• Welcome to Photrio!
    Registration is fast and free. Join today to unlock search, see fewer ads, and access all forum features.
    Click here to sign up

Sheet Film Development By Inspection With Night Vision Technology


Can you give some more details, Sean. Specifically which of the parts you fiddled with to allow closer focussing? Also, if you keep the cap on you dim the light, but it acts as an aperture and GREATLY increases the depth of field.
 
I would merely like such a device for loading sheet film and developing reels and tanks. Is there an economical setup for that? (One of my hands was partially mutilated in an accident recently and I have no feeling left so that working by feel is just impossible now.)
 
All this talk of night vision goggles reminds me of *Silence of the Lambs*
 
Jeremy Moore said:
Can you give some more details, Sean. Specifically which of the parts you fiddled with to allow closer focussing? Also, if you keep the cap on you dim the light, but it acts as an aperture and GREATLY increases the depth of field.
Click to expand...

Hi Jeremy, I think you have the same goggle as me. The first lens element screws in and out to focus, there is also one directly behind that and if you get a good grip on it can unscrew it (yours may need to be cleaned too), it's that second element that I unscrewed maybe 2-3 times to get a closer view, I also adjusted the eye piece. I find with that goggle good lighting is key and although leaving the cap on increased the depth of field it was no dim. But, with the cap off and the new 140led light table everything was very sharp. I wasn't able to dev any sheets last night but will try again today if I have some time.
 
I have a Gen1 monocular that came with headgear. Using it to load sheet film is a huge help since I might as well be loading them in broad daylight. If money were no object I'd get a Gen2 or Gen3 goggle, but the Gen1's are good enough. Mine is made by a company called ATN and I got it new off of ebay. I have never had any fogging whatsoever, but I was concerned about the green light leaking from the eye piece so I fashioned a hood out of an old changing bag (one sleeve of the changing bag fits around the scope tightly). You'll find loading films a breeze. I recommend using an external IR lightsource though, and as long as it's over 850nm should be fine..
 
Very interesting Sean,
Since I got a roll of aerial film I was seriously thinking buying a viper night vision device. I had not thought of this usage...
Thanks !
Claude
 
What an awesome idea, Sean! )

What about those of us wearing glasses? Will these night vision goggles allow for glasses? Is there a better way to manage that?

Thanks -- this could be a real life-changer!
 
Thanks! well, I got the original idea from Jeremy, who I think mentioned why not shine IR light from beneath to really see a lot more, so I ran with that. I see no reason why someone with glasses would have trouble, the eye piece is corrective just for that I believe...
 
The more I read this thread, the more and more I talk myself into doing it and using my Sony F717 as my night vision 'goggles', at least to begin with. The good thing about that is the F717 focuses down to 2cm, so I should be able to get nice and close.

Would you reccomend getting one of the 140 LED banks for 4x5 negs, Sean? I'm wondering if it would just be too bright and if I should stick to less.

I was also checking out an auction for a 48 LED set, with the line "Yes, you can see the red Infra's at night. It's not that bad though.". Would they be using some sort of lower quality LED's, or would it not be enough to worry film?
 
I'd make sure it's above 850nm range (this is what I use for tri-x) you can check the sensitivity of your film, and the 140led bank would be perfect (i'd actually like to have 2 of them for 8x10 but should be fine with 1), just use a translucent cover several inches from it (I use one from an old lightbox). DO NOT LOOK INTO THE LED's with your eyes, you can't really see anything, but it can still damage your retina from what I hear.. Are you talking about a video camera? Not sure how that would work but worth a try I guess just watchout for lightleaks from the camera.. Let us know how you go.
 
I think that this is an interesting concept. it is also interesting to use desensitizing agents. Different people gravitate to different methods.

I have a question: Are you folks developing by inspection because time and tempeture worked poorly for you?
 
I still use time & temp with roll films, but with 8x10 sheet I can't afford to waste it or the time & cost it took to expose it. I still expose carefully and use correct temperature, so it's just a final step to ensure the neg develops exactly as I want it to. It's just plain great to sit there and watch the shadow detail come up, watch to see that the highlights don't blow out. I also am starting to experiment with 2 bath development such as a dilute HC110 for 2 minutes then extremely dilute HC110 and observing the tones then pulling when it's spot on..
 
I have been developing film for many years using DBI, About two years ago I bought one of the cheapie night vision thingies and tried it. It works fine if development is at least half completed, just as you would with a green safe light. I found with Tri x I could fog the film by using the device to early.

