Camera Labs

Hi folks,

We have been having a small discussion about Colour Space over in the Canon forum (here) but I as my last two posts there were not Canon specific I thought it might be an idea to copy them over to the Imaging Software forum, where they are a more natural fit, and also attempt to broaden the conversation from a discussion of sRGB vs. AdobeRGB and introduce ProPhoto RGB.

Bob.

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OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.

There is an article over at CambridgeInColour entitled "Working Space Comparison: sRGB vs. Adobe RGB 1998" which you can read here. It includes a very nice diagram illustrating how the colour gamut changes with luminance thus:

..sRGB IEC61966-2.1 is shown by the white lines and Adobe RGB 1998 by the black lines.

..........25% Luminance.....................50% Luminance.....................75% Luminance

New information for this thread, I think, so if anyone is interested in following this up then click on the picture and head on over to the CambridgeInColour article.

By the way, don't interpret the actual colours of these types of charts too literally. Remember that you are viewing them on a monitor which itself has a restricted colour gamut so such illustrations are only intended to give an indication of the differences, not the actual colours!

Bob.

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OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.

I was browsing the EIZO web-site and came across a resource which is relevant to this thread. Obviously some of the material is manufacturer specific but here are the links for the various essays:

• Color Matching between Your Monitor and Prints
  
• Color Management in Practice
  
• Choosing the Right Monitors for a Color Management System
  
• Monitor Calibration

Each of these links to a multi-page essay.

Bob.

EDIT: Links updated.

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OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.

In the Canon thread, referred to in my first post of this thread, I thought that AdobeRGB was pretty acedemic as I could never justify spending the cash needed for an Adobe RGB capable monitor. However, I have just come across an article over at The Luminous Landscape entitled Understanding ProPhoto RGB which is a very interesting read.

Briefly, ProPhoto RGB is an even wider colour space than AdobeRGB so my initial reaction was "well, if I can't even see AdobeRGB on a montor then why bother?" Here's a brief extract from the article:

So, why bother working in a larger colour space like ProPhoto RGB?

The main reason is the same as why you want to work in 16 bit mode rather than 8 bit mode. It gives you elbow room – room to work with the palette that the sensor has captured, change various aspects of the image to suite your creative needs, and not run into the walls, so to speak.

You'll likely also find that the better inkjet printers and inks are capable of reproducing saturated cyans, magentas and yellows that are outside of the Adobe RGB colour space, making ProPhoto a much better choice.

But, the price that you pay for having all this freedom is that you're capable of creating what some call "science fiction" colours. These lie outside the gamut of output devices as well as good taste, and they therefore can cause all sorts of problems. So, when working in ProPhoto RGB, or any really large colour space, restraint is the watchword.

As I said, the whole article is well worth a read and has some excellent illustrations. It has certainly given me pause for thought.

Bob.

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OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.

Nice write up Bob!

Colour spaces is one of those big cans of worms you wished you'd never opened.

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My Flickr

Wow! look at that Huge diffrence in teh colour

the Adobe RGB covers a much qider colour range, well i gota pretty decent screen but i can notice the diffrence cleary with the black lines so to speak.

Thanx for the monitor calibration link, quite usefll i m going to get that fixed on my parents screen they had it now for quite some time.

I m going to give it a good read that article



To comment the last post you wrote, well our current situation or i guess for most mebers is that we are normal people, hobby photographers some are really good and almost pro but i would say that the majority does it because we love it! and at this stage there no need to bring on the pro things unless you really want to. Persoanly for the time beeing i m just going to stick to what i got. Sometime in the future i migh improve and then i might be thinking something ellse, just like you stated Bob.

Thanx of the good read my freind

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My Picasa

My Flickr

Now I'm going to sound pro-apple again (and I am anyway ) but Apple did a great job to provide more than corerct colorspaces for its screen, out of the box.

Ifyou've ever used a mac, you probably realized that where a classical PC screen is more turning towards the yellow, mac screens are more towards blue, which IMO, gives a better rendition of the pictures and is closer to reality.

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D40 User

I just recognized that I had a problem with flickr-uploads:
- I have set the camera to Adobe-RGB (can't do ProPhoto RGB)
- CaptureNX recognizes this and shows the images (jpg and RAW) exactly as they are shown in the explorer.
- When I do some rework in CaptureNX (on the RAW) I just saved the new jpeg with the option embed color-profile (which was again Adobe RGB)
- Lightroom shows the jpg pretty identical (but not the RAW)
- and then I uploaded those jpgs to flickr using the flickr-uploadr, which does no color-space conversion.
--> WRONG
The images are less saturated than in my machine when I look at them in IE (or Opera).
So what I do now, is export the jpeg 1.st through the export-function of Lightroom with the color-space option in the export dialog set to sRGB, which then starts the flickr-uploadr. It's only now that the images on the web look like directly from my computer
Now I also switched the D300 to sRGB so that the jpegs that are produced in-camera can directly be used for upload to the web.
I'm pretty sure that the gamut of the NEF is not influenced and that this setting is only used to generat the jpeg from it. So I should be safe now

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Thomas (beware: Nikon-fanboy and moderator!) My Lens Reviews, My Pictures, My Photography Blog
D800+assorted lenses

Any thoughts?

Bob.

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OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.

Bob,
thanks, no I had not seen that thread, though I have read the info on Camridge in colour. That is one of the articles which confuses me a little as Adobe RGB is said only to be worthwhile for 16 bit files. I have a Canon 40D which (if I understand things correctly) is 14 bit, ok 14 is closer to 16 than it is to 8 but I don't know if this is relevant. In the 40D manual Canon recommend sRGB. So all very confusing, at least for me!
Muffi

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Working from memory here, but the 14 bits describe how fine the granularity is between the various extremes of the colour gamut. The width of the colour gamut, if "width" is the right term, is independent of the number of bits the camera uses per channel.

Bob.

_________________
OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.