Ra4 safelight

mshchem · Apr 10, 2024

Read the Fuji datasheet.

When I use my Thomas sodium 589nm safelight I have the color filters in place, it's 10 to 12 feet away bouncing off a somewhat dull ceiling. Paper is not exposed even indirectly to the light except for 30 seconds to a minute.

It's a fact that the paper is vary sensitive to 589nm. Filters will not change this wavelength only attenuate it.

pentaxuser · Apr 10, 2024

mshchem said:
Read the Fuji datasheet.

When I use my Thomas sodium 589nm safelight I have the color filters in place, it's 10 to 12 feet away bouncing off a somewhat dull ceiling. Paper is not exposed even indirectly to the light except for 30 seconds to a minute.

It's a fact that the paper is vary sensitive to 589nm. Filters will not change this wavelength only attenuate it.

I take it that you meant to say "when I used my Thomas 589nm safelight" as I assume you have abandoned it and that what you describe above was the setting that used to give you safelight for 30 sec to 1 minute?

Have I got this correct? If I have can I ask: Have you tried the new digital RA4 paper under the safe Thomas light and at the same settings as you describe above If so what was the result?

Thanks

pentaxuser

mshchem · Apr 10, 2024

pentaxuser said:
I take it that you meant to say "when I used my Thomas 589nm safelight" as I assume you have abandoned it and that what you describe above was the setting that used to give you safelight for 30 sec to 1 minute?

Have I got this correct? If I have can I ask: Have you tried the new digital RA4 paper under the safe Thomas light and at the same settings as you describe above If so what was the result?

Thanks

pentaxuser

Thomas Color Safelight Filter Set (FCD)

Thomas Color Safelight Filter Set (FCD) - Thomas Color Safelight Filter Set (FCD) are remove-able vane filters for use with the Thomas Duplex Super Safelight, when processing RA-4 Color paper. Proper placement of move-able vanes and filters (in body and vanes) is…

www.freestylephoto.com

These are the "color" outer vane filters for the Thomas low pressure sodium vapor safelights. You used these on the adjustable vanes, Fully closed. Requires inner filters as well. Even fully closed these things put out an enormous amount of light. 589nm is easy for humans, black and white paper not so much. Color paper is sensitive to the entire visible spectrum (uv too). The cyan emulsion of color paper is very sensitive to 589nm.

I have some toy IR goggles (Spynet Jakks Pacific) IR goggles that I use for loading film reels and film holders. These are amazing ZERO effect which blows my mind. I don't use these for printing as too clumsy, zero depth perception (monocular IR camera).

xtol121 · Apr 11, 2024

No such thing as a "safe" light for RA-4, at least in 2024 readily available materials in my experience. I have the Heiland Color LED Safelight and unfortunately it is not actually color safe, but it is passable if your vision is strong. I wish I saved the tests, but in my darkroom the light is only "safe" at the lowest setting and when more than 6 feet away from the paper for any period shorter than 2 minutes. Basically putting a coin on a sheet of paper and exposing it to the "safe" light for longer than 2 minutes will show visible fog. That's not to say that the paper isn't compromised at shorter times. Similar to pre-flashing this safelight will build exposure prior to visible density. With Fuji CAii paper it will show as a magenta fog.

I used my color safelight to cut down RA-4 paper rolls with a guillotine style cutter. I'll put the roll on a holder and pull paper through the cutter making 8x10 sheets for 30 minutes at a time. Each sheet is only exposed for the time it takes me to rotate the roll, pull out the paper, cut it, and put it in a paper safe, maybe 30-60 seconds. All of the paper processes fine, but I'm sure it would exhibit color shift if it was held up to any sort of exacting standard. Every sheet exhibits a tiny bright magenta strip at the edge of the paper from the prolonged exposure even with the light turned all the way down. The strip appears at the edge because although each sheet doesn't receive exposure longer than 30-60 seconds while cutting, the end of the paper roll is being exposed the entire time.

