ProPhoto Gamma setting

[jule]

I am wanting to start to use ProPhoto as a working space and I am a little confused about how to do this properly. The previous lengthy threads I think were lost during the crash last year, so apologies for covering territory already perhaps covered.

If I want to work with an image in Prophoto, do I need to recalibrate my monitor with a Gamma setting of 1.8 ? Because I am presently working in Adobe1998 colour space, my monitor setting is, and is calibrated with Gamma 2.2, using Greytag Macbeth Eye One Match 3.

Does this also affect the paper profiles I have had made where the information I have provided included the Gamma setting of 2.2?

I would love some help here please.
Julie

[Brian Gilkes]

Julie,
Why do you want ot change to ProPhoto colourspace?
The gamut of current printer inksets is beyond Adobe RGB (1998) , but nowhere near ProPhoto.
For general photography eg landscape and for offset repro the Adobe spce using perceptual rendering is fine. For critical inkjet work , or to ensure you get extremely saturated reds , use
 J Holmes Ektaspace PS5 or similar, and use relative colorimetric. You may lose tonallity by using colourspace you do not need, especially, as I understand it, in 8 bit, which is what the file must be converted to before printing.
You may wish to confirm all this with one of the colour management gurus.
HTH
Brian

[Richowens]

Hi Julie,

To answer your questions, you don't need to change your monitor calibration or your profiles. Anyway I didn't, and I have achieved good results with my prints.

Yes the gamut of Prophoto is outside any printer gamut, but it can be reined in to print quite nicely. Just use softproofing to find the out of gamut colors.

Rich

[61Dynamic]

Skipping right past the "ProPhoto-is-unnecessary-for-anyone-since-I-don't-use-it-assumptions vs ProPhoto-rocks-the-house!" debate...

The gamma for ProPhoto is unrelated to the gamma for your monitor. Photoshop takes care of all of the appropriate conversions thanks to the magic of color management so there is no need to re-calibrate your display.

[jule]

Julie,
Why do you want ot change to ProPhoto colourspace?
The gamut of current printer inksets is beyond Adobe RGB (1998) , but nowhere near ProPhoto.
For general photography eg landscape and for offset repro the Adobe spce using perceptual rendering is fine. For critical inkjet work , or to ensure you get extremely saturated reds , use
 J Holmes Ektaspace PS5 or similar, and use relative colorimetric. You may lose tonallity by using colourspace you do not need, especially, as I understand it, in 8 bit, which is what the file must be converted to before printing.
You may wish to confirm all this with one of the colour management gurus.
HTH
Brian
[a href=\"index.php?act=findpost&pid=58336\"][{POST_SNAPBACK}][/a]

Brian, I just wanted to have a play and see the difference between Adobe 1998 and ProPhoto with the current body of work I am preparing for an exhibition. I am taking images underwater - not the usual coral/fish type ones, and the colours are pushing the gamut range of Adobe 1998 - hence my wanting to experiment and try ProPhoto. I won't know until I have a go!...and because the colour space is unfamiliar to me I was unsure about all the parameters required.

Over the next couple of months I will also give the J Holmes EktaspacePS5 as you suggested a go.

Thanks,
Julie

[jule]

Skipping right past the "ProPhoto-is-unnecessary-for-anyone-since-I-don't-use-it-assumptions vs ProPhoto-rocks-the-house!" debate...

The gamma for ProPhoto is unrelated to the gamma for your monitor. Photoshop takes care of all of the appropriate conversions thanks to the magic of color management so there is no need to re-calibrate your display.
[a href=\"index.php?act=findpost&pid=58345\"][{POST_SNAPBACK}][/a]

Thanks for letting me know. I couldn't quite understand the Gamma for monitor and Gamma for ProPhoto thing....and probably still don't, but as long as I don't need to change any of my monitor settings or calibrations that's all I need to know for the present.



Thanks,
Julie

[jule]

Hi Julie,

To answer your questions, you don't need to change your monitor calibration or your profiles. Anyway I didn't, and I have achieved good results with my prints.

