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Justin K
30-Oct-2018, 07:05
I have a "darkroom" that's really just a very dark basement area; definitely not 100% light-tight, however. I expose and develop BW prints in this space all the time without any fogging or other issues. Now I'm interested in trying tray development of BW negs ranging from 4x5 to 8x10. I have years of experience developing film in a Jobo and standalone tanks, but sometimes the Jobo is overkill for just 1-2 negs, for instance.

My questions about tray development:

1. How dark is "dark enough" to tray develop film safely? Do I need a 100% light-tight darkroom and total darkness?
2. If I do need total darkness, how then do people manage to "develop by inspection" (as I've seen some others mention in various forum posts about tray development) using tray development?

Thanks very much for any tips and advice!

Pere Casals
30-Oct-2018, 07:18
It depends on the film, orthochromatic type film can be developed under red safe light...

But for tray development just use a cheap paper safe. When development done just close lights to move sheets to a regular tray with the stop bath, after some 15s you can open lights and also fix with lights open.183821

You also can also use a toy ir device:
183822

Or an expensive IR night vision device, if your film is not for IR...

Alan9940
30-Oct-2018, 08:42
Well, I guess the answer really comes down to: How dark is dark? How long will the film be exposed to whatever amount of light is present? Will your body somewhat shield the film from the direction of the light? I guess the easiest way to answer your own question is to develop an unexposed sheet of film, stop, fix, etc, then see if any density shows up on the film. If no, you should be good; if yes, you're not.

Development by inspection is not done with the light on. The film is developed in total darkness for roughly 75-80% of the expected total development time, then a very dim safelight is turned on briefly to check the high values. Plus, most folks who do DBI use staining type developers which hardens the emulsion as the film is developed, thereby enabling the film to somewhat resist exposure to light.

Bob Salomon
30-Oct-2018, 08:48
Well, I guess the answer really comes down to: How dark is dark? How long will the film be exposed to whatever amount of light is present? Will your body somewhat shield the film from the direction of the light? I guess the easiest way to answer your own question is to develop an unexposed sheet of film, stop, fix, etc, then see if any density shows up on the film. If no, you should be good; if yes, you're not.

Development by inspection is not done with the light on. The film is developed in total darkness for roughly 75-80% of the expected total development time, then a very dim safelight is turned on briefly to check the high values. Plus, most folks who do DBI use staining type developers which hardens the emulsion as the film is developed, thereby enabling the film to somewhat resist exposure to light.

Best test is to place a coin, in total darkness on a piece of unexposed film, then put the film where you will process and leave it, with the coin on it, for the period of time it will be developed, then develop it and see if the area that had been covered with the coin has a different density. If so you need to find a way to darken that area, or process in your bathroom or use a daylight tank like the CombiPlan.

Ken Lee
30-Oct-2018, 08:55
I didn't see Bob's post (the coin is an excellent idea), but here's a variation:

Cut a sheet of film into some pieces (or use several sheets) and leave them face up on your table in that room for 5, 10, 20, 40 minutes or according to whatever scale you like. Place a coin on each piece.

Develop them all together in total darkness. Fog may become apparent after some length of exposure. If it's between 20 and 40 for example, you can interpolate or test again with closer intervals. This all varies with film ISO, time of day etc.

With my methods, I consider 1 minute for film handling, 2 for pre-soak, 10 for normal development, 1 for stop-bath, 2 in fixer before the film is safe to expose to normal light: 16 minutes total. I would want to be able to leave the film in the room for at least that long, maybe double just to be safe, especially since expanded development takes longer.

koraks
30-Oct-2018, 09:13
Cut a sheet in half. Develop one half in a for you typical way in the "dark" area. Then fix and wash as usual. Fix and wash (not develop) the other half sheet. Compare them when they are dry. The developed half should have only marginally more density than the undeveloped sheet. This works best with a non-staining developer and fresh film since both general stain and fog from age will create base density.
As to the question if dark is dark enough: if you are in the dark room for 10 minutes so that your eye are really accustomed to the dark, if you see any contours or can see the outline of your hand in front of your face, it's not dark enough (but it may still be good enough for your own taste).

Doremus Scudder
30-Oct-2018, 10:09
You can always restrict your tray developing to times when the light leakage is at a minimum, e.g., at night. I read that Brett Weston used to develop film and print at night with his darkroom window swung wide open. The moonless night sky wasn't bright enough to make a difference.

If, after testing as outlined above, you find you have too much light to tray develop, look into acquiring (or building yourself) a set of BTZS tubes. These allow tray-type developing and protect from ambient light.

