670nm red bulbs for sleep therapy as safelights?

[What About Bob]

Recently I bought a few of these type of bulbs to see if they would help out with sleep. They are Neperal brand bulbs at 7 watts, 60 watt equivalent, that screw into a standard socket. I don't have any paper materials to test for but I was curious if anyone ever tried using 670nm deep red bulbs as safelights? Seems to me like they should work being that they are further down the visible spectrum of red. Claim to have no blue and green spectrum at all.

I noticed that if I am at a certain distance with these lights I do get this sensation that is sort of off-putting, uneasiness feeling. What I find interesting is that this sensation is closely identical to the feeling I had when I tried a melatonin tab from CVS years ago.

I never experienced any negative effects with red and amber safelights in all of my time when I printed but these red bulbs do have an effect. My guess is that the sensation might be dependent on distance and time of exposure to these therapy bulbs. At a slightly farther distance these 670nm lights are kind of calming and moody and I don't get that uneasy sensation.

 

[Raghu Kuvempunagar]

If you have a CD/DVD, you can do a test that doesn't require photographic paper.

 

[Klaus_H]

I am using dimmable LED stipes with 670 nm red light in my darkroom. They are compatible with photo papers from FOMA and Ilford.

 

[koraks]

I've been using ca. 660nm red for safelights for years now. I don't notice anything particular about them, except of course that the human eye is relatively insensitive to these wavelengths so you need more power than for shorter wavelengths to get the same visibility. However, as @Klaus_H also indicates, red is compatible with Foma papers, and at low intensity will also work with e.g. green-sensitive x-ray film.

I don't know about the melatonin parallel; I think it's a little far-fetched to be honest, but I do agree that working under (red) safelights can be sort of soothing in a way. But I've never noticed a distinct difference in this regard between e.g. 625nm red and 660nm red - except that the latter is darker at the same wattage, due to human spectral sensitivity.

 

[thinkbrown]

I've also had good luck with 660nm leds and can run them pretty dang bright compared to a traditional safelight. I did experiment with a 730nm near IR light as well but unfortunately while the human eye can see that wavelength it's very insensitive to it so the amount of wattage you have to pump into it to get a usable safelight makes it prone to fogging materials.

 

[What About Bob]

@Raghu Kuvempunagar: I didn't notice any blue/green or any other color banding with the CD test. All was clear red reflected off from the CD's surface. Pretty cool test, or warm. It's good to see that others have success with these type of lights.

@Klaus_H: Strip lights sound good. Kentmere should fall into being workable as well with these lights.

@koraks: Intensity is something I would need to play with. This brand bulb isn't dimmable. Next time around I will look into some dimmable ones.

I left the red light on for the first night and while I did fall asleep I think it was more on account of the working out that I did at the gym, hours ago.

@thinkbrown: Would you know the wattage for a 730nm light before it started fogging materials and how was visibility?

Thanks, everyone.

 

[thinkbrown]

@thinkbrown: Would you know the wattage for a 730nm light before it started fogging materials and how was visibility?

I ran tests with both the 730nm and the 660nm strips I'm using off a 700ma power supply which comes in around 16w. the 730nm unit needed to be directly overhead to provide any sort of useful light which caused fog issues pretty rapidly. The 660nm almost immediately fogged materials at the same distance but was insanely bright. I currently use it mounted to the ceiling about 8ft away and have good workable lighting.

I'm gonna estimate that the 660nm light is perceptually about 10x brighter, but they both look pretty similar through the infrared capable camera I have in my darkroom.

 

[koraks]

Spectral sensitivity of human cone cells. Note there's virtually no sensitivity beyond 700nm, and around 650 things are already marginal. This is to illustrate what I said before and that confirms also what @thinkbrown says above, i.e. that you need a truckload more power at longer wavelengths for the same apparent intensity if you go from standard LED red 620nm to 660 and beyond.

The main issue with 620nm red LEDs in my experience is that many of them emit green and yellow light as well. Although this is proportionally marginal in quantity, because it sits in the sensitive region of the paper, it does constitute a fogging issue. It can to an extent be filtered out with a red filter, but this isn't perfect in my experience. Testing is needed to determine safe intensity limits.

The long & short of it is that there's usually a tradeoff and either a longer wavelength (deep red 660nm) or a shorter one (standard 620) can work, but both do require testing to determine how much exposure the paper can safely handle. Keep in mind the paper itself matters a lot, too.

W.r.t. psychological effects I really wouldn't know; all I know is that the absence of bluye makes a difference.

 

[loccdor]

If I need a particularly sound sleep I pop a melatonin gummy directly and I'm usually out within 30 minutes. The most common cause of early waking, at least for myself, is having a beer too close to bedtime. Melatonin at reasonable doses is very safe and without many side effects compared to other sleep aids, and it's also a powerful antioxidant.

 

[What About Bob]

@thinkbrown, @koraks: Thank you both for the information. At some point I will do some testing when I get paper.

I also noticed on the side of the bulb there is mention of 85V-265V? Variable voltage? The spec sheet says 110V.

@Raghu Kuvempunagar: That Rubylith stuff from the page link is something I'll be looking into.

@loccdor: I might give the melatonin stuff a retry. I'll look around for the gummy version. The CVS brand were itty-bitty-pills.

 

[Alan Townsend]

Recently I bought a few of these type of bulbs to see if they would help out with sleep. They are Neperal brand bulbs at 7 watts, 60 watt equivalent, that screw into a standard socket.

I use red led bulbs in my darkroom and like them. Don't know their frequency though. With red light, our eye pupil dilation mechanism doesn't stop our pupils down like other colors, so our eyes go full aperture regardless of intensity. This is why red lights are used on aircraft instrument panels and amature astronomers gear to not reduce night vision. Mine don't fog fuji hru green xray film with indirect use, but have fogged VC enlarging paper, so must have some yellow.

When I was in college in 1972 they had those low pressure sodium safelights that are monochromatic amber. Anybody remember those? It was bright enough to read the newspaper in the darkroom. I really hated those, made it very hard to focus the enlargers but safe for VC papers.