What LED lightbulbs can I use with these safelight filters

bonk · Dec 16, 2018

From this vendor I own two plastic filters for my light room safelights

4013: Orange, for b&w silver chlorobromide papers

4014: Red, for orthochromatic films and papers, lith and line materials as well as SW papers with solid gradation
http://www.kaiser-fototechnik.de/de/produkte/2_1_produktanzeige.asp?nr=4014
Does it matter what kind of light bulbs I would use behind those filters? I would prefer to use some bright LED bulbs.

What do I need to watch out for when buying bulbs? Can I use regular ones from the household supply store?

glbeas · Dec 16, 2018

Any of the bulbs would work but you would need to be cautious about getting it too bright. Fog testing a new setup like that is recommended. If you are simply wanting to see better in your darkroom try using a brighter bulb than recommended in equivalent watts and point it at the ceiling (assuming its white) for an even diffuse lighting at a safe level. Its a lot easier to see in that lighting than making bright pools of light in a dark room. In my last darkroom I could even see a dropped sheet of paper under the enlarger table.
One thing to watch for with led bulbs is cooling, some will fail prematurely in enclosed spaces due to heat building up.

Patrick Robert James · Dec 16, 2018

Unless you want to use orange for some reason, go with the red, and use a red LED lightbulb. The combination will be safe for a long time.

There is a little red LED bulb at SuperBrightLeds. https://www.superbrightleds.com/mor...equivalent-led-globe-bulb-27-lumens/440/1477/

You don't say where you are at but you could probably find something like it outside the US.

RalphLambrecht · Dec 16, 2018

bonk said:
From this vendor I own two plastic filters for my light room safelights

4013: Orange, for b&w silver chlorobromide papers

4014: Red, for orthochromatic films and papers, lith and line materials as well as SW papers with solid gradation
Does it matter what kind of light bulbs I would use behind those filters? I would prefer to use some bright LED bulbs.

What do I need to watch out for when buying bulbs? Can I use regular ones from the household supply store?

LEDs are very bright but not very safe.I'd recommend a tungsten incandescent bulb at around 2000K and an orange filter.Also,whatever you use, conduct a safelight test before making valuable prints.

Ian Grant · Dec 16, 2018

Safe-lights are only safe at a specific brightness and distance from the material used. So if your safe-light says a 15w Pygmy or conventional sized Tungsten bulb you'd need the equivalent LED as a warm white bulb.

In the past I had my safe-lights in a large darkroom on a dimmer switch that gave greater flexibility. You can do the same with dim-able LED bulbs you need to be looking at the 0.5 - 1.5 watt range in terms of power.

Ian

Patrick Robert James · Dec 16, 2018

I hate to say it, but Ralph and Ian are off a bit based on an incandescent assumption.

If you use a RED led and filter it (I use rubylith) you can get incredibly bright safelights that are truly safe. Any wavelengths that aren't safe (of which there will be a little) from a red led will be cut off by the filter. If you use an incandescent light, most of the light needs to be filtered which is why such weak lights are specified.

In my small darkroom I have three of the bulbs I linked to filtered by rubylith and it is lit up like the 4th of July in there. No problems at all. It is bright enough that for denser negs I have to turn a couple off so I can see the image on the baseboard. The filtered lights are pure red too which is rather soothing. Amber safelights always made things look sickly to me.

I see no point whatsoever to use an incandescent bulb in a safelight. Technology has passed those up as far as safelights go.

Once you get a properly lit "darkroom" you will never go back to the dingy ways of the past.

bonk · Dec 16, 2018

Oh wow, it seems that I never really put much thought into properly lighting my b&w darkroom. I just used those fairly bright East German ORWO/OSRAM red light bulbs I got from my father and put it directly over the developer dish.
I guess that’s not such a good idea?

Reading all of the above I feel I need to go back to zero and learn and invest in properly lighting my darkroom.