Best,

Doremus

Bob Salomon
30-Oct-2018, 10:13
You can always restrict your tray developing to times when the light leakage is at a minimum, e.g., at night. I read that Brett Weston used to develop film and print at night with his darkroom window swung wide open. The moonless night sky wasn't bright enough to make a difference.

If, after testing as outlined above, you find you have too much light to tray develop, look into acquiring (or building yourself) a set of BTZS tubes. These allow tray-type developing and protect from ambient light.

Best,

Doremus

That open window procedure would not be best with the speed of today’s films and would not lead to the cleanest work area!

Pere Casals
30-Oct-2018, 11:01
Kodak is kind enough to provide sensitometric datasheets with absolute scales, this tells how dark.

183859

So 0.003 Lux for a few seconds would start building fog.

We cannot do tray processing with some ambient light during all development !!!

In development by inspection we open for a few seconds the dim light at the end of the development, in that case that exposure to light is not much harmful because to have an effect the newly exposed grains have to wait the induction time to start developing, and when that development start building serious density a couple of minutes have passed, and we perhaps by then we have finished our development by inspection.

... but, as graph shows, if we throw to film some 0.1 Lux·Second during the first two minutes (lirf apart) then we add 1.0D fog to the negative.

...and 0.1 Lux.second in 2 minutes are less than 0.0008 LUX ambient light.

So even with ISO 100 film it is not feasible to do tray developing with some ambient light, just place the sheet in a paper safe and open lights, or use a night vision device.

Drew Wiley
30-Oct-2018, 11:34
It takes very little light pollution to fog the shadows in films with long straight line sensitivity way down into the shadows like TMax 100. Make that TMax 400 and you multiply the risk. Even the illuminated hands or LED's of a darkroom timer can cause havoc. I place the timer below the sink, where the film trays are incapable of "seeing" it. Once someone has pinned down personal exposure and development technique, and learned how easy it is to keep dev temperature stable in a water jacket around the tray, why on earth is dev by inspection even necessary? I know this is how some people have always done it; but why on earth anyone would aspire to this approach today mystifies me.

Andrew O'Neill
30-Oct-2018, 11:46
My door seals aren't the best. During the summer months, when the sun is shining directly on my darkroom door, there is a very slight glow around it that you cannot see until your eyes become used to the dark. When handling film, I'm about 8 feet away from the door. When comparing film developed in the day and at night, the film base fog is the same.

Ken Lee
30-Oct-2018, 11:55
...why on earth is dev by inspection even necessary? I know this is how some people have always done it; but why on earth anyone would aspire to this approach today mystifies me.

Being greatly imperfect, I make mistakes during exposure and development. DBI with an IR viewing device has prevented catastrophe several times.

Here's a recent case: IR viewing device saves the day again (http://www.largeformatphotography.info/forum/showthread.php?148537-IR-viewing-device-saves-the-day-again)

I was able to rescue this shot (http://www.largeformatphotography.info/forum/showthread.php?44249-Large-Format-Landscapes&p=1464760&viewfull=1#post1464760) from oblivion.

Joe O'Hara
30-Oct-2018, 14:39
Regarding the coin tests, I would suggest that better sensitivity to unwanted light can be achieved by using
two pieces of film per test, first giving them an exposure that you know to give some noticeable density above FB+F
(from prior testing; it could be a very brief exposure to printing safelight, etc). In this way, you will be certain that
you are already out of any "toe" region of whatever film/developer combination you are using. Once you have done this,
do the coin test for a worst-case development exposure time, and then process normally. If you then see the outline of
the coin on the test film, you have trouble.

We are trying to avoid getting a false sense of security from testing unexposed film, where it is all below exposure
threshold out of the box, when we are trying to avoid fogging and killing the contrast in the shadow areas of the
actual pictures we are developing, which have some exposure.

Some film/developer combinations are said to have very nearly straight-line response curves (i.e., no perceptible "toe"),
so this may be overkill for your situation.

Mamu
30-Oct-2018, 14:47
I have hooks on the inside and outside of my darkroom(aka bathroom) door. Hanging heavy blankets from both works great. Cover your timer as mentioned above. Modern panchromatic films aren't suitable to development by inspection the way the film Edward Weston was using was. Early orthochromatic films were basically sensitive to blue light only. Shooting graded paper negs will give you a similar range of tonalities relative to color (and force you to compose with light and shadow which can be a great learning technique) If you want to practice tray development before working in total darkness, try a few paper negs under safelight. Rating it around ISO 6 (four stops more exposure than ISO 100) is a good starting point.

aaronnate
30-Oct-2018, 14:59
if you can see anything, including outlines it is too light. These are your negatives. Why take a chance.

freecitizen
30-Oct-2018, 18:29
When developing film in trays in total darkness I like to keep track of the time as development progresses.

