Safelight for B&W contact printing

[dwill]

I just built a darkroom 11x12 and am looking for safelight options for B&W contact printing. I see that many use the Thomas Duplex super safelight, is it necessary to have such a big metal box hanging from the ceiling? Can a red light bulb in the light socket work or one of those Kodak safelamp model A's that you just screw into the socket but has a filter around the bulb work? Or what about those little vintage safelight lamps that you just plug in the wall? I am just wondering if I am missing something as I am why one would put up the heavy and bulky Thomas Duplex Super Safelight when you can just plug in something.
Thanks
Dan

[Leigh]

Hi Dan,

I use a Thomas Duplex in my 10x12 darkroom, and would never consider anything else.

After all, the purpose of a safelight is to enable you to see what you're doing.
The Thomas is bright enough to read labels on bottles anywhere in the room.

- Leigh

[Tin Can]

I use and many others do too.

Only this particular RED LED (https://www.superbrightleds.com/moreinfo/led-globe/g11-led-bulb-8-smd-led-globe-bulb/440/) as bare bulb, actually I put them in Ye Olde Kodak Bullet fixture without a filter. Looks authentic...

And the rule is everybody must test their own safe lights. So you trust your setup.

I do not recommend any other LED.

[jk0592]

I use Thomas Duplex in 8x10 darkroom. I put it high enough so that it's large mass up there is not a bother.

[Bruce Barlow]

I got a string of red Christmas tree lights and hung them around the perimeter of the darkroom. They're plugged into a circuit controlled by a switch with a dimmer, so I can test them to make sure they don't fog, and if they do, turn down the dimmer. It's very festive.

[John Kasaian]

I got a string of red Christmas tree lights and hung them around the perimeter of the darkroom. They're plugged into a circuit controlled by a switch with a dimmer, so I can test them to make sure they don't fog, and if they do, turn down the dimmer. It's very festive.

That's what I have---a short string of leds bought on sale at season's end to replace my GE Guide lamps, which haven't been sold here in decades. The Christmas lights are much brighter, and as you said, festive!

[Ted R]

Multigrade papers are sensitive to blue and green light. Long ago the amber filter was introduced as an improvement over the red safelight for use with graded and multigrade papers, this has the advantage that it is much easier on the eye, whereas working by red light always feels weird (to me at least) whereas working in amber light is more comfortable. Try to find an amber safelight, they were made by Kodak and Ilford and are not expensive, the Kodak safelight filter code for enlarging papers is OC, the Ilford codes are SL1 and 902, look on ebay, used ones are affordable. The Thomas safelight is overkill, it is a multipurpose beast for professional darkrooms doing color work.

[Leigh]

The Thomas safelight is overkill, it is a multipurpose beast for professional darkrooms doing color work.
You're certainly welcome to your opinion.

I strongly disagree, as do many other users of the Thomas Duplex Safelight.

They're not terribly expensive.
They provide absolutely superb lighting of the entire room.
You can read graduates and bottle labels in every corner of a darkroom.

- Leigh

[Alan9940]

Been running a Thomas Duplex in all my darkrooms since 1978; only thing I've ever done to it is replace the gel filters when the originals finally dried out. IMO, absolutely the best safelight for any darkroom. And, how can you argue with nearly 40 years of service?

[Tin Can]

Well the Thomas Duplex bulb is $120 at Freestyle, but where do we get new filters?

For that matter, how many of them are still alive?

All my Kodak bullet OC filters have big pinholes in them. In the past others taped over the holes. I just store them somewhere...hidden holes.

What causes those holes?

I run 6 of the red LED's I linked to, day and night, except when I sleep. The red does cheer up the room when the 'white' led's are on and I keep my red leds at least 4 feet away from any sensitive material.

If I had a Thomas Duplex I would use it, but I haven't found one anywhere. And now I don't need one, or do I...

[Kevin Crisp]

The same bulb is available elsewhere for $29 or so. They last a long, long, long time. The bulb is commonly used in street lighting -- there is nothing unique about it for this application.

