Joseph Holmes Ekta Space P5

[Kirk Gittings]

Is anyone using any of Joseph Holmes' spaces (like Ekta Space P5) for their scanning profile? Tell me about what you think the real advantages are if you would.
Thanks.

[tim atherton]

Kirk,

I've used it because a drum scan shop I use have picked it as their color space (as a result I also did some of my own scans using it)

I read all the blurb about it and it's potential benefits.

In theory it is supposed to offer some advantages.

In practice, with my printing workflow - I couldn't say I've ever noticed any major difference. Perhaps if I ran some rigorous side by side tests? Or on a particualr image where it's benefits especially applied to that one image. But I've given up using it on a regular basis, apart from converting the drum scans across to Adobe RGB

More based on instinct than empirical testing.... :-)

[Doug Dolde]

I use it because I also have Joe's Chroma Variant profiles (both Chrome 100 and Ekta Space) and use them instead of normal saturation methods. The variants are assigned profiles (rather than converted to) and you can change them anytime in the workflow without and file degradation (since the don't affect the file itself).

To quote Joe Holmes:

"The full set contains 17 profiles, including the master profile, Ektachrome Space, J. Holmes. When assigned (not converted into the various variants, the image chroma is increased or decreased by an amount equal to the lable of the variant (from minus 50% up to plus 50% in increments of about six percent).

The effect can be seen by converting an image into Lab in Photoshop, and then using the Hue/Sat tool to increase "saturation". Compare that effect to the same adjustment with the Hue/Sat tool in RGB mode. The latter is the problem and the variants are the solution. Image colors retain lightness much better as their colorfulness is being adjusted. And yet the system allows for the color to be adjusted in this way at any time in your image editing process, non-destructively, unlike conversion into and out of Lab, which both means the adjustment you made in Lab becomes permanent and not undoable, but involves a conversion penalty unless the file is a 48-bit file.

I use them for every image and they are a revelation for many photographers who use them."

[steve_782]

Yes, I have the profile and use it on my Imacon. The colorspace is huge. Easily 2x larger than Adobe 1998. However, that's also part of the problem. You can't currently print out that large of a colorspace. You can edit in PS in the larger colorspace, but, if you compare the Ektaspace colorspace to what you can reproduce on paper - in the end it doesn't matter, you end up having to make the Ektaspace colorspace fit whatever paper you're printing on.

Another problem is that the profiling targets are all made in Adobe 1998. This means that if you want to try profiling a paper using a larger colorspace, you have to create the targets yourself for paper profiling to use Ektaspace as the embedded profile in the target.

While this can be done, I haven't convinced myself that the extra work is worthwhile for the following reason. I haven't found a paper that can accomodate the Adobe 1998 colorspace much less a colorspace that's nearly 2x larger.

His comments on editing the image in Ektaspace and making adjustments are true, but the question is can you translate that into a print? Or, do the colors merely get reassigned through either the perceptural or relative colorimetric print settings anyway?

This can all be easily seen through color analysis software. I have both Monaco GamutWorks and X-Rite ColorShop X; either program will produce 2D and 3D plots of colorspaces and plots of images within a colorspace or profile. Once you see these rendered in graph form, you can easily see the problem with translating from Ektaspace to a paper profile.

The reason I use the colorspace is for some of the editing advantages, and the idea that maybe in some future print process I'll have a larger colorspace to work with.

[bglick]

Steve, nice post... I came to the same conclusions several years back when contemplating using Joes Color Space. So what is the motivation, since Joe prints on Epson printer anyway? He must have had something in mind for this color space?

[Jack Flesher]

The advantage to being Joe's space to begin with is then being able to apply his saturation profiles. By doing so, you alter saturation without changing contrast or losing color data, both of which can (and often do) happen when using the saturation, contrast, levels and/or curves adjustment sliders.

[bglick]

Jack, so i guess this falls under the " more ceiling space for edits" category, just like 16 bit vs. 8 bit issues? Ok, so this is could be a potential benefit, is there any drawbacks?

[Kirk Gittings]

How complicated does it make the workflow and how expensive are his programs?

[John Hennessy]

Kirk,

I use Ekta Space P5 as a working color space but not as a scanning profile. For scanning, I use a profile made with the profile-creating capabilities of Silverfast which uses a target specific to the film I use.

Am I missing something in your question? Or in my workflow?

[Jack Flesher]

To be clear, a color-space is a color-space, regardless of whether you are trying to represent it with 8-bits or 16-bits of data per channel. But as for headroom, your comment is on the mark.

The problem really has been that conventional "standardized" color spaces have not been matched to the photographic medium. For example, Adobe RGB is not big enough to contain all of the colors that can be output by the current line of professional digital printers, while the Profoto space is so huge that it contains colors the human eye cannot even see! sRGB is tiny and matches only what a basic computer monitor from 15 years ago could render. Joe's space OTOH, originally matched the color gamut of color transparency films and by odd coincidence (or not), this gamut is very close to what current digital printers can match. (Actually he has a new one, Chromespace 100, that is a bit more tailored to the digital workflow. As for cost, I believe the entire set is $100, Mac or PC.)

So by using Joe's space, we have a more optimal color palette to begin with, which allows us to maximize efficiency; not too many extra colors we can't use, and not too many lacking. With the saturation profiles, we have the ability to alter color saturation while at the same time keeping all the colors at the same relative brightness so contrast remains stable. We also stay inside our working space and don't "lose" any color data. By contrast when you start pushing pixels around digitally with a program like PhotoShop -- for saturation, contrast, brightness or hue changes -- you can easily push colors outside the edge of the usable portion of color space (called "clipping"). When this happens, that data is simply lost -- it is like a pipe backing up and all the subtleties of color that fall outside your space take on the last hue available before they landed outside the space. How those border colors ultimately get represented gets us into discussing rendering intents, which another topic all on its own. Suffice it to say, this become a less critical issue when you keep all of your colors within a tuned space like Joe's to begin with.

As to why you don't see much difference much of the time: Either all or enough of your colors remained inside the range of your output space to begin with (indicating a good capture), or those that fell outside were limited enough that the rendering intent chosen did its job and successfully camouflaged the changes. When you hear people start to complain they can't get their sky the proper blue, or the clouds look funny, or my greens are off, you can bet they are dealing with clipped color issues.

Hope this helps,