Olympus-OM
[Top] [All Lists]

[OM] Re: Velvia 50 returns

Subject: [OM] Re: Velvia 50 returns
From: Moose <olymoose@xxxxxxxxx>
Date: Wed, 15 Nov 2006 03:13:28 -0800
AG Schnozz wrote:
> <clip> You can't calibrate unless you have a reference
> to calibrate to.  I've used a gray-card and color patch chart
> for years.
>   
Any neutral color item will provide a reference for color in post. 
However =>
> One common mistake people make, though, is to try and get the
> film image to match the digital camera image.  It's highly
> unlikely that you'll succeed because the reponse curves of film
> are not nearly as linear as they are with a digital camera. 
>   
Working with a film scanner and current film, one may create color 
profiles for each film. The first, and simplest, advantage is that you 
don't need any reference in subsequent shots. The color response 
characteristics of the film are known and can be corrected for. One shot 
of the target in sunlight and you have all you need for all future shots.

As in the recent thread, this will result in shots under different 
light, like early and late light, to look as you expect, warm. If there 
is a need to correct different light to match midday light, just take a 
shot of the target in the subject light and make an alternate profile 
for that light.

The second advantage is that the problem to which AG refers should be 
VERY much less than when using a simple neutral reference. I say "should 
be" because that's what the experts say, but I haven't tried such a 
comparison. You can also profile the digital camera, if a match is 
desired.  The IT8 target used to create the profile has over 400 
different color patches, so the curves can be corrected much further 
than simple gray balance.

The disadvantage of profiles is that they correct for just those color 
inaccuracies that you may like about particular films. Shoot Velveeta, 
Ektachrome, Portra, etc., and the results will be close to identical. 
Again, I say "close", because I haven't tried controlled tests for 
myself, so I can't say if differences would be visible to me. I do have 
profiles for several films and find them to work well for me.

I can offer this test of profile vs. none that I've posted before. All 
comparisons are straight out of the scanner, with and without profile. 
The final frame is the IT8 target 
<http://www.moosemystic.net/Gallery/tech/Scan/VuesProf/>.

Moose

==============================================
List usage info:     http://www.zuikoholic.com
List nannies:        olympusadmin@xxxxxxxxxx
==============================================

<Prev in Thread] Current Thread [Next in Thread>
Sponsored by Tako
Impressum | Datenschutz