The safelight is nice if you are processing in trays, but I have to stress that you could easily practice and achieve the same tasks in pitch black. The light dimmed to a "safe" level gives about the same amount of light as a light leak around the edge of a door. It's minuscule and your eyes take more than 1 minute to adjust to that level of light in my experience. If the room lights are on while I'm prepping for an exposure, and I turn the lights off to make an exposure my eyes aren't adjusted until I'm pulling the paper from the developer tray.

Thankfully I've upgraded to an RCP20 for processing, and a finger "safe" guillotine cutter that I'm comfortable operating carefully in the dark. I'm not upset about the purchase even though it's practically useless as a color safelight. It's still a great narrow spectrum safelight for black and white printing.

koraks · Apr 11, 2024

xtol121 said:
With Fuji CAii paper it will show as a magenta fog.

Ah, that's interesting; so they use LEDs with a fairly short wavelength - more greenish yellow than orange. It's also a somewhat unfortunate choice on Heiland's behalf since the magenta-forming layer is so much more sensitive than the cyan-forming layer, so you can get away with a little more exposure on the latter.

xtol121 · Apr 11, 2024

koraks said:
Ah, that's interesting; so they use LEDs with a fairly short wavelength - more greenish yellow than orange. It's also a somewhat unfortunate choice on Heiland's behalf since the magenta-forming layer is so much more sensitive than the cyan-forming layer, so you can get away with a little more exposure on the latter.

Correct! Visually the light is a dim muddy yellow color. I will try to take a photo of it this weekend. If you have any quick tests that might be informative to this thread I would be open to dedicating a few minutes before getting to work.

koraks · Apr 11, 2024

xtol121 said:
Correct! Visually the light is a dim muddy yellow color. I will try to take a photo of it this weekend.

Oh great, very interesting! I tried photographic my safelights, but the color doesn't render the way it really is. I think it has to do with digital camera sensors struggling with narrow-bandwidth light at this wavelength; it probably intersects the sensitivity curves of the red and green photosites on the sensor, resulting in weird color rendition. I found I had to dial the color temperature on the RAW file back to 3000K or so in order to make the orange safelight look close to what it does in real life.

xtol121 said:
If you have any quick tests that might be informative to this thread I would be open to dedicating a few minutes before getting to work.

Well, I'd be curious to see the same set of tests I did on my safelights:
1: A step wedge that shows at what point the paper starts to produce color. Just like a test strip where you use a piece of cardstock etc. to uncover the paper strip-wise at set time intervals. I used 10 second intervals.
2: Using the longest time that does not yet produce colored fog on paper white, expose one half of a strip or small sheet to your safelight while masking the other half. Then expose a photo onto that same sheet. This should show the effect of the cumulative exposure of the safelight + the actual image exposure.
3: Same as (2), but with a much shorter safelight fogging exposure; e.g. 2 or 3 stops less than the time used in #2.

So for instance, test #1 might show the longest time before fog shows up as 90 seconds. Then use 90 seconds for test #2, and use something like 15 seconds for test #3.

My expectation is that you'll get the exact same results (although with a different color; magenta instead of cyan) I did when I did these same tests a few days ago.

pentaxuser · Apr 11, 2024

xtol121 said:
No such thing as a "safe" light for RA-4, at least in 2024 readily available materials in my experience. I have the Heiland Color LED Safelight and unfortunately it is not actually color safe, but it is passable if your vision is strong. I wish I saved the tests, but in my darkroom the light is only "safe" at the lowest setting and when more than 6 feet away from the paper for any period shorter than 2 minutes. Basically putting a coin on a sheet of paper and exposing it to the "safe" light for longer than 2 minutes will show visible fog. That's not to say that the paper isn't compromised at shorter times. Similar to pre-flashing this safelight will build exposure prior to visible density. With Fuji CAii paper it will show as a magenta fog.

I used my color safelight to cut down RA-4 paper rolls with a guillotine style cutter. I'll put the roll on a holder and pull paper through the cutter making 8x10 sheets for 30 minutes at a time. Each sheet is only exposed for the time it takes me to rotate the roll, pull out the paper, cut it, and put it in a paper safe, maybe 30-60 seconds. All of the paper processes fine, but I'm sure it would exhibit color shift if it was held up to any sort of exacting standard. Every sheet exhibits a tiny bright magenta strip at the edge of the paper from the prolonged exposure even with the light turned all the way down. The strip appears at the edge because although each sheet doesn't receive exposure longer than 30-60 seconds while cutting, the end of the paper roll is being exposed the entire time.

