8 bit and 16 bit Files Question

[jbm]

My camera writes 8 bit files. My Noise Software offers the option of writing an 8 or 16 bit file. Is there any advantage to writing a 16 bit file from an 8 bit file?

Thanks,
Jim

[cbretteville]

No, they will just take up more space.
- Carl

[jbm]

Thanks Carl! That seemed logical, but what seems logical is not always true.

--Jim

[DTD]

In PhotoShop it is sometimes worth converting an 8 bit file to 16 bit to perform adjustments and then converting it back to 8 bit.

[ho_co]

As noted above, using 16-bit files gives more range for making global corrections, but has the disadvantage of taking up much more space.

I know some heavy-duty Photoshop users who use 16-bit files for all initial global adjustments, then save as 8-bit when getting closer to finished.

I've also attended Photoshop seminars where we were told 'just convert to 8-bit and don't worry about it.'

But David is right. Working in 16-bit is demonstrably better, though perhaps not enough so to be worth the disk space needed to store the files in that mode.

--HC

[jrc]

There are some Photoshop CS2 filters that don't work with 16-bit files.

JC

[ho_co]

Originally Posted by jrc

There are some Photoshop CS2 filters that don't work with 16-bit files.

Good point, JC! But each generation of CS2 expands the list of features that accommodate 16-bit files. And one can always switch into 16-bit mode to make less destructive modifications, while staying in 8-bit most of the time.

Basically, 8-bit is fine. For highest quality, stay in 16-bit as long as possible.

But since the question is whether to save to 16 bit from a noise reduction program, don't bother. Just go to 8-bit.

Theoretically, if working from RAW, you'd stay in 16-bit till all global adjustments were made, then move to 8-bit.

--HC

[lct]

Does anyone can see a difference between 16 bits and 8 bits pics on prints or monitors?
Just curious.

[ho_co]

Originally Posted by lct

Does anyone can see a difference between 16 bits and 8 bits pics on prints or monitors?

LCT--
No, I don't think so. I believe most monitors and printers are fed 8-bit data anyway, or am I wrong?

But I've seen it demonstrated in Photoshop that making a given change--Curves, say--will cause greater data gaps in the histogram when beginning with an 8-bit original than when beginning with a 16-bit original.

In other words, if you've got more buckets to start with, you've got more room to spread the data.

I've seen it demo'ed, but I've basically dropped 16-bit practice from my workflow due to file size constraints.

--HC

[lct]

Thank you Howard, in fact i have not tried 16 bit so far and i wanted to know if i'm missing something actually.

[jbm]

Thanks all for the very informative comments. I think I won't bother with 16 bit.

--Jim