Wednesday, September 16, 2015

Stitching - Way to save that photo!

One of the benefits of joining a photo club is that you get to see how others solve simple problems.  I am fortunate to have a friend/mentor through my local club in how to do simple 'touch ups' that will make a photo stand out from the others. 

One such photo that really sparked ides to me was that of a replica early Wright brothers airplane.  The subject was in a museum.  As with most museums, space between large objects was at a minimum.  I don't know if he would have taken the shot with a wide angle lens if the whole aircraft would have fit in the frame.  But what he did was to take multiple shots at 50 mm (considered normal focal length) and 'stitch' the images together.  The result was absolutely fascinating.  It was a good photo, technically.  Even he'd admit - it was going to win anything.  But that photo will stick with me for as long as I'm with photography.  The most interesting feature of that shot was that all the lines were straight.  There was no distortion due to being shot with a wide angle focal length.  Since I've adopted this hobby, that was one of the two to three most influential images I've seen.

Stitching is a process of combining multiple images into one image.  Sounds complicated, but software does all the heavy lifting.

What I've discovered about stitching is all the work goes up front.  Here goes:
1.  I usually shoot photos in Aperture Mode.  This is a must.  Usually the scene is uniformly lit and if Aperture Mode is used, the speed of the shot will usually be consistent.  The lighting has to be consistent.
2.  An overlay of 33% will usually get the trick done.  I usually try to go in the area of 50% to 60%.  This gets a good coverage and, not that it happens often, will cover if one photo doesn't turn out as expected.  Digital images are cheap.  The more, the better.
3.  The best images are shot portrait.  What I'm showing in this example is landscape - only to show it can be done.  But what ever orientation you use, make sure the focal length is 50mm.
4.  If you look up how to shoot a panorama, you will find all sorts of equipment to purchase.  I hand hold my camera.  Yea, sometimes the edges are a bit out of alignment, but you are going to lose the edges anyways.
5.  If you are going to make image corrections, make them on the originals.  Also be very careful not to make corrections in the middle of the project.  In the third photo below, there is a plant that is taking away from the entire picture.  That had to be removed on the original, prior to stitching.

So here is my example.  This is a local park pond on a sunny day.  In order to get as much of the scene as possible, I could take a wide angle shot.  If I had done that, the trees and other vertical object would have a distortion.  Or - I could stitch the shot.

These are the four shots used:

Using Elements 13, I used the Photomerge Panoramic function, the resulting image is:

At this point, depending on the format used other post processing actions can be taken.  I usually save to a TIFF file and send it to Photomatix.

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