The safelight is nice if you are processing in trays, but I have to stress that you could easily practice and achieve the same tasks in pitch black. The light dimmed to a "safe" level gives about the same amount of light as a light leak around the edge of a door. It's minuscule and your eyes take more than 1 minute to adjust to that level of light in my experience. If the room lights are on while I'm prepping for an exposure, and I turn the lights off to make an exposure my eyes aren't adjusted until I'm pulling the paper from the developer tray.

Thankfully I've upgraded to an RCP20 for processing, and a finger "safe" guillotine cutter that I'm comfortable operating carefully in the dark. I'm not upset about the purchase even though it's practically useless as a color safelight. It's still a great narrow spectrum safelight for black and white printing.

My sympathies It sounds as if you paid good money for a safelight that barely works Out of curiosity does Heiland gives any details on what illumination setting it recommends for a variety of distances and what are the safe times for those distances?

If you are using trays when it is nice to have a safelight are you able to take the paper from its box. place in easel, expose, move from the easel to the trays while seeing well enough to do so and see the outline of the trays well enough to move the paper from tray to tray without fear of mishap

Thanks

pentaxuser

BMbikerider · Dec 25, 2024

I have been away from the forum for several months having a hip replacement that didn't go as well as it should but I went back to RA4 printing when I got home a few weeks ago. I have a Duka as I said before and it is placed on the blacked out windowsill which is about 7 feet behind where I work, but the light is directed upwards to reflect off the ceiling which means the light is really diffused over a greater distance. I have not measured the reflected distance but that has to be around 12 - feet or so.

The luminance is not terrific, when the adjustment is set at 9, but enough for me to work in and once my eyes get accustomed to the reduced level it is better than can be expected.

pentaxuser · Dec 25, 2024

I note that in its details on the use of Adox Colour Missíon paper(Fuji CAii?) it suggests that any safelight may result in a cyan cast but it refrains from the use of words such as "will" or "does so does this indicate an acceptance of what it has been told by Fuji rather than its own tests

I presume that Fuji carried out tests but íf so, I have never seen the source/ evidence

Another question: Is the whole range of Fuji paper affected exactly the same way and if Kodak paper is still being produced is it equally susceptible?

Thanks

pentaxuser

mshchem · Dec 25, 2024

The only safe way to be able to see color materials developing is with infrared goggles strapped to your head.

Color materials are sensitive to all of the wavelengths of visible light

If the exposure time is very short (10-30 seconds) you may be able to get away with it.

mshchem · Dec 25, 2024

MattKing · Dec 25, 2024

That last image makes me think of Terry Gilliam's "Brazil".
Do you see yourself as the Robert De Niro character, by chance?

koraks · Dec 25, 2024

pentaxuser said:
Is the whole range of Fuji paper affected exactly the same way and if Kodak paper is still being produced is it equally susceptible?

All Fuji paper is sensitive to all visible light and Kodak paper hasn't been manufactured for a year and a half at least. The same was true for that, but some of the more recent Kodak papers were a little slower than Fuji, making them a little more resistant to fogging.

pentaxuser said:
I presume that Fuji carried out tests but íf so, I have never seen the source/ evidence

Of course they know, but darkroom printing is not an application they tailor their information provision towards. It's straightforward to do your own testing, so there's no reason to second guess. As demonstrated in this thread, it's imperative to understand that fogging is cumulative.

Michael Firstlight · Dec 26, 2024

Interesting review: https://tinker.koraks.nl/photography/unsafe-lights-the-iffy-business-of-ra4-safelights/

Donald Qualls · Dec 26, 2024

koraks said:
All Fuji paper is sensitive to all visible light and Kodak paper hasn't been manufactured for a year and a half at least. The same was true for that, but some of the more recent Kodak papers were a little slower than Fuji, making them a little more resistant to fogging.

