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.CRF colour profile help needed

 
 
David Kilpatrick
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      04-02-2004
I had a one-hour conversation this morning with a photo library owner
who shoots using a certain brand of leading digital SLR with a full
frame sensor. Complaints: the images need sharpening to setting 2
(despite advice not to sharpen at all for library use) or they look too
soft to be marketable; the colour saturation is impossible to get high
enough even when exporting on setting 4, Saturated sRGB. He has been
given some odd conflicting advice and has been doing strange things like
assigning his sRGB exported 160bit TIFFs as 'AdobeRGB' when opening them
in Photoshop just because it looks more saturated...

I checked his website and did not agree that the pix were low in
saturation; I thought his saturation, exposure and quality looked fine
on the watermarked thumbnails:

www.imageclick.co.uk

He's going to send me a CD with a .CRF original file and his processed
version. Mind you, he told me he'd been comparing his DSLR work with
scanned 6 x 7 polarized Velvias. He's worried because other library
sites have highly saturated pix. Well, we are not all back in the 1980s
trying to shoot the colour equivalent of Grade 4 black and white, but
maybe some buyers are still after that.

Maybe another D1S owner can assist? I've suggested maybe he should get
PhaseOne's Capture One.

David

 
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Bart van der Wolf
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      04-02-2004

"David Kilpatrick" <(E-Mail Removed)> wrote in message
news:c4jrdn$m9b$(E-Mail Removed)...
> I had a one-hour conversation this morning with a photo library owner
> who shoots using a certain brand of leading digital SLR with a full
> frame sensor. Complaints: the images need sharpening to setting 2
> (despite advice not to sharpen at all for library use) or they look too
> soft to be marketable; the colour saturation is impossible to get high
> enough even when exporting on setting 4, Saturated sRGB.


Sound like he needs to adopt better colormanagement practices, possibly
including the creation of a profile for his (if he is the only person
shooting), and an improved sharpening technique. On the other hand he
(and/or his clients) might like oversaturated images (a bit like Velvia). I
also don't know what the purpose for the images is, I mean screen display or
print, both of which require different sharpening.

SNIP
> I've suggested maybe he should get PhaseOne's Capture One.


That might help some, but It still depends on operator skill.

I've been getting excellent sharpening results with some specific
mathematical deconvolutions and with some photoshop actions, but it does
take some knowledge to get the best results geared to specific equipment
features. I wouldn't mind trying some sharpening on a crop of his image to
see what's feasible and how that compares to his film scans that might well
be superior for their ultimate goal.

Bart

 
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andrew29@littlepinkcloud.invalid
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      04-05-2004
David Kilpatrick <(E-Mail Removed)> wrote:
> I had a one-hour conversation this morning with a photo library owner
> who shoots using a certain brand of leading digital SLR with a full
> frame sensor. Complaints: the images need sharpening to setting 2
> (despite advice not to sharpen at all for library use) or they look too
> soft to be marketable;


If you want something that behaves in a similar way to Velvia, you'll
sharpen a bit -- look at the MTF curve in
http://www.fujifilm.com\/JSP/fuji/ep...0FAF3-148E.pdf,
which rises to about 130% at 10lp/mm and then falls away. If you want
to do that on a digital camera, you sharpen.

> the colour saturation is impossible to get high
> enough even when exporting on setting 4, Saturated sRGB.


sRGB? For high saturation? Really?

> He has been given some odd conflicting advice and has been doing
> strange things like assigning his sRGB exported 160bit TIFFs as
> 'AdobeRGB' when opening them in Photoshop just because it looks more
> saturated...


I don't understand this. Surely if you want high saturation, you just
turn up the saturation knob. That's what digital is all about: you
don't have to use something like Velvia all the time.

> I checked his website and did not agree that the pix were low in
> saturation; I thought his saturation, exposure and quality looked fine
> on the watermarked thumbnails:


> www.imageclick.co.uk


> He's going to send me a CD with a .CRF original file and his
> processed version. Mind you, he told me he'd been comparing his DSLR
> work with scanned 6 x 7 polarized Velvias.


Ah. Well, that's hard. Velvia is nothing like accurate, whereas high
end digital SLRs are designed to be. Also, the D1s is very nice, but
the amount of data on a 6x7 trannie is great.

Andrew.
 
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David Kilpatrick
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      04-05-2004


http://www.velocityreviews.com/forums/(E-Mail Removed)lid wrote:

> David Kilpatrick <(E-Mail Removed)> wrote:
>
>>I had a one-hour conversation this morning with a photo library owner
>>who shoots using a certain brand of leading digital SLR with a full
>>frame sensor. Complaints: the images need sharpening to setting 2
>>(despite advice not to sharpen at all for library use) or they look too
>>soft to be marketable;

>
>
> If you want something that behaves in a similar way to Velvia, you'll
> sharpen a bit -- look at the MTF curve in
> http://www.fujifilm.com\/JSP/fuji/ep...0FAF3-148E.pdf,
> which rises to about 130% at 10lp/mm and then falls away. If you want
> to do that on a digital camera, you sharpen.
>
>
>>the colour saturation is impossible to get high
>>enough even when exporting on setting 4, Saturated sRGB.

>
>
> sRGB? For high saturation? Really?
>


Yes, all cameras which offer a 'Vivid' or 'Saturated' mode or a number
of colour modes - like Portrait or Landscape - tend to do this using
sRGB as the 'host' colour space for their adjusted rendering. What you
get is an sRGB file, but with modified colour. Generally an Adobe RGB
from the same camera includes the entire gamut of all the possible
adjusted sRGB variants - meaning that is is pointless to use these
settings, as all you are actually doing is throwing away colour!

Kodak's 'Looks' seem different, and the adjustment made from the raw
file seems to me to reflect a wider source space from the camera, as you
can save a 'Look' into an Adobe RGB file.

The Canon colour modes though are riding on sRGB (as are Minolta's
Standard and Vivid colour... etc)

David

 
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andrew29@littlepinkcloud.invalid
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      04-06-2004
David Kilpatrick <(E-Mail Removed)> wrote:


> (E-Mail Removed)lid wrote:


>>>the colour saturation is impossible to get high
>>>enough even when exporting on setting 4, Saturated sRGB.

>>
>>
>> sRGB? For high saturation? Really?
>>


> Yes, all cameras which offer a 'Vivid' or 'Saturated' mode or a
> number of colour modes - like Portrait or Landscape - tend to do
> this using sRGB as the 'host' colour space for their adjusted
> rendering. What you get is an sRGB file, but with modified colour.


I see: the file is tagged as sRGB, but that's not really what it is.
There's a risk that's going to cause gamut clipping with a highly
saturated subject, particularly something like a sunset.

> Kodak's 'Looks' seem different, and the adjustment made from the raw
> file seems to me to reflect a wider source space from the camera


You'd expect that, I suppose: I'm sure raw images have a larger gamut
than Adobe RGB.

Andrew.
 
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