These slight variations in individual photographs become a big deal when trying to stitch this stuff.
Found this article online that may be helpful:
http://www.naturephotographers.net/article.../ejp0103-1.html
Because light conditions change literally in seconds while you are shooting it (especially since we are dealing with moving clouds and contrasty scenes that are constantly in motion), you have to take the individual shots in as quick of a succession as possible - within seconds of each other.
One of the things this article mentions is to avoid using a polarizer when shooting a panorama. I found this out when I recently did a panorama of the New York skyline (I need to get some of these photos up for you guys to see) ... I used a polarizer, which polarizes the light at a 90 degree angle from the sun. So as I took this series of photos of the skyline at sunset, the polarized light makes a BIG difference in the levels of the individual photographs ... ugh. Another big player is the software you use ... you are able to do some tweaking in some software to better match up the exposure levels of the individual photos. I need to do some more research into the subject, but I think it is well worth it.
Notice in the article above the recommendation to vertically stack another layer of imagery to the panorama to avoid creating a narrow field of view. This is a slick trick and I can't wait to try it the first chance I get as well. (who needs a box camera?) If you are shooting with a 35mm digital SLR, then these images can easily become overwhelmingly huge for your computer to handle, so if your end goal is just to get a photo on the net, individual photos have to be properly resized prior to stitching, or else your software WILL have trouble opening and working with the image ... you can easily end up with a 40 meg file or more on these things.
This is a recent panorama of a shelf that worked better during the stitch process than the original Hallam meso. (This is significantly reduced to fit on the screen - it's a huge file of six, 6.3 mp photos stitched together) ... I also need to play with the exposure a bit. Shot this with a 24mm fixed lens, by the way - so much less distortion (you can make out the smiley face effect on the edges, but since there were hillsides involved it's not as bad of a distraction as it could be) ... I don't think I lost much, if any data at all on the edges of the photo after the stitch.
Here is the original Hallam project thread:
http://www.stormtrack.org/forum/viewtopic....ht=photo+stitch
