Lighting in the screen room

[kingscreen]

We got ours here: https://www.1000bulbs.com/category/uv-blocking-fluorescent-tube-guards/

[jsheridan]

if you don't want to deal with the tubes they have these sleeves that roll onto the bulb.


http://www.uvprocess.com/product.asp?code=FILTER+++I

[TCT]

if you don't want to deal with the tubes they have these sleeves that roll onto the bulb.


http://www.uvprocess.com/product.asp?code=FILTER+++I

These are the exact ones we use. They come rolled up pretty small. If either of you guys outside the states wants some and has trouble getting them, pm me, if be happy to buy them and send them your way.

[ABuffington]

Thanks for the link John: http://www.uvprocess.com/product.asp?code=FILTER+++I
Another manufacturer is Encapsulite: http://www.encapsulite.com/graphicarts.html

A test for any room is to put a couple of coins on a coated screen and place it on the floor beneath the lights, or even higher on a rack if it is under the lights.
Leave lights on overnight.  Wash out in the morning.  If you see circles appear and wash out faster than the surrounding area there is light contamination.

LED is typically single wavelength, so this may be possible, haven't tested this yet. 

Al

[mk162]

we have tube LED's and they would expose a screen in about 4 hours.  It was worth the test though.  One day I will slap some other bulbs in and see(actually I have some other ones, I'll give it a shot)

[Maxie]

Al, which tube is required for our emulsions, the clear UV or the Amber?

[ABuffington]

I have seen both work,  Being old school I like Amber just to prevent someone from using regular light in the screen room.

[kingscreen]

We use Amber. 

[jvanick]

we have tube LED's and they would expose a screen in about 4 hours.  It was worth the test though.  One day I will slap some other bulbs in and see(actually I have some other ones, I'll give it a shot)

I think M&R experienced this at their factory too... I wonder why LED's that are typically single spectrum sources are putting out so much UV?

Anybody have any LED FL retrofit tubes that are known to work?  I'd love to work under white light in the screen room, but I don't have the time to test a bunch of different brands to see what may or may not work.

-J

[mk162]

I will be testing the Hyperikon brand either tomorrow or next week.

The InnoLED brand fails miserably.

Regular fluo tubes are fine to be honest.

[Sbrem]

we have tube LED's and they would expose a screen in about 4 hours.  It was worth the test though.  One day I will slap some other bulbs in and see(actually I have some other ones, I'll give it a shot)

I think M&R experienced this at their factory too... I wonder why LED's that are typically single spectrum sources are putting out so much UV?

Anybody have any LED FL retrofit tubes that are known to work?  I'd love to work under white light in the screen room, but I don't have the time to test a bunch of different brands to see what may or may not work.

-J

I think that maybe the LED's peak outside of the UV part of the spectrum, that doesn't mean there isn't some; most lights are designed to work at specific wavelengths, but generally aren't restricted to a single wavelength...

Steve

[jvanick]

doing some reading this morning, it turns out that some 'white' LED's are created by using a UV LED with a flourescent layer of some sort over it that the UV light excites to turn white. 

Not sure if those are the cheaper ones, or the more expensive, as there doesn't seem to be a lot of info out there.

From wikipedia:

There are three main methods of mixing colors to produce white light from an LED:

    blue LED + green LED + red LED (color mixing; can be used as backlighting for displays)
    near-UV or UV LED + RGB phosphor (an LED producing light with a wavelength shorter than blue's is used to excite an RGB phosphor)
    blue LED + yellow phosphor (two complementary colors combine to form white light; more efficient than first two methods and more commonly used)

digging a bit deeper, blue LED's have a color spectrum starting in the mid 400nm range, which is likely right at the top end of some emulsion's sensitivity.

[ABuffington]

A lot depends on how long you store your coated screens.  Light contamination can take days.  So if you coat and expose quickly you may see nothing.  If you store for weeks it is wise to do an overnight test with screens on a counter near your lights, (or floor), put some coins on the bottom of the screen and then wash out screen in the morning.  If you see any circles lighter than surrounding emulsion and they wash out before the surrounding area the light will eventually ruin the screen.  It may still create an image, but details will be hard to wash out, and edges may sawtooth due to paritally exposed screen.  Vapor barrier doors also need to be UV proof.  Went to a new shop and the screen room door faced the back shipping door 12 feet away and they had clear vapor barrier entry.  All the screens near the door were exposed by blue sky or reflected sunlight off of a nearby building. 

Al

[Alex M]

we have tube LED's and they would expose a screen in about 4 hours.  It was worth the test though.  One day I will slap some other bulbs in and see(actually I have some other ones, I'll give it a shot)

I think M&R experienced this at their factory too... I wonder why LED's that are typically single spectrum sources are putting out so much UV?

Anybody have any LED FL retrofit tubes that are known to work?  I'd love to work under white light in the screen room, but I don't have the time to test a bunch of different brands to see what may or may not work.

-J

You would be correct, after around 4 hours with a quarter on the screen we would wash out the spot easily.
We now use amber in the coating room, but still use the white led bulbs in the screen room b/c the screens are only out of the STE II for a short time (25ft of walking).

[screenxpress]

It's 2015... not the 'dark' ages anymore.

Light that room bright as day with LED lighting

^^^^^^

Although for moderately brief periods (taping film, etc.) I have never had a problem with full-blown fluorescent lights.