Yes, I have had the same problem with some pre-dawn panoramas. No solution
found. Manual everything.

Under good lighting, I get excellent results.

Stumped.

Try PTGui, they have greatly improved their brightness and color
balancing between photos.  

Scott

I understand that PTGui5.5 is the current standard bearer for stiching
software. At least, according to this guy it is. Check this out:
http://www.pbase.com/apy_jr/image/52786746/original
Albert is also very amenable to helping out with tips and guidance, so why
not drop him an email. Alternatively, he can be found frequenting our Kodak
SLR forum at dpreview.com under the handle 'APY_Jr'.

hth

Nigel

SNIP

Vignetting?

It's a guess because you didn't tell which lens was used and at which
aperture, and you didn't provide a link to an image that shows the
issue.

Bart

I occasionally forget and leave a polarizer on the lenses I used to
shoot outdoors... might you have done this?  That would change the
brightness of the sky as you rotated the camera.

Sounds like a pain in the a.s to use.  Try "Autostitch."  It's more or
less free and is very good at auto brightness matching and
reconforming any lens distortions.

http://www.cs.ubc.ca/~mbrown/autostitch/autostitch.html

Don't use auto exposure in the program because the difference of
brightness in subject data in the separate exposures may trigger a
different "correction" in them. If the shots were take seconds apart,
no correction should be needed.

Also, look at the individual frames and compare the brightness. If
they are different try making a gamma adjustment on each file and
again when stitching do not use auto correction.

JPB

The stitching software that I use are Panorama Factory and Canon 360. I
haven't encountered the layers problems you have encountered. Both are
very good programs but the program that I like but don't have yet is
Ulead Cool 360. It's been my understanding that Panorama Factory is the
most popular photo stitcher on the market. Seeing what it can do, it
probably is the most popular. But I have tried Ulead Cool 360 and I
think it's a better program than Panorama Factory or Canon 360. What's
good about Canon 360 is it's the simplest and easiest to use and it's a
freebie. Being the simplest means it doesn't have many of the controls
the other programs have.

BTW,  don't process shots individually then do the stitching. Do the
stitching first then process the shot. Yesterday I stitched three wide
angle images of a beach scene using Canon 360. I can post the stitched
image but I can't see you learning anything from image that would help
in solving your problem. No Problems encountered in the stitching
process; total time maybe two minutes or less.

Thanks for your help everyone. I think "Just Plain Bill" hit the nail on the
head - I had the program set to automatically adjust exposure etc - when I
turned off a lot of the automatic stuff I instantly got perfect results.

Thinking about it, I guess the program is written to encompass all sorts of
images from all sorts of cameras - including P&S models that will suffer
from exposure / vignetting (etc) issues - it never occured to me until now
that many of these adjustments aren't needed with "L" glass, and still other
adjustments are better done in PS. So definately a case of "less is more" in
this circumstance.

I did download the PTGui demo and had a play - it too looks like a powerful
piece of software - however I came unstuck when it merged the images, but
then presented me with controls to set the horizontal and vertical angles
(?) and I got hopelessly lost from there (also crashed the program with a
divide by zero error with one of the horigontal control set to the extreme
left). I'm sure it's a simple case of reading the instructions - just
haven't had the time to invest in that get.

Thanks again for all your help.

Cheers,

Colin