[argyllcms] Re: Wrong gamma reading with Spyder 3.

  • From: Florian Höch <lists+argyllcms@xxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Tue, 09 Nov 2010 19:05:44 +0100

Am 08.11.2010 17:58, schrieb Darzur:
On Mon, 08 Nov 2010 07:41:00 +1100, Graeme Gill
<graeme@xxxxxxxxxxxxx>  wrote:

As explained in the link I posted before, Argyll reports an approximate
gamma that is the equivalent zero based (ie. no offset) power curve that
has the same value at 50% as the real curve. A visual scale based on
black and white stripes will (probably) be a power curve offset
at zero, because it is composed of a real black that is non-zero.
Naturally, these two different ways of interpreting gamma are
not the same.

Hello Graeme,

I still have no idea how to calibrate monitor properly. Please look
here:

http://img72.imageshack.us/img72/8079/outputx.jpg

I see you're using 'very low' calibration quality (-qv parameter). This means only little effort will go into actually matching your chosen target values. I'd at least use low or medium imho.

it's clearly visible that actual output from my monitor (at 50% input)
is a little bit darker than actual target. It should be corrected at
LUT level by slight brightening at 50% input what perfectly
corresponds to my visual observations. Unfortunately after calibration
I have curves like this:

http://img695.imageshack.us/img695/1075/curvesz.jpg

so my question is - why is it happen and how to avoid it?

Regards
--
Florian Höch


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