I would like to use multigrade (usually Ilford) and regular b&w paper. What safelights from here https://www.fotoimpex.com/darkroom/darkroom-safelights/ would you suggest I‘d buy. And how far away from the paper would I need to hang them?

koraks · Dec 16, 2018

Patrick Robert James is absolutely spot on correct.
In fact, most VC (and all gradedl papers will work just fine with most red LEDs even at rather high light levels. A notable exception appears to be foma VC papers, which tolerate most red LEDs but apparently not all going by the experiences of others (I have never had any issues with these papers and red led bulbs whatsoever).
When working with more sensitive ortho materials such as xray film, some red LEDs may cause problems; in these cases, additional filtering with rubylith and reducing light intensity have gotten me out of the woods.

Red led bulbs allow for ridiculously high light levels in your "darkroom" making work much easier and more comfortable than weak incandescent bulbs with filters that eventually fade and crack. As far as I'm concerned, there is no scenario at least with b&w materials to stick to the old-fashioned incandescents. I'm glad I replaced them.

mfagan · Dec 16, 2018

I also concur with Patrick Robert James. I have one of the LED red bulbs he cites, and it passes the Kodak safelight test completely at seven feet from the developer tray while providing what used to be (to me) a frightening level of illumination in the modestly large bathroom. It is mounted in a bathroom ventilator fan and is attenuated only by the cheap plastic milky cover of the fan/light assembly.

RalphLambrecht · Dec 17, 2018

Patrick Robert James said:
I hate to say it, but Ralph and Ian are off a bit based on an incandescent assumption.

If you use a RED led and filter it (I use rubylith) you can get incredibly bright safelights that are truly safe. Any wavelengths that aren't safe (of which there will be a little) from a red led will be cut off by the filter. If you use an incandescent light, most of the light needs to be filtered which is why such weak lights are specified.

In my small darkroom I have three of the bulbs I linked to filtered by rubylith and it is lit up like the 4th of July in there. No problems at all. It is bright enough that for denser negs I have to turn a couple off so I can see the image on the baseboard. The filtered lights are pure red too which is rather soothing. Amber safelights always made things look sickly to me.

I see no point whatsoever to use an incandescent bulb in a safelight. Technology has passed those up as far as safelights go.

Once you get a properly lit "darkroom" you will never go back to the dingy ways of the past.

if filters would just work that way.

Ian Grant · Dec 17, 2018

Patrick Robert James said:
I hate to say it, but Ralph and Ian are off a bit based on an incandescent assumption.

If you use a RED led and filter it (I use rubylith) you can get incredibly bright safelights that are truly safe. Any wavelengths that aren't safe (of which there will be a little) from a red led will be cut off by the filter. If you use an incandescent light, most of the light needs to be filtered which is why such weak lights are specified.

In my small darkroom I have three of the bulbs I linked to filtered by rubylith and it is lit up like the 4th of July in there. No problems at all. It is bright enough that for denser negs I have to turn a couple off so I can see the image on the baseboard. The filtered lights are pure red too which is rather soothing. Amber safelights always made things look sickly to me.

I see no point whatsoever to use an incandescent bulb in a safelight. Technology has passed those up as far as safelights go.

Once you get a properly lit "darkroom" you will never go back to the dingy ways of the past.

I have to disagree because of the Herschel effect which I've seen first hand in a small darkroom, this can limit the contrast grades obtainable with VC/MG papers. It's not fogging it's latent image bleaching and I had this problem in a darkroom in the mid to late 1980's, switching to an OC/902 type VC safe-light filter cured the problem which was known about and described in some magazine articles at the time.

In my current darkroom I have 4 different safe light systems available, I much prefer Ilford 902/Wratten OC or equivalent for variable contrast and graded papers, then I have Ilford 900/Wratten 1 for lith films etc, an Ilford 906 filter for Harman Direct Positive paper and finally Wratten 10/10H for colour printing (used indirect).

I'm not against using LED's as you suggest, quite the opposite but long experience and many darkrooms has shown it's better to use the correct safe-light and in particularly overall brightness kept to the recommended levels, that means using the correct equivalent LEDs. My darkroom's a reasonable size so I use 3 Ilford 902 equivalent safe-lights.

