As usual, you're having severe difficulties connecting the dots.
1. The video is called "The benefits of wide gamut working space for print output" and that's exactly what it shows.
2. Yes, this is in a way, a direct response to Gary and no, you don't have to pay to hear his flat earth theories on color management.
3. Yes, there is a big world out there where people like Fong, Crockett, Rockwell and others suggest their audience use sRGB for evertything! The video shows why that's a dumb idea.
4. Any of the actual images in the test page could have been shot and converted in-camera to sRGB. Or shot raw and encoded into sRGB for all further output. The video shows why this is far from an optimal workflow!
5. You're still obsessed and confused about rendering intents, they all clip OOG colors (but do it differently) so I'll ignore your latest post about this here, as should others, as yet another of your rabbit holes and stick to my original idea to put you on the do not call list/ignore. But here I'm replying because you've again failed to understand the points. If you so desire and wish to create your own video addressing these ideas, please do so. I did show that, another video that goes into detail was referenced, the results of that wide gamut data was presented with a file anyone can use to see this. Again, make your own video demonstrating what you think a video on gamut's of working space should show. This thread is many, many pages long, the only one who's come here to suggest the video is flawed is you sir, and the lack of anyone replying to your posts is telling. As such, time to but on the Ardill filter again, you've proven you simply don't get it! That you still don't understand that going from ProPhoto RGB to sRGB can and can/will clip colors despite any RI used illustrates you're unable to understand a very simple concept of color management and until you do so, going down another Ardill rabbit hole is pointless.
Why do you get so angry if you're right and I'm wrong?
Rendering intents do not all 'clip' colors, unless you include the compression of colors into a smaller space as being 'clipping'. Of course I understand, as you very well know, that the whole purpose of color management is to attempt to address the misfit between our various input, display and output devices, and that one very important aspect of this is modifying the image colors so that the image can fit into a smaller destination color space in as pleasing (or as accurate) a way as possible.
Here is a definition of Clip: "To cut, cut off, or cut out with or as if with shears". Neither the Perceptual nor the Relative Colorimetric mappings do this. If they did then the colors would simply disappear. Instead, as you know, the colors are compressed or shifted: in the case of Perceptual the mapping attempts to preserve the relationship between the image's colors; in the case of Relative Colorimetric the mapping brings the out of gamut colors into gamut without attempting to preserve this relationship.
The effect of these two rendering intents can be very different and the more the image gamut is outside the destination gamut the greater the difference: then one intent may give a much better result than the other. So having the choice of which intent to use is very important, as the ICC has recognized by defining v4 which DOES allow both perceptual and rendering intents to be used between working spaces (you can download the sRGB v4 icc profile here:
http://www.color.org/srgbprofiles.xalter and you will be able to check out, for yourself, the difference between the two rendering intents when applied to a mapping from ProPhoto or Adobe RGB to sRGB).
I do understand that with v2 profiles that the ONLY rendering intent available when going from working space to working space is Relative Colorimetric and that even though the other intents are shown as available in Photoshop they will all use the RC mapping. This is not necessarily the case with v4 which allows for working space profiles to use tables, so that they can now implement other intents. Whether they do or not is optional, and, as far as I know, the only color space that currently allows for a Perceptual mapping as well as a Relative Colorimetric mapping is the (Beta) ICC sRGB v4 profile. But no doubt profile makers will produce versions of ProPhoto and Adobe RGB etc., which will provide both intents.
You certainly go to a lot of trouble in your video to show the benefits of ProPhoto over sRGB, I'll give you that. But the sense that one gets from the video is that sRGB is inadequate or defective and will in all likelihood yield inferior results compared to ProPhoto. Well, that may not have been your intent, but that is certainly what comes through to me. And, as you know, it is NOT true that sRGB will inevitably yield inferior results than ProPhoto.
Depending on the profile maker, some images may print much BETTER from sRGB, ESPECIALLY if the rendering intent chosen is Perceptual. Have a look at this really excellent explanation (with animation) if you don't believe me:
http://graphics.stanford.edu/courses/cs178/applets/gamutmapping.html. The rendering intents implemented here are by no means optimal, but they are rigorously correct.
The key is that if the image gamut is contained by both the working space and the destination space then a Relative Colorimetric mapping is the best and safest one to use as the colors will not be changed. If it is NOT then what we need to do is to check each rendering intent to see which gives the best result: and this will depend on how well the profile implements the mappings. So a profile from one supplier (say XRite) may give a better result with a Perceptual mapping while one from another supplier (say Argyll) may give a better result with a Relative Colorimetric mapping (or vice versa).
The situation gets even more complicated with v4 as this allows for an optional intermediate gamut called the Perceptual Reference Medium gamut (PRMG) when converting from one color space to another. This has pros and cons that can (probably will) affect which rendering intent gives the best result.
So do we agree on anything at this stage? Well yes, I do agree with you that we should absolutely NOT convert a wide-gamut image held in a working space into a smaller-gamut working space unless this is unavoidable. It is, unfortunately, currently unavoidable for the web: but it is not, by any means, unavoidable for printing. If we do the conversion before printing then we will be using a RC mapping which WILL bring all of the out of gamut colors into gamut, and in so doing do the kinds of things you demonstrated with your test image. By converting the image to sRGB we will be damaging the image and so we will get an inferior print. But if the image was already in sRGB, putting it into ProPhoto would not improve the image (and might even result in a slightly worse print).
I also agree that if we want to use only ONE working space then we are better using a big one like ProPhoto. But I see absolutely nothing wrong with using sRGB for images with small gamuts (black and white, needless to say); and Adobe RGB for images with medium-sized gamuts; and ProPhoto RGB for images with large gamuts. You might say that this is just complicating one's workflow - yes, perhaps it is, but it's nevertheless perfectly valid and will not result in worse prints.
In the example I've given here:
http://www.luminous-landscape.com/forum/index.php?topic=93997.0, part of the image colors were outside both sRGB and Adobe RGB and also outside the gamut of a wide-gamut print: in that case, how can I tell what the actual color is? All I can do is print and hope for the best. Soft-proofing doesn't help (how could it if the print gamut is wider than my monitor gamut?). Some of us might prefer to sacrifice some very saturated colors in exchange for being able to view all of the colors on our monitors. That's a choice ... one which I, for one, am happy with (most of the time, but not, inflexibly, for ALL images). I am not asking you or anyone else to do the same: that's for each of us to decide.
That others on this forum haven't come out in agreement with me is really irrelevant: this is not an election, it's a matter of fact. If all of the world agreed (as it once did) that the world is flat, this would not make it so (fortunately
.
It seems to me that you are doing what Fong et al are doing (I do speak from ignorance as I haven't read/watched these gentlemen's advice, but you tell me they advocate sRGB all the way, so I'll take your word for it) ... but you are doing it at the other end of the spectrum: you're advocating ProPhoto all the way. Fine, it's your right to do so ... but it is equally my right to disagree with you and to disagree with how you present your argument.
But it would certainly be very good if we could agree to disagree ... without the personal attacks.
Robert
