Wet Print Evaluation Issues - Age Related? Help!

[John Layton]

A bit alarming and I’d like to share…that recently it feels like I’m having a bit of trouble in assessing various parameters (density, contrast, etc.) of test strips and wet prints.

Might this be age related? Or something else?

About two years ago, I installed a lighting track above my sink…allowing me to place two of my gallery spotlights (7 watt, 50ish watt equivalent, 3500K dimmable LED’s) in position and then aim them precisely to create even light over the holding tray - which I could further adjust, brightness-wise…to both match the needs dictated by the print(s) “endpoints” (my gallery, someone else’s gallery, art fair, etc.), as well as to account for dry down. A great system which worked well for awhile…until recently it seems.

Now, despite getting a given print right to where I think it needs to be, cognizant of the above mentioned variables…it seems like a crapshoot as to whether this print will actually hold to this - with the exposure and contrast values having wandered from my initial impressions. Very frustrating!

I do have a question about lighting. Previous to my having installed the above mentioned LED lighting system, I’d used a single incandescent bulb (40watt), set about thirty inches above the print holding tray. Should I go back to this? Is there something relating to the spectral output of an incandescent (or maybe halogen) bulb which might help me to get my wet print evaluating capabilities back into the right ballpark? Any other ideas? Thanks!

[ic-racer]

I still have quartz halogen lamps above my inspection tray and bleaching area.

[Vaughn]

Your LEDs are probably getting old and losing strength...as are your eyes.

You might try having a decent wet print handy for comparison.

[Bernice Loui]

"white" LEDs typically do not have broad spectrum since the "white" light they produce comes from Red-Green-Blue narrower spectrum LEDs combined with phosphors to produce what is perceived as white light. This can produce mis-leading color and tonal judgement for prints.

Best choice remains 3200K quartz halogen spot light directly above the fix-wash tray. Tungsten light source is broad spectrum and does better at color and tonal rendition.

If the light source's output is varied, the color temperature will change adding more difficult to this problem. Use the quartz halogen tungsten lighting source at it's rated voltage/power. Keep it stable if possible just like the light source in the projection enlarger.

Know the mind-brain will "fill-in" the missing colors to achieve what is perceived as white light with shifts in color items. This is why tightly controlled and stable light sources are a MUST for color and print assignment.

What remains is evaluation of the wet print and how much dry-down alters the print.


Bernice

[Doremus Scudder]

If I were you, I'd go back to using incandescent lighting to evaluate prints.

When printing, I usually view my prints hung up on a magnetic white board with clips under a mix of 3200K and daylight tungsten floods that I've placed to give me what I consider ideal gallery lighting. After zeroing in on the best exposure, I then usually let the prints dry down completely, before deciding on the very final exposure. Dry down can change a print so much that I never make a final print anymore without having evaluated it dry. Even so, I have to leave some room for toning, since toning changes things a bit as well.

For toning, I have the same mix of light over the toning tray and I always have a wet, untoned, print close by for comparison.

Best,

Doremus

[Tin Can]

I thought all pros were using gallery or museum lamps for control

a second ? is, are LED bad for old eyes

[Vaughn]

Just one other possibility...do our eyes adjust to changes in light intensity differently as we age?

[neil poulsen]

I have a print evaluation station outside my darkroom, and I've adjusted the lighting so that wet prints look the same under this light as the same dry print appears under regular lighting. So, I have a way of gauging the degree of enlarger exposure, manipulations, etc.

But, I also have a 16x20 print dryer nearby. The above lighting gets me close. The print dryer enables me to dry the print relatively quickly and check it for real under regular lighting.

In a video, Ansel Adams checked a print by drying half of it (ripped it in two) it in a microwave. I tried this, and to my eye, it affected print color.

[John Layton]

Many thanks for all of the well informed, insightful responses. As I’d mentioned, I had already arrived at what was, for awhile at least, a very effective print evaluation setup…allowing for dry down compensation and adjustable to meet existing ambient conditions (to the extent that I could evaluate these) at a given print’s intended destination.

Furthermore, I was able to accomplish the above with LED lighting - which itself offers, for me at least, some important and practical advantages (over either tungsten or halogen based systems), which were compelling enough for me to overlook what I also know are some of LED’s pitfalls, mostly relating to their relatively narrow spectral output, which indicate possible compromises in the realm of wet-print evaluation. But I soldiered ahead…and my system worked, until recently it seems.

So it is with this, and with all of your great responses, many of which suggest that I consider moving away from using LED’s for print evaluation - I will now do one or two things…first, I will evaluate any other possible variables, such as might exist chemically and/or with possible voltage fluctuations. If nothing untoward is found there, I will then look for one or two halogen bulbs, at or close to 3200K. My assumption (more like hope) is that a halogen light source will offer a more “holistic” print evaluation experience, which might thus be a bit more forgiving of my aging eyes. At any rate…I would like bulbs of very high quality, and as I have not had much experience with halogen (at least for print evaluation), I am open to suggestions!

[Doremus Scudder]

John,

I'd think that just about any halogen bulb from a major manufacturer would be more than adequate for the job. If you really want exactly 3200K or some other specific color temperature, then you'd have to get bulbs advertised as such or drag out the trusty color-temperature meter and check. I think most of them are quite close to that, however. I don't know what else you mean by "bulbs of very high quality." As far as output, the color temperature determines the spectral distribution; a black-body spectrum is a black-body spectrum... Any incandescent bulb has a continuous spectrum, which may be what your are missing.

Best,

Doremus