly linear (i.e. straight, uncurved), from his shooting position. Only a QTVR file will do that, which looks very natural but is not printable, or a rectilinear projection, which seems to give poor results, at least in PTGui. If there is a solution to this problem, please let me know.
Thanks
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Concerning Ellis Vener's posted pano of the railroad tracks: it does not seem to me that there is a camera pitch, or post-processing pitch adjustment that will make both the tracks and the horizon undistortedly linear (i.e. straight, uncurved), from his shooting position. Only a QTVR file will do that, which looks very natural but is not printable, or a rectilinear projection, which seems to give poor results, at least in PTGui. If there is a solution to this problem, please let me know.
Thanks
poor results in what way? (concerning the rectilinear projection)
and of course a rectilinear projection doesn't work with a 180° angle of view. the wider you go, the more extreme gets the "rectilinear wide angle effect" (sorry don't know how to describe it, just look at some pictures with a 14mm on a full frame).
also the wider you go (when you choose rectilinear projection), the more have the images on the edge of the stitched image to be stretched. so you loose resolution there. the solution to that problem is to start with a higher center resolution (much more than you need/want) so that you still have the desired corner resolution (of course when you then see the amazing center resolution, then you might also want this in the corner and you might want choose an even longer focal length, and then again and again and before you go completely crazy just keep in mind that you probably already have a much higher resolution than if you shot this image in one shot, so just ask yourself how large do I wan't to print it and then stop:).
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'Poor' in the way that the sides of a rectilinear pano are disproportionately stretched out. When you convert a very long pano to a .mov file for qtvr viewing, the result is very natural as you rotate around the image - no bending RR tracks. I wonder if it is possible to 'unroll' the .mov on to a flat image that would look natural.
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Concerning Ellis Vener's posted pano of the railroad tracks: it does not seem to me that there is a camera pitch, or post-processing pitch adjustment that will make both the tracks and the horizon undistortedly linear (i.e. straight, uncurved), from his shooting position. Only a QTVR file will do that, which looks very natural but is not printable, or a rectilinear projection, which seems to give poor results, at least in PTGui. If there is a solution to this problem, please let me know.
Thanks
This assumes that the railroad tracks, the highway and the horizon are straight and possibly parallel to each other.
In fact they are are not and each has its own complex set of changes in curvature, and elevation change (grade).
Can't post a screen shot of the google map aerial view for some reason but the co-ordinates are 33.800493, -84.391566
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I think no. if you unroll it you get curved lines. which I think for some images works quite well and looks quite natural.
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Three panoramas with Arca Swiss P0