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  1. #1
    optV's Avatar
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    Nightvision tray development questions

    I've been reading for the last 3 hours on the concept of NightVision DBI (develop by inspection). There are a number of posts on APUG and also on the AZO forums about it and I'm almost convinced. Here's a short summary of my findings:

    It seems that most people agree to purchase a monocular style Night vision unit. One specifically mentioned often is the ATN Viper which goes for $240 on ebay.

    Also in my findings, most people seem to turn off the IR projection LED to prevent fogging and reflection issues and purchase an external IR LED bank with 50 to 140 LEDs. I've also read that most of these LEDs are about 850nm. This leads me to my question:

    I came across a few people that complained about fogging at 850nm. Specifically with fuji acros film. One guy did a 30 second exposure test on unexposed film (which seems mindblowing considering development times can reach 8+ minutes). Can anyone elaborate on experiences with fogging. Specifically those using the clear tray IR lightbox technique? I shoot Delta 100 and Tri-X 320. I was thinking of purchasing 950nm LEDs which apparently put out no visible red light.

    If anyone is interested HERE is a link to a thread where guy who made an IR lightbox to develop with a clear tray on top of it.

    Sorry for the long post, in short I want to hear experiences, especially tips on preventing fogging.

  2. #2

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    Quote Originally Posted by optV
    I've been reading for the last 3 hours on the concept of NightVision DBI (develop by inspection). There are a number of posts on APUG and also on the AZO forums about it and I'm almost convinced. Here's a short summary of my findings:

    It seems that most people agree to purchase a monocular style Night vision unit. One specifically mentioned often is the ATN Viper which goes for $240 on ebay.

    Also in my findings, most people seem to turn off the IR projection LED to prevent fogging and reflection issues and purchase an external IR LED bank with 50 to 140 LEDs. I've also read that most of these LEDs are about 850nm. This leads me to my question:

    I came across a few people that complained about fogging at 850nm. Specifically with fuji acros film. One guy did a 30 second exposure test on unexposed film (which seems mindblowing considering development times can reach 8+ minutes). Can anyone elaborate on experiences with fogging. Specifically those using the clear tray IR lightbox technique? I shoot Delta 100 and Tri-X 320. I was thinking of purchasing 950nm LEDs which apparently put out no visible red light.

    If anyone is interested HERE is a link to a thread where guy who made an IR lightbox to develop with a clear tray on top of it.

    Sorry for the long post, in short I want to hear experiences, especially tips on preventing fogging.
    The primary objective in using DBI in development of sheet film is to be able to see highlight formation representative of adequate desired density range for your materials so the sheet of film can be pull from the developer tray. For this purpose you do not IMO need this magnitude of illumination as it is wraught with such technical pitfals. First, recognize that the LED's that are being sold are for security applications (and being used for this application) and the true wavelength being represented is obviously not as critical as it is for this purpose. Plus, I have no way of testing what I have acquired. Second, single sheet development is terribly time consuming (I have done over 10 8x10 sheets in an 11x14 tray in a single run with perfect results - to do that many sheets individually would take a VERY long time). I do not relish being a lab technician by any means and want to get it over with. Secondly, I get more consistent results with multiple sheets in a tray being developed together. You just have to learn to pull the sheets from the bottom of the tray and push them down on the top of the stack. No big deal as modern sheet film is pretty scratch resistant. Efke film is very fragile but can still be tray developed without damage. Washing the film is where many scratches can also occur so one be careful in this procedure.

    As a result, I feel that while this glass bottomed developing tray looks pretty cool and being able to have that much "illumination" is appealing for some folks it is a complete waste of time and resources and is unnecessary.

    Bounce a small IR light source off of a wall and use your NVG without the IR source on them to see how that goes. Test some film with the light bank source closer to the film and pointed at it for a typical development cycle by putting a piece of black electrical tape down the center of a sheet of film in complete darkness and pull it off after an IR light bank exposure and develop it in complete darkness to see what I mean. The fact that folks report that they have not necessarily had a problem with "fogging" only tells you that they cannot descern this condition on their developed film not that it does not exists. Without proper testing you do not have your hands on this variable and excess FB+F is not worth it because you have to print through it and will eventually cause you more trouble than it is worth.

    Folks continue to use a very dim green light for DBI as they have for 75 years with success. DBI is a skill that needs to be learned not a quick fix. We need to continue to think clearly about our objectives as photographers and the minimum we need to attain the stated results.

