DIY safelight

joe7 · Jan 9, 2010

i have a few questions,regarding the safelight.i’m still a beginner,and would like setup a darkroom for B&W printing.Right now I’m looking for a safelight,and if possible, I would like to DIY it.

1)i found this filter at Freestyle,

Premier 10x12 Red Filter
http://www.freestylephoto.biz/1012184-Premier-10x12-Red-Filter?cat_id=1603

Premier 5x7 Red Filter
http://www.freestylephoto.biz/57184-Premier-5x7-Red-Filter?cat_id=1603
other than size,what is the difference between this two filter?it seems that both is having a different colour.

Can I just buy this filter and make my own safelight?is it still the same as the one that is sold,like here
http://www.freestylephoto.biz/191210-Premier-10x12-OC-Safelight?cat_id=1603

2)what size of the safe light that is suitable for me, 10x12 or just get the 5x7?
right now,my temporary darkroom(my toilet actually) size is 6x9x6 ft.

3)can I just use the Fluorescent lamp,instead of the normal light bulb,because its produce less heat,and can be operated at a long hour..

4)i believe,this safelight is paper safe,but how about B&W film,is it also safe?

thanks in advance for any of your reply

glbeas · Jan 9, 2010

Either filter will do and yes you can build your own safelight if you want, it's been done often enough. And yes a flourescent will work, just be sure you get the level of illumination right. The lamp may be a bit bright compared to the 25 to 40 watt bulbs these are made for. in such case you should point the safelight at the ceiling to tone it down. This also has the advantage of making the light more uniform and will appear brighter than it really is. You should do the usual tests to assure the safelight doesn't fog the paper. Red is usually pretty good at not fogging.

wildbill · Jan 9, 2010

I've been using the same little red scoreboard light bulb as my "safelight" for over 5 years. I they cost less than $3 and don't fog any paper I've used. It's screwed into a socket dimmer and never gets adjusted. Freestyle sells red bulbs as well, #12622. I wouldn't use a safelight with b+w film.

Lee L · Jan 9, 2010

If you're thinking a compact fluorescent that screws into a standard bulb socket, check on it. They are not always rated for use in enclosed fixtures, and some are not rated to be used with the base up. Using them out of spec will result in shortened life. Also keep the wattage at or below the equivalent incandescent wattage light output recommended for the safelight filter you're using.

Lee

RalphLambrecht · Jan 9, 2010

joe7 said:
i have a few questions,regarding the safelight.i’m still a beginner,and would like setup a darkroom for B&W printing.Right now I’m looking for a safelight,and if possible, I would like to DIY it.

1)i found this filter at Freestyle,

Premier 10x12 Red Filter
http://www.freestylephoto.biz/1012184-Premier-10x12-Red-Filter?cat_id=1603

Premier 5x7 Red Filter
http://www.freestylephoto.biz/57184-Premier-5x7-Red-Filter?cat_id=1603
other than size,what is the difference between this two filter?it seems that both is having a different colour.

Can I just buy this filter and make my own safelight?is it still the same as the one that is sold,like here
http://www.freestylephoto.biz/191210-Premier-10x12-OC-Safelight?cat_id=1603

2)what size of the safe light that is suitable for me, 10x12 or just get the 5x7?
right now,my temporary darkroom(my toilet actually) size is 6x9x6 ft.

3)can I just use the Fluorescent lamp,instead of the normal light bulb,because its produce less heat,and can be operated at a long hour..

4)i believe,this safelight is paper safe,but how about B&W film,is it also safe?

thanks in advance for any of your reply

Safelights are paper-safe for a few minutes. Red filters are safer than the orange OCs. What's wrong with theses?

http://www.amazon.com/Premier-5x7-Safelight-OC-Filter/dp/B0002EE80M

Not worth making your own. Distribute two or three, depending on the size of your darkroom.

Film needs to be processed in total darkness!

