Light levels for examining prints.

[Shen45]

Do you print your Black and White images in your darkroom for a particular light level?

Based on advice from Ansel Adams he seemed to suggest examining dried tests under a light source of 100 foot candles which is approximately 8 - 8.5 EV. Others suggest as low as 5.5 EV.

Is there a standard illumination level for galleries or is that just wishful thinking?

Any personal experience would be valued.

[Drew Wiley]

There is no single standard. I personally use a bank of light sources of different
intensities and color temperatures, which I can switch on or off. If I know how a print is going to be ultimately displayed, I can print for that source. However, display light can itself change, or we often print in advance without any idea of the
ultimate use for the print, if any. Therefore, my initial "standard" is a pair of 4200K
approx CRI 95K fluorescent about four feet above the viewing surface. 4200K is about midway between open sky daylight and typical indoor tungsten, and represents a good general-purpose compromise. Adjacent to this are other optional light sources. Then I have still other kinds of lights available on a mock gallery wall. But remember, some kind of light like halogens and sunlight contain UV which makes optical brighteners fluoresce in silver gelatin prints. Visit a serious lighting
store which has a bank of viewing booths containing different specific light sources,
and you'll get the idea. For the most critical work, I have a smaller lamp containing
expensive CRI98 5000K color-matching bulbs. I also keep on hand a Minolta color
temp meter and a footcandle luminance meter for measuring light on display walls.

[Drew Wiley]

I just went to the dkrm to measure my viewing area. My overall viewing and retouching surface receives around 160 fc, but for inspecting shadow values and micro detail I boost this to 300 fc. But my test display wall is set at 120 fc to limit fading. And nowadays in museums the lighting is often set very low if the prints are considered very valuable and at risk of fading - often a big issue if the prints are borrowed from private collections, even though the public often complain about how hard it is to enjoy the prints in a dim room - often I'd guess around 60fc. So 100 fc isn't so bad.