[argyllcms] Re: [Possible bug in Spyd2.c] Inconsistant readings from Spyder3

  • From: howdy555@xxxxxxxxx
  • To: Lars Tore Gustavsen <argyllcms@xxxxxxxxxxxxx>
  • Date: Fri, 6 Mar 2009 14:57:25 +0100

Dear Lars!
> I think I remember that you writed earlier that your colormeter gave
> you strange results, and I suspect that was with manufactures
> software.
Yup. Original DataColor software gives decreasing results of about 0.5 within 3
minutes of constant hitting the "measure" button while measuring pure
white, so for example if the first measurement shows
After about 50 measurements you would get
First there is a slight increase then the results start dropping...

With Argyll it is more or less the same. Before you start thinking
that this is irrelevant, note that for profiling most of us use no
less than 1000 patches; I tried using 5000...

Could any Spyder3 owner confirm this?
1) Run MSPaint or any other non-colormanaged program (I do not think
it is relevant at all), position it in the senter of the screen
and fill the canvas with the purest white (RGB of 255,255,255).

Run the unmodified spotread (the one you compiled from the source
given by Graeme:
spotread -yl
Then hit space as often as the software allows and see the trend in
your measurements - mine first go up a bit but then they start sinking
lower and lower...

Note: my previously posted change in Spyd2.c does NOT even TRY to
solve this problem (if it is a problem, that is).

> So maybe you should compare it to another device if you have
> the possibility? These results don’t look very good.

Gosh, I wish I could do that... Unfortunately I do not have access to
any better equipment and buying it is out of question for now due to
financial constrains :(.

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