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shortfatguy

Merged photo

13 posts in this topic

Here is my first attempt at merging shots to create a panoramic view. All comments and critique welcome as always!

mergedbarnphoto.jpg

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It looks really good, sfg. How many images were stitched, and were they initially composed horizontally or vertically?

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Its 3 stitched together. they were horizontal originally. I bet if they had been vertical shots and maybe around 6 of them it would make a nice poster size shot

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Not bad sfg. I can see the two seams in the merge though, they are pretty noticable in the sky. What software did you use for the stitching?

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I used the software that came with my camera. So its probably not the worlds greatest software. Also I did not have a tripod when the photos were shot so part of the "seam" may have been caused by a slight difference in the photos due to my movement

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sfg, I had to look repeatedly and blur my vision slightly to make out the seams. Depending on your main post-processing software, subtle sky seams like these are very easy to mend.

For the stitching itself I use PhotoStitch, the software that comes with Canon DSLR cameras, and it works great. I've just left it on automated settings so far and have not had problems. Lack of tripod wouldn't have caused these seams unless you missed actually overlapping the images, in which case it might cause that.

More likely it was an exposure issue. If you are not on manual exposure and are using one of the automated settings that allows the meter to set exposure, you may get a slightly different exposure from one frame to the next as you pan the scene. If you were using the DRebel XT like you did on the similar barn/landscape shot you posted awhile back, and on the same settings, it looks like from that image exif that it was evaluative metering, which is a great metering system overall but not the best for capturing images to stitch.

To make sure each image has exactly the same exposure, which generally eliminates seams caused by different metering, I take a test image and check the histogram to make sure nothing's blown out and it's properly exposed. If it isn't quite right, I adjust using exposure compensation and then take another test shot. Once it looks good to me I switch to manual mode and duplicate the aperture/shutter speed settings, so each of the images to be stitched is exactly the same.

Some other things that can cause goofy stitches include a lens that has noticeable vignetting (darker corners) or distortion (which can skew the edges of photos and make them impossible to stitch well).

Generally, I like using the middle to the far length of a zoom lens' focal length. With full frame sensors, wide angle lens distortion is noticeable with some zooms set as wide as they can go, and some other lenses can vignette quite noticeably on FF sensors, where in crop sensors these things don't happen as much.

I've been able to do some handheld series stitching with success, as well as some from a monopod, but of course to get really serious about it a tripod is important. And with the tripod, leveling it is important so your series doesn't slant up or down as you progress through it.

Sorry if you already knew all this, sfg. Figured I'd throw the tips in there in case some don't. Stitching is such a great way to extend a DSLR's sensor capability (in some situations), that I use it whenever I can.

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Thanks for the info! I looked more closely at the image on my computer and after zooming in I can see that the seam on the right is slightly miss aligned and gets wider toward the top. I will have to mess with it and see if I can straighten it out. Steve, I also am using the same software as you.

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I can still see the seam on the left and the one on the right looks better. Keep in mind folks that if your monitor is not calibrated it is entirely possible you would not see the seams in either of these shots, especially with the lighter sky.

I see a darker band with the sky darker on the left side of the seams. You can also make out double trees all the way through your merge from top to bottom on the left photo and center photo seam. Look between the houses, next to the falling down building.

With out a tri pod these are very difficult to line up perfectly. I think it is a great try and with tripod support you would have a winner for sure!

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Though they are subtle, I can still see the seams, too.

IMO, it may be a matter of no tripod, but it may not. There's no doubt that a tripod is the best way to go, but in situations where I've had to hurry and did not have time to pull out the pod, I've in several cases been able to compose images freehand that have stitched together perfectly. I've also had some failures that way, for sure. Mostly it's a matter of making sure not only that there's overlap, but that the camera/lens is not skewed slightly from one image to the next, and as Dan said a tripod is totally the right way to ensure consistent and level panning.

sfg, can you post small, undoctored versions of all three images for us, or e-mail the original three jpegs to me, so we can see the exif data? If the apertures/shutter speeds are identical in all three, I'm thinking it might have been a missed overlap that is causing the visible seams, in which case the tripod would have immediately cured the problem. If there are slightly different settings among the images, however, then I think it's a case of the meter changing the exposure slightly as you panned.

In any case, as long as the conditions are good for images to be stitched together (consistent lighting, not overly windy), if you do the manual exposure drill and the tripod and take some care, all will be well.

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sfg, I looked them over and noted that, while you were on evaluative metering instead of manual, each was 1/125 at f5.6, so exposure was not the issue with the noticeable seams. Nor did there appear to be any lens issues.

After merging, I enlarged the image and saw irregularities not only in the sky seams, but also in the land below. In Photoshop CS2, I mended both seams (only took a couple minutes), and will e-mail the stitch to you.

In this case the seam issue is what Dan described. Careful use of a leveled tripod would have made the stitch perfect from the get-go. As it was, it was almost just right, and an easy tweak or two in post-processing to mend those seams took care of it.

So next time, manual settings and a tripod will be the way to go. smilesmile

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