I use DBI for one reason only, to save my fanny on very difficult exposures.
Time and temp works fine with normal negatives, however in near guess work type of exposures the DBI will allow you to at least get something on the film. I find it totally unnecessary for such tasks as loading and unloading or anything else normally done in the darkroom. The only use I have for the system of DBI is if I am in doubt about an exposure. The Night vision scope does not do one whit better than a green safelight at a few (4) feet or so.

I will say that it takes practice to see what you are supposed to see when developing by inspection, but you will soon be able to read the shadow densities very easily. I have absolutely no need to have illumination from under the tray, Seans idea is neat, but really not necessary to produce great negatives.
 
I'm not sure which goggle you have, but with everything I have in place It's like looking at a huge sharp transparency on a lightbox the entire time the sheet develops. Full IR illumination from above and below sometimes for 12+minutes and zero fogging, that is from the moment the neg goes in the soup till it comes out. It's possible you are getting some goggle light bouncing off of your face or your IR light is not above your film's sensitivity? Are you using an IR LED light system?
 
It may be the night vision scope he is talking about is not a true IR scope but an image intensifier that operates in the visible spectrum. These take any ambient light and amplify it enormously to create an image where the IR scope simply translates the IR to a visible image.
 
Fogging from IR light source

Hi,
I have purchased the same IR light source the same as Sean and am using it in the same way to develop Fuji Acros Film. I am getting substantial fogging from the light source even when the total on time is only less than 60 seconds. I can see a faint red light emitting from the LEDs when the unit is on. Is this normal? I suspect that this is what is fogging the film. Sean, can you see any visible light from you LED bank? Anyone with any suggestions or comments is welcome.
Thanks in advance
Art Nichols
 

Yes, it is normal and is the reason that I pointed out several times my complete failure with the technique Sean previously advocated with a high intensity IR light bank under a glass bottomed tray.

In my experience there are two things to consider. First is the fact that these infrared LED's are manufactured for security applications and as a result, they have not 100% infrared as evidenced by the fact that you can "see" a red glow when they are on and having this many LED's that close to film is asking for trouble. As John Sexton advocates with a darkroom safe light, I tested a small light bank of 24 LED's about a 18" away from a sheet of 100 ASA film and compared it to a sheet of the same film that was unexposed and the film was contained 0.35 + units of fog after only 5 minutes. One could reasonably expect that 400 ASA film would have been fogged proportionally more. That was enough data for me to make the conclusions I am sharing in this post.

Secondly, I believe that there is an "energy" conponent that contributes to the fogging of film in this application and having that many infrared LED's this close to sheet film only exacerbates this condition.

The solution is simple.

Get rid of the glass bottomed trays as this technique simply does not work IMHO if you want to print with a base density that is consistent with fresh film and conventional closed tank processing. There are far to many variables with LED light sources and other variables to assume anything here.

Bounce your infrared light off of a refrective wall at least four to five feet away from the conventional tray you are developing your sheet film in and leave your IR source light off on your IF light source off on your headset. I have placed a small IR light source behind a diffused globe on a wall several feet away from my sink and I activate it with a foot switch for short bursts of critical film inspection to minimize fogging issues and it seems to work fine. If you think that I am off base in these recommendations then simply test your film with yur technique and you will see what I am talking about.

IR goggles and IR LED light sources are great tools, but you must be aware of the consequences of using them incorrectly as this counteracts the porpose of why we are using them. I personally want to mitigate the base fog to the degree possible as it allows me to extract the best image out of the materials I use without an extra monkey on my back in the form of excessive film fog.

Just my $0.02.

Cheers!
 
MIchael,
Thanks for comprehensive reply.
With your technique can you do DBI by transmission or only by reflection? I guess that Fuji Acros must similair to TMax 400 when using NVG. Are developing TMax 400 this way?
I have done quite a bit of DBI using the usual green safelight with conventional films and have gotten great results, but it seems that Acros is another beast altogether and is tricky even when using NVG.
It is quite an enticing possiblity to be able to develop film in a glass tray using an IR backlighting especially the new generation films. So it may be worth investigating further.
Some additional thoughts:
1.I wonder if 950 instead of 850 nm LEDs would eliminate the problem
2.I wonder if a dark blue filter would block the visible red light.
Once again Thanks for your help!
Art Nichols
 
I conduct my DBI mostly by reflection by reflected IR light bounced off of a wall until I want to check highlights. About 80% through the anticipated development time I use a foot switch to engage the IR light source behind the negative being inspected and for short bursts I use DBI via transmission. This seems to work well with TMY which is quickly becoming the only film I now use, particularly with ULF.

