I have CS3 here at work, CS2 at home plus I have used every version from 5 up and I don't ever remember it defaulting to TIFF. In fact TIFF is at the very bottom of the list in the save as window.
Is it using tiff internal and still using the PSD extension?
Yeah, PSD is still at the top. I could swear that a fresh install of Photoshop 7.0 defaulted to TIFF -- I remember it because it was also the first OS X compatible version, so all changes felt intriguing... But I don't know if they changed that later due to feedback, or if I hallucinated the whole thing due to spending so much time staring at the rainbow spin cursor (Photoshop on Mac OS X 10.1 and a G4 was not particularly snappy).
"Everything that can be saved in a PSD can also be save in a layered Tiff-6.0 file format...everything, paths, channels, layers, transparency, layer effects...there is nothing that PSD has "special" any longer and when that happened, Bruce and several engineers and I realized that the end of the Photoshop native file format had arrived.
"Tiff has better compression (zipped tifs), can save everything that a PSD can save and be as large as 4 gigs in size (I think PSD is still limited to 2 gigs). Tiff is publicly documented where PSD requires a special NDA to access the internals. As a result, tiff is a more "archival" format while losing nothing by being used."
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"So, since Photoshop CS, only PSB is a format unique to Photoshop which does not fall under the heading of having to work with the Suite...and when once looks at all the pluses and minus, I think layered TIFF's offer the best file format for pixels today-unless you are talking raw and then it's DNG-which is essentially, a TIFF-EP file, a variant of Tiff-6.
"Which was one reason that Mark Hamburg, when Lightroom was first released in beta fought really, really hard AGAINST allowing PSD files into Lightroom. He lost that battle.
"So, at best figure that PSD and TIFF are equal but since TIFF is a documented file format and PSD isn't, I lean towards using tiffs whenever possible...because PSD files, suck-and have since Photoshop CS."
As a reluctant Photoshop upgrader who has recently moved to a new machine, I can confirm that a new install of Photoshop 7.0 defaults to PSD (on Windows, at least).
Is it using tiff internal and still using the PSD extension?