Led exposures

[Thisisjah]

Hello friends
Jah here from New Zealand
I’m currently in the process of setting up my own thing from home and using a 500 halogen flood light to expose screens, its sweet but takes forever and I have seen all the hoopla regarding LED lights.
im very keen to give this a go but when I went into the hardware store I spent more time getting blinded by the lights ( Springsteen reference there ) than knowing what to actually buy.
what lumens will expose a screen is my real question
appreciate any info given
chur

[opaezosu]

Hello there!

It is more about wavelength than lumens in this case. The range is above 360 nm wavelength. Depending on the emulsion you use. Double check wirh your emulsion provider.

[Chuggins]

Hello Jah!

Opaezosu is mostly correct, Ideally you want to find LED's with a wavelength of 405nm. While 360 or 390 will "work" it will not harden the emulsion as well as you want. There is a definite difference in how hard your emulsion gets, how resistant to breakdown it becomes, and how the emulsion resins react to light waves - between the different light frequencies.

Ideally, you want a bulb like Metal Halide that is multi spectrum to do your exposures with. However those bulbs are expensive and use A LOT of electricity. This is part of why LED has become so popular.

The other thing you want to look at is wattage of the LED. The higher the wattage, the more "punch" the light has. This directly equates to a stronger and faster exposure.

If you have a 50 watt led light, this is better than a 20 watt. The next thing we look at is how far away the strips, or flood light square, is from the image. The further away, the greater your power loss will be. There is a lot of information on the web about strength of light and how much it diminishes over distance.

[hemaye]

Actually we comprehend that to effectively extend your item through a publicizing medium to a focused on group of spectators you will require the WOW factor. We expect to accomplish this by introducing LED screens in a financially savvy and bother free way.

[hemaye]

Preferably, you need a bulb like Metal Halide that is multi range to do your exposures with. Anyway those bulbs are costly and utilize A LOT of power. This is a piece of why LED has gotten so mainstream.