night vision in darkroom question

A friend has an inexpensive night vision (ATN, $300) monocular headset for darkroom use.

He says it is really set up for infinity focus, blurry but usable for close work.

It occurred to me...wouldn't a +1 diopter close-up lens help?

Murray

I use the ATN Viper monocular in the darkroom. The focus point is adjustable from about 12” to infinity. DOF is much less the closer you focus though, which makes sense. Maybe that is what he means by “blurry”. I use it mainly for developing by inspection and have no trouble getting good focus at this distance.

Ask your friend if they have tried to adjust BOTH the objective lens AND the eyepiece.

Charley

OK. His IS a few years old...ATN said it's 1st generation.

I actually asked him if I could borrow it since he hasn't been developing film lately.

Is there infrared light in a darkroom? Esp if it's a basement (ie the barriers to light are not just black cloth but brick walls).

Hello Murray,

I have a Viper and it works well. There is a lens cap with a small hole (aperture) for use in bright light to protect the sensor. There is usually enough light from the built in illuminator to use the cap, with an expected increase in depth of field. I have had no fogging problems, although I only use it when necessary (like loading the second tier of super 8 film in a Lomo tank).

IIRC they sell a close-up lens for this unit, but I haven't found it necessary. Also, I think one could buy one for somewhat less than $300.00.


Cheers,
Clarence

Thanks. Their tech support was apparently unfamiliar with either the option or my idea. :O)

M

Xmm, this is an interesting topic. AFAIK, ATN and similar devices are actually a regular night vision, i.e. light intensifiers which means they just apply a high gain to the weak available light in the surrounding. Hence, often, in military applications they called star light intensifiers working reasonably good under available star light or moonlight at night, but, of course are useless in complete darkness.
Now, this thread mentions using these in darkroom where complete darkness is presumed. I'm curious how that kind of night vision devices can work in the darkroom (unless there are light leaks inside)....?? Do I miss something ?

What should work though is thermal night imaging. These do not depend on ambient light availability, work fine in complete darkness as long as there are temp. gradients between the material around (almost always is). Using thermal uncooled device may indeed be useful in fully sealed darkroom...

Most he IR viewers I have used in the darkroom have had an IR LED as a a light source, in one lab there was IR illumination in the darkroom. This had to be turned off if we had IR films to process.

That may indeed explain their usage in darkrooms...

Alexz,

Actually the Viper has an illumination source. While it does emit some in the visible range, it does not seem to be a problem with the emulsions with which I have used it. Some have expressed concern that the light spill-over from the ocular could be a problem. I have not found this to be a problem either, but I use mine very carefully and only when necessary.

Cheers,
Clarence

CRhymer said:

Alexz,

Actually the Viper has an illumination source. While it does emit some in the visible range, it does not seem to be a problem with the emulsions with which I have used it. Some have expressed concern that the light spill-over from the ocular could be a problem. I have not found this to be a problem either, but I use mine very carefully and only when necessary.

Cheers,
Clarence

Click to expand...

Unless you have tested your affixed IR light source in a controlled environment and can state factually that you do not have increased FB+F you are (respectfully) at the best very lazy in this assumption and at the worst dead wrong.

My Argus Gen 1 IR monocle fogged the living crap out of my film from A-Z particularly T Max 400. That is why I do not even have batteries in my affixed IR light source and instead opt to bource an electrical IR LED bank off of an adjacent wall in my darkroom. If you can see it, so can the film. I only turn on the capture monocle.

If you are reaching into your pockets for ever increasing costs to purchase film, the least we can do is to take the time to insure that you are not trying to take a step forward and are actually two steps in the wrong direction. Put a strip oif black electrical tape down the center of a sheet of film in complete darkness and them turn on your attached IR source for a minute or two at about the distance you load holders at. Close the lights and pull the tape and develop the film in complete darkness and read the densities.

Then tell me that upwards of 0.2+ density units is not that big a deal.

Unless you test your system you simply don't know.

Cheers!

I would say the same things about testing safe lights which is another of my pet peeves.

Michael,

Of course, you are right. I was responding to note that the Viper has an illumination source and it is slightly visible. I should not have been careless in giving vague and generalized assurances. The illuminator, IIRC, can not be turned off on this unit, but can easily be masked. I made an LED array in the longer of two common IR wavelengths available, but found that the Viper was not very sensitive at this wavelength. I don't have my notes at hand, but will post them when I have an opportunity. It is possible, but unlikely, that my array was not working properly. I have no other means at hand to measure the illumination, but the voltages and current were within expected values. I am intending to try different LED's at shorter wavelength in the IR, but the project is on the back-burner at present.

I apologize to the other posters for giving vague assurances. Of course one must do controlled tests on the actual emulsion used.

Thank you for the reminder.

Cheers,
Clarence

I have been using the viper for a while. When loading film, I usually have the cover on as the film is just to bright. I Develop in clear acrylic tanks that I made. I develop in pyrocat-P minimal agitation. I can tell you that I have looked at one spot in a neg at closest focus (Less that 12") for over 30 seconds more than once during development, with no, let me say that again, no ill effects. As pyro developers desensitise the film as it develops, you might have a different outcome with a solvent developer. I do believe that is the answer to the real question all wonder about with this handy toy. My recomendation is to keep your time and temp program and let it show you what the negs should look like. I don't keep negs in a seperate box as the ones overexposed for underdevelopment will jump to the fore telling me of an early pull. When starting out you WILL pull early, even more so in a white trays than tanks.

You are a true professional Clarence and for that I thank you. We all need to remember that this venue is used at times as a reference for others that want to learn and grow and learn from others experience so we all benefit.

Sometimes low end densities are very difficult to see with the naked eye and until you read them with a densitometer, you may not be seeing the whole picture (no pun intended). I will read anyone's test negatives as a courtesy with my densitometer if you do not have this equipment. Just PM me. We are all on this journey together. I just want people to continue purchasing film.

Cheers!