Infrared goggles in the darkroom

[Dan_3766]

The thought of processing sheet film by inspection is very appealing and makes perfect sense. Many do it with a dark green safelight but some, I understand, use an infrered light source with infrared goggles to "see" the film thru the entire process as opposed to the few seconds a green safelight can offer.

Question is, what is the cost of an appropriate infrared system and where does one get such a thing?

Regards.

[Steve Baggett]

A pair of Gen-I (generation 1, the oldest technology) IR goggles will cost about $500 and can be found (among many other places) here (http://www.night-vision-goggles.com). I have a pair that will focus down to about 12 inches, which should be good enough. You will need to have an IR source in a totally black darkroom. The goggles come with an IR source mounted on them you can use. However, these sources give off a faint amount of visibile light way down in the red region. (You can see this with the lights off and the IR source on.) So, I would recommend getting a separate IR source to use. You can get one cheaply from some place like here (http://www.maxmax.com/aXNiteFlashlight.htm).

[Daniel Blakeslee]

Take a look at nightvisionmall.com, too. I had the same idea you have, but in my not-very-thorough investigation I discovered that many of these devices don't focus close enough to be of any use for developement by inspection.

[Jay DeFehr]

Hi Dan. I'm thinking along the same lines. I've seen googgles on ebay for a few hundred dollars, and IR lightsources for around $30. I'm thinking of making an IR light table, and developing my film in glass trays on top of it, using Jorge's brush technique. I haven't found a better technique to guarantee perfectly even development. IR goggles would also be very useful for loading film holders, cutting down bulk film, loading reels etc. Worth the investment, I think.

[Alan Davenport]

This makes me wonder: what do you see if you look at a processed film by transmitted infrared light? Or reflected light? Does the depositied silver stop the IR, or simply pass it just like the substrate (IOW, would you be able to see what you're inspecting?) For that matter, how well does the base material pass IR? I suppose the film base is probably transparent to IR, but??? So many toys, so little time......

[Steve Baggett]

For that matter, how well does the base material pass IR?
According to this (http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=001DS4) thread, E-6 films act as IR filters, i.e. they stop IR transmission. Also, see this (http://www.rit.edu/~andpph/text-infrared-filter.html) link.

[John Cook]

I have done some press work with a horizontal process camera and ortho film under a red safelight. Back in the days when halftone dots were all the rage in offset lithography.

Perhaps before spending the big bucks on IR, you could run some experiments with Ilford Ortho film and the appropriate safelight. Unlike the litho film I was using, this film can easily be developed to pictorial contrast.

Here’s Ilford’s pdf:

http://www.ilford.com/html/us_english/pdf/ortho_plus.pdf

One lab I worked in had a homemade fiberglass-over-wood sink with a small clear area, under which was a red safelight. We developed the film in a pyrex glass cake pan set on top of this lighted area. The film being backlit, we could still-develop by inspection. Never had to touch the film. Worked great.

But be careful of fogging this film.

[Graeme Hird]

Steve,

Just a minor point: IR filters don't stop IR light transmission - they allow only IR light to be transmitted (i.e. they filter out all light except IR).

Cheers, Graeme

[Jay DeFehr]

Mr. Cook, that's exactly what I have in mind, except substituting an IR source for the red safelight. It's good to know that I'm on the right track. Thanks!

[Michael A.Smith]

What to look for when developing by inspection with an IR light? Does not seem to matter which side. When I saw film through an IR light it looked like it was on a light table. Admittedly, this was already developed film, but I suspect it would be the same while actually developing it.

[Jay DeFehr]

What you're judging by the IR light is negative density. The metallic silver in a negative is opaque to IR in proportion to its density, just like it is to visible light. Michael has remarked that he has used a friend's IR goggles in a darkroom, and I assume that that friend was using the goggles to develop film by inspection, from Michael's comments. How do you imagine that IR would distort negative densities? Development by inspection offers many advantages over time/temp development, even for those of us who do know the properties of our films and developers, but you are under no obligation to use that technique, or any other. The fact that film can be easily and reliably processed by another technique takes nothing away from the unique advantages of another.

[Mike Troxell]

I mentioned this thread to Michael W. Smith on his forum. He said he has not tried it but he had seen a IR darkroom setup and that it worked perfectly.

[Jay DeFehr]

Any relation to Michael A. Smith? Thanks, Mike. I assumed as much from Michael's comments, but I welcome the confirmation.

[Eric Woodbury]

To see what the IR viewer sees, you need some sort of display that you can see (and which the film can see). If you wear IR goggles, they would have to be very well sealed so that the display didn't fog the film.

Other than that, I believe most films don't see "near-IR" radiation and would look pretty much the way they do in the deep red. Most BW films don't even see deep red LEDs.

[Mike Troxell]

Sorry. I did'nt see Michale's post before I posted.

Michale W. Smith is the singer. I get them mixed up. Must have something to do with Ansel Adams comparing the negative to a musical score :)