Red safelights may be good for our eyes

Doremus Scudder · Jun 30, 2020

It seems that exposure to red light in the 670nm to infrared range might be good for preserving vision as we age.

https://www.cnn.com/2020/06/30/health/declining-eyesight-red-light-scn-wellness/index.html

I'm heading for the darkroom...

Doremus

bdial · Jun 30, 2020

Sounds good to me.
My darkroom has been neglected for a bit, time to change that I guess.

grain elevator · Jun 30, 2020

White light contains plenty of red light. The summary doesn't explain why that normal exposure doesn't do the trick.

pentaxuser · Jun 30, 2020

grain elevator said:
White light contains plenty of red light. The summary doesn't explain why that normal exposure doesn't do the trick.

Plus the study was laughably small by normal standards of such studies and with no randomised control installed. There you are: You can always trust two Europeans to put a dampener on proceedings

pentaxuser

mshchem · Jun 30, 2020

Before my 4th and 5th enlarger and my 2nd sink I had a recliner in my darkroom. Always cool, option of nice sodium vapor safelights. Very relax.

Nodda Duma · Jun 30, 2020

grain elevator said:
White light contains plenty of red light. The summary doesn't explain why that normal exposure doesn't do the trick.

white light includes UV light which causes problems.

grat · Jun 30, 2020

pentaxuser said:
Plus the study was laughably small by normal standards of such studies and with no randomised control installed. There you are: You can always trust two Europeans to put a dampener on proceedings

So your argument is that if you pick a random group of 24 people and study them, there would be improvement to eyesight to all 24 for no reason whatsoever.

Seems reasonable to me.

AnselMortensen · Jul 1, 2020

Well, the Tunnel Rats in Vietnam were issued flashlights with red lenses because it preserved night vision, from what I have heard.

Jim Jones · Jul 1, 2020

When I joined the U. S. Navy in 1950. red illumination was used at night to preserve night vision.

Truzi · Jul 1, 2020

Red illumination has also been used for ages in observatories for the same reason.

Sirius Glass · Jul 1, 2020

Now I have to spend more time in the darkroom, rats! @$$#%*^%^$##!!!

pentaxuser · Jul 1, 2020

If red safelights are good for your eyes and are safe for all papers whereas the likes of Ilford 902 isn't safe for all papers, then shouldn't we be recommending that all newcomers to darkroom work use red safelights only. Indeed on the basis of the study linked to as the thread opener shouldn't we all be changing to red if we currently use the 902 type of light? I am sure I have read threads on safelights that said that red was more of a strain on the eyes or is this a figment of my imagination?

Usually one of the reasons why the Ilford 902 (amber/ brown) is recommended is that it is less of a strain on the eyes in a darkroom. How do we reconcile this with red preserving night vision?

pentaxuser

MattKing · Jul 1, 2020

It is the lack of UV in red light that benefits our eyes.
Our eyes, however, are less sensitive to red than to amber light, so for the same amount of illumination, amber safelights make it easier to see what we need to see, while still protecting the light sensitive paper we work with.

Vaughn · Jul 1, 2020

Going in and out of a darkroom (communal darkroom, so one had to exit to see tests, prints) so many times in my life, I think my pupils can crush tin cans.

Andrew O'Neill · Jul 1, 2020

I'll keep wearing my rose coloured glasses, then.

pentaxuser · Jul 1, 2020

MattKing said:
It is the lack of UV in red light that benefits our eyes.
Our eyes, however, are less sensitive to red than to amber light, so for the same amount of illumination, amber safelights make it easier to see what we need to see, while still protecting the light sensitive paper we work with.

So red safelights "strain the eyes but not in a permanently detrimental form. Would the analogy be that reading in poor light, contrary to popular belief does not harm the eyes but just makes it more difficult to see things

Is this a reasonable summation of your post, Matt? If it is then isn't my contention that on that basis we should be using red safelights still correct? Of course that assumes that any red darkroom safelight lacks UV compared to any other colour of safelight light. Is this the case? Is the usual safelight anywhere near the wavelength that was used in the study or does this not matter?

What colour of safelight do you use, Matt?

