My zenphoto is installed at http://gallery.jeremyisaaclee.com/. All this while i have been uploading 640X480px pics, and it's been working fine. However, i uploaded a number of approx. 3500X2200px pics, and the thumbnails are not generated. Moreover it can't be viewed in the gallery until one clicks on a direct link to the picture.

The gallery with the hi-res pics which is facing the prob is at:
http://gallery.jeremyisaaclee.com/HDR/
When i try to access the single photo page, it still does not show, e.g.:
http://gallery.jeremyisaaclee.com/HDR/garden.jpg
Only when i click once more on the direct link to the photo does it show, e.g.:
http://gallery.jeremyisaaclee.com/albums/HDR/garden.jpg

Please help. Thanks.

PHP's just running out of memory! Processing images of that size requires approximately 50MB of memory to even load and reprocess, and that's a lot. I'd recommend either raising that PHP memory limit, or resizing the images before upload, because that's really huge...

http://gallery.jeremyisaaclee.com/HDR/image/640/court.jpg?debug

That shows the error with the image. Your memory limit is currently about 20MB, it will need to be tripled or more (60-70MB minimum) to process images of the size you want. Read more here:

http://www.zenphoto.org/trac/wiki/ZenphotoFAQ#WhydoesZenphotomakemyservercrashwhileprocessingimages

The reason the full-sized image works is because it's a direct link to the original, and doesn't go through any processing, as you might have guessed.

This is a problem with any PHP-based image gallery software. In future versions, you might be able to use ImageMagick as an option to get around these memory limits. Keep checking for updates, that should be in 1.1 or 1.2.

Thanks a lot for the valuable info. I've resolved the issue.