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Old Jun 7, 2008, 6:32 PM   #1
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I have had my DA 10-17 for almost 2 years now and have never tried defishing and stitching. In many ways the FE effect is not that pronounced (the way I have been using the lens - so far), however its not rectlinear. I am taking a trip, starting next weekend on a slow (10 days) ship (helicopter carrier) to Hawaii (Navy for work), and thought that I would try it (defishing and stitching) out before hand to see what if, there are any better ways to take the images, so as to have this technique work better. I would rather not try a bunch of stuff and then get back and see that there was something basic I should have taken in to account when taking the image.

I know, some are thinking, why bother stitching something that is already has a 100 to 180 degree field of view. I want to try out stitching portrait rather than landscape, so as to get the field of view along the vertical axis and have some ideas I would like to try (but have never had the time nor the subject matter). Some of the items I know I will have a shot at, are very tall and wide, and I want to try some things that are a bit different.

That was why I have been looking to get the DA 12-24 (its rectlinear and gets rid of the FE effect), but you can read my other post about that saga. So, I am just going with what I have - which I have to admit is not all that terrible - actually with the 16-45 and 18-55, I really can not complain at all.

So, if you have some experience - I would like to hear about it. If you have some ideas, I would like to hear about them also. Suggestions too, are always very welcome.
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Old Jun 7, 2008, 8:48 PM   #2
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I went out to the front yard with camera in hand and did a very quick and dirty expirement. We have a tree that is wide and tall with some foreground plantings - you might notice that its gotten too hot this afternoon (105) to continue to prune and haul away.....

So I took 4 pictures, with the 10-17 vertical, defished with PT-Lens ($15 a great deal) and stitched them together with Photoshop Elements 6) and this is what I got...

First up is one of the single landscape defished image, followed by the defished stitched pano un-cropped. Note that the defished panels are hourglassed shaped (in the vertical frame) pinched in the center from the left and right. I tried to stitch the hourglass results together, but it did not work so well. So I went back and clipped them down and then stitched.

Oh yes - I forgot to reset my camera's ISO back to automatic [200-800] so these were taken at 1600. See Harriet, your not the only one who forgets what they were doing and puts the camera down only to use it again at an unknown setup.....

I forgot - everything is at 10mm so the field of view is 180 degrees.

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Old Jun 7, 2008, 8:53 PM   #3
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Here is the landscape single defished image covering the same sean as the defished stitched pano image. Basically this is what you would see just taking a single image with the FE lens and then defishing it with the 180 degree FOV in the horizantal - no stitching!
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Old Jun 7, 2008, 8:54 PM   #4
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Here is the finished product - defished stitched pano (but not cropped square). You may notice that in the upper left hand corner, there is a branch that appears to be right on top of the camera lens - well it was!!! Also, the bush in the lower right, that appears to be a couple of feet away - well its about 6 inches away from the lens.
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Old Jun 7, 2008, 9:31 PM   #5
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I actually thought that stitching FE images would have problems, but I was wrong, because just for a lark, I took the original FE images, had Photoshop Elements 6 stitch them together and after taking a while, it came up with this. Now of course there are not a lot of straight lines, but I am very happy!

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Old Jun 7, 2008, 10:00 PM   #6
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I wanted to take the panos and lay in the field of view from the non pano landscape with a set of lines, there is a very significient difference in the amount of real estate that the pano provides (especially in the vertical) - which is just what I wanted. I thought that the tree branching would create such a complex problem that the stitching would fail - but it did not (really surprisized). Now, I have an idea about running (driving - its still 105 out) about 5 miles away to a set of buildings that has a lot of straight lines and squares to see how that is handled.

Based on what I see now, the 10-17 images does an excellent - wonderful job stitched in to a panorama, either fished or defished (and extra added attraction for me). Actually, and there is more than a bit of work to do, beyond what would be required for a rectlinear lens, but it really (my opinion) provides a lot more options. I was somewhat possibly regretting getting the 10-17 first, thinking that maybe the 12-24 might have been better, however I am of the mind that I did indeed make the right decision. The 10-17 provides a wider range of options and also provides the same capability of stitching of a rectlinear lens (that was my original reasoning - but I never pursued it, to validate the opinion, until now). The one thing that the 10-17 does do is to allow you to get extremely close (like 12 to 24 inches) from the subject and get an image that looks like your yards away, which is perfect for what I want to do.

And by the way - PT Lens is a bargin, - it should be packaged with this lens. The closest it comes up with, in its lens data base is the Sigma 10-20, however thinking about this, it does not matter since, it just uses the 1.5 crop factor and 10mm focal length and applies the defishing. On the PTLens website, it explains that ... "Fisheye images are distinguished by immense amounts of barrel distortion. Special facilities exist in PTLens for converting fisheye images to rectilinear images. In this case no calibration is necessary as sliders are provided for maximum flexibility.", and provides a good example...

http://epaperpress.com/ptlens/ under the examples selection at the bottom.

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Old Jun 7, 2008, 10:35 PM   #7
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Interesting experiment. The only pano I've done that seemed to work out rather well was a vertical one rather than a horizontal one. Any time I've done horizontal ones there seems to be too much exposure differences (even when I set exposure manually) across the frame. I haven't tried PSE - only CS2. The other problem I always seem to have is with slight perspective differences and have to use the skew tool to get things to line up. I get too frustrated and usually give up.

Glad to know I'm not the only one who doesn't always check the camera's settings before starting to shoot. I've been getting better about it recently (of course, now that I've made a comment about it, I'll do something stupid tomorrow...).
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Old Jun 8, 2008, 12:48 AM   #8
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So after the tree, I was thinking that straight lines - vertical and horizontal would be the real test. There is a set of buildings reasonably close by, so I drove over and took some pictures.

This set of buildings, I would consider the worst case nightmare for doing this. Here are two sets of results. The first was NOT defished but just stitched directly. The second was defished and then stitched. Overall I am very happy with the results

On the non defished (first image) there is a section that Photoshop Elements 6 just could not determine what to use - so it appears to have used nothing, thus the void. You can see that on the second, that problem was fixed, however the foreground railing, the stitching program became somewhat confused as to what to use. With a rectlinear image to start with the stitch lines are straight. On these, they are sets of complex curves.

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Old Jun 8, 2008, 12:49 AM   #9
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And here is the panels first defished and then stitched into a Panorama...

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Old Jun 8, 2008, 1:03 AM   #10
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Here is a cropped version eliminating the foreground that may be distracting. I did not have the presence of ind to just take a regular landscape single image on the 10-17 at 10mm for a comparision - maybe tomorrow.

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