TIFF quality

[Brontosaurus]

I am using 3840x2160 ProRes 422HQ. In the past I always used TIFF for exporting stills for use in editing, but now I'm using ProRes I want the highest possible quality. TIFF uses compression does it not? If so is there a better way of exporting stills without any loss of quality, or without any more loss of quality than you get with ProRes 422HQ ?

[Steve Griffiths]

TIFF supports lossless compression* so it's fine for maintaining quality of your exported stills. PNG is another good choice and also uses lossless compression. PNG's lossless compression is more effective and will result in smaller file sizes at the same (original) quality.

i.e  4K still test I exported from Premiere resulted in file sizes of 32MB for TIFF, 12MB for PNG and 3MB for JPEG. The JPEG of course will have some compression artifacts but the TIFF and the PNG will be visually identical. Do a test yourself - take an identical exported still from Premiere (1 x TIFF and 1 x PNG) into Photoshop - into the same composition as two layers. Change the blend mode for the top layer to 'Difference' and the image will be black except for where there are differences between the images. For TIFF and PNG the images should be totally black. If you want to see the compression from a JPEG as a comparison - bring the JPEG into photoshop and do the same thing but with the TIFF (or PNG) as the lower layer. Now when you apply 'Difference' you will see a faint image - indicating the differences between the images caused by the JPEG compression.

(BTW - the 'difference' test can also be conducted in Premiere Pro by layering the stills in a sequence and applying the difference blend mode to the top layer.

So the simple answer for you is - continue to use TIFF or switch to PNG for smaller file sizes (I prefer PNG myself).

But what are you exporting the stills for?

* TIFFs can use a 'lossy' compression as a choice but as far as I know not from Premiere Pro

[Michael Grenadier]

Steve, thanks for your detailed explanation.  Always wondered about the ideal format although never saw any issues with quality using pngs or tiffs...  Just wondering if there's any advantage quality-wise using psd's (photoshop format)?  I often work in photoshop adjusting, compositing,etc and there are certainly workflow advantages working in psd's.   

[Steve Griffiths]

Don't think there are any advantages to Photoshop quality wise ... but of course if your image is already a .psd why change it. Particularly if it has layers/effects etc. that you want to be able to jump back in and edit.

[Brontosaurus]

Thank you very much Steve. That completely answers my question. I'll probably continue using TIFF because file size is not a problem for single pictures. When I export a still it's usually when I want to remove movement in the background, or to add actors not doing a lot where their lack of motion will not be noticed.