Ad
Ad
Ad
Pages: [1] 2 »   Bottom of Page
Print
Author Topic: ProPhotoRGB in JPEG  (Read 5839 times)
Bradley Proctor
Full Member
***
Offline Offline

Posts: 150



WWW
« on: December 15, 2009, 01:51:04 PM »
ReplyReply

This seems like it would be a pretty common question, but I couldn't seem to find an answer.  After working on a RAW image in Lightroom I export to a 16-bit TIFF in ProPhotoRGB and then load it into Photoshop to do additional work.  I don't print my own images and my printing company requires JPEG images.  I usually just covert the image to 8-bit and then save a level 12 JPEG while still being in ProPhotoRGB.  The printer doesn't care what color space I use as long as I have it attached to the file.  My question is, because I have to convert to an 8bit JPEG, should I be converting the color space to something else like AdobeRGB before converting to 8bits?
Logged

Mark D Segal
Contributor
Sr. Member
*
Offline Offline

Posts: 6818


WWW
« Reply #1 on: December 15, 2009, 02:09:03 PM »
ReplyReply

The processing order is important here. It's best to make all you image editing adjustments in 16 bit ProPhoto to avoid risks of banding and posterization which could arise from reworking a relatively small number of luminosity levels in a huge colour space. Once you have done all your editing, flatten the image, convert it to 8-bit and save it as a high quality JPEG. You should be OK. If you make a colour space conversion from ProPhoto to ARGB(98), do that before you flatten and before you convert to 8-bit. You would need to run a few tests with your printer to see whether colour space conversion is either necessary or causing you to lose any hues that are visible in ProPhoto alone.
Logged

Mark D Segal (formerly MarkDS)
Author: "Scanning Workflows with SilverFast 8....." http://www.luminous-landscape.com/reviews/film/scanning_workflows_with_silverfast_8.shtml
ErikKaffehr
Sr. Member
****
Online Online

Posts: 7234


WWW
« Reply #2 on: December 15, 2009, 02:30:46 PM »
ReplyReply

Hi,

Mark's suggestions seem reasonable to me. JPEG has eight bit resolution and it's a bit to short to hold ProPhoto RGB. It may work or it may not. If you convert to sRGB you may miss some colors which could have been printed, but quite a few possible issues could be avoided. So sRGB is the safest choice. You may also ask your printer for his color profile. If his color gamut fits inside sRGB there may be little benefit in sending files in a larger gamut.

If you are on the Mac the ColorSync Utility can show and compare color gamuts. On the PC I used to use Gamut Vision. ( http://www.gamutvision.com ).

Best regards
Erik


Quote from: MarkDS
The processing order is important here. It's best to make all you image editing adjustments in 16 bit ProPhoto to avoid risks of banding and posterization which could arise from reworking a relatively small number of luminosity levels in a huge colour space. Once you have done all your editing, flatten the image, convert it to 8-bit and save it as a high quality JPEG. You should be OK. If you make a colour space conversion from ProPhoto to ARGB(98), do that before you flatten and before you convert to 8-bit. You would need to run a few tests with your printer to see whether colour space conversion is either necessary or causing you to lose any hues that are visible in ProPhoto alone.
Logged

Mark D Segal
Contributor
Sr. Member
*
Offline Offline

Posts: 6818


WWW
« Reply #3 on: December 15, 2009, 02:37:29 PM »
ReplyReply

Quote from: ErikKaffehr
Hi,

Mark's suggestions seem reasonable to me. JPEG has eight bit resolution and it's a bit to short to hold ProPhoto RGB. It may work or it may not. If you convert to sRGB you may miss some colors which could have been printed, but quite a few possible issues could be avoided. So sRGB is the safest choice. You may also ask your printer for his color profile. If his color gamut fits inside sRGB there may be little benefit in sending files in a larger gamut.

If you are on the Mac the ColorSync Utility can show and compare color gamuts. On the PC I used to use Gamut Vision. ( http://www.gamutvision.com ).

Best regards
Erik

Thanks Erik.