RalphLambrecht · Jan 9, 2010

glbeas said:
Either filter will do and yes you can build your own safelight if you want, it's been done often enough. And yes a flourescent will work, just be sure you get the level of illumination right. The lamp may be a bit bright compared to the 25 to 40 watt bulbs these are made for. in such case you should point the safelight at the ceiling to tone it down. This also has the advantage of making the light more uniform and will appear brighter than it really is. You should do the usual tests to assure the safelight doesn't fog the paper. Red is usually pretty good at not fogging.

I would be worried about the irregular spectral output of fluorescent light sources. Incandescent is more predictable and more towards the red end of the visible spectrum.

joe7 · Jan 9, 2010

RalphLambrecht said:
Safelights are paper-safe for a few minutes. Red filters are safer than the orange OCs. What's wrong with theses?

http://www.amazon.com/Premier-5x7-Safelight-OC-Filter/dp/B0002EE80M

Not worth making your own. Distribute two or three, depending on the size of your darkroom.

Film needs to be processed in total darkness!

actually i'm from Malaysia,the shipment of the complete safelight like this to my country will cost more than the light itself,that's why i would like to DIY it,and at the same time,i love to DIY

tkamiya · Jan 9, 2010

When I used my master bathroom as a darkroom, I had one 5x7 with 15 watts incandescent bulb few feet over my dry side. Now that I have second bedroom as darkroom, I have the same unit but two of them on opposite side of the room. After my eyes adjust, they are quite bright enough. I bought mine from Adorama already made.

I guess I'm impatient but in my darkroom operations, I turn on my room light on/off quickly and often. They are CFL type. Few seconds it takes to light up become quite irritating after few dozen times. Something to consider if you go CFL route. I'll be changing them to regular incandescent type soon.

Jon Shiu · Jan 9, 2010

Do a search on using LED's for safelight.

Jon

RalphLambrecht · Jan 9, 2010

joe7 said:
...and at the same time,i love to DIY

I can't argue with that.

Ian Grant · Jan 9, 2010

If you really want to DIY I posted some instructions on making your own safelight filters in a thread maybe 6 months ago. At one time that's what many people did until companies like Wratten began making good reliable filters, later they were taken over by Kodak.

Ian

fotch · Jan 9, 2010

I made a couple of housings out of wood years ago and used red filters. No problems. Just make a wood box, make is large enough so the heat doesn't build up. You could even make a few light tight vents to vent the heat build up although I did not do that.

I would not use anything larger than a 25watt bulb and would not use a CFL for reasons already stated plus chance of afterglow.

The ones I made had dimensions of about 1 cubic foot and a 10x12 filter size.
Worked great, unfortunately, I don't know what happen to them after I moved.

glbeas · Jan 9, 2010

RalphLambrecht said:
I would be worried about the irregular spectral output of fluorescent light sources. Incandescent is more predictable and more towards the red end of the visible spectrum.

You're right they are irregular, but all we need is what gets through the red filter. I've worked in darkrooms that had flourescent safelights, never a problem. As Lee said you just need to keep the assembly to specs so everything works and is safe.

RalphLambrecht · Jan 9, 2010

glbeas said:
You're right they are irregular, but all we need is what gets through the red filter. I've worked in darkrooms that had flourescent safelights, never a problem. As Lee said you just need to keep the assembly to specs so everything works and is safe.

Here is a test for believers in specifications. Take a red laser pointer or an LED tail lamp from a bike. Check the spec to see what wavelength it emits, usually a very narrow band >630 nm. Now take your favorite photographic paper, and check it's sensitivity limit, usually <580 nm. Now go to the darkroom and shine the laser pointer or the tail lamp onto the paper from different distances for just a few seconds. Should not expose the paper, right? It took only seconds to ruin the paper when I did it. :confused:

John Koehrer · Jan 9, 2010

You cannot use the red/amber filter with film.
There was a green filter that could be used for several seconds halfway through development.

