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  1. #11

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    I use the colour safetorch from RH designs. It hangs round your neck and has a little button you press when you need some light. It's weak, but in total darkness is surprisingly effective.

    http://www.rhdesigns.co.uk/darkroom/html/safetorch.html

  2. #12
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    If you want a really cheap color safelight, just get some yellow leds. Not orange-yellow, not greenish-yellow, but just yellow. They can give you a very small illumination without fogging the paper. But LEDs have a bandwidth of about 50...60 nm and this limits the illumination level quite a bit. Better than nothing, though; I'm using this kind of safelight. It gives me 5 minutes to work with no fog. And, if you get Wratten 13 filter somewhere, you can always upgrade this LED system by adding the filter. Then you can at least double the illumination level. I'm looking for cheap wratten 13 filters but cannot find any... Anyway, where you can buy these filters?

    As far as I know, all color material can be used in IR safelights (except IR films). Again, LEDs are a cheap and easy way to make your safelight. Buy 940 nm LEDS; they are far away from red and should be 100% safe. I bought these: http://cgi.ebay.com/50-X-5mm-infrare...item2c50552dba
    Not expensive, huh!

  3. #13

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    The problem is Daniel and I aren't working in community labs, we are in individual closet/rooms where it is too small for any kind of safelight... maybe the LEDs would work ok though?

  4. #14
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    My experience is that the tiny handheld safelights, hung in a basket in the tiny closet darkroom was just enough to get it set up. During print and delivery into the machine processor, I turned it off to avoid any fogging.

  5. #15
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    Quote Originally Posted by PeteZ8 View Post
    Any reason you can't/don't use a color safelight?
    Color safelights only work because they're so dim that they don't cause any fogging. As a rule of thumb with those safelights, if it's bright enough to see what you're doing, you're fogging the paper. I got heavy cyan fogging last time I tried. The kodak publication even says "the safelight WILL EFFECT results." My theory is that white illumination is much less of all the wavelengths therefore fogging is spread across all three layers whereas our eyes perceive all of it. Probably completely wrong, but if it ain't broke don't fix it.

    My safelight filter cost $10 or so. Completely useless, but very cheap. I got mine at B&H.

  6. #16
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    I think that there is a big difference between persons in eye sensitivity. I cannot find any other reason to the fact that some people say that a color safelight is very good thing and some that it's completely useless. If you have a good night vision in your eyes, you will enjoy the color safelight without fogging the paper.

    It IS true that any safelight WILL effect results, but if it gives a fog level of, say, 0.05D, then this effect is not VISIBLE to a person who looks at the finished print.

    I have ran fogging tests and my safelight is okay for 5 minutes. I can barely see the paper in dark but it's not enough to help with contact prints. But, I have a button, when pressed, it gives much brighter safelight for a few seconds. I use it when it's time to move paper from DEV to STOP. It can also be used when arranging negs for contact print. It doesn't fog the paper if pressed only 3-4 times. In addition, I use a method of decreasing total safelight exposure by means of blinking the safelight at 0,5 Hz and a pulse width of about 30%; that reduces the total fog to 30%. If I added a very good filter passing only 580-600 nm to my LED safelight, I could probably at least double the illumination level without any visible fogging and get quite a good safelight. It's even more safe when the light source is yellow LEDs to begin with, compared to a light bulb.

    But if the safelight filter passes anything other than 580-600 nm, then it is probably completely useless, at least with an incandescent bulb. You have to be sure.

    I would recommend you to look at the paper datasheet, eg. http://www.kodak.com/global/en/profe...4042/E4042.pdf at page 5: spectral sensitivity curves. You can observe that there is a pit between 580-600 nm that is four stops less sensitive than red layer at 690 nm, and eight stops less sensitive than green layer at 550 nm. If you just had a broad yellow filter, you could have a safelight that really has to be very dim, but if your safelight really is only 580-600 nm, then it could be 16 times brighter. In addition, our eyes happen to be quite sensitive to about 580 nm, much more than to red light, for example.

    So, if you want to use leds and don't have a spectrometer or LED datasheet available, just take the color that is basically yellow but a very little orangish. Not orange, but even worse is to take greenish-yellow -- the reason can be seen easily from the spectral sensitivity curves of the paper.
    Last edited by hrst; 10-18-2009 at 07:23 AM. Click to view previous post history.

  7. #17

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    I use a Kodak #13 safelight filter. It doesn't appear to fog the paper. It takes my old eyes a few minutes to adjust, but I can see well enough to cut roll paper on a paper cutter, and see my way around the darkroom. I minimize the time the emulsion is exposed to the light. I cut the paper and place it emulsion side down until it goes into the paper safe. It's exposed to the safelight for about 10 sec. when I'm cutting it. When printing, the emulsion is exposed to the safelight only for the time it takes from the paper safe to the easle and from the easle to the tube, about 5-7 sec. The small glowing dots on my enlarger are more dangerous for fogging the paper than the safelight. Try to minimize the time the emulsion side is exposed to the safelight by using paper safes and tubes, and you'll probably be OK. I dont think I would use the safelight filter I have if I used trays, although it might be OK if you kept the paper emulsion side down in the trays, and use black trays to minimize safelight exposure.
    Rick Jason.
    "I'm still developing"

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