I think the key distinction which needs to be made here is what happens during image editing versus what happens afterward. There's a near-consensus I believe that converting to 8-bit and then doing image editing in a very wide colour space could be asking for trouble. I think it is much less risky converting to 8 bit and remaining in the wide space AFTER all the editing is completed, but whether the wide space is then necessary or worthwhile becomes the empirical question to test with the printer - and I agree with you - soft-proofing with the printer's profile could be indicative- but not fully determinative because most of our displays do not really "see" all the colours which a number of contemporary printers can reproduce.
Logged

Mark D Segal (formerly MarkDS)
Author: "Scanning Workflows with SilverFast 8....." http://www.luminous-landscape.com/reviews/film/scanning_workflows_with_silverfast_8.shtml
Panopeeper
Sr. Member
****
Offline Offline

Posts: 1805


« Reply #4 on: December 15, 2009, 03:17:28 PM »
ReplyReply

Quote from: MarkDS
You would need to run a few tests with your printer to see whether colour space conversion is either necessary or causing you to lose any hues that are visible in ProPhoto alone.
Mark, I don't understand this. I don't know if there is any printer capable of printing ProPhoto directly, but if there is, then that is the very exception. Thus the color space has to be converted, either by the user or by the printing service - but then why would the user/photographer leave that so, instead of doing the conversion himself and verifying the result immediately?
Logged

Gabor
Mark D Segal
Contributor
Sr. Member
*
Offline Offline

Posts: 6818


WWW
« Reply #5 on: December 15, 2009, 03:59:04 PM »
ReplyReply

Quote from: Panopeeper
Mark, I don't understand this. I don't know if there is any printer capable of printing ProPhoto directly, but if there is, then that is the very exception. Thus the color space has to be converted, either by the user or by the printing service - but then why would the user/photographer leave that so, instead of doing the conversion himself and verifying the result immediately?

I have been routinely sending (thousands of) images in ProPhoto colour space to my Epson 3800 and before that my Epson 4800 and before that my Epson 4000. As the printers advance, the size of the colour gamut they can reproduce expands. The 3800 can print some colours exceeding the Adobe RGB98 space and all the more so for the newer Epson 3880 and Epson 7900/9900, so there is nothing exotic about this procedure. It's just a matter of capturing all the colours the printer is capable of reproducing. I don't know exactly what printer or printing process is in play for this gentleman because he sends the work out, why I suggested it just needs a bit of experimentation.
Logged

Mark D Segal (formerly MarkDS)
Author: "Scanning Workflows with SilverFast 8....." http://www.luminous-landscape.com/reviews/film/scanning_workflows_with_silverfast_8.shtml
bjanes
Sr. Member
****
Offline Offline

Posts: 2756



« Reply #6 on: December 15, 2009, 05:33:44 PM »
ReplyReply

Quote from: MarkDS
I think the key distinction which needs to be made here is what happens during image editing versus what happens afterward. There's a near-consensus I believe that converting to 8-bit and then doing image editing in a very wide colour space could be asking for trouble. I think it is much less risky converting to 8 bit and remaining in the wide space AFTER all the editing is completed, but whether the wide space is then necessary or worthwhile becomes the empirical question to test with the printer - and I agree with you - soft-proofing with the printer's profile could be indicative- but not fully determinative because most of our displays do not really "see" all the colours which a number of contemporary printers can reproduce.
I agree with Mark and Eric, but before converting to sRGB (if you choose that route), I would make certain that no significant colors are being compromised. sRGB is a reasonable fit to most printers using photographic paper, but must high end inkjet printers considerably exceed sRGB and even Adobe RGB. Why don't you ask your printer for a profile so you can convert directly to that profile with soft proofing and the proper rendering intent. That way only one profile conversion would be needed. Converting to 8 bit ProPhoto is not advisable because of possible banding.

If you have already applied the printer profile and have sized your print at the proper resolution, some printers will give you a discount as all they have to do is sent the file to the printer.

Bill
Logged
Mark D Segal
Contributor
Sr. Member
*
Offline Offline

Posts: 6818


WWW
« Reply #7 on: December 15, 2009, 05:44:19 PM »
ReplyReply

Quote from: bjanes
Converting to 8 bit ProPhoto is not advisable because of possible banding.

