contrast range in zone system

[pierods]

I just read "The zone system for 35mm photographers" and I am not clear about something.

If I have a scene with an exaggerated contrast range (too high/too low) what is the course of action that I need to take?

So let's say, for the sake of example, I am taking a picture with shadows and highlights (as opposed to uniform lighting) under a regular contrast range (5 zones between the darkest shadow and the brightest highlight if I remember correctly).

I have the choice to put object X in zone Y, and I will have to live with that choice (in 135/120 format) or make a note on the film holder and develop accordingly (large format).

Now let's put contrast range to 10 zones, or 2 zones.

What are my options then?

I appreciate any input..

piero

 

[Andrew Moxom]

For really large subject brightness ranges, you would usually need to increase exposure for shadow detail, and decrease development time to stop the highlights from blocking up. For roll film shots where there are varying degrees of subject brightness ranges on one roll, it's a compromise. You are probably better off doing an N-1 exposure/dev combination, and using VC paper to make up ground with any thinner negs. OR, use pyrocat HD or MC developer, and rate the film at one stop slower, and be done with it. I have never had ANY problems with highlights blocking up with any of Sandy King's Pyrocat developers.

 

[RobC]

If you are going to expose a roll of film where the subjects are of greatly varying brightness ranges with some extreme brightness ranges, then using a compensating developer will help a lot. It will have little effect on normal range subjects but where you have extreme brightness range, it will pull the hightlights down to manageable printing levels.

This is why I beleive the likes of Barry Thornton, and many before him, went to great lengths making developers which did this. They developed films from clients with wildly varying brightness ranges and less than perfect exposure. A developer which stops extreme highlights from blocking up is ideal for this.

Once you have normal film speed and dev worked out for film dev combination, then you expose and develop as nomal.

For an image with only 2 stop range, then you would need very high contrast film and appropriate developer. Normal film wouldn't do it combined with normal range exposures. But then a 2 stop range is a specialist subject and you wouldn't try and photograph it on the same roll as some normal exposures would you. Or would you? Don't.

 

[RobC]

see this thread which is currently running and is discussing two bath (compensating) developers.

(there was a url link here which no longer exists)

 

[david b]

What cameras are you shooting with?

You mention 120 so I am curious if you are using a camera with removable film backs.

If so, you might try this (you'll need 3 backs):
one film back loaded with film to be developed N-1
one film back loaded with film to be developed N
one film back loaded with film to be developed N+1

I am not a fan of this method but it sure does work.

 

[RobC]

One word of caution with these compensating developers. They do pull the highlights back but what this is actually doing is reducing contrast in the mid to high values. That might be great for making it print but at the same time it can kill the highlight contrast leaving the highlights looking very flat.

Don't make the mistake of believing that just because your negative range fits the paper, that you will automatically get really good prints with the right contrast.
You should be taking the approach of photographing in the right lighting conditions to get the look you want. If the lighting is wrong then your images may be less than desired. Messing with development will only fix that to a point.
And if its the high values that really important in the image, which they often are, then expose for the high values and forget the shadows. They will go where they go.
IMO too much is made of preserving the shadows when in reality it is the mid and high values which really make the print. Blocked up shadows can actually make the mid and high values jump out even more. But that is just my subjective opinion of some images. Preserve shadow separation if you can, but not at the expense of ruining highlight contrast.

 

[pierods]

One word of caution with these compensating developers. They do pull the highlights back but what this is actually doing is reducing contrast in the mid to high values. That might be great for making it print but at the same time it can kill the highlight contrast leaving the highlights looking very flat...

I will apply the advice about shadows and highlights.

I don't think I will use 2 bath devs (I haven't visited the thread yet) since I usually "think up" the photograph while I am shooting in terms of zones and make the necessary compromises then and there (choose where to put the most detail, or maybe go for max contrast, or seek flare etc, I mean), if I want average results then I shoot digital.

Thank you for the advice.

 

[pierods]

What cameras are you shooting with?

You mention 120 so I am curious if you are using a camera with removable film backs.

If so, you might try this (you'll need 3 backs):
one film back loaded with film to be developed N-1
one film back loaded with film to be developed N
one film back loaded with film to be developed N+1

I am not a fan of this method but it sure does work.

F80 (N80 in the states).

I cited 120 format for the sake of the example.

