Green light and inspection

Thomas Bertilsson · Feb 7, 2014

Michael R 1974 said:
It is likely the tanning process which helps slightly. In any case ABC (Kodak D-1) doesn't produce such heavy stain unless you alter the dilution for less sulfite. Kodak later came up with formulas which were designed for more imagewise staining.

I'll also throw in my white elephant for the fun of it: why anyone would bother in this day and age with DBI versus time/temperature control is beyond me. In the days of Weston it made some more sense because light meters were primitive, and materials were subject to more variability (film speeds, developer activity, etc.). At this point, what value can it possibly add?

Oh, I agree. But in the same token, a lot of the discussions here are of that nature - interesting but often times not adding much, if any, value to the actual practice of darkroom photography.

I find that by keeping things as simple as possible, I reach higher and farther with my photography. But it's still interesting to learn, even about things I will never use. It helps paint a bigger picture, and better understand the things I do use, and it throws perspective on those processes that I'm tempted to try, as well as their actual utility.

And cool factor.

Gerald C Koch · Feb 7, 2014

True desensitizing dyes greatly reduce an emulsions sensitivity to light . Such dyes as scarlet N and pinakryptol yellow allow a much brighter safelight illumination. So if oxidation products do act as desensitizers their effect is rather small by comparison. The level of illumination used for this development technique is probably too low to have any visible effect on the film provided that exposure is short.

Shawn Dougherty · Feb 7, 2014

Michael R 1974 said:
Gerald - I think there was a thread on this once in which PE validated the desensitization effect. It was in the context of BTZS tubes and how they are supposed to work without total darkness even though you have to keep removing the top to pour in chemicals.

Thanks, Michael, I'll have to dig up that thread. When spinning my homemade BTZS style tubes I use a small red safelight behind me when I take off the lids and transfer the then uncapped tubes into a tray of fixer. I've done it with and without the safelight and can see no difference whatsoever...

Gerald C Koch · Feb 7, 2014

I did a brief search on people who have used a desensitizer. One user with pinakryptol yellow said it allowed the safelight (with a 15w bulb) to be on continuously and at a distance of 2 feet without fogging.

removed account4 · Feb 7, 2014

Shawn Dougherty said:
That's right, they do use ABC pyro. I watched Paula develop film this way and I've dabbled in it myself. Never noticed any fogging that seemed different than what I'm used to... by eye anyway. I've never measured it with a densitometer. My understanding is that there is only a SLIGHT increase if done properly.

I'm just curious about what is actually happening. I would LOVE to get some nice IR googles, glass trays with an IR light source underneath them some day.

i use the green light often
with caffenol-130
i mean sumatranol-c-130
works like a charm

cowanw · Feb 7, 2014

Gerald C Koch said:
The problem with evaluating the negative based on the emulsion side is that you are seeing reflected light only. So you are seeing only the surface of the emulsion, the rest of the emulsion may be undeveloped. Stopping development at this point will lead to thin negatives. This is why the base side is used since if you see a satisfactory image it means that the entire emulsion has been developed. Thus the warning to inspect the base side of the film. Every discussion of the technique that I have read always mentions doing this.

The idea that the oxidation products of the developer act as a desensitizer is very old. If the effect ever existed it would be dependent on the developing agent(s) used. I seriously doubt that the developing agents used now would have the same effect. The oxidation products of phenolic developing agents like pyrogallol are vastly different from those of a developer like Xtol.

Gerald, does that mean you are supposed to use transmitted light from the base side? I have been looking at the base side with reflected light. Is that wrong?

cliveh · Feb 7, 2014

When Gerald mentioned this, I thought how can you view other than reflected light from both sides until cleared with fix.

Bill Burk · Feb 7, 2014

Michael R 1974 said:
I'll also throw in my white elephant for the fun of it: why anyone would bother in this day and age with DBI versus time/temperature control is beyond me.

My favorite DBI negative is the indoor swimming pool at Hearst Castle... I KNEW it was going to be a thin neg when I shot it. When I saw it in the tray, still thin after the prescribed time, I kept it in as long as I possibly could... about 4 more minutes till my wife said we absolutely positively HAD to go. Otherwise I would have left it in longer. Can't remember the occasion. The negative still is a bit thin for my taste, but makes a beautiful dark print.

Gerald C Koch · Feb 7, 2014

cowanw said:
Gerald, does that mean you are supposed to use transmitted light from the base side? I have been looking at the base side with reflected light. Is that wrong?

No, the emulsion is opaque so you must use reflected light. But to see if development is near completion you have to look at the base side.

Development by inspection does not work very well if the film or its base contain a lot of dyes. So the newer t-grain films are a problem.

Let me say this again: for most people and for most situations the time/temperature method of development is much easier and more accurate. Development by inspection requires a good deal of experience to get it right. I know that it has a certain mystique for some people but that in itself is not a sufficient reason to use it. I used it many years ago when light meters were an uncommon luxury. I would have preferred not to.

Sirius Glass · Feb 8, 2014

Bill Burk said:
When I saw it in the tray, still thin after the prescribed time, I kept it in as long as I possibly could... about 4 more minutes till my wife said we absolutely positively HAD to go.

Lessons Learned when I was still a child "Never stand in the way of a man [or woman] on the way to the bathroom."

Mainecoonmaniac · Feb 8, 2014

I'm not good at it. But I'd imagine it's like cooking. Some recipes recommend a cook time, then finish the dish by looking at the doneness. Finishing the dish by eye. But before then, you don't have to peek. I would only inspect the film's highlights the last few minutes of the development cycle.

cliveh · Feb 8, 2014

Gerald C Koch said:
Let me say this again: for most people and for most situations the time/temperature method of development is much easier and more accurate. Development by inspection requires a good deal of experience to get it right. I know that it has a certain mystique for some people but that in itself is not a sufficient reason to use it. I used it many years ago when light meters were an uncommon luxury. I would have preferred not to.

This is very good advice. I have only developed by inspection about twice for the experience of doing so and can't think of a situation where I would need to do this again.

Gerald C Koch · Feb 8, 2014

I would like to add that in order to use this method the eye must be fully adapted to the dark. For the average individual this is about 30 min of sitting in the dark before one can start. This can be incredibly boring. Some good music helps but still I would prefer to be doing something else.

Truzi · Feb 8, 2014

Mainecoonmaniac said:
I'm not good at it. But I'd imagine it's like cooking. Some recipes recommend a cook time, then finish the dish by looking at the doneness. Finishing the dish by eye.

Ever try this method when cooking?
http://www.youtube.com/watch?v=90PrWtnpHtM

Sirius Glass · Feb 8, 2014

Truzi said:
Ever try this method when cooking?
http://www.youtube.com/watch?v=90PrWtnpHtM

That looks like SOP [Standard Operating Procedure] to me.

Mainecoonmaniac · Feb 8, 2014

Film. It's what we're shooting.

Green light and inspection

Privacy & Transparency

Privacy & Transparency