The ligh levels you are looking at are reasonable,
especially if the design room colors are light gray.
As I mentioned in a previous post, you can always increase
the ilumination near the inspection tables. The effect
would be similar to what is done in road tunnel lighting,
to adapt the light level as you get closer to the work
place.
If you are going to ask about the individual CRI, also ask
them about their grade for daylight simulator according to
CIE 51 (or CIE Standard 12, a newer version):
CIE 51.2-1999 : A Method for Assessing the Quality of
Daylight Simulators for Colorimetry
CIE S 012 /E:2004, Standard Method of Assessing the
Spectral Quality of Daylight Simulators for Visual
Appraisal and Measurement of Colour
This is the method which gives a grade based on the
metameric indices I mentioned before. I suspect they will
just say "no" to this one, but you never know.
Danny Pascale
dpascale AT babelcolor DOT com
www.BabelColor.com
On Fri, 15 Jul 2005 14:19:12 -0400
Charlie Rieger <email@hidden> wrote:
Rodger,
I agree, that peaks look nasty, but I think that is a
graph of standard
4000k metal halide bulbs - the graph at http://www.venturelighting.com/NaturalWhite/NaturalWhite_TechCenter.html
looks much better. Although it still has some spikes, it
at least mimics
daylight fairly well (though I could be reading these
wrong)
As per Danny Pascale's suggestion, I am contacting
Venture to see if I can
get information on the 8 special indicies that make up
the CRI rating.
As far as lighting levels go, the ISO 3664 spec of 2000
for inspection and
64 for computer design both seen a bit extreme. I can
only imaging the
amount of time it would take for my eyes to adjust going
from one to the
other - I was thinking something more like 80 for the
computer design, and
1200-1400 for the inspection area. These seem to me to
be better practical
levels. Any thoughts?
Charlie
On 7/15/05 1:57 PM, "Roger Breton" <email@hidden>
wrote:
Charlie,
I'd be weary of all those peaks as they will surely
cause metameric
nightmares. Just look at the SPD here:
FWIW, I advised the unversity where I teach to put in
regular Phillips
ColorTone fluorescent tubes instead of the ulgly warm
white they used. This
is for a graphic design 25 G5s student lab. I
recommended they instead got
Solux desktop tasklamps for each stations but, believe
it or not, that fell
under another budget. At least they were able to change
the lamps and they
made all the difference.
Regards,