The filters can be replaced with Roscoe filters, you cut them and put them between the sheets of glass and tape them up. I just rehabbed a Thomas with broken filters and a bad bulb and a rat's nest in it. I used the color of the gel that is widely recommended for this -- R19 "Fire." It works fine. Add a little tissue paper in the glass sandwich before you tape them up. Or you can by new filters from B&H.

[Oren Grad]

For at least 20 years now I've used a Jobo Maxilux. It's a compact LED lamp that doesn't need to be wall- or ceiling-mounted - perch it somewhere convenient, plug it in, and you're all set.

[Leigh]

Permit me to explain the difference between the Thomas Duplex and other safelights.

Here are comparative spectra of four common light sources. At upper-left is regular light bulbs:
http://www.atwaterkent.info/Images/Img_light%20source%20spectra_SO%20SPD%27s.jpg

The Thomas uses a low-pressure sodium-vapor lamp that emits only yellow at any significant intensity.

Its spectrum includes other colors at very low intensity, not significant for paper but may be for film.
That's what the filters are for.
Here's the spectrum:

http://www.atwaterkent.info/Images/Img_Thomas%20duplex%20safelight%20spectrum.png

In contrast, any thermal light bulb emits strong colors across the entire visible spectrum.
That requires significant filtration for paper as well as film (if useable at all with film).

LEDs can be highly monochromatic, but only very powerful ones emit significant amounts of light.
Also, there are no yellow LEDs. Those marketed as yellow contain both red and green emitters.

- Leigh

[Leigh]

Well the Thomas Duplex bulb is $120 at Freestyle, but where do we get new filters?
For that matter, how many of them are still alive?
My wife went to South America for Halley's Comet in 1986.
She came back with lots of photos of it and other subjects.

I built the darkroom as a cheaper (and politically better) alternative to sending the film out.
The Thomas Duplex was bought used.

The TD safelight still works fine today, just as it did when first installed 30 years ago.
I bought a replacement bulb from B&H at the time. It's still sitting in the drawer.

- Leigh

[N Dhananjay]

Another reason for liking the Thomas is the fact that it is less tiring on the eyes. Dim safelights mean that your pupils are constantly adjusting to deal with the extremes of a dim safelight followed by the large amounts of light required for printing exposures on contact papers. This used to screw up my print evaluation. I now have a Thomas that is going constantly and I have print viewing lights switched on with a footswitch and adjusted in intensity to ensure my eyes are not thrown off.
Cheers, DJ

[MartinP]

It looks as thought the OP is setting up their first darkroom. All of the answers above seem to be suggesting different types of safelight based on fashionability.

Decide what paper will be used (traditionally a silver-chloride based paper), follow the manufacturers datasheet to choose the type of safelight filter.

No specific brand or design of safelight is essential so long as it's output is consistent with the requirements of the paper. All sorts of safelight are used by somebody, somewhere - the variables of size of room and practical availability of the safelight are important factors.

[dwill]

Thanks for all the feedback everyone. Martin, will check the paper as you mentioned. I will only be doing contact prints using Lodima paper and the new adox lupex paper, developing in amidol. Using mostly FP4 film and developing with abc pyro. For anyone who cared to know exactly my paper and materials.
I have looked for a Thomas duplex and found one on eBay for $270. I seriously doubt it sold and probably won't unless they drop the "2". Lol. I will keep looking and just test a few options (bulbs) to see what works.

[sepiareverb]

Kodak bullets and two-ways here. They are cheap, and I have a bunch of them. Three bullets over the sink, a two way over the enlarging counter and another over the wash sink. Then another bullet at the desk. Plenty bright, perfectly safe after testing and adding some ND to the light over the developing tray. I have light grey walls, and a white ceiling.

I use night light bulbs, and appliance bulbs, low wattage, dirt cheap, and long lived. When the incandescent wars began I stocked up on bulbs, I don't think I've gone through one package yet, so am set for life.

I've got a collection of filters as well, some eBay, some from a local shop closing doors.

Ceiling height in my darkroom precludes a TD. The bullets are not a lot shorter, but they hang out of the way, over the sink and desk. I approached the darkroom like one approaches a kitchen: some general lighting and then more specific task lighting.

