"Turtle" LED for safelight?

Michel Hardy-Vallée

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I've been having pretty good success in the darkroom with an amber LED light I bought a long time ago, but now the product is discontinued. Searching for existing amber LED light products, I kept stumbling upon so-called "turtle-safe" or "wildlife" lighting.

Here's one example among many:
https://www.accessfixtures.com/led-wildlife-lighting/

Based on the spectrum, this seems appropriate for most multigrade papers. Does anyone have any experience with this kind of product in the darkroom? And why is it that none of the suppliers ship to Canada, goddamnit?
 

Donald Qualls

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That certainly looks as if it should be safe for almost all multigrade, single-grade, orthochromatic, and alt-process materials. If dim enough, it might even have a reasonable safe time before introducing a color cast on RA-4 paper (it's close to the 575nm sensitivity minimum for those papers).

Mind you, all the "wildlife safe" label does it allow the retailer to mark the item up, probably between 3x and 20x what they'd normally be able to get for a near monochromatic LED. Same thing happens with "aquarium safe" -- the exact same clear silicone caulk will cost 3x as much for 1/3 the quantity if it's marked for aquarium use.

Any electronics supplier (Mouser, if they ship to Canada) ought to be able to supply LEDs in the 575 to 595 nm peak emission range and offer spectrum curves as well.
 
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Michel Hardy-Vallée

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I wasn't sure these would be bright enough, so I didn't buy them, but they were in my sight. Yes, do let me know if that works, I might place an order.

I ended up buying this "Turtle" light: http://dabmar.com/index.php/products/dl-tb-led-96-amb.html

They are pretty much expensive when new, but I found a eBay seller who had one for peanuts.

It has a pretty narrow spectrum at 590-620nm, so that's good, but it's also much brighter, being a 12W LED (looks like a 100W equiv). I'll probably place it far from the enlarger/developing area, bounce it on the ceiling or the walls, and do a proper safelight test.
 

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Michel Hardy-Vallée

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Limit? No, I find that amber is actually much easier on the eyes than red. I'm mostly printing on multigrade papers, and get the red light out only when I develop Harman Direct Positive.
 

rjbuzzclick

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I just bought four of these myself. Tested fine with Ilford Multigrade RC paper for 10 minutes at about 6' away. I didn't test for longer times as that covers most of my needs. I put just one in the ceiling light in my roughly 10'x12' basement workshop/darkroom (~7' ceiling height) and it's surprisingly bright. I've also used it for tray developing Arista Ortho Litho 3.0 film, and Fuji HRU X-ray film and didn't notice any issues.
 

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I have been suspicious of red safelights for MG paper ever since I learned of the Herschel effect. I use amber exclusively. And if you're going to spend on one of those Turtle-safe lights, you might as well go for a Heiland LED safelight, get amber or red at the flick of a switch.
 

tezzasmall

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Pieter12 said:
I have been suspicious of red safelights for MG paper ever since I learned of the Herschel effect. I use amber exclusively.
Click to expand...
Hi Pieter. I had to look up 'Herschel effect': https://www.merriam-webster.com/dictionary/Herschel effect

You say that you 'learned of' the effect, but have you ever noticed this effect actually happening with your work? I ask as I, like so many others on this and other forums, quite happily use red leds in our darkrooms with no noticeable effect of anything that may ruin the print.

Terry S
 

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Terry, I have just looked up the definition you link to and it mentions partial latent image destruction. I wonder if this can possibly have any effect over what must be a very short time period of seconds from removal from the enlarger easel to the developer tray.

In the case of those MG papers for which red is specified( Foma, I think) what has been done to the paper to remove the possibility of the Herschel effect?

So 2 valid questions, I believe, to which I'd welcome answers

pentaxuser
 

Donald Qualls

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And how does this relate to the Becquerel method of developing latent images (on Daquerreotypes) with prolonged (roughly a week) exposure to red light? This was known since the 1840s, and is sometimes suggested as a safer, more environmentally friendly alternative to mercury fuming for those using halide fumed silver over copper to record their images.
 

ic-racer

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Amber appears brighter than red to the human eye. Especially so for dark-adapted eyes.


 
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Donald Qualls

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Yep. Human eyesight maximum sensitivity is close to the yellow sodium line at 555 nm, so starting from red, every little step toward green lets you make the actual light dimmer and still see as well or better. And amber light at around 640-650 is excellent for nearly all multigrade, materials, though true ortho may be better with red around 700.
 

MattKing

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But do they make cheap 645nm amber LED rope lights?
One of the reasons I like the rope lights is because it gives me really even light that is well distributed through my darkroom - almost no problem with having to work with something in my own shadow.
 

Pieter12

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I can't speak for others, I don't know what their prints look like. It may not show on every, all or any print that I make--I just feel more comfortable not introducing a possible limitation to what I might be able to print. Maybe next time I'm in the darkroom (It's too damn hot right now) I will try a side by side comparison of red and amber safelight on a print.
 

Donald Qualls

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If the rope lights come in yellow, it's probably close to that, but you'd have to get the spec sheet from the manufacturer (perhaps the manufacturer of the actual modules in the string) to be sure -- 575 nm is too green for multigrade materials, will tend to fog the low-contrast layer (but is just right for RA-4 safelight, if you can make it dim enough).
 

David Brown

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Led (for) safelights was quite the bone of contention on this forum for a few years, several years ago. And, of course, it still comes up from time to time. I was a skeptic about using colored bulbs, of whatever technology, but I finally decided to test the Superbright leds and put it to rest. To my surprise, they tested perfectly safe for Ilford Multigrade paper out to 10 minutes. I still use them in my darkroom, and they are very bright. They also come in amber. HOWEVER: the caveat as that any new light source MUST BE TESTED for any paper. I'm still concerned that a vendor like Superbright will have the same bulbs from the same supplier year after year. I would not hesitate to order more of these bulbs, but I would not assume that they are safe until TESTED! See this thread: https://www.photrio.com/forum/threads/best-safelight-99-99-safe.104023/#post-1374616, specifically post #22.
 
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Michel Hardy-Vallée

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Quick update here. I did the Kodak safelight test for my "turtle" light, but it hasn't been very encouraging. Although the light is strongly monochromatic, and I could use it to print photos, when tested properly it created fog at the 3 minute mark.

I also reverted back to my red LED, since I found out in the same breath that my amber safelight could cause some light fogging as well. The red was bulletproof: lots of light, not fog, so what's not to like?
 
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