Friday, May 21, 2010
Tiff files for printing
I received a question today - in a roundabout way - about using Tiff as a format for printing at a lab.
The correspondent shoots in Raw format, then edits and takes Tiff files to his lab for printing. Apparently, this particular lab needs Jpegs for their print process, so they convert his Tiffs to Jpegs before printing.
The correspondent's question was "Is Jpeg ok for printing, or should I be looking for a lab who can print Tiff files?"
I'll answer the second part of the question first. No, you needn't look for another lab just because your present lab can't print Tiff files. There are plenty of reasons you might need to switch labs (eg poor colour reproduction, inferior paper, slow turnaround, lousy customer service, etc) but file format certainly isn't one of them.
Jpeg files are perfectly ok for printing. In fact, for most people's workflows, they are the absolute best option for printing, and I wouldn't recommend anything else.
The use of Tiff files for printing stems from two sources, I believe - a historical problem, and a basic misunderstanding.
The historical problem originated more than a decade ago in the printing (not photographic) industry, when print processing software (called RIPs) couldn't handle the compression algorithms in Jpeg files. Only non-compressed files could be printed this way. I'm pleased to say this problem was rectified many years ago.
The basic misunderstanding is about the benefit of shooting Raw. Some people believe that the reason they are advised to shoot in Raw format is to avoid the "compression damage" of shooting in Jpeg format. Of course it's true that Jpegs are compressed, but the so-called "damage" is vastly over-rated. A well-taken high-quality Jpeg is a beautiful file, let me assure you.
No, there are two real reasons you shoot Raw:
1. The high dynamic range. You can recover clipped shadows and blown highlights in Raw, whereas you cannot do so in Jpeg.
2. The high bit depth. There's a heck of a lot more levels of colour to play with in a Raw file.
The high dynamic range only exists in Raw data. As soon as you convert your Raw file to any kind of image file format (Tiff, Jpeg, PSD, etc), the extra dynamic range is lost. Therefore, there is no benefit to providing Tiff files to the lab instead of Jpeg files - both have exactly the same tonal range.
The high bit depth can be preserved in a Tiff file, and it's not a bad idea to do so, if you think there's risk of banding in your image. But there's hardly a printer in the world that can print high-bit data - it will be converted to 8-bit for printing. So once again, we see that there is no benefit in providing Tiff files to your lab.
(I won't discuss bit depth comprehensively here, though I hope to do so in the future. Suffice to say that the benefit of high-bit files is for editing, not for printing.)
My advice is to edit your Raw files as thoroughly as possible in your Raw processor first, then bring them into Photoshop for more editing, and save in a non-compressed format whilst doing so. I use PSD, but Tiff is just as good. Then save as Jpegs just for the purpose of printing, but keep the Master file intact. Here's some further advice in this regard.
(See also here and here for related information.)
When saving a Jpeg for print, I'd keep the quality Level at 7 or above. 10 is a good option, because it's a fantastic quality file, with a reasonably small size, making it easy to send to the lab. Don't bother saving at 11 or 12, because the difference in quality is utterly indistinguishable from 10, and the files are quite a bit larger for no purpose.
Comments or Questions?
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