    Good Luck

  3. #3

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    I use the atn viper with it turned on for the entire development cycle. I have reported no fogging before, but that may be incorrect, I really don't know for sure. My negs look clean to me, they print very well, and I am very happy with the simple process that I use. That's all that matters to me.

  4. #4
    optV's Avatar
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    You make a valid point about single sheet processing. Mainly, I just like the concept of being able to see in the dark with tray processing. This will greatly minimize development errors and allow me to work more efficently without having to deal with the downfalls of other development methods: eg. tons of chemestry for daylight tanks and dip n dunk tanks. I also like the idea of being able to easily develop N+, N-, etc in the same batch.

    Also, it is common sense that I should test for fogging myself. However, before investing in 250.00 goggles, I'd like to hear other's experiences.

  5. #5

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    Quote Originally Posted by optV
    You make a valid point about single sheet processing. Mainly, I just like the concept of being able to see in the dark with tray processing. This will greatly minimize development errors and allow me to work more efficently without having to deal with the downfalls of other development methods: eg. tons of chemestry for daylight tanks and dip n dunk tanks. I also like the idea of being able to easily develop N+, N-, etc in the same batch.

    Also, it is common sense that I should test for fogging myself. However, before investing in 250.00 goggles, I'd like to hear other's experiences.
    To be perfectly honest, seeing in the dark is a relative concept. You do not really NEED to completely illuminate your darkroom to accomplish the stated objective.

    I purchased my NVG from a company in Salt Lake and I believe that they had a 10 day money back guarantee. Check to make sure that wherever you purchase yours do it with a credit card and make sure that you have a short time to check them out. If they do not get it done for you then send them back and you are only out shipping.

    All I can say about testing is that I am always surprised at how many people consider testing a waste of time when queried about their efforts in this arena. But I have heard first hand that safe light testing is one of the first things that one does in a John Sexton workshop wheither you think you need it or not.

    Back to the subject at hand, I have seen probably 15 various IR illumination LED banks and when I plugged all of them in a differing degree of red or dark orange glow was present. I have yet to find an inexpensive IR LED light bank that was 100% IR. The reason that I have not (I suspect) is that it would be very expensive to produce them in that condition. When I tested a 32 LED light bank about 18 inches away from 125 and 400 speed film I could see with my naked eye obvious density variations between the film that was covered under the black electricians tape during the sample exposure and the uncovered film.

    When I bounce the independent IR LED off of a wall three feet plus away from unexposed film there are NO density increases on the test film.

    An untrained eye would probably not be able to detect .2-.4 density units of fog on your film as it would have the same effect as one Zone of pre-exposure, letting your film go out of date or a couple of trips through the airport xray. No thanks. Film is to damn expensive to assume anything for me.

    To each their own.

  6. #6
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    Quote Originally Posted by optV
    Also, it is common sense that I should test for fogging myself. However, before investing in 250.00 goggles, I'd like to hear other's experiences.
    A total waste of money. Just learn how to use a green safelight.
    Don Bryant

  7. #7

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    Quote Originally Posted by donbga
    A total waste of money. Just learn how to use a green safelight.
    I purchased the safe light and the green filter and found it nearly impossible to use conventional DBI with T Max 400 no matter how hard I tried. I could accomplish DBI with many other films but something in the coating or the emulsion with that particular T Grain film was a different animal.

    If I could have used DBI with TMY I would have never searched for an alternative and promoted this technique because it would have been (as you said) completely unnecessary.

  8. #8

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    I had the same problem with TMY and a green safelight. TMY can be DBI'd with a red safelight though. Something to do with the magenta dye I think.

    Night vision is useful for other things though too.

  9. #9
    Sean's Avatar
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    Quote Originally Posted by matt miller
    I had the same problem with TMY and a green safelight. TMY can be DBI'd with a red safelight though. Something to do with the magenta dye I think.

    Night vision is useful for other things though too.
    yes, being able to load 5 8x10 holders with film in a matter of seconds is nice. Some may say they can do this anyways but I bet they are not near as clumsy as me..

  10. #10
    RobertP's Avatar
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    Quote Originally Posted by donbga
    A total waste of money. Just learn how to use a green safelight.
    Don, What green safelight are you using? thanks

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