Yes the gamut of Prophoto is outside any printer gamut, but it can be reined in to print quite nicely. Just use softproofing to find the out of gamut colors.

Rich
[a href=\"index.php?act=findpost&pid=58342\"][{POST_SNAPBACK}][/a]

Thanks Rich. I will softproof to check out of gamut colours.
Julie

[digitaldog]

The TRC gamma of a working space defines how edits are applied over the tonal range and as pointed out has no relationship to the TRC gamma of a display. They only share the term "gamma".

A 2.2 gamma is more perceptually uniform meaning you perceive the changes made over the entire tonal scale to appear even. A tweak in Photoshop produces roughly the save visual change over the entire tone curve due to this gamma encoding.

[jule]

The TRC gamma of a working space defines how edits are applied over the tonal range and as pointed out has no relationship to the TRC gamma of a display. They only share the term "gamma".

A 2.2 gamma is more perceptually uniform meaning you perceive the changes made over the entire tonal scale to appear even. A tweak in Photoshop produces roughly the save visual change over the entire tone curve due to this gamma encoding.
[a href=\"index.php?act=findpost&pid=58355\"][{POST_SNAPBACK}][/a]

Ahhhhhh... becoming clearer now. I get a bit confused sometimes when terms are 'shared', and because of this lack of understanding, I didn't know whether I was supposed to match up the Gamma of 1.8 of Prophoto with my monitor gamma. I know now so thanks to all for your assistance.

-gosh there is a lot to learn and grasp!

Julie

[bjanes]

Julie,
Why do you want ot change to ProPhoto colourspace?
The gamut of current printer inksets is beyond Adobe RGB (1998) , but nowhere near ProPhoto.
For general photography eg landscape and for offset repro the Adobe spce using perceptual rendering is fine. For critical inkjet work , or to ensure you get extremely saturated reds , use
 J Holmes Ektaspace PS5 or similar, and use relative colorimetric. You may lose tonallity by using colourspace you do not need, especially, as I understand it, in 8 bit, which is what the file must be converted to before printing.
You may wish to confirm all this with one of the colour management gurus.
HTH
Brian
[{POST_SNAPBACK}][/a]

Brian,

One reason Julie might want to use ProPhotoRGB is the article by the host of this forum:

[a href=\"http://www.luminous-landscape.com/tutorials/prophoto-rgb.shtml]http://www.luminous-landscape.com/tutorial...photo-rgb.shtml[/url]

ProPhotoRGB is also recommended by Bruce Fraser. Of course, 16 bit is necessasry with this wide space.

What is the gamut of Joe Holmes' Ektaspace?

Although the gamma of aRGB is 2.2, in the rendering process the actual gamma produced by the RAW converter or in camera processing may not be 2.2 and often varies from highlight to shadow. For example, here is stepchart image rendered by Nikon capture. The average gamma is 1:1.73, but it becomes much steeper in the shawow portion of the image.[attachment=251:attachment]

[Brian Gilkes]

Joe Holmes Ektaspace is larger than Adobe RGB98, and just nicely encompasses the Epson Ultrachrome K3 inkset .
Brian
www.pharoseditions.com.au

[Stephen Best]

Joe Holmes Ektaspace is larger than Adobe RGB98, and just nicely encompasses the Epson Ultrachrome K3 inkset .
Brian
www.pharoseditions.com.au
[a href=\"index.php?act=findpost&pid=58503\"][{POST_SNAPBACK}][/a]

This isn't true, at least according to a comparison of Atkinson's profile for Epson Premium Luster using the ColorSync utility. There's a lot of printer space in the deep blue/green region outside of Ektaspace. I think it depends more on where the files are originating from. If film, Ektaspace (both the freebie and paid version) or Beta RGB (which I use) is probably a better choice, but for raw capture only ProPhoto will enable you to exploit the K3 printer gamut to the max.

Note that I'm not advocating the use of any one working space over another ... they all have their pluses and minuses. This is an endless debate which I don't want to get into!