Ian

J 3 · Dec 30, 2018

One things you have to watch out for is if you plan to use a red LED bulb, and no filter - Some red LED bulbs are actually a white LED with a red filter (It's easier for some producers to source only one LED). These are problematic - the filters are not darkroom quality and the LEDs will leak a little of the unwanted frequencies. If the bulb is a true red LED though they are quite safe. It' it's not, and you don't put it behind a proper filter your relying on low exposures to keep the blue light from fogging stuff. The true red LEDs produce almost all of their light within something like a 10nm wide band.

Ginette · Dec 31, 2018

bonk said:
From this vendor I own two plastic filters for my light room safelights
4013: Orange, for b&w silver chlorobromide papers
4014: Red, for orthochromatic films and papers, lith and line materials as well as SW papers with solid gradation
Does it matter what kind of light bulbs I would use behind those filters? I would prefer to use some bright LED bulbs.
What do I need to watch out for when buying bulbs? Can I use regular ones from the household supply store?

First, I think you should have bought this one "4015: Multigrade" if you use modern VC papers. The 4013: Orange is listed for chlorobromide papers, not very modern papers are in this category.
Your question is about using LED lamp behind standard safelight filters, no ones answered this aspect.
I also wish to use LED instead of tungsten bulbs, for the purpose of reducing the heat on the filters and also the power consumption. I use mostly 10x12" safelight (25W tungsten) in Ilford 902 or Kodak 0C, #1, #2, #10 filters depending of the papers. I bought some very low wattage LED bulbs 6W equivalent 30W for the 10x12" et some equivalent 10W for the smaller Kodak A round safelight (the same as the red at SuperbrightLeds but in warm white https://www.superbrightleds.com/mor...equivalent-led-globe-bulb-27-lumens/440/1480/) but still not install them and test them!
Bonk, best way is to test your safelights in your own darkroom conditions (google How safe are your safelights):
https://www.kodak.com/uploadedfiles..._motion_products_filter_K4_Safelight_1106.pdf
https://www.freestylephoto.biz/how-safe-are-your-darkroom-safe-lights
https://www.ilfordphoto.com/testing...=ilford_brochure&__from_store=ilford_brochure

Nodda Duma · Dec 31, 2018

If you are in the US, the Red LED bulbs (40W equivalent) available from Lowes, filtered with rubylith, will simply not fog paper from a distance of 4 feet or greater for any reasonable period of time you might require to make a print.

The unfiltered orange LED bulb will not fog Ilford MG paper from a distance of 4 feet for at least 5 minutes.

With an orthochromatic emulsion ~25 speed plate, I’ve tested for fog from a distance of 3 feet from the Red LED bulb, and found no measurable fog for at least 45 minutes (I did not test further).

These plates will also not fog a foot away from the LED bulb for at least 5 minutes.

Note the walls of my darkroom are painted off-white, so I get no help from a darkly painted darkroom.

An orange LED will not work well behind a red (such as Kodak 0C) or rubylith filter. The wavelengths that the LED emits are blocked by the filter..might as well just work in the dark. The Red LED works well behind a red filter, but it doesn’t transmit any measurable light below 600nm to begin with (I measured with a spectroscope). I keep them behind rubylith just to be paranoid, and my darkroom and the room where I make emulsions and coat plates are nice and bright.

This is not theory or speculation, and it’s not second-hand knowledge. This is cold hard data taken directly from my notebook, and what I tested to ensure I would not fog emulsions, plates, or paper with more margin than I would ever need. However, be sure to test in your own setup.

Cheers,
Jason

Ian Grant · Dec 31, 2018

Jason the Kodak OC filter isn't red it's the same as an Ilford 902 and light amber so a red/green mixture.

You have to be aware that a safe light may well easily pass the simple safe light tests but actually be detrimental to MG/VC papers because of the Herschel effects, this is particularly noticeable with red/orange filters. The Hershel effect is is Latent Image bleaching which a safe light test is not looking at, the results can be inability to achieve the higher grades.

It's no co-incidence that Ilford use 902/OC filters in their cutting and packaging room (for paper) at a brightness level well below normal darkrooms.

