LED Safelight Findings

[Gallery 44 Toronto]

Hello, we got some help from members on the forums here when we did a safelight overhaul in our darkrooms, it definitely made a huge difference and now over a year later the light appear to still be working properly without having to change the Rubylith. Below is a report of our findings just in case it would be of use to anyone thinking about switching to LED.

If you have any questions, let me know.

Darren

Darkroom LED Safelight Report


This is a report by Darren Rigo, Head of Membership and Facilties covering installation of LED safelights in both Gallery 44 darkrooms in 2015 as a part of a grant to improve Health and Safety.


All paper tests were done with a basic coin test in direct light at a distance of 60”. Tests for impoved luminosity were measured with a low-light, light meter.


Notes on this report provided by Marco Buonocore are included in italics.



Initial Safelighting Setup


Mix of self constructed fluorescent suspended up lights, Duplex, Ilford and Kodak.



Problems


- Looked very janky

- Multiple colours of light, some not safe for some papers, Ilford tested fine to 6 minutes.

- Ruby on uplights would wear thin in ~6 months

- Light was very ambient, not enough light on walkways where if was needed for new darkroom students safety.


Marco’s Notes

- looking janky isn't relevant, darkrooms are supposed to be ugly.

- Ilford paper was safe for close to 7 minutes with fresh rubylith, but considerably less as the filter faded from the heat of the light source. The teaching darkroom tested at less than 3 minutes before the change. Other papers, Foma, Fotokemika, Slavich, were not safe from fogging in the old environment.

- It's called Rubylith

- It's called a Thomas Duplex light.

- Stress how with all of the old style safelights, filters needed to be changed regularly, and they were expensive and increasingly hard to find. Also, the main safelights had to be consistently re-taped with gaffer tape to keep which light from getting out of the cracks. The gaffer tape, like the filter, got brittle from the heat of the lamps over time.

- also stress how the old system was white light being filtered, and that photographic paper is sensitive white light. The new lights are emitting only red spectrum light, which is much much safer.



Test 1


LED Globe Bulbs

https://www.superbrightleds.com/mor...lobe-bulb-360-degree/440/#/tab/Specifications


This bulb looked great since we have existing unused light sockets. Also the possibility of wiring them into the enlarger timers to flick off during exposure. However, during testing they were found to not be particularly safe, as you can see in the graph there was a small amount of light emitted down to around 550nm, placed in a standard clamp light with reflector this was enough to fog Ilford paper after 3 minutes. Also, the bulbs were pretty bright and not dimmable. We returned most of what we ordered and keep a few for use in the Kodak safelights with a filter, and some other clamp on lights which we taped a ruby filter over. Apparently most LEDS have impurities in their manufacturing that cause them to not emit a more pure range of light.


Also looked at these but they are way too expensive for our budget:

http://www.ledtronics.com/Products/ProductsDetails.aspx?WP=1366



Test 2


LED Strip Lighting


Contacted SuperBrightLEDs to try and get a similar spectral graph for their red strip lighting. The person I contacted wasn’t very knowledgable unfortunately and said that they could help me. I went to a local business to source the strip lights, again they weren’t very knowledgeable but let me just take a small piece of a strip to test out before purchasing. It tested safe to a couple minutes at full intensity, we decided to a 2 strips of ruby, at which point it was safe to 4 minutes at full intensity.


I also got a remote control dimmer from them but it had limited settings and lots of buttons that were otherwise unnecessary (different blinking patterns etc.) I ended up ordering one from superbrightleds linked below. Which has about 20 evenly (roughly .5 stop each IIRC) spaced steps from 100% down to almost nothing. It also had the advantage of having 4 signal channels since we were separately wiring two darkrooms, it was convenient to have separate controls for each of them.


We chose a KLUS housing from SuperbrightLEDs (linked below) because it was sleek and came with clips that we jerry rigged to a suspension system that allowed us to slightly angle the lights away from the enlargers toward the sink area. We tested both the standard lens and diffuser that come with the housing but in then end found that a different thicker frosting (linked below) offered much more diffused light that was easier on the eyes while working.



Marco’s Notes

The issue with the first attempt was that the housing / lens was too bright, and the light too specular. The last housing you bought changed that dramatically, and papers tested much safer. The addition of rubylith strips really raised the safe time. The original dimmer / remote was cheaply made and was an obvious weak link. The blinking was crazy, I forgot about that! The new dimmer is much more robust and effective. There are 8 usable "clicks" on the dimmer, each click reducing the light by 1/2 a stop. There's got to be a better way to describe how much of a reduction in light that is to a layman. The brightest level is perfectly adequate for the RC paper that the groups use, and provides a very bright, safe environment. Ilford fibre based paper is safe for 7+ min at 3 clicks down in the brightest area the darkroom of, and Foma papers are safe for 7 min at 6 or 7 clicks down.