I have an ancient device known as a " tape recorder ". I made a tape of myself as a speaking stopwatch ...... and I just play that while I am working.

Works a treat.

Justin K
30-Oct-2018, 18:49
So many helpful and creative suggestions here. Thank you all for taking the time to reply.

Alan9940
30-Oct-2018, 20:41
Being greatly imperfect, I make mistakes during exposure and development. DBI with an IR viewing device has prevented catastrophe several times.

Here's a recent case: IR viewing device saves the day again (http://www.largeformatphotography.info/forum/showthread.php?148537-IR-viewing-device-saves-the-day-again)

I was able to rescue this shot (http://www.largeformatphotography.info/forum/showthread.php?44249-Large-Format-Landscapes&p=1464760&viewfull=1#post1464760) from oblivion.

Ken,

What IR device do you use? I've looked a few times over the years, but most are dreadfully expensive. Thanks!

Ken Lee
31-Oct-2018, 04:52
Ken,

What IR device do you use? I've looked a few times over the years, but most are dreadfully expensive. Thanks!

Apparently the ATN Viper which cost somewhere around $200+ at the time if I recall, is no longer made: the company appears to have decided to concentrate on higher-end models.

There are probably other makes of the same basic type: "first generation" which combine an IR emitter of modest power with a simple monocular, not binocular. These designs are good enough for simple darkroom work, loading and unloading film etc.

On this forum there have been several threads over the years which discuss various options. You might try a Google search like this: "ir device" site: largeformatphotography.info

Some people have put an emitter on their darkroom wall and used simpler devices to view. If they don't mention the exact models, you might want to contact them if they're still around here.

Jim Jones
31-Oct-2018, 06:35
When developing film in trays in total darkness I like to keep track of the time as development progresses.

I have an ancient device known as a " tape recorder ". I made a tape of myself as a speaking stopwatch ...... and I just play that while I am working.

Works a treat.

In the 1930s the Kodachrome process was perfected by two professional musicians, Godowsky and Mannes, who used a musician's sense of timing to conveniently work with the film in total darkness without clocks or timers.

aaronnate
31-Oct-2018, 07:39
Didn't Adams use a metronome to keep track of time.

koraks
31-Oct-2018, 08:46
Yes, for exposing prints including burning and dodging. Not for development as far as I know. It's quite hard to reliably count out several minutes with a metronome; it's surprising how fast you lose your count (well...I do!)

Drew Wiley
31-Oct-2018, 10:15
Use a cricket. Their chrrrrr's vary dependent on temperature. That way you have a cheap compensating timer. Only problem is that they respond to air temperature, and they would probably drown in developer; but maybe you could design a little scuba tank for them. I use the Zone VI compensating timer myself. But crickets are still good for fishing.

Bill Burk
31-Oct-2018, 20:57
I can see a little light from time to time in my darkroom. Nevertheless I rarely have more than 0.05 density above base. So I know the amount of stray light in my darkroom for the fifteen minutes or so that the film is vulnerable... the light that actually strikes the emulsion... is negligible.

I think it might be hard to hear crickets in a film can. But jumping beans might work. They’re waterproof already.

Doremus Scudder
1-Nov-2018, 10:58
Yes, for exposing prints including burning and dodging. Not for development as far as I know. It's quite hard to reliably count out several minutes with a metronome; it's surprising how fast you lose your count (well...I do!)

I now work in my new Eugene, OR darkroom equipped with Zone VI compensating timers.

However, for my almost 30 years living in Vienna, Austria, I used a combination of metronome and digital oven timer to develop film. I set the timer to the total developing time plus five seconds and the metronome to tick at 60 bpm (once a second). The timer got wrapped in plastic wrap and set next to the developer tray. The metronome was started just before "lights out." Then film unloaded and presoaked. When ready to develop, I felt around for the start button on the timer, pushed it (in synch with the metronome, of course) and then counted down the five seconds to when the first sheet hit the developer.

After that, I used the metronome to time my agitation (usually one flip every five seconds with six sheets in the developer tray). When the timer went off, I transferred the film to the stop.

This worked just fine for many, many sheets of film.

Best,

Doremus