Joseph Holmes Ekta Space P5

[Jack Flesher]

PS: If you scan into a large space like Profoto, then when you do a convert to Joe's space you will not be giving up much since the bulk of the original capture is still inside Joe's space. However if you scan or capture inside say Adobe RGB, you may in fact clip some of the color information during capture and this can never be regenerated, so it's still lost when you convert to Joe's space.

Silverfast (and most quality raw converters) allow you to define the output colorspace -- so selecting Joe's space at this stage and setting Joe's space as your PhotoShop working space makes sense.

[bglick]

Jack, wonderful post..... I am curious of your comments....

You mention that Joes color space can match that of most chrome films, which of course, makes perfect sense for its existence. However, then you mention, it also matches the color of digital print output. How can these two be true? What digital print output can match the gamut of film? I am very very curious of your response on this.

Also, since so much of digital processing was a result of scanned film, how is it possible that Adobe did not create such color spaces to accomodate this for so many years now? Seems odd they continue to make new color spaces throughout the years, yet never, created one for color chrome film? Why didn't makers of the digital darkroom printers create such? Without this, it could continually represent the bottlneck to the final output....and when you have a $250k printer sale that is dependent on output quality, well, thats a good incentive!

How does digital capture compare with scanned film, as it relates to the size of the color space required? Is proRGB bigger then Joes space? If the two are radically different, does it make sense to keep your digital capture files in the color space which the camera maker provided and your scanned chrome film in Joes space? TYIA

[Kirk Gittings]

Interesting points Jack. I sometimes work with a truely great printer here sometimes when I need a large print. I found however that what he was printing large, I could not get smaller on my 4000. The reason was a worflow similar to what you describe above with scanning in ProPhoto and then converting to Joe's space for printing on his 9600. His prints had a glow to them that I could not match with my workflow.

[steve_782]

Pro RGB is so big, it won't even fit on any of the color analyzing software programs that I have. It's literally outside of the entire L*a*b* space - which is why the comment that it can reproduce colors you can't see is absolutely true.

The comment on the Ektaspace capturing all of the range of a the film is correct - which is why I use it for my scanner colorspace. I'm not sure what color printer Joe is using (I'd like to hear more about that), but with an inkjet system, I haven't been able to reproduce all of the Adobe RBG colorspace. You run out of gamut from the base material's (paper) reflectivity as well as the gamut range of the ink itself.

If there is a way to extend an inkjet printer's color reproduction capability - I'd certainly like to hear how to do this.

[Doug Dolde]

There are actually two sets of profiles. Best if I quote Joe's email for all the details.

""Ekta Space PS 5, J. Holmes" (aka Ekta Space) has not been changed.
I always had two master profiles. The one I changed was Ektachrome
Space, J. Holmes, which became Chrome Space 100, J. Holmes.

I have new chroma variants for each of them. The two master spaces
have different tone curves, but are otherwise functionally identical.
The chroma variants share the tone curve of the master profile for
which they were made. That's why if you have a file in Ekta Space,
and you assign Chrome Space 100, the image's tone curve changes,
opening up the deep shadows.

This property of Chrome Space 100 (and Ektachrome Space before it) is
a useful one for people who have gotten scans that were saved into
Ekta Space PS 5, and who wanted more open values near 0,0,0. If the
scan already has enough shadow detail, then you're better off using
my new set of chroma variants for Ekta Space PS 5. I used to
occasionally sell a set of 6 variants for Ekta Space PS5 for $50, but
have built a much larger and also revamped (better) set of 23 that I
sell for $80. Since you already have the other one, I'd sell you
that one for $50, because the combined price of both sets has been
$150 where I've sold both together."

[Kirk Gittings]

If allot of this is new to you as it is me, here are a couple of articles by Bruce Frazier that relate to the issues above:

http://www.creativepro.com/story/feature/6541.html

http://www.creativepro.com/story/feature/8582.html

[Jack Flesher]

My appologies -- I always get into trouble when trying to keep a complex issue simple

The Epson Ultrachrome and K3 inks have a surprisingly large gamut. For example, they are both larger than AdobeRGB in most colors, though it does fall inside Adobe along the yellow corner -- regardless, both of these inks are larger than what current monitors can display. If you look at a map of Joe's space and of Epson's K3 space, you will find they are very close, though Joe's space is of course larger, containing even some non-visible colors.

My main point was the fact Joe's space is not as overly huge as Profoto, but larger enough than Adobe so it at least contains what current printers can print. This in turn means it is probably a practical color space to be working in, at least given present day technology -- and assuming you won't want to re-scan 10 years from now when things improve even more

As to why Adobe's space does not meet current printers, I really don't know, though I suspect they standardized it to match output capabilities at a time when processing images in 16-bit was still a futuristic concept and well prior to Epson's breaking the printer gamut barrier with Ultrachrome ink in the 2200/7600/9600 printers.

Lastly to Kirk's point, that "glow" was most likely the fact that using Joe's space instead of Adobe allowed the 9600's UC ink to display the additional color it was capable of rendering; before that it couldn't print what it wasn't given.

Again, sorry for any confusion,

[Kirk Gittings]

Well said Jack.

"Lastly to Kirk's point, that "glow" was most likely the fact that using Joe's space instead of Adobe allowed the 9600's UC ink to display the additional color it was capable of rendering; before that it couldn't print what it wasn't given."

What I believe exactly.

And Bruce space? Any thoughs? Smaller gamut than Joe's space I believe.

[Jack Flesher]

Re Bruce space...

I have never tried it...

In general, when I'm using something that aint broke, I usually don't try to fix it

[Kirk Gittings]

Perhaps a dumb question, but I assume you would have to develope custom printer profiles to take advantage of the wider gamut of a larger color space like Joe's.