Ian

Nodda Duma · Dec 31, 2018

Not 0C... I meant 1A. Interesting how people tend to nitpick a typo and ignore the truth. Regardless of typo, my test results still stand.

I can only report what works for my needs and my setup. I saw no issues with using MG paper (my go to paper).

Ian Grant · Jan 1, 2019

Nodda Duma said:
Not 0C... I meant 1A. Interesting how people tend to nitpick a typo and ignore the truth. Regardless of typo, my test results still stand.

I can only report what works for my needs and my setup. I saw no issues with using MG paper (my go to paper).

Your mistake itself isn't the issue as you did say Red safe lighting.. My point is that too bright a Red safe light can cause the Herschel effect this is more likely to happen in a small darkroom or with prolonged safe light exposure.

It's not a mythical effect it's something I've come across first hand and also lead to many manufacturers releasing 902/OC type Variable Contrast filter filters for their safe lights. In my case I'd gone from using MG papers in large commercial darkrooms to quite a small darkroom at home same red/orange safe light type and at slightly more than the recommended minimum distance. To start with I had no issues until I needed to print using Gd4 or 4.5 filtration, I just couldn't get the higher contrasts, around the same time there was an article I think in the British Journal of Photograph about how Red saf lighting was causing issues with MG/VC papers in a few instances explaining this was due to the Herschel effect. I changed to a VC (902/OC) type filter and could then get all the higher grades.

Direct Positive films (long gone) and papers actually use the Herschell effect, they are pre-fogged to a specific wave length of light and exposure causes the latent image bleaching of the fogged emulsion giving a Positive image by development (no reversal processing).

My point is don't assume that a safe light isn't have an effect on an emulsion despite no issues with prolonged fogging tests, it maybe be having subtle or even noticeable effects on image contrast if too bright.

Ian

Ian Grant · Jan 4, 2019

Nodda Duma said:
Not 0C... I meant 1A. Interesting how people tend to nitpick a typo and ignore the truth. Regardless of typo, my test results still stand.

It's a very important issue. I've recently bought two 20x16 boxes of Kodak Elite paper and by chance just found a datasheet I've had for years sat on top of a pile on manuals, datasheets etc for the paper.

The datasheet recommends an OC filer and a maximum of 3 minutes exposure at a minimum distance of 1.2 metre 25w 24ov bulb (UK data sheet). It also says the greatest risk of fogging is after exposure and prior to development, this is also the period where the Hershell effect is most likely to occur which is itself a form of fogging although it has an opposite image bleaching effect.

My point is that manufacturers are recommending OC/902 filters for most papers no longer 1A etc.

Ian

RauschenOderKorn · Jan 4, 2019

Ian Grant said:
Direct Positive films (long gone) and papers actually use the Herschell effect, they are pre-fogged to a specific wave length of light and exposure causes the latent image bleaching of the fogged emulsion giving a Positive image by development (no reversal processing).

You should mention that the film/paper needs special sensitisers greatly enhancing this effect. Without sensitiser or a great amount of redlight, this effect will remain mainly unnoticeable. But you are right: the Herschel effect is real and keeping redlight at a low level is a good idea.

Ian Grant · Jan 5, 2019

RauschenOderKorn said:
You should mention that the film/paper needs special sensitisers greatly enhancing this effect. Without sensitiser or a great amount of redlight, this effect will remain mainly unnoticeable. But you are right: the Herschel effect is real and keeping redlight at a low level is a good idea.

When I had commercial darkrooms all the safe-lights were on dimmer switches, I was using SL1/Ia red filters. This was particularly important in the smallest darkroom used for emulsion manufacture where the safelight was used at a very low level and only when necessary.

Yes you're right dye sensitised emulsions will be more prone to the Herschel effect than unsensitised which is why MG/VC papers are more prone to issues and fogging. What's interesting is Ilford states "However, Ilfobrom Galerie FB is extremely resistant to safelight fogging" but then a look at the Spectral Sensitivity shows it's quite different to the Blue/Green sensitised Multigrade products Ilford manufacture.

Ian

What LED lightbulbs can I use with these safelight filters

Moderator

Privacy & Transparency

Privacy & Transparency