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OPR Workshop Information Exchange => General Techniques => Topic started by: DaveG on July 08, 2006, 08:05:50 PM

Title: Colour matching and profiles?
Post by: DaveG on July 08, 2006, 08:05:50 PM
Just wondering how much we need to worry about colour matching and profiles in the images we receive, and send back to OPR.  I've got a 24" Dell LCD at home and while the colour looks fairly accurate, I havn't used a calibrator on it, so it's likely off somewhat.

I've been tempted to pick up a USB calibrator (infact there's a nice $60 rebate on the Spyder 2 Pro right now), but if it doesn't have to be perfect, I might save myself some money :P

Likewise, when I got a photo from OPR to work on, I got a profile mismatch warning when Photoshop opened it.  Just wondering how other people are handling it (use embedded, convert to working space, discard).

I'm guessing that if there are any final colour corrections to do, they'll be applied before printing (BTW: are the people who owned the photos getting the digital versions as well, or only prints?)

Dave
Title: Re: Colour matching and profiles?
Post by: happyheart on July 31, 2006, 07:48:45 PM
I'm using the Adobe RGB color space, and haven't received any warnings about mismatch, so they must be scanned using this colorspace.  I have my software set to use the embedded colorspace.  I have the GretagMacbeth EyeOne Pro and a 23 inch Viewsonic Flat panel.  The calibration does make a difference, but the flat panels are very limited as to what types of adjustments you can make.  There are a few on mine that I can't get within the recommended range of the EyeOne.  I do notice a difference in the color on the 23 inch that I calibrate and my 19 inch that doesn't have any adjustments (to speak of).  I use the calibrator at my business also.  I had been wanting one for a long time and finally just bought one.  I like using it, but I could live without it if I had too.
Title: Re: Colour matching and profiles?
Post by: marylou on September 08, 2006, 10:23:10 AM
I'm new here, so while I'm waiting for further instructions to begin working, I thought I would make myself useful. To read about some useful information as to how we should prepare our files, as far as color management is concerned, you might want to read the West Coast Imaging FAQ page, here's the link:

http://www.westcoastimaging.com/wci/page/info/FAQ/uploadfaq/colormgt.html

I found their link at the OPR blog under friends, so I immagine that they will be printing the photos. Hope you find this useful.
Title: Re: Colour matching and profiles?
Post by: schen on August 30, 2007, 07:11:39 AM
This is an old thread and it seemed to stop without a conclusion.  So I am trying to see I can resurrect it.

I am using a Sony Trinitron monitor.  sRGB would be a better fit profile.  The photos I downloaded so far were all Adobe RGB.  If I convert it to sRGB, will it be converted back to Adobe by the QC?

Is it better to work on them in Adobe RGB without conversions?
Title: Re: Colour matching and profiles?
Post by: Mhayes on August 30, 2007, 11:40:28 AM
Schen,

I went to the link posted by Marylou that is the FAQ page for West Coast Imaging. While they do not say specifically which RGB profile to use, I would say Adobe RGB. Here is a quote that makes me lean that way: "My digital camera lets me use sRGB or AdobeRGB. Which should I choose?
Most people find that they make better prints when capturing into Adobe RGB."

I use a Sony Artisan and the two printers I use online give an example of the profile they expect you to follow. Both places use AdobeRGB and they take care of the conversion to CMYK.

Margie

Title: Re: Colour matching and profiles?
Post by: cmpentecost on August 30, 2007, 12:49:13 PM
Adobe RGB is the preferred profile.  the sRGB is more for web content.  If you get a warning saying you do not have a matched profile, it means that the profile you have your Photoshop set at is different than the settings we had our cameras set at. 

Christine
Title: Re: Colour matching and profiles?
Post by: kstruve on August 30, 2007, 12:51:50 PM
I'm not sure much of this color management discussion is necessary, as OPR does final color correction as part of quality control on their end before sending them off to be printed.  However, if saving our images with a certain profile would save them any time, it would make sense to do it.  Thoughts, Christine?  Dave?

Kurt

*** edit ***

Ah, you already answered, Christine. 
Title: Re: Colour matching and profiles?
Post by: schen on August 30, 2007, 02:23:29 PM
I agree that this discussion is mostly academic in regard to OPR.  Few of them were high quality color studio photos before they were damaged.  Most of them were in such a poor shape after damage that we are resorting to "restoring the memory".  But I like academic technical discussion and this might help taking my energy off the other thread.  I will do whatever I can to help our fearless leader.

http://www.oprworkshop.org/forum/index.php?topic=872.msg8285#msg8285

If the picture was taken using AdobeRGB and will be post-processed in AdobeRGB, then using AdobeRGB profile in restoration will avoid the conversions and loss of color gamut.

