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Old Jul 3, 2006, 3:32 PM   #1
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Hello all,
I am wondering if there is any software out there that can compensate for camera angle while shooting a multi shot 180 degree wide panorama for display on a screen without scrolling. For example, suppose I put a 10 foot ladder almost directly above some railroad tracks and shoot maybe 10 shots covering 180 degrees wide. Ideally the stitched image should show the railroad tracks going from the far left of the stitched image to the far right and perfectly horizontal across the frame, but in reality, most stitching software will show the railroad tracks as a U shape either vertical or almost vertical at the corners and horizontal or almost horizontal at the center. It seems to me this is because the stitching software is "stupid" and doesn't consider the angle of the camera (w.r.t. the railroad tracks) and doesn't "know"the desiredresult (I want railroad tracks completely horizontal). I would think it is too difficult a task otherwise someone would have done it by now. Other problems are distance of subjects away from the camera effect this type of projection distortion. I was wondering if anyone knows a way to help alleviate this problem. I basically want to shoot a 180 degree wide panoramic and then display it in a way similar to what our eyes see but without having to scroll. I suppose I could shoot the panorama of something close to the camera by just sliding (panning) the camera in a straight line. That is, moving it along the railroad tracks instead of rotating the camera about a point, but what technique would I use for shooting fromthe edge of a pool so that the pool edge where I am shooting from remains straight and horizontal and I can still get decent depth to the shot (good background scenery)? I will post a picture sometime to illustrate the problem I am having but in the meantime, if someone has advice for me I would like to hear it. It seems like the only practical solution is to get a camera that can grab about 120 degrees in a single shot (without moving camera) thus it will preserve horizontal lines much better because once the camera moves horizontally in a panorama, horizontal lines are not preserved. It is frustrating. I wish someone could builda camera that could "see" just like our eyes could see. That is, about 180 degrees wide and about 135 degrees vertical. That would look spectacular if both horizontal and vertical lines are preserved in that shot. If someone knows of a technique to make a 180 degree wide 135 degree tall multi shot panoramic shot capable of being displayed on a single screen without scrolling and looks decent (as described above), let me know. Someone told me this is not possible due to the laws of physics butI feel if our eyes can do it, why cant a camera do it? Thank you.
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Old Jul 4, 2006, 11:16 AM   #2
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i know what u mean about auto stitching software and i agree with you, thats why i do all my panos by hand in photoshop, itll give u a straighter line, never tried what your wanting to do but i dont think it would work. you would have to be further away to get it straighter, u would (and will) get better results when your zoomed in and the lens doesnt distort as much.

the move along sideways idea doesnt work at all. your moving the view point so you are seeing stuff that you couldnt see where you where stood when you took the first picture, try it, i did, with a stretch hummer limo !!! good job i also took a set of images from a fixed point



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Old Jul 4, 2006, 12:13 PM   #3
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The reason why what you are asking for hasn't been done is that it is impossible to compress a 180 degree angle of view onto a flat sheet of paper without introducing distortions in one form or another. Exactly the same difficulties face map makers trying to represent a map of the world on a flat sheet of paper. There is a software package that enables natural distortions in images to be manipulated into a more acceptable form, which may go some way to meeting your requirements: see http://www.altostorm.com/
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Old Jul 4, 2006, 12:22 PM   #4
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In Photoshop, you can use the Edit / Transform / Distort or Skew functions to sequentially pull down the left & right side of a pano to adjust it to what you saw. This works for panos of scenes where dimensional accuracy is not critical...Harvey:-)
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Old Jul 4, 2006, 12:28 PM   #5
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Hi,

Thanks for the reply.The "sliding" technique where you move the camera but point in the same direction works ok if there is not much depth to the shot and is shot using maybe 50mm or more of focal length (or anything in the cameras middle zoom range). This technique would work if you wanted to photograph something like the gutters on your house but up close so you can get detail, not just a single wide shot from a distance. Obviously if you were standing close to the gutters and you used the pivot technique, your stitch would have some serious warping of the gutters. There is software that will take a curved stitched image and allow the user to mark 3 points on a curved "line" in the image and force it to be perfectly straight. I just wish cameras were smart enough to do this while they shot. Like if they had a compass in them and you would push a button to tell it the forward aiming position, then as you pivot the camera to the left and eventually to the right, it would record the angle off of center that you shot and compensate or at least put that info in the Exif data so stitching software could compensate for that. Attached is a picture of a window using handheld 5 portrait shots overlapped about 50% each using a "cheapie" 3MP camera. I did not cheat and straighten the frame in software. The straightness is due to setup, not postprocessing. I used that "slide" technique. Granted there are other optical issues but if squareness is your main goal, this technique works fairly well in some cases. Obviously I resized this bigtime and I cropped it some too to get it to 1024 pixels wide. This is also a great way to effectively increase the MP of your camera. The 5raw images totaled 15MP so there was a lot of detail before the downscaling.
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Old Jul 4, 2006, 2:36 PM   #6
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this is nearly 180 degrees shot the other day with 8mp olympus dslr, 5 or 6 shots, now distortion at the edges, shot free standing without tripod fixed exposure.

