Re: Cheap 5000K lamps

["J. Arthur Davis" <jarthurdavis@earthlink.net>]

Here is some information on the proper viewing lamps for your work.

 The choice of a specific daylight source and custom fluorescent should
be made based on the standard governing your industry or application:

 Choosing the Right Daylight Source

      D75 North Sky Daylight at 7500K is used for visual evaluation of
opaque materials as outlined by ASTM D1729. 
      D65 Average North Sky Daylight at 6500K is used to provide visual
correlation with spectrophotometric readings or in conformance with
European or Japanese standards. 
      D50 Noon Sky Daylight at 5000K is used for the evaluation of color
quality and uniformity in conformance with ANSI and ISO specifications
governing the graphic arts. 

 Choosing the Right Custom Fluorescent

      TL84 at 4100K is a commercial narrow band fluorescent used in
Europe 
      Ultralume 30 (U30) at 3000K is a commercial narrow band
fluorescent used in the U.S. 

You can get additional information at http://www.greytagmacbeth.com

Have a happy holiday season.

Jim Davis
mailto:jarthurdavis@earthlink.net


"Gary L. Hunt" wrote:
> 
> At 10:23 PM 12/23/1999 -0600, SRJ wrote:
> >.....<SNIP>
> >Note the suffix SPX50.  This is a high-efficiency tri-color phosphor.  You
> >should be able to get tubes with this phosphor.  If you can't, a C50 (Chroma
> >50) suffix will also give you a 5000K light, but at lower output since the
> >phosphor is not that efficient.
> 
> This point raises a question--what's a reasonable light level for print
> viewing?
> I just remembered I had an illumination meter, so I checked the level at my
> computer-area-now-converted-to-5000K-lamps.  I'm reading about 600 lux
> down at the keyboard level where I usually hold prints for viewing.  It isn't
> quite as bright as my darkroom (which runs about 850 lux at countertop
> level), but it seems pretty bright.  Are there standards for this for graphic
> arts or some related area?
> 
> Gary Hunt <glh@srv.net>
> 
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