Zone I SET

[Fred V]

Ok, so this is new territory for me. In an effort to gain more control over my exposure and development process, I am trying to find my film speed (.1 over film base + fog) for TMAX 400. With the help of a generous forum member here, I now have that determined.

In trying to find my Standard Development Time I have encountered problems. I have adjusted my enlarger so the light barely covers an 8x10 enlargement. My exposure to get any kind of separation between complete black and the next lightest grey tone was 2 seconds at f16. 2 seconds does not sound right to me. My only thought is that setting the enlarger for an 8x10 print may have been suggested when using a 35mm negative and that a 4x5 negative should have a larger projection onto the enlarging easel. Or something else.

Any efforts to help me will receive mucho good karma!

Thanks.

[Alan9940]

Standard development time is determined based on Zone VIII. The way I determine this in the darkroom is the following:

1. Set the enlarger height for a fairly generous coverage of an 8x10 area of, say, a printing easel.
2. Insert a negative and focus the enlarger.
3. Insert a blank negative (Zone 0) and make a test strip (I use 3 sec increments)
4. Process this sheet as you normally would and let it dry (archival washing is not necessary here)
5. Determine which stripe reveals black where the subsequent stripes don't get any darker. Be careful here because all you need is an acceptable black.
6. Insert a probably Zone VIII negative, cover half a sheet of paper, then give your minimum time to reach dMax black (from step 5)
7. Process this sheet as you normally would and let it dry.

What you're looking for a just a hint of tonality between the exposed and white unexposed part of the paper. If no difference, decrease development time by 20% and repeat the above. If the exposed side goes to gray, increase development time 20% and repeat the above. Rinse-n-repeat until you've found a proper Zone VIII print value; usually doesn't take more than a couple of trials.

Others use density strips, etc, but this was the way I did it before I got a densitometer many years ago.

Hope this helps.

[neil poulsen]

Standard development time is determined based on Zone VIII. The way I determine this in the darkroom is the following:

1. Set the enlarger height for a fairly generous coverage of an 8x10 area of, say, a printing easel.
2. Insert a negative and focus the enlarger.
3. Insert a blank negative (Zone 0) and make a test strip (I use 3 sec increments)
4. Process this sheet as you normally would and let it dry (archival washing is not necessary here)
5. Determine which stripe reveals black where the subsequent stripes don't get any darker. Be careful here because all you need is an acceptable black.
6. Insert a probably Zone VIII negative, cover half a sheet of paper, then give your minimum time to reach dMax black (from step 5)
7. Process this sheet as you normally would and let it dry.

What you're looking for a just a hint of tonality between the exposed and white unexposed part of the paper. If no difference, decrease development time by 20% and repeat the above. If the exposed side goes to gray, increase development time 20% and repeat the above. Rinse-n-repeat until you've found a proper Zone VIII print value; usually doesn't take more than a couple of trials.

Others use density strips, etc, but this was the way I did it before I got a densitometer many years ago.

Hope this helps.

This was my approach early on. I think that it's also important with this approach to determine a "maximum black" exposure for your enlarger. Determine the shortest enlarger exposure time that will render a Zone I negative as maximum black on whatever paper you plan to use. Use this exposure to print your Zone VIII negative.

But over the years, I've become comfortable using as my "N" standard development time, that which renders a Zone VII negative at 1.35 density units on a densitometer.

Also, don't underestimate the amount of time a densitometer can save in doing these calibrations. It can be substantial.

[Fred V]

Everyone...my apologies for sending you down the wrong path. See, I warned you this was new territory for me. What I should have said was Standard Enlarging Time (SET). I was trying to find the proper printing exposure to determine the first noticeable tonal separation from black. I finally realized my mistake when some of your answers referred to adjusting development times to achieve Zone VIII.

Testing is being done with TMAX 400 4x5, Omega enlarger, 135mm lens and Ilford MGIV paper with no filter.

