2007.12.17 09:29 "[Tiff] Large file support in libtiff 3.8.2", by Jannes Bolten

2007.12.17 22:01 "Opening >2GB TIFF files [was: Re: [Tiff] Large file support in libtiff 3.8.2]", by Scid

my issue with Enblend (the software that it's all about for me) is that large TIFFs (2.42GB in 16-bit) are created without any problems. but Photoshop won't open them.

And just below the 2 GB threshold they work fine? If so it might be the offset to IFD0. If IFD0 starts at the beginning of a file, Adobe Photoshop (at least CS2) won't have a problem with it. But if it starts above 2 GB it won't work anymore (probably a signed/unsigned issue). This might have been also true for other offsets, I don't remember.