Minimum developing time fir shadows?

[l2oBiN]

I have shot a 4x5 foma 100 negative in a high contrast scene ( night with street lights). I have found that developing in full conc xtol for 5min with 1 min agitation gives me the negs which look quite contrasty (much more contrasty than I expected) however, I would like now to recover the maximal detail from the negative (produce minimal contrast in the form of drastically reducing the street light intensity). However I am afraid of not allowing the shadows todevelop if I go under 5min. How short in time can I go to produce minimal contrast? Is ygere any other techniques I could use to achieve this?

[Maris Rusis]

The shadow area of a negative develops very quickly because there are very few exposed silver halide grains there and they tend to be concentrated at the outer surface of the emulsion where the developer can get at them easily. Its all over in the first minute or so for the shadows. Extending development beyond this does little for the shadows except built fog density.The strongly exposed highlights, street-light images for example, can keep delivering silver even in extended development.

I have "wasted" time chasing photographs of night scenes with street lights and have come to the following conclusions:

There is no exposure so short that will prevent something (the pattern of street lights) registering on the film. That pattern may be interesting, maybe not.

There is no exposure long enough (even an all night effort) that will put shadow detail into the darkest parts of a typical night scene. What exposure hasn't delivered development will never discover.

Trying to do exact light metering and applying extravagant reciprocity corrections is just a way of buying disappointment.

No development technique truly bridges the gap between grossly exposed film, the street lights, and unexposed film, the dark shadows.

What do I do now? Shoot as soon as the street lights come on and while there is maximum ambient light still bouncing around.

[ki6mf]

I suggest longer development times with a weaker developer and adequate reciprocity failure compensation for exposure. I are writing about technique anecdotally and you may have to test to determine times etc
Night photography and large Normal minus scenes both have many too stops between shadows and highlights. For Night photography you may also have reciprocity failure to account for.
The problem to solve is having your developer working on too much contrast. With a 5 minute development time in full strength developer your shadows probably would not have enough time to develop. Longer times with full strength developer also blow out highlights. Strong agitation also blows out highlights. Remember the highlights will have enough exposure. Compensating developer solves your problem.
My results came about after testing D 76 used as a compensating developer (20 % developer 80 % water). Testing with Xtol should provide similar results.
Diluted developer and gentle agitation is what is needed to hold back development from the highlights and give the shadows enough time to let the shadows come up.
Agitation: 14 minutes is my normal development time. For compensating and night photography I use 15 minutes development with 2 minutes between agitations. Agitation is almost nonexistent and is 5 seconds max over 2 minutes. Yes it’s a pain to stand for this long!
For night photos you will have to test for what proper exposure time and F stop are. I use F22 and 5 minutes time duration with 2nd and 3rd shots going 7 minutes, 10 minutes, and 15 minutes. Try and remember what the ambient lighting was like. Over time you will develop a sense on how much time to use based on lighting conditions. It’s virtually impossible to measure Night Scenes with a light meter and trial and error is the only way to get good results.
I use a water bath to set temperature at 68F for developer, stop, fix and hypo wash .

[Nathan Potter]

Maris describes the difficulty well. However I would fool around with a divided developer scheme. I like Diafine for that purpose but divided D76 can also be very useful. The idea is to use a first bath containing only a developing agent while the second bath contains an accelerator. The emulsion absorbs a limited amount of developer in the first bath which is quickly exhausted in the second bath limiting density buildup in the highlight areas (streetlights), while the shadow areas continue to develop. There are, of course, limitations as to how far this can be pushed. In your situation I would suspect that you will need to overexpose initially to obtain shadow information then use the divided developer to limit the absorption of developer in the first bath then work the second bath for a longer than usual time.

I've not fooled much with this technique so you'll need much experimentation. BTW you don't want to use a presoak since that will inhibit the absorption of the developer. OTOH such a presoak could be used I suppose to partially inhibit such developer absorption and so inhibit the silver buildup in the scene highlight areas.

Nate Potter, Austin TX.

[Peter Gomena]

To answer the OP's question, I was taught in photo school that shadows have finished developing at the 3-minute mark. I've since learned that this is basically true but not absolute. Much depends on overall development time, technique, developer and initial exposure.

I'm of the same opinion as Maris regarding night scenes with lights. Make your exposure when there's still some ambient fill around and the lights are just coming on, which is tricky enough.

I would choose to expose the ambient details before the lights come on and give them a short exposure later just for the lights (double-expose the film.) Make the first exposure at one to two stops under your meter reading so they appear dark in the final image. This requires a lot of waiting around, but it's very effective.

Peter Gomena

[l2oBiN]

great tip Peter.. Does the developemnt time vary with different type of processing as well?

[Brian Ellis]

I used to read that the shadows fully develop about 30% of the way through the total developing time. Of course this will vary depending on how dense the shadows you're talking about are (i.e. Zone I presumably will be fully developed before Zone III).

[imagedowser]

What Peter said... but it may matter where the light is coming from in the scene... (sunrise/sunset) and shoot the lights first, then second exp.

[Peter Gomena]

I don't think shooting the lights first is going to work. They'd still be on when you tried to expose for the ambient light.

In school this was referred to as a dusk/dark double exposure. Frame your image at dusk, and underexpose the scene from your meter reading by one to two stops. I like to go about 1-1/2 under. Then wait for the sun to go down (really dark!) and make your exposure for the lights. Do not change the aperture setting, only shutter speed/time exposure. Adjusting the aperture will change the size of the circles of confusion on the film plane and give less sharp results. It is a good idea to tape your film into your holder so the film can't shift. I used to use double-stick tape that had had the side facing the film de-tacked a bit with a fingerprint or six. Makes it easier to remove the film later. I've used this technique with building lights and fireworks displays.

Peter Gomena