LED safelight wavelength?

[Darrell Harmon]

I a planning on constructing a LED safelight for my darkroom. I want to use Lamina Light Engines LEDs. These are a ceramic substrate with many LED dice attatched. There is a red (618 nm) and an amber (589 nm) available. Both can be run at up to 18 watts and cost around $20. I do plan to include a current regulator with a brightness knob. Do you think the amber one would be safe? It should be really close to the Thomas sodium safelight. The LEDs do need a heatsink and current regulation to operate.

http://www.laminaceramics.com/products/bl2000.aspx

[chris_4622]

try this, http://www.w-led.com/

[Henry Ambrose]

Save yourself the trouble and buy one of these lamps:

http://www.optiled.biz/products/products.html

Scroll down to the "Festival" model - it comes with a standard household base so just screws in any fixture.
You'll notice in the .pdf they supply, a spectral distribution chart. These lamps are very sharp cutting and I've found the red and red/orange to be safe in my little darkroom for seven minutes (thats as long as I tested). Super bright and super safe.

I think someone wrote that they are now avaiable on eBay. I bought mine direct from the company several years ago.

[robc]

if you are printing colour then red is NOT good!

589nm is the same as sodium which is used for colour printing.
I use a duka 50 which uses a sodium lamp. For B+W I use its red diffuser which gives me very long safe times for B+W. Over 20 minutes for all papers I have tested providing it is not turned up too bright.

[Sal Santamaura]

You'll notice in the .pdf they supply, a spectral distribution chart. These lamps are very sharp cutting and I've found the red and red/orange to be safe in my little darkroom for seven minutes (thats as long as I tested). Super bright and super safe.

The link leads to a "The page cannot be found" message. Anyone know whether that's just a temporary problem or indicative that OptiLED is changing the FESTIVAL's specifications?

[Henry Ambrose]

Sal,

I just tried the page from the link I posted and it works for me - you might try again.
Scroll down a bit and you'll find a .pdf to download.

Henry

[Malcolm Stewart]

I have the Barbieri Colorlamp 50 safelamp and when I dis-assembled it, I noted that in addition to the (orange) LEDs there was also some form of sheet plastic filter. (The filter had got our of alignment with the aperture so needed re-alignment.) The emitted colour is a sort of orange/amber, and brightness can be varied.

There used to be a website describing it, but that's now disappeared.

[Bobf]

Can't speak for colour, but I use a 590nm(ish) Lumiled in my darkroom and it is fine for over 15mins with MGIV and Kentmere Fineprint - I have to dim it as it's too bright otherwise and I can't see to dodge/burn with too much light on the easel...

Cheers, Bob.

[Sal Santamaura]

Sal,

I just tried the page from the link I posted and it works for me - you might try again.
Scroll down a bit and you'll find a .pdf to download.

Henry

Just tried it again at home with the same result. Perhaps the file is in your cache from a previous viewing, Henry. I emailed the manufacturer right after my first post with the question; no reply yet.

[Henry Ambrose]

aaaahhhh.........

I was referring to the web page not the .pdf. I see now that the .pdf is not there.

I do have this info from their on-line store -- http://www.lightworld.com/optiled/index.asp?id=4
Red = 626 nm
Amber = 590nm

And from memory, they cut off about 10nm either side of those values.