Viewing light brightness

[Michael E]

Hello everyone,

I just finished my new darkroom and have a question about your experience with the viewing light: You know, the light fixture over your fixer tray that lets you judge your test strip or final print without surprises later. I went all over board and got a dimmable 5600K LED strip, but now I have to set it at the best level. There must be a golden and measurable standard, right? All I found was "The New Darkroom Handbook" quoting Kodak at 50 footcandle for color work, and they recommend 80 - 100 footcandle to match gallery light. ISO 3664:2009 specifies 2000 Lux for the viewing of prints, which seems a lot to me. How did you figure out what worked best for you? I know the brightness depends on the conditions of the final presentation of the print, so what did you choose as your comparison?

Curious,

Michael

[Drew Wiley]

You need to view your work in more than one option with respect to both color temperature and brightness. That 5600K light will probably not actually be 5600 K anyway. You'd need to check it with a color temp meter. Some have adjustable color temp. I use 4000K as a nice midway point between daylight and residential tungsten light, as well as having on hand critical 5000K lights, and then a selection of other lights in another room. Then I'll take a print or test strip outdoors and check it there. At one time I also had a test gallery wall in my studio. Use common sense. Galleries are not standardized, and residences certainly aren't either. You need to view test strips dry anyway. When in doubt, I put them in a little toaster oven for about 20 sec. Then toning becomes a factor. With experience, it all gets easier.

[LabRat]

I backed off the brightness, as my eyes were dark adapted, and the 250w flood was too much...

I had a footswitch on it but had to be careful where it was as I could possibly trip or press it at the wrong time during the process, so I found a place behind a sink table leg for it...

I found just bright enough where I got a good white light was fine, and mostly used to check for possible stains on whites...

I never trust a wet print for image or density, as this changes so much when truly dry...

Steve K

[Maris Rusis]

I use a tungsten filament inspection light, 20W Pearl, ceiling mounted that gives me 40 lux at the fixer tray. This is too dim to judge fine detail but the tones seen this way are near to what the wet print will dry-down to eventually. If the inspection light is too bright the wet print in the fixer tray will look beautiful but the final dry down result will be too dark. Final inspection of dry prints is done at 400 lux. I never change these light levels. It seems to help the eye retain its calibration.

As for gallery lighting, it's all over the place. I've measured a yellow tungsten 50 lux in the state gallery and 650 lux daylight fluorescent in a commercial gallery. There's no way to allow for all that unless you know in advance.

[Bob Salomon]

I use a tungsten filament inspection light, 20W Pearl, ceiling mounted that gives me 40 lux at the fixer tray. This is too dim to judge fine detail but the tones seen this way are near to what the wet print will dry-down to eventually. If the inspection light is too bright the wet print in the fixer tray will look beautiful but the final dry down result will be too dark. Final inspection of dry prints is done at 400 lux. I never change these light levels. It seems to help the eye retain its calibration.

As for gallery lighting, it's all over the place. I've measured a yellow tungsten 50 lux in the state gallery and 650 lux daylight fluorescent in a commercial gallery. There's no way to allow for all that unless you know in advance.

That gallery exhibiting color prints with fluorescents?

[Michael E]

I never trust a wet print for image or density, as this changes so much when truly dry...

I don't dry every test strip right away. Or print for that matter. Fix them, wash them, dry them over night. Of course they change a bit, but I've been doing this long enough to take that into consideration. While my darkroom was a construction site, I did a few 8x10" contacts in my bathroom, and they all turned out dark and dull because of the bathroom light. So I want to put in some effort and set up a good viewing light in the new darkroom. I often print at nighttime, so I can't just go outside to check.

[Drew Wiley]

Bob - I once pulled a bunch of my color prints out of one of the most expensive galleries in SF. They had the damn projector halogens so hot that they were starting to melt the acrylic pigments on adjacent paintings by a major abstract expressionist. I've seen it all.
Never assume someone knows what they are doing.

[Jim Noel]

SOmewhere in the many books I have there is a recommendation as to the best amount of light for this purpose. I use a 50 watt bulb at between 3 and 4 feet. Brighter bulbs result in prints being too dark when viewed in normal room light.

[Ken Lee]

I've had the same experience: there's no standard enforced and few people are well-informed about lighting intensity and color.

I've visited and shown my work in galleries where the actual lighting hardware varied within the same room and mixed with window lighting.

Once the work goes to someone's home or office or business, all bets are off about how they light it... if they do at all.

[Vaughn]

My only suggestion is that when one turns on the viewing light, give yourself a few seconds for one's eyes to adjust to it before looking at one's print. I find that my first impression of the print/image when seen with dilated eyes and lots of light tends to bias me towards a darker print.