Bill

Bill, wouldn't you agree that most of this risk occurs DURING the image editing process, rather than afterward? I've tried to reproduce banding after completion of all editing by converting ProPhoto images to 8 bit before changing the colour space (rather than the other way around) and quite frankly I've very seldomly seen it.
Logged

Mark D Segal (formerly MarkDS)
Author: "Scanning Workflows with SilverFast 8....." http://www.luminous-landscape.com/reviews/film/scanning_workflows_with_silverfast_8.shtml
Czornyj
Sr. Member
****
Offline Offline

Posts: 1369



WWW
« Reply #8 on: December 15, 2009, 06:01:36 PM »
ReplyReply

Quote from: MarkDS
I've tried to reproduce banding after completion of all editing by converting ProPhoto images to 8 bit before changing the colour space (rather than the other way around) and quite frankly I've very seldomly seen it.

But in the end there's another conversion from ProPhoto to output color space, so maybe it may make things worse then?
« Last Edit: December 15, 2009, 06:02:01 PM by Czornyj » Logged

Jonathan Wienke
Sr. Member
****
Offline Offline

Posts: 5759



WWW
« Reply #9 on: December 15, 2009, 06:07:12 PM »
ReplyReply

8-bit ProPhoto is not wise practice. You can get away with doing it sometimes without causing banding, but that doesn't mean it's a good idea to make your standard practice. If you need something wider than sRGB for your JPEG, I'd use Adobe RGB 1998, but nothing wider-gamut than that.
Logged

Mark D Segal
Contributor
Sr. Member
*
Offline Offline

Posts: 6818


WWW
« Reply #10 on: December 15, 2009, 06:09:12 PM »
ReplyReply

This is safe advice.
Logged

Mark D Segal (formerly MarkDS)
Author: "Scanning Workflows with SilverFast 8....." http://www.luminous-landscape.com/reviews/film/scanning_workflows_with_silverfast_8.shtml
Mark D Segal
Contributor
Sr. Member
*
Offline Offline

Posts: 6818


WWW
« Reply #11 on: December 15, 2009, 06:10:25 PM »
ReplyReply

Quote from: Czornyj
But in the end there's another conversion from ProPhoto to output color space, so maybe it may make things worse then?

Not that I've actually seen.
Logged

Mark D Segal (formerly MarkDS)
Author: "Scanning Workflows with SilverFast 8....." http://www.luminous-landscape.com/reviews/film/scanning_workflows_with_silverfast_8.shtml
Bradley Proctor
Full Member
***
Offline Offline

Posts: 150



WWW
« Reply #12 on: December 15, 2009, 06:32:45 PM »
ReplyReply

Thanks for everyone's advice.  I put my printers profile into ColorThink and compared it.

Here are a couple of images showing the printer profile compared to AdobeRGB (in red).  There is a little bit of color that the printer can do that is outside of AdobeRGB but it is not bad.



Here is the printer profile compared to sRGB(wireframe).  Huge amount of color that the printer can do that is outside of sRGB.



Logged

Mark D Segal
Contributor
Sr. Member
*
Offline Offline

Posts: 6818


WWW
« Reply #13 on: December 15, 2009, 08:01:40 PM »
ReplyReply

Very nice demos Bradley, and shows that ARGB(98) should be safe enough for you. These results are not surprising - BTW what printer and paper are we talking about?
Logged

Mark D Segal (formerly MarkDS)
Author: "Scanning Workflows with SilverFast 8....." http://www.luminous-landscape.com/reviews/film/scanning_workflows_with_silverfast_8.shtml
Wayne Fox
Sr. Member
****
Offline Offline

Posts: 2808



WWW
« Reply #14 on: December 15, 2009, 08:44:32 PM »
ReplyReply

Quote from: bproctor
This seems like it would be a pretty common question, but I couldn't seem to find an answer.  After working on a RAW image in Lightroom I export to a 16-bit TIFF in ProPhotoRGB and then load it into Photoshop to do additional work.  I don't print my own images and my printing company requires JPEG images.  I usually just covert the image to 8-bit and then save a level 12 JPEG while still being in ProPhotoRGB.  The printer doesn't care what color space I use as long as I have it attached to the file.  My question is, because I have to convert to an 8bit JPEG, should I be converting the color space to something else like AdobeRGB before converting to 8bits?