But I am using a CRT monitor.  I would expect sRGB profile to match the monitor better.  So should I or should I not use sRGB profile?
Title: Re: Colour matching and profiles?
Post by: kiska on August 30, 2007, 02:50:34 PM
This is how I have my color settings.

http://upload.pbase.com/image/84754817 (http://upload.pbase.com/image/84754817)

(http://i.pbase.com/o6/93/579993/1/84754817.Kc7lulSe.color.jpg)
Title: Re: Colour matching and profiles?
Post by: cmpentecost on August 30, 2007, 05:25:19 PM
My color settings are the same as Kiska's, and if anyone has Katrin Eissman's book, she also give instructions for setting up Photoshop at the beginning of her book.

Chris
Title: Re: Colour matching and profiles?
Post by: glennab on August 30, 2007, 08:56:19 PM
My understanding from the beginning was that the restorations would be color corrected before being sent for printing (or at West Coast).  If we should be using specific color settings, it would be good to know.  My understanding is that any changes to files (including color profiles) degrade the image, and we're dealing with enough of that already.  I just renewed my NAPP membership through OPR and got Ben Willmore's DVD on Mastering Color.  Until I can delve into that, I'm wondering what profile to use if it's other than what we receive in the files from the gallery.  Chris and kiska, I'm also curious about the dot gain settings.  I thought those were only for images to be printed on press.  Am I behind the times?

Glenna
Title: Re: Colour matching and profiles?
Post by: kiska on August 31, 2007, 03:40:22 AM
Glenna, my PS instructor, Sherry London, suggested those settings thru her class. The 'custom' part at the top is a result of choosing US Prepress (her suggestion as she surmised most of her students would be using desktop printers). The dot grain settings are default...dunno what they're for.
Title: Re: Colour matching and profiles?
Post by: schen on August 31, 2007, 09:29:09 AM
Dot gain is a phenomenon of printing process that the effect of a printed dot is greater than the size of the dot on the printing plate due to the spread of ink and the optical effect of ink on the area surrounding the dot.  The amount of dot gain depends on the paper and the viscosity of the ink.  I believe dot gain in the profile is used to reduce the values of CMYK in the conversion to CMYK so that the end printed image will have the expected darkness.  If we start with RGB and end with RGB, dot gain values should have no impact.
Title: Re: Colour matching and profiles?
Post by: kiska on August 31, 2007, 09:52:35 AM
oh.
Title: Re: Colour matching and profiles?
Post by: kstruve on August 31, 2007, 11:06:40 AM
Thank you Wikipedia!  ;)

Kurt
Title: Re: Colour matching and profiles?
Post by: schen on August 31, 2007, 12:55:09 PM
Sorry Kurt, I did not know originality is required.   :-[
Title: Re: Colour matching and profiles?
Post by: schen on September 09, 2007, 11:15:45 PM
Hope I am not boring you with all these technical details but I am having fun finding new things about my computer.

After these discussion about color profiles, I decided to change my camera's color mode to AdobeRGB. The first thing I noticed was that the file name format changed.   :(   What a disappointment.  I was expecting to see some color changes of the photo.  I called the Nikon digital camera technical support hot line and was told that was the way it supposed to happen.

I went out and took about 70 pictures yesterday with the AdobeRGB color mode.  It slowed down my PC when I opened the folder of the pictures with Windows explorer thumbnails mode.  Each thumbnail took more than one second to paint and the CPU of the computer was running near 100%.  I could not do anything with the computer for about two minutes.  Every time I reopened that folder, I had to wait for a while before I could use the computer again.

A whole day passed before I found out that under Display Properties->Settings->Advanced, there is a tab called "Color management".  I added AdobeRGB1998 to the color profile and it replaced the previous one of sRGB something.

Now, it takes about two seconds to paint all the thumbnails of the folder regardless of the color profiles of the files in that folder.

I don't know what all these mean.

 
Title: Re: Colour matching and profiles?
Post by: Hannie on September 10, 2007, 04:05:09 AM
Hi Schen,

That is a great tip. (very poor though that the Nikon tech did not try s little harder...)
But isn't it fun finally to figure things out yourself after working so hard at it!
Hope you see some color change in your photos now.

Hannie