Even if I shot 120, I don't think I would apply that method, because I only shoot b/w with film, and b/w film has got such a range that having 3 backs (for that purpose) looks overkill to me.

As far as color is concerned, I do either slides, so you have to expose exactly, no tweaking, or digital, which has about the same dynamic range than color negative film, which in my opinion is largely obsolete these days.

Actually I have a question about color film, how did they get those crazy saturated colors in the '80s, but I should start a separate thread.

Thanks for your answer.

 

[Christopher Walrath]

When you get a wide SBR in your subject area (seven stops or more) you really have to decide what is expendable and expose around the vital components of your subject. If you can live with a little black in the back of the shadow areas, are the highlights small and insignificant enough to block out? For low contrast subjects I either increase exposure if I want it flat or decrease exposure for increased contrast.

 

[RobC]

There are times when a compensating dev can be useful. For example, an indoor shot where you have a window onto a garden. Obviously the lighting for indoor and outdoors will be different and each would require a different exposure. Exposing for the indoor lighting and using a compensating developer can bring some detail into what is seen through the window.

 

[Saganich]

In any zone system thinking the point is to previsualize the final print which means that the highlights and shadows that your measuring are appropriate for your vision of the final print. Which highlights are important, and which can you ignore? I've also found I do not like compensation when processing and prefer full development.

 

[Christopher Walrath]

Or you could preexpose your negs to bring up the shadow values to recude contrast in the negative.

 

[pierods]

Or you could preexpose your negs to bring up the shadow values to recude contrast in the negative.

What do you mean exactly?

 

[RobC]

Both film and paper have a threshold point which requires a certain minimum amount of exposure before anything registers on the film or paper.
For printing there is technique called flashing which you should find plenty of information about if you search the forums.
Pre exposure of film is the same as paper flashing except that paper flashing effects the paper highlights whereas film flashing effects the shadows.
How it works. You give the film an exposure of an evenly illuminated subject. It could be a piece of white card or a grey card or a dark grey card. It doesn't matter as long as the colour is neutral. You expose at a low zone such as zone 1.
You then use the same frame to expose a high constrast subject. Say it has 13 stops of range from a zone 0 to zone XIII. Set exposure for zone VI and expose. Then use a compensating developer to pull the highlights back a zone or two.
The preflash of the film gives some density to the base shadows. Any additional exposure of low shadow values will add some detail to those shadows because the threshold has already been reached with the preflash. The compensating developer then brings the extreme highlights back into printing range.

The film preflash has no effect on mid and high values. Remember that film sensitivity is exponential so a small exposure only affects low values.
So the effect of the preflash is to bend/lift the toe of the characteristic curve up a little in the same way as reducing development bends the shoulder of the curve down.

Works in theory and it can in practise but don't expect good shadow separation if you try it becuase that bending of the curve is flatenning the curve a little at that point in the same way as reducing dev flattens the curve at the shoulder. But it can put some detail into low values that would have been blocked up if you had just exposed for high values.

[edit]
p.s. some people put a diffuser over the lens to do a film preflash so no evely illuminated subject is required.
[/edit]

 

[Christopher Walrath]

Pick a non-textured, evenly illuminated surface such as a wall and set up your camera before it. Meter the surface and record the reading. Set up your camera to expose, placing this reading on Zone II (reduce exposure by three stops). FOCUS TO INFINITY so as not to record unwanted detail on the neg to interfere with your photograph. Expose the film.

Now you have a negative that will raise your shadows. Zone O adds 0 unit of exposure. Zone I prvides 1 units. Zone II provides 2 units. Zone III provides 4 units. Zone IV provides 8. Zone V provides 16. Zone VI provides 32. And so on.

If you expose as mentioned above you are giving a Zone II preexposure. This adds 2 units of exposure to all exposure zones. So you raise anything that would normally be placed on Zone O from 0 to 2 untis of exposure, effectively raising Zone O components up to Zone II (2 units). Anything on Zone I (1+2=3) raises to between Zones II and III (2 and 4 respectively). Anything on Zone II (2 units) raises to Zone III (2+2=4). Anything on Zone III (4 units) raises to slightly more than halfway (5.6 units) between Zones III and IV (4+2=6). Above this the change is not really noticeable.

You can preexpose for a Zone I setting or a Zone III setting. Even a Zone VI setting. Whatever you decide 'cause it's your negative.

This requires practice to know what it is going to do to your negatives. However once mastered it's just one more tool at your disposal.