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bicycle LED as safelight
On Tue, 24 Feb 2004 11:04:01 -0500, Luigi de Guzman
wrote: I know that this has been asked here before, but google doesn't supply a suitable answer. Everybody seemed to want to talk about lowering the voltages on bulbs, not using LEDs. There are red led Christmas lights that are very reasonable to purchase. About $6.00 for a string of 35. Personally I like the Thomas safelight with the low pressure sodium bulb. |
#2
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bicycle LED as safelight
I use 13 red LEDs (mounted close together) as a safelight.
Did all the standard tests with VC paper and no fogging. Make sure they are red and not red/orange. Jorge Luigi de Guzman wrote in : I know that this has been asked here before, but google doesn't supply a suitable answer. Everybody seemed to want to talk about lowering the voltages on bulbs, not using LEDs. I have a pair of red LED bicycle taillights; three red LEDs each, red lenses, and intend to use them as safelights. I use variable-contrast papers. These are LEDs, not bulbs, so I figure they're more or less monochromatic. And I've used VC papers in red-bulbed safelight darkrooms before. Will this work? Seeing as there are commercially-availble LED safelighting solutions, it would be kind of silly for me to buy them specially, if I have something suitable already at hand. -Luigi www.livejournal.com/users/ouij Photos, Rants, Raves |
#3
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bicycle LED as safelight
Why don't you just test it? Put a coin on some paper, shine the bicycle
light at it for 5 minutes and see if the coin image shows when the paper is developed. This is not really a question that anyone can answer on a newsgroup. It is also faster to just test it. PSsquare "Luigi de Guzman" wrote in message ... I know that this has been asked here before, but google doesn't supply a suitable answer. Everybody seemed to want to talk about lowering the voltages on bulbs, not using LEDs. I have a pair of red LED bicycle taillights; three red LEDs each, red lenses, and intend to use them as safelights. I use variable-contrast papers. These are LEDs, not bulbs, so I figure they're more or less monochromatic. And I've used VC papers in red-bulbed safelight darkrooms before. Will this work? Seeing as there are commercially-availble LED safelighting solutions, it would be kind of silly for me to buy them specially, if I have something suitable already at hand. -Luigi www.livejournal.com/users/ouij Photos, Rants, Raves |
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bicycle LED as safelight
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#6
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bicycle LED as safelight
Luigi de Guzman wrote in message news:
These are LEDs, not bulbs, so I figure they're more or less monochromatic. They are likely to work, but LEDs are nowhere near monochromatic. The safelight test using coins should be done on paper that is already uniformly exposed to give a mid to light grey. What you are looking for is the absence of a slightly paler grey where the coins were. If you don't, your test will not be sensitive enough to ensure safety. Kodak have a pdf file on safelight testing. |
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