> -----Original Message----- > From: Frantisek Vlcek [mailto:[EMAIL PROTECTED]] > > > > Here I want to share the idea, hear some criticism, opinions... > > why LEDs? > - very narrow spectrum. Red leds - ~640nm, +/- 20nm > !!! Nothing > below 600nm, nothing above 680nm! It's really a monochromatic > light. Ideal for VARIABLE CONTRAST papers, which have > sensitivity to about 530nm IIRC. Possibly, orange > leds could be > used, which would be better for assesing the contrast > of the B&W > print than red light.
There are commercial options available, you might want to check and see what wavelength they use. I know JOBO makes a couple. > > cons: > very focused light. Not much diffused. Diffused > colour leds are > available, but not in superbright variant. However, there are > superbright leds with 30-40 degrees cone of light, > but harder to > find. Or a diffusor of some kind could be used, although this > would cut down the light. White leds are diffused enough > (because they use a second level of luminofors which emits the > white light), but unusable for darkroom, obviously. I know what one of the Jobos is able to disperse the light by bunching the LED's under a sort of frosted glass panel thing. Go look at the JOBO site and see what they do. There are some other options as well, including do-it-yourself options, that are easily found with a google search. I think there are many foks who have gone the LED route. Personally, I bought 2 of these used for $30 and they're fine: http://www.camerastore.com/dl_cat_J/-J21_safelight.html (scroll down to PREMIER 5x7 Safelight) I get more light than I really need, and I tested them out to 15 minutes. I have the OC filters. Used darkroom stuff is plentiful and cheap. tv
