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antbiker
08-05-2009, 07:36 AM
Please see Scott Specks picture http://f295.f295.org/uploads/Blah.pl?m-1249351242

Scott said :
"Also, for some reason, after I posted it on flickr, a subsequent viewing of it showed a slightly 'dimmer' image. The original, as I view it in Photoshop, looks brighter."

I am really glad you mentioned that Scott. You have stumbled upon something, and done something to your picture that I wouldn't recommend.
Let me explain....
I had great difficulty getting my prints to look like my screen image. I profiled my monitor and lots of other fiddling about. I then found that I couldn't get consistency viewing my pictures in different software on the same monitor! How can you get a decent print with that?
I even sent stuff to Delio to check for me as I got so frustrated with it.

Here on f295 we spend a huge amount of time ensuring detail is seen in those shadows (we avoid 'blocking') and likewise detail in the highlights (we avoid 'burn out'). It would be good if we all could see the image as the photographer made it - then our comments on contrast control for example will be as accurate as the picture we are referring to.

We process our image in Phototshop and it will look precisely how we want it. So how frustrating is it when you put it on the web and it looks different, or view it in your cataloguing software (ACDSee maybe) and it looks different to Photoshop?

It is all about profiling.

You will be using color management in Photoshop (most likely). When you save your picture the profile you have used will be embedded in the image for any profile enabled software to use. This means the colours/shades will be 'mapped' to your software/hardware and display as in Photoshop.
The problem is that web browsers generally ignore the embedded colour profile.
Internet Explorer 7 will recognize embedded profiles but it has to be enabled in preferences.
I think the same holds true for Firefox.
This doesn't mean that web browsers don't colour manage, they do. It's just that they default to a universal standard which is sRGB. If you use any other profile you will get unpredictable results (like Gamma 2.2 for a grayscale image like Scotts).

It's all a mess to be honest, you produce a picture in Photoshop and end up not knowing what it will look like on someone else's monitor. You don't even know what it will look like on your own monitor through different software (unless you are careful and knowledgeable enough to set up your color management).

The following page is fascinating, roll your cursor over some of the images to get an idea what happens to an image regarding profiling. Take particular note of the grayscale image at the bottom and watch shadows block up
http://www.gballard.net/psd/go_live_page_profile/embeddedJPEGprofiles.html#

All I have said so far is for an RGB image with an embedded colour profile which is bad enough.
The thing you have done to your picture Scott, is create it in Grayscale - quite sensibly.
Heaven knows what a browser will do with a Grayscale profile of which there seem to be several! Does it get completely ignored even if color management is turned ON? Or does browser software have the capability to deal with grayscale accurately?

With your black and white images, I recommend you save them as desaturated RGB images, not Grayscale (which will have a Gamma or Dot Gain profile). At least you have then limited your options to a more universal standard (sRGB) which inactive browsers will default to.
If you like to use duotoning/tritoning/quadtoning then you have no choice but to use grayscale in the interim. Just convert to RGB on completion.

To have complete control, you need to do what Delio suggested to me. Create two images.
One is your master, this will have an embedded profile and printing etc should be no problem as your monitor/printer/software are all in sync.
The other image is for viewing on the web and assumes that the software being used is defaulting to the sRGB profile. You should prepare this picture using the sRGB profile then save using Photoshop's 'Save for web'. This image may look different to the master as the profile may be different, and the colour gamut may be narrower too.

Colour is a coplex issue when you think of all the different software and hardware that has to work to a common standard. Profiling is a method of levelling all these differences but as I said before it is all a complete shambles and leaves me quite confused. Any comments any of you can offer will be very welcome. My guess would be that a lot of photographers out there, including many of you reading this are unaware of the damaging influence of profiling. Imagine you are trying to sell prints via the web.....

bradjudy
08-05-2009, 09:26 AM
Great post Tony.

One update to the article you linked. With Firefox 3.5, color management is enabled by default for tagged images. See this KB article for info - http://kb.mozillazine.org/Gfx.color_management.enabled

It sounds like Chrome might have just added some color management support, but it isn't clear to me what version is required, if it exists on both platforms, and how to enable it. This page has some descriptions - http://code.google.com/p/chromium/issues/detail?id=143 and links to this blog post reporting working color management under Chrome - http://lagemaat.blogspot.com/2009/05/chrome-color-managed.html

I need to get into this more - get a monitor calibration tool and get my workflow set up properly to do things the right way WRT color.

Marv
08-05-2009, 10:05 AM
Well this certainly explains a lot. Thanks for the research Tony and Delio. Now for some study time.....

Delio
08-05-2009, 11:19 AM
Ummm. This reminds me of Daryl entertaining his master printer with a bottle of fine Shiraz wine, while taking pinhole shots. His thinking went something like this “.....he is the most important link in the chain, he is the one that will make you look good once the print is on the wall.” I should go and visit Sandra; she is the one that printed my stuff for the Italians. Haven only knows what she did with a ½ Mill$ printer; unfortunately she is way too young to have a bottle of Shiraz with an old man.
But I will let you know what words of wisdom she has. :) :)

bradjudy
08-05-2009, 11:20 AM
Quick follow-up, apparently Firefox made a change with version 3.5 that still allowed v2 profiles to be used, but broke v4 profiles. (It sounds like they changed the underlying color management mechanism from 3.0 to 3.5 and that 3.0 supported both versions)

This page allows you to see if your browser supports v2 and v4 profiles.

http://www.color.org/version4html.xalter

On my computer (Windows Vista), Firefox 3.5 shows v2 support, but not v4 and IE 8 shows no support for either. If I open their PDF, Adobe Reader appears to support both v2 and v4. This matches up with what I've read online.

For simple photo viewing/editing, it sounds like Irfanview has color management, but Picasa does not - I'll try to verify this tonight using the sample images from the website.

bradjudy
08-05-2009, 06:17 PM
Using the test images from the website linked in my last post, I was able to confirm that the current version of Chrome browser supports neither profile version, Windows Vista supports both natively in the explorer, Picasa 3.1 supports both, and Paint.NET 3.35 supports neither.

antbiker
08-08-2009, 02:52 PM
If you want maximum quality & control over how your images look, perhaps the best approach would be to save your image to PDF as bradjudy confirms above.
This supports v2 & v4 profiles.
I don't know how many versions back this remains the case (of PDF reader) but at least the latest version is a free download.

renon
08-08-2009, 05:30 PM
Tony, a great post and good contributions from the other ones. I'm fighting with the same problems. I made the experience that sRGB is the best compromise for the most output devices. Online printing servies can usually also handle sRGB pictures only. If you send something else then you can experience big surprises.