16 bit per channel question

[RichardC]

Well, I'm back to the "box" now after a long summer outdoors. Anyway, my scanner gives me a 16 bit option. My question is, if I scan into PS at 16 bits per channel and then change the image mode to 8 bits so I can have more editing options am I defeating myself? I mean, is the 16 bit depth from the scan preserved? Can I switch back to it after editing or is that necessary? I'm laboring under the impression that I may get a better print at 16 bits. [confused]

 

[theKeeper]

Hey glad to have you back Rich...

I'm not the expert to ask about this really... but my guess is that you're gonna lose that 16bit info when you downgrade to 8bit. You have to really... otherwise, you'd still be in 16bit mode... right? hehee

You can switch back to 16bit afterward, but i don't think it'll be the same 16bit image it was when it was first scanned.

And as for getting better prints from 16bit... mmm... i think i'll leave that one for someone better skilled in the print department than i. [honesty]

 

[Guest]

Yes, I think it's quite normal that you lose information when you go from 16 to 8 bit. There's not much that you can do about that Richard.

 

[sPECtre]

hello!
There is a lot of info about 16 bit from Bruce Fraser at Creative Pro:

why
and how

Also, look at Ian Lyons take on 16 bits.

Can't wait to see your (corrected in 16 bits) photos!

 

[Guest]

Thanks for the links Pierre. Especially that first one is quite interesting.

 

[RichardC]

Thanks everyone.
Pierre......those links answered a lot of questions. Thanks again! [excited] .....RC

 

[sPECtre]

You're welcome, now, I can't wait to see the result!

 

[mrdinh]

thats a good question...kinda similar...i take my digi pics and edit in bibble with 16bit but going to ps7 it requires 8bit...very little option in ps7 if you use 16bit....what is the advantages/disadvantages for 8bit or 16bit?...can you really notice the difference in the prints?....i'm using epson 1280

thanks

 

[Guest]

Originally posted by mrdinh
what is the advantages/disadvantages for 8bit or 16bit?

That question is well answered in the link that Spectre posted earlier in this thread: http://www.creativepro.com/story/feature/7627.html

 

[sPECtre]

Mrdinh first, hi!

The main idea of 16 bit work is trying to loose the least data as possible when you color correct the picture. Adobe gave us only the retouching tools needed for that.

Indeed, the printer is 8 bit output. so working is 16 bit seems strange, and the difference might be very subtle, it is up to you...

 

[RichardC]

Hi all...I tried several scans of an under exposed B&W neg and the 16 bit version was the best and the printer cooperated fine. [stuned] It appeared that there was not enough shades of gray to blend smoothly otherwise so there was white ?blotches? on the others. The ?fix? may have been caused by another inadvertent tweaking though......I?m not sure. I was mistaken in my original post in that my scanner gives me a 14 bit option (not 16) but PS recognizes it as 16 bits. Can anyone shed any light on that?[doh] ......RC

 

[BabbleGrabble]

Hi RichardC, we were just talking in another thread. [honesty]

I'm not sure if I'm interpreting the question correctly, so I apologize if my answer is meaningless. [confused]

It would be best to utilize the full 14 bits in the scan process to grab all the data you can. Photoshop will put any scan greater than 8 bits into the 16-bit-per-channel space, which allows for less data loss during editing even though you don't have access to all of the tools.

I hope that made some sense.

 

[RichardC]

Yes, that makes sense BG...I'm just confused about the fact that everyone and everything talks about 8 vs 16 bits and then my scanner blurts out "14". [doh] I have an 8 or 14 bit per channel scanning option rather than 8 or 16.[confused] Not knowing much about it I assumed that "16" was some kind of standard. No cause for alarm? Thanks for your response....RC

 

[BabbleGrabble]

Right - no cause for alarm... scanners vary greatly (10-bit, 12-bit, 14-bit, etc.) I would be plenty happy with a 14-bit scan, and think of it in Photoshop as "up-to-16-bit-per-channel." Photoshop will still take full advantage of the 14.