Re: [Gimp-user] [Gimp-developer] Test images and test suite (was Re: GIMP should fork babl and GEGL)

[Elle Stone <ellestone ninedegreesbelow com>]

On 11/13/2014 10:02 AM, Simon Budig wrote:
> I do have access to a x-rite color checker which should be in a
> reasonably good condition (it is slightly older but has been stored in
> the dark).
>
> I could try to set up a colorful scene and shoot it in RAW with my
> Nikon D40. Would this be of any help?

Yes. A colorchecker is very often found in composite test images. Given 
the number of websites that post pictures of colorchecker charts, 
hopefully there are no copyright restrictions on photographs of same.

> (I am right now unsure about the correct lighting, there *should* be
> some daylight neon tubes around, but I am at the moment unsure where
> they are...)

You raise a good point. On the one hand, natural daylight on a sunny day 
(D65ish) and direct morning and late afternoon/early evening sunlight 
(D50ish) are wonderful full spectrum light sources that really bring out 
colors. On the other hand, studio lighting is either iffy or expensive 
and probably sometimes both (my own studio lighting is on the "cheap and 
iffy" side).

Where I am sunlight is in short supply until spring, so it's studio 
lighting or nothing. For flourescent and LED lighting, the fact that the 
label says "daylight" is not very informative by itself. The other half 
of the story is the CRI, "color rendering index" 
(http://en.wikipedia.org/wiki/Color_rendering_index). Anything 92 and 
above is probably good enough.

Elle