[HMG]

I have a small (roughly 8'x8') darkroom so I didn't think I needed the Thomas light I was saving for many years. I installed it to test before selling. It's such an improvement that I kept it. I did have glass cut and build filters. Keep in mind that the filters aren't needed for typical use, but in my case I had to cut down the light a bit.

I consider it a luxury.

BTW, it's getting tougher to find Rosco filters at photo stores, but I've had success at a local shop that deals with theatrical lighting.

[Tin Can]

So the secret to a Thomas Duplex is the narrow and correct spectrum bulb. Yes, I realize the Thomas Duplex box has good adjustability with flaps.

The LED I use I selected based on it's correct and tested spectrum.

Apples and lemons...

[bob carnie]

I use the Thomas light boxes and really enjoy them , gives the darkroom a lovely creepy glow, Rob Zombie at high levels and there you go great prints.

[Tin Can]

I use the Thomas light boxes and really enjoy them , gives the darkroom a lovely creepy glow, Rob Zombie at high levels and there you go great prints.

Bob, my safelight argument is, most likely there is not enough Thomas Duplex to go around.

Similar to my DIY enlarger head rationale. Not enough 8X10 enlarger heads to match chassis extant.

I think we discourage newbies and experimentation by insistence on the superiority of some tools.

If a rock works as a hammer, it may be good enough. Refinement comes with increased usage.

[Leigh]

I think we discourage newbies and experimentation by insistence on the superiority of some tools.
And how is a newbie to know which tools are superior if we don't provide that information?

Purchase decisions are based on many factors. Product quality is certainly an important one.

- Leigh

[Pere Casals]

red LED's



This is a great idea... by nature color LEDs have a narrow band and have to be a very good safe light.

I'll do the same...

[Leigh]

by nature color LEDs have a narrow band and have to be a very good safe light.
As I mentioned in post #13 above, RED LEDs are fine, YELLOW LEDs are definitely not fine.

Yellow is the color of maximum sensitivity of the human eye.

- Leigh

[jk0592]

Perhaps amber leds are a better choice, for black and white work.

[Tin Can]

Perhaps amber leds are a better choice, for black and white work.

NO definetly not!

In post 3 this thread I link to this RED LED Bulb that does work as a safelight, every other RED LED I tested did not work as well.

Here is the link. https://www.superbrightleds.com/moreinfo/led-globe/g11-led-bulb-8-smd-led-globe-bulb/440/

Here is the spectrum chart. Compare to your paper spectrum.

156582

[Leigh]

Perhaps amber leds are a better choice, for black and white work.
If the emitter is truly amber (600nm), without other spectral components, that would work.

A close examination of the device datasheet would be needed to confirm.

- Leigh

[jk0592]

Before getting the Thomas Safelight, I had ye olde Kodak safelight with an Amber (OC?) filter, it was OK. I did consider at one point replacing it by Amber leds.

[Pere Casals]

Amazon has:

the High Resolution Quantitative Spectroscope - 400-700nm, +/-5nm" $7.95 ,

"Public Lab Spectrometer 3.0"

"DIY Foldable Paper Smartphone Mini Spectrometer Analyze and Catalog Materials"

For my job I use an Ocean Optics USB 2000, relatively cheap a good. It is nice knowing exactly illumination SPD and subject spectral reflectance...


Then we can compare trusted filter safelight to LEDs, today we have leds for near each 10nm interval , EPITEX brand for example.

Also one can peek a single led of each central wavelength, place it on paper and see at what wavelengh paper starts reacting.


The graph Randy shows explains it very well... that graph is important because we see if the emission band is narrow or wide. Perhaps a LED can look "more red" but because emission band in wider it can be worse.


So if one wants orange/amber light then graph with a narrow shape is the good choice, testing it, of course...

[Bruce Barlow]

Yellow is the color of maximum sensitivity of the human eye.

- Leigh

No wonder gentlemen prefer blondes.

[Tin Can]

Amazon has:

the High Resolution Quantitative Spectroscope - 400-700nm, +/-5nm" $7.95 ,

"Public Lab Spectrometer 3.0"

"DIY Foldable Paper Smartphone Mini Spectrometer Analyze and Catalog Materials"

For my job I use an Ocean Optics USB 2000, relatively cheap a good. It is nice knowing exactly illumination SPD and subject spectral reflectance...