- explain that 7 minutes is the benchmark, set by Kodak, and by real world practice. A piece of paper is realistically only exposed to the brightest area of the darkroom for less than 4 minutes. Once a paper is in the stop bath, safelight fog will no longer be an issue.



Final Solution


I got the red led strip lights, with power converters and barrel connectors from my local LED store. We used KLUS housing which was available from SuperBrightLED’s and cut 2 strips of Ruby to put between the leds and lens. Tested the brightest working area after installation, safe on Ilford at 100% to about 4 minutes. At 3 clicks down on the dimmer its safe to about 7 minutes and works better with other more sensitive papers.


The light is much better directed, allowing an easier work environment (the range of light in working areas decreased from 5 stops to 3 stops). The installation also looks aesthetically better. Our hope, is that the lower temp and specific red output of the LEDS will allow the ruby to last much longer allowing us to not have to replace it so often. Also the amount of ruby needed for this housing is a fraction of what was needed for the previous lighting boxes.



Red Strip Lighting (similar, but not what we used)


https://www.superbrightleds.com/mor...-5050-with-lc2-connector/1465/#/attributes/13


Power Converter (similar, but not what we used)


https://www.superbrightleds.com/mor...dc-cps-series-power-supply-cps-24vdc-xw/1043/


KLUS Housing


https://www.superbrightleds.com/mor...t-anodized-aluminum-led-profile-housing/2040/


https://www.superbrightleds.com/mor...1m--led-profile-lens-rigid-frosted/1319/3042/


Dimmer


This dimmer came with no instruction manual, but wiring was pretty self explanatory. To sync the dimmer with the receiver you must depress the control and the small sync button on the receiver at the same time and quickly release. To reset, hold down the sync button on the receiver for around 10 seconds.


https://www.superbrightleds.com/mor...ch-transmitter-for-easy-dimmer-receiver/2018/


https://www.superbrightleds.com/mor...eries-wireless-led-dimmer-receiver/2017/4510/


Ruby


http://www.screentec.ca/index.php?m...id=523&zenid=2983534211d354bf19ec3cab3fdbd317



Marco’s Notes

With the addition of the dimmer, *any* paper can be made safe for the ideal time of 7 minutes, which was the goal. Some of the Eastern European papers, which are not common, require a dimmer work environment. But the paper will be safe from fogging, which was not at all the case with our old setup. With Ilford Fibre papers, which are the most commonly used papers, the environment is brighter and safer than it used to be. The light is much more even, which the pictures you took demonstrate wonderfully.



In regards to the rubylith pieces that we have installed, I took light readings on 8-June-2015 that we can refer to in 6 or 12 months time, and see if the amounts have changed. If they have changed dramatically, we can deduce that the rubylith has faded and that we will have to come up with a schedule to replace it. I've got all the recorded in my logbook. The LED lights generate so little heat compared to the halogen tubes, my feeling is that it might be years before we have to replace them.

Understand that all testing that was done was in the absolute brightest area of the darkroom (the middle of the sink). This was a worst case scenario approach. In normal working conditions, the paper won't be exposed to nearly as much light as that, and safetimes will be much longer than what we think.



If you have the scans of that test that I conducted - the final one with the step wedge - I can give details as to the approach. It's sound, and thorough, and I think will show that we really looked at the whole picture, and really improved the workspace for the membership. When you get right down to it, there are very few things involved in black and white printing that are more important than having proper safelights. Our old safelights were simply not proper.



Off the top of my head:

1 click down, Kentmere and Ilford RC safe for 4 minutes - understand that RC paper takes less than 1 minute to develop, as opposed to between 2.5 and 6 for fiber paper.

3 clicks down, all Ilford products safe for 7 minutes

6 clicks down, the one VC Foma paper that we tested was safe for 7 minutes

8 clicks down, Slavich paper tested safe for 5 minutes. Advice is that members using this paper (and I've only seen 1 person!) cover the paper while it is developing with another tray on top. Understand that 8 clicks down is quite dark, and really on the cusp of being not usable.

 

[ac12]

A comment that I have which applies to yours and similar constructed and dark painted darkrooms is, to consider putting a few safelight strips down in the walking area, rather than rely only on the safelight from the ceiling. This makes the walking area safer. While difficult to do in the past with large safelights, with thin strip lights, it is easier and practical to do it today.