BetterSense · Jan 9, 2010

If I was going to make a safelight, I would just use LEDs. Oh wait, that's what I did.

http://farm3.static.flickr.com/2630/3800889437_e84ea40d5d_b.jpg

I wouldn't use a CFL for safelights for spectral reasons, enclosure reasons, being too bright reasons, as well as the fact that they turn off and on a lot if you hook them up to your enlarger timer.

RalphLambrecht · Jan 9, 2010

John Koehrer said:
You cannot use the red/amber filter with film.
There was a green filter that could be used for several seconds halfway through development.

Yes, I think it's called a dark-green, but it is so dark, you cannot see a thing.

Nicholas Lindan · Jan 9, 2010

For the cheapest (most cost-effective) filter buy a sheet of 'ruby-lith'. You can get it at the art-supply store. A 20x30" sheet costs $5. Get/build a box with one side open, paint it white inside, put in a 7 1/2 watt bulb and put the ruby-lith over the open side. You can also use a large tin can instead of a box.

ricksplace · Jan 10, 2010

RalphLambrecht said:
Here is a test for believers in specifications. Take a red laser pointer or an LED tail lamp from a bike. Check the spec to see what wavelength it emits, usually a very narrow band >630 nm. Now take your favorite photographic paper, and check it's sensitivity limit, usually <580 nm. Now go to the darkroom and shine the laser pointer or the tail lamp onto the paper from different distances for just a few seconds. Should not expose the paper, right? It took only seconds to ruin the paper when I did it. :confused:

The light was too intense. If you take a sheet of paper and hold it up against your safelight, it will fog immediately. Intensity is proportional to the square of the distance, and lasers don't lose their intensity the same way as diffuse light does.

laphro · Jan 10, 2010

If you can find that :
http://picasaweb.google.fr/lh/photo/4rfhdiolGdEn-AJAow_CSg?feat=directlink
It can be the best way to obtain a safelight for cheap, no need for any additional filter and it's only about 5 in France.
I use 3 of these red bulbs in my darkroom, and it works very well.

salihonba · Jan 10, 2010

I agree with laphro, that red LED bulb is exactly what I am using now, works very well, I live in Taiwan, and 3 watts red LED bulb is available in E27 standard thread in market now, they said 5 watts are coming soon.

RalphLambrecht · Jan 10, 2010

ricksplace said:
The light was too intense. If you take a sheet of paper and hold it up against your safelight, it will fog immediately. Intensity is proportional to the square of the distance, and lasers don't lose their intensity the same way as diffuse light does.

Exactly, but why is light at a wavelength outside the spectral sensitivity of the paper creating an exposure?

Ian Grant · Jan 10, 2010

There's a phenomena where light that in theory is completely safe has an effect on an emulsion, if the intensity is high enough it can have an effect on an emulsion, it has a name which escapes me at present.

So below a certain intensity the emulsion isn't fogged, the then there's point where the fogging is enough to seriously affect the contrast in VC papers, yet still show no visible fogging.

Ian

RalphLambrecht · Jan 10, 2010

salihonba said:
I agree with laphro, that red LED bulb is exactly what I am using now, works very well, I live in Taiwan, and 3 watts red LED bulb is available in E27 standard thread in market now, they said 5 watts are coming soon.

I wish I could find them on the web. I found product specifications but no retailer.

Ian Grant · Jan 10, 2010

The problem with certain red safelights

The Herschel Effect

If a photographic emulsion is exposed to blue light and subsequently to red light before development, some of the effect of the original exposure are destroyed; this was discovered by Sir John Herschel in 1840.

While this can in theory affect all modern B&W paper emulsions it really only causes problems with VC papers when the wrong safelight is used (too close or at too high an intensity) while the red light may be insufficient to cause physical fogging, but enough to seriously affect the contrast grades achievable.

The early emulsions Herxchel worked with where of course all blue sensitive.

Ian

DIY safelight

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