The main thrust of RA-4 safelight is that there is a wavelength (590 nm, IIRC) in which both Fuji and Kodak are least sensitive and a dim enough light with that precise wavelength and no other can give enough working time to get a print into the easel, then from the easel into a developing tray or drum, without perceptible fogging. This is in the same realm as the safelight flashlights used by workers who need to go into the coating and cutting/rolling rooms where film is being manufactured; they use an extremely dim flashlight (in this case, a color to match the peak of human eye sensitivity, which is a little greener than the RA-4 safelight) and it lets them move confidently without bumping into (potentially running) machinery without giving enough exposure to produce measurable fogging with short exposure.

Unlike a red (or even amber) safelight used with B&W enlarging papers, the "safe time" for RA-4 is fairly short even with a light that's perfectly on wavelength and quite dim, but such a light is a big improvement over trying to cut (from a roll), align, and load paper in total darkness, especially in a prolonged printing session.

koraks · Dec 26, 2024

Michael Firstlight said:
Interesting review: https://tinker.koraks.nl/photography/unsafe-lights-the-iffy-business-of-ra4-safelights/

Thanks; I wrote that partly in response to some of the earlier discussion in this thread. Essentially the same empirical evidence I presented here as well.

Donald Qualls said:
Unlike a red (or even amber) safelight used with B&W enlarging papers, the "safe time" for RA-4 is fairly short even with a light that's perfectly on wavelength and quite dim, but such a light is a big improvement over trying to cut (from a roll), align, and load paper in total darkness, especially in a prolonged printing session.

I've tried to use a very, very weak safelight in the proper wavelength for cutting sheets from a roll. The long & short of it was that it didn't work; either the light was far too dim to be of any help, or it fogged the paper. There was no workable compromise. YMMV.

pentaxuser · Dec 26, 2024

Donald can I ask if your 91 is based on your experience of those safe lights such as the DUKA operating that wavelength? it is always good to get actual experience as this forms a range of experience from which each potential user of such lights can try and form his or her own conclusion

Thanks

pentaxuser

Donald Qualls · Dec 27, 2024

I tried to get a working Low Pressure Sodium lamp (Duka or Thomas) when I was setting up my darkroom, but couldn't find one with a reasonably assured source of replacement bulbs -- apparently LPS bulbs in any format are low enough in demand that, like flashbulbs in the 1990s, they've gone out of production -- and unlike flashbulbs, there aren't tens of thousands of them in New Old Stock. The only lamp I have that could be usable as an RA-4 safelight is a "turtle light" LED 590 nm that itself is way too bright -- I'd have to add a lot of neutral density to even risk opening a pack of RA-4 paper.

Beyond that, I've never printed color by any method -- I've only had the theoretical capability since setting up my current darkroom and I haven't made a single print in there (working full time with an hour commute each way will reliably eat all your spare time). Based on the above discussion and link, it's very likely that everything I thought I knew about RA-4 safelight was based on the old, slower papers from the analog printing era, which (I've been told by people who printed RA-4 in the '90s) allowed a fairly bright darkroom with a Thomas Duplex.

Our market isn't large enough to have any chance of getting paper made that includes a 590 nm notch filter in the overcoat, that will wash out in processing...

koraks · Dec 27, 2024

Donald Qualls said:
590 nm notch filter in the overcoat, that will wash out in processing

Which isn't how it was done anyways.

Donald Qualls · Dec 27, 2024

koraks said:
Which isn't how it was done anyways.

I know it wasn't -- but it's what we'd need to have to use modern faster paper with a safelight bright enough to bother.

koraks · Dec 27, 2024

Well, it would be one way, if it would be technically feasible, which I doubt.
For those who need/want to see when handling the still sensitive paper, IR goggles are a very affordable and effective option.

Donald Qualls · Dec 27, 2024

koraks said:
IR goggles are a very affordable and effective option.

Unfortunately, I expect difficulty with light sealing the goggles against the face for those who wear glasses. And the affordable ones are monocular, which means no depth perception while working.

koraks · Dec 27, 2024

Working in the dark means no depth perception either. It has always worked for me, so I can't imagine that the monocular view through a basic IR viewfinder would be much worse.

pentaxuser · Dec 27, 2024

Thanks Donald for your answer

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