And consider painting the darkroom LIGHT gray or even white. With flat black only around and above the enlargers. The light color paint makes a BIG difference in how much more the safelight illuminates the darkroom. I discovered this visiting another school's yearbook darkroom, and it literally was an eye opening experience. So much so that I painted my own darkroom WHITE, and used white floor tiles and counter tops. It was sooo much easier and pleasant to work in than the BLACK darkroom at school. With only 2 safelights (25 and 7-1/2 watts), my friends could not believe the difference in how much brighter and more visibly comfortable my darkroom was to work in, than the BLACK darkroom at school.

 

[Bob Carnie]

Darren and Marco- great post thank you I need to come down and see this , looks great

Bob

 

[mgb74]

First, this should be a "sticky".

Second, you state "Our hope, is that the lower temp and specific red output of the LEDS will allow the ruby to last much longer allowing us to not have to replace it so often.". Is that the only reason to use red leds?

 

[rthollenbeck]

Great idea for research relivent to traditional photography. Thanks for shareing.

 

[AgX]

A issue I see is the high luminous intensity per unit area, making these lights specular (be it in a longitudinal way).

Of course a simple remedy could be letting the strip light face upwards against the ceiling, turning it into indirect lighting.

 

[adelorenzo]

Thank you for sharing this wealth of information. I have just ordered a set of the LED globe bulbs similar but not identical to the ones in your test. I'll make sure to fully test them to see if there are any issues.

 

[Jim Jones]

A graphics arts darkroom I occasionally worked in years ago used Rubylith to darken windows that faced room light. They had faded to a conspicuously lighter density.

 

[RalphLambrecht]

A comment that I have which applies to yours and similar constructed and dark painted darkrooms is, to consider putting a few safelight strips down in the walking area, rather than rely only on the safelight from the ceiling. This makes the walking area safer. While difficult to do in the past with large safelights, with thin strip lights, it is easier and practical to do it today.

And consider painting the darkroom LIGHT gray or even white. With flat black only around and above the enlargers. The light color paint makes a BIG difference in how much more the safelight illuminates the darkroom. I discovered this visiting another school's yearbook darkroom, and it literally was an eye opening experience. So much so that I painted my own darkroom WHITE, and used white floor tiles and counter tops. It was sooo much easier and pleasant to work in than the BLACK darkroom at school. With only 2 safelights (25 and 7-1/2 watts), my friends could not believe the difference in how much brighter and more visibly comfortable my darkroom was to work in, than the BLACK darkroom at school.

I'm saying this for years,d darkroom walls should be painted white, except around the enlarger.

 

[Gerald C Koch]

Darkrooms do not have to be painted in a dark color. It is best to use a light color to maximize the little light that is available. I have always followed this advice and never experience any problem. Sure saves bumping into counters. There is a great Kodak publication on constructing darkrooms. One of the J series.

In addition unless a red safelight is specifically required an amber one provides better visibility. The human eye is more sensitive to the middle region of the visible spectrum. Then too the longer wavelength of red light make it harder to see fine detail. When developing film, even a panchromatic one, by inspection a GREEN safelight is used not a red one. Why, there is better illumination for the human eye.

 

[mshchem]

I'm saying this for years,d darkroom walls should be painted white, except around the enlarger.

White walls and sodium vapor lamps. I have 3 Thomas duplex safelights. I can read a newspaper. You can look up Na emission spectra.
Mike

 

[MattKing]

On the subject of wall colour, we recently re-painted the room that spends most of the time as a bathroom, except when it serves temporary duty as my darkroom.
The colour change was one from a fairly dark tan to a much lighter tan.
I previously used a mix of three separately powered and placed safelight sources - two red LEDs and an amber coloured, tungsten safelight bulb. The three sources were spread around the room with all safelights bounced off the mostly 9 foot high, tan coloured ceiling. The setup passed a modified version of the Kodak safelight test.
With new paint on the wall, I repeated the safelight test. The same setup failed miserably. When I swapped out the amber tungsten bulb and replaced it with a third red LED, the revised setup passed the test.
I take from this that the paint on the walls and ceiling is important when determining whether a safelight setup is indeed safe.

 

[Ai Print]

Wow, big thanks!!

This is fantastically great timing for this report, I am about to order a similar setup and also decided to dial in more safety via rubylith. I also agree with others about a white darkroom at least on the wet side but still want my enlarger area to be dark due to light scatter when making bigger prints. So mine is split, mostly white overall with dark grey in the cove as the pics portray:

 

[chris77]

great stuff.
i use one 10w deep red super-led (660nm).
too bright, therefore 2 layers of rubilith.
bouncing off the wall, brightened up my darkroom!
safe for at least 7 minutes on the brightest worktable..

 

[Jim Jones]

A circuit with a dimmer is useful for incandescent safelights. Additionally, this can greatly extend the life of the lamps.

 

[ac12]

@AP
I'm hugely jealous. That is a LOT of space you have.
I wish I had a quarter of that space.