As to your questions concerning the wavelength changes or using filtration, I have not touched my physics books since engineering school many years ago. Even if you do the academic research there is still the practical testing that needs to be done just to make sure and it does not take that much time to accomplish. With the cost of materials and a variable such as this that clearly we have control of there is no reason to not check it out for yourself.

I am sure that some will argue that their LED's do not fog. I would pose a simple solution. If you can see a red glow, your film is at risk of being fogged - period. The closer the film is to the IR LED source, the more LED's you use and the higher the ASA of the film you use does attentuate the situation. You are just not aware of the situation and are assuming that it does not exist with your developed negatives and are printing through in all likelyhood with varying degrees of success. It is analogous to overexposure on the net result and I will simply not tolerate it in my work.

Until you actually take a sheet of film and place it about the distance your tray would be from the IR light source below and let it set there for a normal development time (or even five minutes) and develop this film with one that comes fresh out of the manufacturers box and look at these sheets over a light table (or measure it with a densitometer if you have one) you are not fully aware of the implications. When you do the condition will reach out and slap you in the face as it did me.

It is not about being right or wrong here, it is only about being better photographers.

Cheers!
 
Well, John McCallum was over the other day and dev'd an 8x10 sheet of tri-x using the glass tray method and my very bright IR lighting. He also did it with highly diluted rodinal and semi-stand development. For over 20 minutes with the headlamp on and with a massive IR light bank on underneath the entire time. There was zero fog, the neg was crisp and clear and looked very nice. I can see a red from the ir light but I can only see it looking directly inside of the led, there is no red glow coming from the led (careful looking at them apparently they can damage the eye). When I have some time I'll do a proper test. I believe people getting fog must be coming from either a room that is not 100% light tight, green light leaking out of the eyepiece area for the goggle (which is why I created a hood for my goggle) or faulty IR led's that are too close to the films sensitivity. I've seen faint to heavy fog on film so know what it looks like and can say without doubt my film is not being fogged by this method at all.
 
The big difference in reciprocity response between the Fuji and the Tri-X could account for the fact the I am getting fog and Sean is not. I know that the fog is neither from a non light room or the green glow from the goggles. I am confident that it is coming from the LED's. I may try some 950 nm LEDs and see if that corrects the problem.
 
If you can see some light emanating from the LEDs, then you should definitely use other LEDs, or maybe filter out the visible spectrum.
 
Sean said:
There was zero fog, the neg was crisp and clear and looked very nice. I can see a red from the ir light but I can only see it looking directly inside of the led, there is no red glow coming from the led
Click to expand...

Depending upon the particulars, it is very probable that you would not see the increase in fog with the naked eye so that alone proves nothing. An increase in .3+ density units can still look perfectly acceptable. Been there and done that. Unless you put the negative on a light table to compare it to a negative that has not been exposed to your under the developing tray set up and read the densities you have proved nothing.

As soon as you physically perform this test it will be the last time you use this technique. Results are the only thing that I care about when I am in the darkroom.
 
My 2c.

I can see the point you make Michael. Subtle fogging may not be detectable by eye, and could still affect the printed image. However I must say in the case Sean mentioned the neg looked good. The image itself was of a high contrast situation and shadows that needed to be clear, were clear. To qualify this, I haven't done specific testing and it was only by eye.

Incidentally, this was the first time I had used Sean's system and found the [size=-1]antihalation layer on txp320 dense enough to [/size]make the appearing image [size=-1]difficult (for me) to see. Nevertheless, the resulting neg was significantly better than I imagined[/size] it would be.

Not wishing to take anything away from your own experience and good suggestions Michael.
 
It would be great if a few folks that have the resources and the time would proceed with the test and post their results and the actual data for the benefit of the entire APUG community. I did not read my densities once I put my test negatives over the light table. The conclusions were so obvious that I did not even have to cut a corner on the unexposed sheet film to tell one from the other. It was not a good day in my darkroom. Once I bounced the IR source off of the wall and turned off my IR source on my headset, life got back to being wonderful. I tray developed 10 sheets of TMY in trays this afternoon and this technique worked marvelous.

One persons experience is about as valuable as an opinion. Several people with the same result are a good start toward a qualifiable conclusion that others can use in their darkroom.

Cheers!
 
You must log in or register to reply here.
Menu
Log in
Register