Then we can compare trusted filter safelight to LEDs, today we have leds for near each 10nm interval , EPITEX brand for example.

Also one can peek a single led of each central wavelength, place it on paper and see at what wavelengh paper starts reacting.


The graph Randy shows explains it very well... that graph is important because we see if the emission band is narrow or wide. Perhaps a LED can look "more red" but because emission band in wider it can be worse.


So if one wants orange/amber light then graph with a narrow shape is the good choice, testing it, of course...

There is also the, tip oft posted on LFPF to use DVD reflections to check a lamps spectrum. It works.

[LabRat]

I keep a ultrabright red LED bicycle taillight for developing lith film in my darkroom supplies... Powered by a pair of AAA batteries, it is intensely bright, so I place it in a bowl etc and aim it at the high ceiling so not shining directly at the materials as it is so bright... I have never had to change the batteries EVER with it so far, and can put it anywhere it's needed... I have used it with MG paper and no fogging so far... :-)

Steve K

[MrFujicaman]

Kevin..could you list a part # and a supplier?


The same bulb is available elsewhere for $29 or so. They last a long, long, long time. The bulb is commonly used in street lighting -- there is nothing unique about it for this application.

The filters can be replaced with Roscoe filters, you cut them and put them between the sheets of glass and tape them up. I just rehabbed a Thomas with broken filters and a bad bulb and a rat's nest in it. I used the color of the gel that is widely recommended for this -- R19 "Fire." It works fine. Add a little tissue paper in the glass sandwich before you tape them up. Or you can by new filters from B&H.

[MrFujicaman]

If you look, you can find Rosco filters on Ebay from time to time.


I have a small (roughly 8'x8') darkroom so I didn't think I needed the Thomas light I was saving for many years. I installed it to test before selling. It's such an improvement that I kept it. I did have glass cut and build filters. Keep in mind that the filters aren't needed for typical use, but in my case I had to cut down the light a bit.

I consider it a luxury.

BTW, it's getting tougher to find Rosco filters at photo stores, but I've had success at a local shop that deals with theatrical lighting.

[Barry Kirsten]

I built my own safelight by modifying a reading lamp. I removed the halogen lamp and inserted a dozen LEDs of 680 nm wavelength. It required a small modification to the power supply in the base, but all-up cost about $20. I've tested it extensively allowing a huge margin for safety and found that it's completely safe. Happy to share details if anyone's interested.

156617

[Kevin Crisp]

Try Phillips #32781-7. 18,000 hour life so you can really take your time in the darkroom. Currently $28.40 on Amazon.

[Kevin Crisp]

I noticed a nice looking Thomas on CL in Long Beach, CA for $50.

[TroyG]

I use and many others do too.

Only this particular RED LED (https://www.superbrightleds.com/moreinfo/led-globe/g11-led-bulb-8-smd-led-globe-bulb/440/) as bare bulb, actually I put them in Ye Olde Kodak Bullet fixture without a filter. Looks authentic...

And the rule is everybody must test their own safe lights. So you trust your setup.

I do not recommend any other LED.

So, Randy, just to clarify: You only put those in the Kodak fixture for aesthetic purposes? Nothing would come negatively of this just in any ole screw base lamp?

[Tin Can]

Yes I do it for fun only.

I also put them in regular sockets anywhere I want them.

Such as my bathroom ceiling fixture.

No filters are used anywhere.

I do maintain 4 feet distance in almost every placement.

Do a test in your Darkroom.

They are so cheap, why not?





So, Randy, just to clarify: You only put those in the Kodak fixture for aesthetic purposes? Nothing would come negatively of this just in any ole screw base lamp?

[Ken Sinclair]

No wonder gentlemen prefer blondes.

Many, many years ago a friend of mine used to 'claim'...

"He Would NOT know what to 'do' with a blonde.. he was too used to squeezing 'blackheads' "

My bad....

Ken

[Bruce Barlow]

Many, many years ago a friend of mine used to 'claim'...

"He Would NOT know what to 'do' with a blonde.. he was too used to squeezing 'blackheads' "

My bad....

Ken

Oh, that's nice!!