When is JPG OK?

[Ed Richards]

All of my PS workflow is 16 bit, and my master files are stored as PSD. I generate 8 bit flat tiff files with different sharpening for printing in different sizes. Would I lose anything storing these as JPG at max quality (12) instead of tiff?

[Michael Gordon]

Yes. Jpeg's are compressed, thus the reason a max quality jpeg produces a smaller file size than the same file in tif.

[Bruce Watson]

All of my PS workflow is 16 bit, and my master files are stored as PSD. I generate 8 bit flat tiff files with different sharpening for printing in different sizes. Would I lose anything storing these as JPG at max quality (12) instead of tiff?

Standard JPEG, yes. The JPEG algorithm is destructive. There was a JPEG2000 standard around for a while that supposedly was better. I seem to remember that it had a setting where it wasn't destructive but made bigger files. But I just store everything as TIFF files and don't compress any off it. Print files I generate as needed and delete when finished.

[Frank Petronio]

Why not save them as max jpgs and print them out and compare? I suspect they will be fine, all the maximum jpg does is link up areas with the same values into clumps. But you can test for yourself right now -- it's not likely the jpg will change over time. If you can't see it in a large print then I doubt anyone else will.

The key thing is not to keep tweaking the jpg and to always go back to the master PSD for the creative and color changes. Tweaking and resaving a jpg will degrade the image.

You've got to continue to maintain that perfect 16-bit layered master PSD or TIF file no matter what.

When you have your world famous retrospective you'll be dead, blind, or senile so what's it matter?

[Kirk Gittings]

I believe Ed that you are using Imageprint these days. I store my 16 bit master file with layers in TIFF. One of these layers is a fairly heavy High Pass Sharpening adjustment layer, which I adjust the opacity on depending on the need of the print. ImagePrint automatically flattens files, so I never make or store a specific file just for printing. One master file serves all needs.

[Ed Richards]

Good strategy, Kirk. I am somewhat more compulsive about sharpening - I resize to match the printer input DPI and resharpen for each size so that imageprint does nothing but feed the file to the printer and control the color. I will have to do some experimenting to see if am getting any better results than your method.

[Alan Davenport]

Or you could save them as PNG files. The PNG format uses a lossless compression algorithm.

[Jack Flesher]

The biggest disadvantage to jpeg is not the compression per se, but rather the fact the colorspace is limited to the very narrow sRGB. I have printed quite excellent 24x36 inch prints from customer's jpegs -- no doubt they would have been better as tiffs -- but nonetheless, the customer was happy with the result.

IMO in general, jpeg should really only be used for web images, email and aunt Edna's 4x6 snapshots

Cheers,

[robc]

Tiff files can be compressed but it is not lossy and will not be as small as jpg at maximum.

Please explain why you would go to all the trouble and effort of 4x5 photography and huge amounts of forum postings about getting the finest detail in an image and the best quality scans and post scanning processes to preserve detail and how to optimise your printing to retain maximum detail and sharpness and then go and save your precious highly detailed file to a jpeg file. Especially when disk space is so cheap. Buy yourself an external hardrive or two for archiving.

[false_Aesthetic]

imho jpgs are for the internet.

psds and tiffs are for print.


Even the least amount of compression has compression. I'd just raather have more than less.


T