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

[Hans Berkhout]

I use and recommend ColorView bulbs (frosted, 29Watt, 3000 K) from the Solux company. I have three bulbs from ceiling aimed at to be evaluated print area. Bulbs are arranged as to achieve EV 7 when spotmeter aimed at white board placed in print location, which is on an acrylic sheet upright behind the holding tray. EV is a personal choice, it works well for me related to dry-down.

The wet print is placed on the acrylic, gently squeegeed to remove distracting shiny water drops, and then evaluated.

On the acrylic sheet I can place for comparison unexposed(white) and/or exposed(black)processed printing paper when assessing the dark and white print areas. Not an option I use very often, I see it a bit like only looking at laboratory test results instead of looking at the entire patient.

Aging eyes with cataracts see whites as somewhat yellowish, ask anybody who had cataract extraction followed by lens implants.

[Tin Can]

Hans, I am buying those bulbs asap

and yes after cataract implants i stopped cleaning my glasses constantly

yet Glaucoma is also here


I use and recommend ColorView bulbs (frosted, 29Watt, 3000 K) from the Solux company. I have three bulbs from ceiling aimed at to be evaluated print area. Bulbs are ar

Aging eyes with cataracts see whites as somewhat yellowish, ask anybody who had cataract extraction followed by lens implants.

[John Layton]

Hans, thanks for the reference! After going to the Solex site and looking over specifications...I've ordered four of these (29 watt, 3000K, frosted) bulbs, and look forward to trying them out!

[Hans Berkhout]

Thanks John, Tin Can.

I'd be interested to read your comments after using them.

In my case had to lower the EV value a bit. To do this, I just hung some polypropylene film in front of the bulbs. I thought a dimmer switch might just add another variable (for instance if the setting was inadvertently changed).

The polypropylene may change the spectral output of the emitted light somewhat, but in practice I did not run into problems in that respect.

[Drew Wiley]

I put a light neutral gray backdrop panel behind my sink where the toner tray typically goes. The overhead bulbs are angled toward it, to bounce the light onto the tray. I have decent halogens, but will improve those when I happen to order a larger number of well-balanced bulbs. Most LED's and CFL's are quite poor for hue evaluation - none are "black body". But there's no substitute for fully drying a print and evaluating it under ideal color matching lights with rested eyes. I wouldn't even try right now, after using a computer screen much of the day. My retouching station is equipped with 5000K 98CRI German color matching tubes, a set of 3200K tungsten spotlights is nearby, and white natural softbox daylight (due to coastal fog) is often available right outside the door.

[Tin Can]

Hans I ordered 10 for $25 delivered

https://www.amazon.com/gp/product/B00NPA9HJC/ref=ox_sc_act_title_3?smid=ASQD3613WIQY3&psc=1

may be a while

[Drew Wiley]

Solux are nice but awfully warm, color-temp wise. Ideally, one would match the print to the actual display lighting anticipated. But since that is generally out of our hands, if the print sells, I aim for a middle ground ground between tungsten and daylight, around 4000K. However, for critical color evaluation, like when calibrating a fresh batch of color paper to a specific colorhead setting, or when spotting any print, either color or b&w, I stick with the industry standard of 5000K.

There is a new category of LED light strips (not bulbs), for sake of overhead lighting, with violet filters over the blue elements, which allegedly achieves a very high CRI at 4000, and produces very little heat. But are very expensive and need a dedicated solid state power control. That would be voodoo anywhere in my lab building due to the almost certain risk of EMI (electrical magnetic interference) to my solid state enlarger feedback circuits. Even when the light itself is switched off the problem can persist in nearby electronic components. Same goes for electronic fluorescent ballasts, versus the ordinary kind. Never again.

Regular hardware and big box store "excellent color" bulbs : take the labeled CRI rating and divide by the BS marketing coefficient of 2 to get an approximate real figure. And as far as rated bulb life goes, divide by 20.