Re: re[2]: filmscanners: OT (slightly): Epson 640U

["Richard N. Moyer" <dickmoyer@mail.earthlink.net>]

This has been worked to death by the experts. See Bruce Fraser, or go 
directly to J Homes, who created the EktaSpace gamut in the first 
place - so that there was a wide enough space to completely envelop 
E6 - judiciously, meaning that "no levels out of the 256 are wasted". 
Or, if you choose, obtain software such as ColorThink (CHROMix.com 
site) or ICCTools.com site for gamut analysis profile viewing 
software, which will illustrate in 3 dimensional views the nature of 
these profiles.

Then there is this type of data:
                                Percent of Visible Spectrum included
Kodak Prophoto                       27.94%
Wide Gamut RGB                       22.94%
Ekta Space (J. Homes)                20.65%
Adobe RGB 1998                       18.04%
sRGB                                 14.47%
Epson 1270 "Standard"                13.39%
Radius ColorMatchRGB custom          12.78%
1270 PQP 2/21/01 custom              10.72%
Epson 1270 Premium Glossy (std        9.63%
Epson1520 PQPP custom (Steve Upton)   8.24%
EuroscaleCoated.icc                   8.05%
Epson 1270 Olmec Glossy (Ian Lyons)   7.95%
CS ColorMatch 3.01 SWOP Sf C          7.63%
USSheetfedCoated.icc                  7.27%

The Ekta Space was developed by J. Homes using a Q60 Target of and 
for Ektachrome obtained from Kodak, but you can go to the Chromix 
site (profilecenter.com) and look into it. Plus there is a wealth of 
correspondence on this particular subject.

These people (color scientists, and others who publish) consider sRGB 
an inferior space, sort of like "viewing your image through a keyhole 
- - ". Meaning small space. After doing quite a bit of my own 
analysis using a multitude of gamut spaces represented by targets and 
ICC profiles, I agree.

It is true that sRGB is lacking in the blue/green sector, 
particularly at low luminosity values. But you can easily get chroma 
levels off an Ektachrome slide that blow outside the sRGB confine. 
Which is why color expert Homes created Ekta Space in the first place.

Negative film and E6 Ektachrome are different animals.


>In a message dated 3/3/2001 5:46:16 PM EST, dickmoyer@mail.earthlink.net
>writes:
>
>>  If you use Ektachrome E6, you will obtain saturated colors far
>>   exceeding the gamut of sRGB.
>
>No, this just isn't true.  Take a look at the data for the Q60 and
>you'll see that there's very little out of gamut, mostly highly
>saturated yellows and cyans that don't occur in most people's
>pictures.  There's virtually nothing out of gamut when scanning
>negatives because of the orange mask.
>
>Regards,
>Ed Hamrick