Go Back   RetouchPRO > Technique > Photo Restoration
Register Blogs FAQ Site Nav Search Today's Posts Mark Forums Read

Photo Restoration Repairing damaged photos

8/16 bit images! What's the difference !

View Poll Results: In reading the article on 8/16 bit images. Can you tell the difference?
Can not tell the difference. 7 28.00%
Can tell the difference and let me explain. 9 36.00%
16 bit images is just a waste of space(longer processing). 3 12.00%
I would like to remain neutral on this subject. 6 24.00%
Voters: 25. You may not vote on this poll

Thread Tools
Old 12-24-2004, 09:36 PM
gmitchel gmitchel is offline
Senior Member
Join Date: Apr 2004
Location: Tallahassee, FL
Posts: 316
The important issue is not whether you can see a difference when viewing a scanned image or one just loaded from a digital camera. The differences between 8-bits and 16-bits per channel will almost certainly not be visible to the naked eye.

The important point about 8-bit images is that they are much more likely to posterize as you edit them. This is quite easy to see by eye on a monitor *AND*, as Trimoon notes, especially easy to see on a print.

Most 16-bit images are not 16-bits per se. Most digital camera images are 12-bits per channel. PS treats anything over 8 as 16-bits. Still, a Canon DSLR RAW image has 4,096 distinct tonal possibilities for each channel compared with 256 for an 8-bit JPEG image.

Generally, I find people who advocate 8-bit images are shooting JPEGs.

16-bit images give you a lot more editing options. I keep my images 16-bits until I am ready to print them *OR* I need a feature in PS CS that does not support 16-bits (some filters, for example).

Happy holidays!

Reply With Quote top
Old 12-24-2004, 10:42 PM
Robt Robt is offline
Senior Member
Join Date: Apr 2004
Location: Seattle
Posts: 131
Happy Holidays Mitch,

In the post above, you indicate that you convert to 8 bit before print. I could see this for the tiff final would certianly be smaller but why otherwise.

I think my 2200 does its own 8 bit conversion but is it any worse or even different than PS? I also seem to remember that you use the IP rip, how does this figure in.

I guess I'm asking for an explation of your final [after output sharpening- if this is yur last common step prior to print] workflow. Now that sentence would have gotten me a fine grade back in college..

Robert Collins
Reply With Quote top
Old 12-25-2004, 07:01 PM
gmitchel gmitchel is offline
Senior Member
Join Date: Apr 2004
Location: Tallahassee, FL
Posts: 316
Hi Robert:

My output files are sharpened for their intended output device. Files destined for my Epson 2200 are resampled to 280 dpi, because I use ImagePrint Lite and it will resample, if I don't.

The rationale you mention is why I convert from 16-bits to 8-bits for output files. Output to desktop printers are inherently 8-bits. So, why waste the extra harddrive storage.

My working files remain in 16-bits, unless I need a feature that is 8-bits only. Then I switch to 8-bits at the last possible moment to avoid posterizing my images.


Reply With Quote top
Old 12-28-2004, 10:52 AM
cspringer cspringer is offline
Senior Member
Join Date: Jun 2004
Posts: 135
16bit vs. 8 bit demonstration
Reply With Quote top
Old 01-12-2005, 07:23 PM
CJ Max CJ Max is offline
Join Date: Jan 2005
Location: Pearland, Texas, U.S.A.
Posts: 67

Originally Posted by john_opitz

The 8/16 bit article starts on page 310 of this pdf. file.
I did some test prints 2 months ago with my Epson R800. All images were 8"x10" as that's the size that I print mostly.

I was able to see a difference in images with TIFF 16-bit coming out the best.

Where's the difference? Highlights aren't quite so bright. Shadows have a wee bit more detail. Saturation is better. Color transitions are smoother looking.

The least desireable images were JPEG q.12.

Also, I found that I got better images when cropping and printing from Qimage. I called Epson and talked with a tech. rep. about my findings. He said that he owns and uses an R800 and gets the same results. We have different dSLR's, but we both came up with approximately the same workflow. Interesting.

The workflow for my Sigma SD-10 is: process RAW file in Sigma Photo Pro, save as TIFF 16-bit file, postprocess in Photoshop if needed, save as TIFF 16-bit file, crop and print TIFF 16-bit file in Qimage.

I mentioned to the Epson tech. rep. that I felt that the R800 printed better from Qimage than from Photoshop. He said that he had found that to be true too. He said that the R800 software handles the compression and printing better from Qimage than Photoshop.

Whatever the reasons, color me very pleased with my TIFF 16-bit/R800 prints. I don't think that they can get any better.

Reply With Quote top
Old 01-13-2005, 04:10 AM
Lasse Lasse is offline
Join Date: Dec 2004
Location: Europe
Posts: 54
Too long a thread, so i havent read the other posts and might repeat some of them.

I shoot in raw so i get 16 bit conversions if i whant to. when extreme editing is recruied you can see it as you are thoosing which 8 bit you whant. so edit the colors in 16 bit and then convert. there is adifrence if its wort it i dont know. Raw support 16 bit and not 8 bit, so there is no reason not to use it.

if i had to scan i wouldnt use 16 bit, since there it would only be small color adjustments (i wouldnt scan the bad ones, but if requred i would use 16bit).

Reply With Quote top

  RetouchPRO > Technique > Photo Restoration

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
16 Bit images Simon Knight Hidden Power Support 5 01-20-2007 09:03 AM
Resizing images for RetouchPRO jeaniesa Photo Retouching 18 09-26-2005 12:20 AM
Review: Optipix Doug Nelson Software 11 10-25-2002 08:46 PM
Using the Difference blend mode in Photo-based Art DannyRaphael Photo-Based Art 5 07-15-2002 11:44 AM
High Bit Scanning? Doug Nelson Input/Output/Workflow 1 08-18-2001 02:06 PM

All times are GMT -6. The time now is 06:37 PM.

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2016, Jelsoft Enterprises Ltd.
SEO by vBSEO ©2011, Crawlability, Inc.
Copyright © 2016 Doug Nelson. All Rights Reserved