Q:

What would be the right approach to take pictures of a long counter?

I am trying to take a picture of a long counter in a super market. It is about 15 yards long. I inched along (at about a distance of 3 yards) and took straight on 30-35 pictures with my 16-35mm at around 16mm. I also did another series (with more images) at 35mm. 
When I was at the computer and wanted to stitch them together I noticed that it just would not work, even though I had enough overlap. But the angles had changed. The items behind the glass of the counter would have slighly different "sides" showing forward which made it impossible to stich. Even worse was the "background" - only being 1 or 2 yards behind the counters items moved closer and farther away from objects on the counters (i.e. scales). 
I then made a test taking more pictures - but the problem with the background remained. What is the right approach to taking such pictures? What focal length is the best for this?
Thanks

A:

As you found out, if you move the camera along the counter, as opposed to just pivoting on a point, you'll find it very hard to stitch seamlessly, since you are constantly changing the point of view of each successive image.
You can do a faux panorama by taking one or two shots that capture the entire counter, and cropping out top and bottom.
Or if you had room to move way back and use a long lens, you'll have less distortion, and could pivot and do a standard panorama.
If you don't have the space to do either of these, I guess you could stand in the middle, take a number of shots for a standard panorama, stitch together, and apply some perspective correction in post processing to try to flatten out the perspective.

A:

The only way to do this is to take a very large number of photos with very small movements in between and use a very thin vertical strip from each image to create your composite. By doing this you will limit the disparity in the background and avoid imaging the sides of objects.
Using a longer focal length will also help.
In fact the absolute best technique would be to shoot a video moving along the counter maximising the number of images and minimising the gap between them.
Microsoft research's Image Composite Editor apparently has a function to assemble such panoramas from video sequences.

A:

One possible approach to this kind of thing would be to use a tilt-shift lens, as wide a one as possible. (The Canon 17mm TS-E on a full frame camera is as wide as it gets.) Now, mount the camera on a tripod dead center of the counter, at an appropriate distance from it (ie where you can actually fit the entire counter into the three-photo mosaic you are about to make). Shift the lens to the left, take a shot, take one shot with the lens centered, and one shot shifted to the right. Stitch the three together on the computer. Parallax should be a very minor problem I believe because the actual point of view has not moved by more than a few centimeters.