What type of prints ... who is your printing company?  If you are using a company outputting to silver halide photo paper on printers like Durst and Noritsu, they will most likely push it to sRGB if you don't.  These printers are designed around the assumption of an sRGB file coming in.  Most likely you would be better off converting to sRGB yourself earlier in the process than having them do it right before printing.
Logged

Bradley Proctor
Full Member
***
Offline Offline

Posts: 150



WWW
« Reply #15 on: December 15, 2009, 08:55:40 PM »
ReplyReply

Quote from: MarkDS
Very nice demos Bradley, and shows that ARGB(98) should be safe enough for you. These results are not surprising - BTW what printer and paper are we talking about?

I use White House Custom Colour.  They are photographic printers rather than inkjet. They print on Kodak Professional Supra Endura VC Digital Paper and use
Noritsu printers for prints 12x18 and smaller which is what I usually order and they use Durst Theta 76 printers for larger prints.
Logged

Bradley Proctor
Full Member
***
Offline Offline

Posts: 150



WWW
« Reply #16 on: December 15, 2009, 08:58:11 PM »
ReplyReply

Quote from: Wayne Fox
What type of prints ... who is your printing company?  If you are using a company outputting to silver halide photo paper on printers like Durst and Noritsu, they will most likely push it to sRGB if you don't.  These printers are designed around the assumption of an sRGB file coming in.  Most likely you would be better off converting to sRGB yourself earlier in the process than having them do it right before printing.

WHCC is my printing company.  And they are using Noritsu printers for their smaller prints which is what I typically order.  Thanks for the tip.  I might have to just start doing that.
Logged

Mark D Segal
Contributor
Sr. Member
*
Offline Offline

Posts: 6818


WWW
« Reply #17 on: December 15, 2009, 09:20:41 PM »
ReplyReply

Wayne's point is a good one insofar as it gives YOU control over the process - especially if you have their profile for the Noritsu and the paper. (I'm assuming here that this process uses ICC profiles - I'm not familiar with it.) Wayne?
Logged

Mark D Segal (formerly MarkDS)
Author: "Scanning Workflows with SilverFast 8....." http://www.luminous-landscape.com/reviews/film/scanning_workflows_with_silverfast_8.shtml
Panopeeper
Sr. Member
****
Offline Offline

Posts: 1805


« Reply #18 on: December 15, 2009, 10:22:56 PM »
ReplyReply

Noritsu silver-halide printers are using Noritsu's own color space, which is somewhat smaller than sRGB. One should use sRGB, or ask the printing service for their own profile and use that. Once I contacted a Noritsu guy (a regional sales manager) and he wrote me, that they do not give out the profile, because that depends on the paper and chemistry at the printer. Some, like Costco, do provide the profiles. This gentleman wrote me, that that profile should be APPLIED to the print file, do not CONVERT the print file to the profile. I still don't understand it, but the location I used did not have profile anyway.
Logged

Gabor
Wayne Fox
Sr. Member
****
Offline Offline

Posts: 2808



WWW
« Reply #19 on: December 16, 2009, 02:37:42 AM »
ReplyReply

Quote from: MarkDS
Wayne's point is a good one insofar as it gives YOU control over the process - especially if you have their profile for the Noritsu and the paper. (I'm assuming here that this process uses ICC profiles - I'm not familiar with it.) Wayne?

WHCC may be using profiles (it sounds like they are), but not in the conventional manner as we think of using profiles.  The printers are designed around an sRGB model.  It sounds like what they are doing is using profiles to adjust the files to compensate for the variations in the printers (a real problem with these type of printers).

WHCC operates on the premise you should adjust your monitor to match their output, and they will adjust their processes to maintain a consistent output across all devices.  This is why you have to submit 5 files to be printed ... then you adjust your monitor to match the resulting prints.  Sending them 8bit AdobeRGB or sRGB files should yield good results if you are willing to tweak your setup accordingly.

In my previous company we operated 180 locations with Noritsu processors.  We controlled the entire process so our method was to tweak the files at capture for the output device.  Works great until they send the file to the central lab for different product, where we had to tweak the files for that printer.  We didn't use profiles to do this, but certainly could have done it that way.

Logged

Pages: [1] 2 »   Top of Page
Print
Jump to:  

Ad
Ad
Ad