not the final edit of the pic, a bit more work on the sky is needed


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Old Jul 5, 2006, 10:15 AM   #7
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Hi,

For a distant shot, 180 degrees is rather easy. I wanted to know how to get a 180 degree wide 135 degree tall (about 4:3 aspect ratio) having both near and far subjects in the shot. For example, sit at the edge of a pool and look using your peripheral vision at the edge of the pool while looking forward into the distance. That requires a 180 degree wide field of vision which our eyes has but just barely. I want to be able to capture that in my picture so that the edge of the pool is perfectly straight and horizontal in the stitched panorama and also so that the background is natural looking not big time warped, tilted, skewed, wrong size, stretched... Photography is so frustrating sometimes because it seems like I cant make my camera/software do what I want it to do. Someone may argue that it is impossible to do but my arguement is our eyes can do it without major distortion, so it should be able to be reproduced using some type of camera techniques. Also, would I need a curved screen to properly view a 180x135 degree image? I understand I am trying to view a 3D image on a 2D display. Maybe someday they will have better technology for consumer cameras so that we can get more realistic pictures. Maybe some of those 3D goggle things. If you think about it, a regular 2D picture is not a very good reproduction or representation of the real thing. I didn't realize how good our eyes are until I saw how restrictive cameras are. The main advantage I see of cameras over our eyes is zoom. Our eyes cannot zoom but they are so good, many times they dont have to. Plus we can see a wonderful wide angle panoramic view pretty much all the time. That is what I am trying to capture using a camera. I want my pictures to look like I am there at that location not looking at a flat monitor or printout. Even some 3D glasses with supporting software would be an improvement. Anyone know if they have that technology out yet for the average Joe? Thanks.
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Old Jul 15, 2006, 6:18 PM   #8
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The reason cameras are unable to do what you want is because the film or sensor is flat. In order to record the scene without disortion, it would have to be (at least roughly) spherical. It can be done with film, though, using a camera with a rounded back. I recall seeing pinhole cameras made from oatmeal containers which give an undistorted panorama.

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Old Jul 19, 2006, 12:24 AM   #9
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I have to agree with VTPhotog.

You are trying to replicate something that cannot be done with current technology.

And VTphotog is right. Our eyes are round, plus we have two of them. Our brain interpretes the two images into one, which gives us depth along with the 180 degree view.

Because the film or senor is flat, the 180 degree view is not going to fit correctly on the rectangle.

Take any kind of ball, cut it in half. This represents a 180 degree view. Now try to flatten it on a surface without any distortions. It is not possible.

It is an interesting idea that you have, and are trying to accomplish, but not possible with current technology

-Travis-
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Old Jul 19, 2006, 1:34 AM   #10
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Hello,

I guess I am just frustrated at how many camera and software "tricks" it takes to do something that our eyes can do rather easily. Even to just capture 180 degrees wide and 135 degrees tall requires at least 4 shots with a super wide angle lens and maybe 9 to16 with a standard 35mm EFL lens yet our eyes see it all the time using only 2 simultanously captured "shots". I wish someone else who thinks like me would develop some way of capturing and displaying these types of images just like our eyes see. Maybe someday they will have 3D cameras (with 2 or more lenses) and 3D software capable of displaying 180x135 degree images so that the picture looks real and not distorted and flat. Think about it, they have those microphones that they place in the ears of a replica of a person's head to capture sound more like our ears hear so why not develop a camera that captures images like our eyes do and automatically stitches them into a nice panorama?

Another really irritating thing about cameras is how wide angle lenses distort the corners so that as you move your camera and sweep across a scene, it looks like it magnifies and stretches the corners to be a different size then when it was towards the center of the frame. I have seen this behavior in those 360 degree VR tours and it is annoying. It is amazing (and frustrating) at how many distortions creep up when trying to capture a scene that our eyes can do virtually flawlessly. Maybe cameras should have 2 lenses like our eyes and smarter firmware like our brain so images like I want could be captured correctly. Right now it seems like the technology is only good for normal totele shots where you capture maybe 52 degrees or less AOV and display on a flat 2D monitor. Those look fair.

No I'm not done complaining yet. Cameras (especially when using wide angle lenses) also have an irritating characteristic in that as you angle the camera up, buildings tend to appear tipped. Many times straight objects such as telephone poles appear to bend inwards towards the center of the frame. Again when our eyes pan across a scene or look upwards from the ground we dont see this type of distortion or at least it is much more milder than with cameras. I realize there is software to help correct this but this is yet another level of correction and takes a lot more time to process the images this way.

Next time you look at a very expensive camera and are impressed, think about all it's limitations and then think about how well our eyes see panoramically and if you are like me, you will be 10 times as impressed with our eyes as with any big $ camera. I guess God knows a few tricks the camera companies dont. Kudos to the big "G".
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