I have previously had no problem with working on a psd file and saving to tiff for reopen in ACR to remove chromatic distortions. Now I find myself in the same sitaution but with a tiff that will not open from bridge or photoshop in ACR. I have checked that the single layer is "background". I saved it this time with no compression and unchecked the "save transparency" to give it the cleanest save. The file is 1.4 GB so I increased the cache to 2 GB from the default 1GB in Bridge and ACR ( or one of them, can't remember which), all to no avail. In Bridge it is interesting that all the other tiffs and jpegs in the file will open in ACR but not this one. So I suspect that there is something about the tagging/configuration/saving method or something that makes this one different. Can anyone tell me what parameters make a tiff unopenable in ACR? I saw in another thread wherein someone said that the tiff could not have previously been worked on in Photoshop but that has not been my previous experience. Can anyone help?