Still not sure how to reconcile your second sentence above with other posts suggesting that red aids night vision if anothe colour like amber makes it easier to see what we need to see in the darkroom

pentaxuser

MattKing · Jul 1, 2020

Nope.
The link is telling us that exposure to red light is good for our eyes.
It has nothing to do with eye strain.
When it comes to the efficiency of safelights - how much they aid in our seeing things in an environment that protects our photographic paper - that is a function of how our visual system works.
We can see better if something is illuminated with amber light than if it is illuminated with the same amount of red light.
The most efficient system would use green light - the colour our eyes are most sensitive to - except the paper is sensitive to green light as well, so it will fog under a green safelight.
I expect that observatories and other places that historically needed to preserve night vision would have used green light instead of red if it wasn't easier to make red sources.

MattKing · Jul 1, 2020

I'm using (or at least I was before my recent move) a 16 foot red LED rope light in my darkroom. The reduced efficiency of using red is more than made up for by the efficacy of having the safelight illumination spread evenly through the darkroom.
If I could access a narrow spectrum "OC" or "902" LED rope light, I would use it instead, because it could be even brighter than my red rope light.
In the past I've worked in commercial darkrooms with specialized sodium vapour discharge safelights. You can easily read a newspaper in that level of safelight illumination.

pentaxuser · Jul 1, 2020

MattKing said:
Nope.
The link is telling us that exposure to red light is good for our eyes.
It has nothing to do with eye strain.

I expect that observatories and other places that historically needed to preserve night vision would have used green light instead of red if it wasn't easier to make red sources.

Yes I understood all of what you said and I had thought I had in effect repeated what you had said in different words. It was clear what the link was saying. It was saying what you have said it was saying and this is what I too concluded it was saying: Hence my question : If it is to be believed then shouldn't we be recommending to all newcomers to darkroom work that they use a redlight exclusively.

It may be that like me you have yet to form a conclusion based on this study. In which case that's fine. It was just that we seemed to have a swing towards the benefit of red light so I thought I'd take it a stage further and ask the question to the forum participants

pentaxuser

john_s · Jul 1, 2020

MattKing said:
....................In the past I've worked in commercial darkrooms with specialized sodium vapour discharge safelights. You can easily read a newspaper in that level of safelight illumination.

The spectrum of sodium vapour lamps has a sharp cutoff. Unfortunately LEDs that appear to our eyes as similar in colour (amber) do not. The graphs showing the spectral spread of LEDs is usually in arithmetic units and when redrawn in log units (relevant to photography as we all know) it's worse.

My solution, like other posts here, is red, very red, LEDs for general darkroom work. Also, I use a yellow LED lamp which I use briefly if I have to evaluate something like a test strip. Not as good as white light but a revelation after working with red light.

AnselMortensen · Jul 1, 2020

A good way to check if a red light source is pure red is to put the business side of a CD next to it...if it reflects anything but red, it's not a pure red light source.

RalphLambrecht · Jul 1, 2020

pentaxuser said:
Plus the study was laughably small by normal standards of such studies and with no randomised control installed. There you are: You can always trust two Europeans to put a dampener on proceedings

pentaxuser

The UK it's part of Europe at least geographically.

pentaxuser · Jul 2, 2020

RalphLambrecht said:
The UK it's part of Europe at least geographically.

Yes it is Ralph and long may we regard the U.K. where I live, in this way in terms of our ties with the rest of Europe. I pointed out my reservations about the validity of the study's conclusions as did another poster who is from Germany. Hence the reference to 2 Europeans casting some doubt ( putting a dampener on proceedings) about the study's conclusions.

pentaxuser

Brendan Quirk · Jul 2, 2020

The theory that red to near infrared light improves cellular metabolism is known as photobiomodulation (PBM). My research group has published extensively in this area. There are hundreds if not thousands of articles describing usually small improvements in animal and cellular models, most commonly with 670 nm and, somewhat less, 830 nm light, plus many other wavelengths from the 500s to beyond 1200. Clinical results, however, have been mostly equivocal or negative. In addition, basic science has so far been unable to determine the mechanism for action. At this point, it is unclear whether the phenomenon of PBM will ever be clinically useful. A small intro to the literature may be found here.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3048832/

MattKing · Jul 2, 2020

I am content to accept that the red safelights in my darkroom are good for the soul, and let the science evolve on any benefits that my eyes might receive!

Red safelights may be good for our eyes

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