 

[Bob Carnie]

Wow, big thanks!!

This is fantastically great timing for this report, I am about to order a similar setup and also decided to dial in more safety via rubylith. I also agree with others about a white darkroom at least on the wet side but still want my enlarger area to be dark due to light scatter when making bigger prints. So mine is split, mostly white overall with dark grey in the cove as the pics portray:

View attachment 174188 View attachment 174187

Wicked construction really impressed, is this going to be your private darkroom or are you printing for others?

 

[Marco Buonocore]

Nice post, Darren!

AgX makes a point about having the strips face the ceiling, and bouncing the light. In a normal darkroom with a flat ceiling, I would say that is the way to go for sure - it's much easier on the eyes. We used to have a bunch of Thomas Duplex lights, bouncing them off the ceiling. The problem with the space is that it is not a normal darkroom really. There is *a lot* of piping, ductwork, etc... up on the ceiling, and when you bounce light off it you get a bunch of dark spots and shadows. So we had to work with that environment. Darren found a diffusing piece of plastic for the Klus housing that does a magnificent job, and the light is quite even and clean.

We went for the red LEDs because we found them to be the safest for a broad range of papers. Seeing as this is a group darkroom - I think there are 300+ members - we had to accommodate as many printing scenarios as possible. We have youth groups printing on RC paper who have never been in a darkroom before, so being able to turn the dimmer up and make a safe, bright room is wonderful. We have members printing on all sorts of papers, and doing all sorts of processes. Often there are multiple people printing at the same time. I found that Foma or Slavich paper absolutely needed deep red safelights, or they would fog. Ilford paper was much more easy to work with.

Having them dimmer is brilliant. If you're lith printing, or chopping up paper on the Rotatrim, turn it way down. If you're just knocking out contact prints on RC paper, you can pretty much make it as bright as you like.

 

[Ai Print]

@AP
I'm hugely jealous. That is a LOT of space you have.
I wish I had a quarter of that space.

Thanks!
Up until this, I was in a storage closet with no plumbing that was around 15-20 square feet so I was wishing for a quarter of this too, lol! It's just shy of 500 square feet, a dream come true really.

Wicked construction really impressed, is this going to be your private darkroom or are you printing for others?

Thanks Bob, it's mostly private but it will have three enlargers so I plan to teach workshops out of it as well.
It's been loads of fun figuring it out, digging things out of storage I wondered if I would ever get to use like the sinks, couple of Hass D250's, etc.

My target date for it being done is May, still lots to build. I'm working on ventilation and shelves right now....

 

[Patrick Robert James]

I have been using various red leds covered with rubylith for about 12-13 years now. Always worked great. I used the rubylith at the beginning because the leds were not really pure red. Nowadays I have no idea if they are or aren't, but I keep using the rubylith just in case. The nice thing about the setup is the amount of light that can be used safely. No more dark darkrooms for me!

 

[Patrick Robert James]

Wow, big thanks!!

This is fantastically great timing for this report, I am about to order a similar setup and also decided to dial in more safety via rubylith. I also agree with others about a white darkroom at least on the wet side but still want my enlarger area to be dark due to light scatter when making bigger prints. So mine is split, mostly white overall with dark grey in the cove as the pics portray:

I have my 4550 flocked and flashed. It leaks no light, or should I say all the light that it leaks is cut off at the pass. I should really take some pictures one of these days since it would probably be a help to those that have the enlarger.

I am jealous of that darkroom too. That is going to be something special.

 

[Ai Print]

I have my 4550 flocked and flashed. It leaks no light, or should I say all the light that it leaks is cut off at the pass. I should really take some pictures one of these days since it would probably be a help to those that have the enlarger.

I am jealous of that darkroom too. That is going to be something special.

Please do post that, I have two 4550XLG's I will be using in this space. My previous flocking was temporary at best.

 

[Gerald C Koch]

When I swapped out the amber tungsten bulb and replaced it with a third red LED, the revised setup passed the test.
I take from this that the paint on the walls and ceiling is important when determining whether a safelight setup is indeed safe.

Unless the amber tungsten bulb was approved for use as a safelight I would not implicate the light colored walls. The emitted spectrum might not be correct. I tested red tungsten bulbs and found them unsatisfactory. It all depends on the spectrum that is produced.

 

[MattKing]

Unless the amber tungsten bulb was approved for use as a safelight I would not implicate the light colored walls.

It was sold as a safelight in a "camera" store.
I expect the new paint has a higher green component.
It (the bulb) looks a lot like this: Dead Link Removed

 

[mgb74]

I'm confused. If your safelight is only emitting light in a "safe" wavelength, why does the color of the wall matter? I didn't think it could alter the wavelength when "bounced".