George the Macaw (Yorkshire Wildlife Park)

[Doug Kerr]

Hi, Asher,

Is that a color space, or does that "mode" normally use some particular color space?

Well, I see that it is. This helped me:

http://www.cambridgeincolour.com/tutorials/high-dynamic-range.htm

I still have to read it carefully to get the details (if possible).

Best regards,

Doug

 

[Bart_van_der_Wolf]

Is that a color space, or does that "mode" normally use some particular color space?

Hi Doug,

32-bit HDR is a high dynamic range file format, not a colorspace. Stricktly speaking it doesn't have a colorspace, but instead a recording of luminosity levels in a couple of channels (could be in XYZ coordinates). For coding efficiency it can use non-linear gamma encodings.

I think it's a bit unclear what does happen under the hood of Photoshop. One would expect that the input file colorspace is respected, but it apparently isn't. It also doesn't seem to 'convert to' sRGB but presumably just assigns it. That will create unpredictable results. It seems that Adobe figured that the input would come from sRGB JPEGs, instead of something with a bit more potential quality.

I also see strange colorshifts in the CS5 HDR functionality (which was overall improved from previous versions), so it is probably not limited to CS4 (although there might be another issue causing it). That's one of the reasons I stick to SNS-HDR when I need that type of functionality.

Cheers,
Bart

 

[Mike Spinak]

I don't know about Adobe, but I know that Unified Color uses a proprietary color space for its HDR software.


Here's a video made by one of my four business partners, which (among other things) explains the cause of HDR color shifting, and how his company's software solves the color shifting problem, to produce "natural looking" HDR.

http://www.youtube.com/watch?v=5mKjq1KxRw0

(Please note that my business association with him is with a different company, and I have no affiliation with the company that makes this software.)

 

[Cem_Usakligil]

Hi Dan,

lol.. i havent the slightest what you are talking about haha! goes whey to deep for my image editing knowledge! all i can say is that the bird does have vivid colours not to far off from my interpretation! & yes mine looks very saturated in places too!

Sorry that we have gotten a bit off-topic here. Please don't let it get to you in any way. It's not you, it's us!

 

[Dan Siman]

Hi Dan,


Sorry that we have gotten a bit off-topic here. Please don't let it get to you in any way. It's not you, it's us!

no worries lol.. your light years ahead of me anyhow haha!

 

[Doug Kerr]

Hi, Bart,

32-bit HDR is a high dynamic range file format, not a colorspace. Strictly speaking it doesn't have a colorspace, but instead a recording of luminosity levels in a couple of channels (could be in XYZ coordinates). For coding efficiency it can use non-linear gamma encodings.

I think it's a bit unclear what does happen under the hood of Photoshop. One would expect that the input file colorspace is respected, but it apparently isn't. It also doesn't seem to 'convert to' sRGB but presumably just assigns it. That will create unpredictable results. It seems that Adobe figured that the input would come from sRGB JPEGs, instead of something with a bit more potential quality.

Thanks.

Yes, I have been doing a little playing for the last hour or so in PS CS5. What happens here and there is in fact a little mysterious.

I think I'll just move on for now.

Thanks again.

Best regards,

Doug

 

[Asher Kelman]

no worries lol.. your light years ahead of me anyhow haha!

Hi Dan,

One of the nice things about OPF is that everyone wants the best out of your picture. Discussing the challenge of dealing with wide gamut, wide dynamic range mages with much detail is helpful for optimizing your wonderful photo and also learning from this for many other similar cases.

So while the discussion might seem talmudic, as Cem points out, we do remember, you Dan Siman and your original picture throughout all this.

There's a lot of remapping of colors in the workflow to account for the fact of life that most computer screens cannot show all colors the camera records. Also, different parts of a picture might need unique local adjustment. So compromises are made. We're trying to clarify the best ways to do this with a rich picture like yours!

We won't forget your photograph in the process!

Asher

 

[Doug Kerr]

Hi, Mike,

I don't know about Adobe, but I know that Unified Color uses a proprietary color space for its HDR software.

Here's a video made by one of my four business partners, which (among other things) explains the cause of HDR color shifting, and how his company's software solves the color shifting problem, to produce "natural looking" HDR.

http://www.youtube.com/watch?v=5mKjq1KxRw0

Pleasant enough.

Of course, it gives no insight into why simplistic image manipulation on an RGB basis can give chromaticity shift, or why some other paradigm of color encoding facilitates avoiding it.

It really couldn't explain any of that anyway, since it calls chromaticity "color".

Thanks for the link.

Best regards,

Doug