However, all your helpful information regarding determining Zone VIII detail in a negative will be very helpful as this will be the next step in my journey (after I solve the 2 second exposure problem).

To review and clarify, with my enlarger set to provide coverage for an 8x10 print, why is my exposure time only 2 seconds at f16?

Thanks again.

Fred

[Doremus Scudder]

Everyone...my apologies for sending you down the wrong path. See, I warned you this was new territory for me. What I should have said was Standard Enlarging Time (SET). I was trying to find the proper printing exposure to determine the first noticeable tonal separation from black. ...

See my post above for finding minimum time for maximum black.

As for "Standard Enlarging Time": I certainly don't have one. I do find a "proper-proofing time" for finding the minimum exposure it takes to render a clear area of the negative "maximum black" on the paper, but it varies with film and development time (and film developer, enlarger bulb life, etc., etc.). I usually do a quick test before proofing a batch of negatives to find the right time (or times, if I have different films, for instance) for that batch.

Note that this is only for proofing. Proofs give me lots in information, but when making a fine print, I start from scratch with a guesstimate about contrast derived from the proof and a test strip. Whatever enlarging time I end up with for any particular print isn't any "standard" at all; rather the exposure I need at the contrast I want to get the print I like.

Best,

Doremus

[Fred V]

My best guess is the SET might be useful for eliminating the enlarging time as a variable when determining film development times for N+ and N-.

[Doremus Scudder]

My best guess is the SET might be useful for eliminating the enlarging time as a variable when determining film development times for N+ and N-.

Since changing development time changes the film-base+fog density, any standard enlarging time derived from one development scheme will not automatically transfer to another. Ideally, E.I. should probably be adjusted for expansion and contraction developments as well (in practice, it's really only the contractions that we have to watch out for). Still, I'd do a separate test strip to find minimum time for maximum black if I increased or decreased development by 20% or so.

Regardless, the window of acceptable exposure and development is generous enough that one should be able to get in the ballpark fairly quickly for a "Normal" scheme of exposure and development. These days, it is less important that we have a lot of different development schemes, since the contrast controls in printing are greater and more flexible. And, even the classic Zone System as practiced by Ansel Adams never got closer than a "Zone," which means a stop, one way or the other.

Getting enough exposure so you have the information you need on the negative and then developing enough to get the print contrast you want (i.e., between the extremes of possibilities offered by VC paper) is all that we really need to do. Sure, dialing things in is great, but we shouldn't get lost in the rabbit hole of testing everything to perfection when it's not necessary and doesn't make any difference in the final print.

Best,

Doremus

[Fred V]

Since changing development time changes the film-base+fog density, any standard enlarging time derived from one development scheme will not automatically transfer to another. Ideally, E.I. should probably be adjusted for expansion and contraction developments as well (in practice, it's really only the contractions that we have to watch out for). Still, I'd do a separate test strip to find minimum time for maximum black if I increased or decreased development by 20% or so.

Regardless, the window of acceptable exposure and development is generous enough that one should be able to get in the ballpark fairly quickly for a "Normal" scheme of exposure and development. These days, it is less important that we have a lot of different development schemes, since the contrast controls in printing are greater and more flexible. And, even the classic Zone System as practiced by Ansel Adams never got closer than a "Zone," which means a stop, one way or the other.

Getting enough exposure so you have the information you need on the negative and then developing enough to get the print contrast you want (i.e., between the extremes of possibilities offered by VC paper) is all that we really need to do. Sure, dialing things in is great, but we shouldn't get lost in the rabbit hole of testing everything to perfection when it's not necessary and doesn't make any difference in the final print.

Best,

Doremus

Good point Doremus about getting lost in the rabbit hole. At my level of experience I should probably take a more lenient approach initially instead of trying to fine tune things prior to going out and taking photographs.

However, I am still puzzled regarding my 2 second enlarger exposure time...

Thanks to all for your help.

[Doremus Scudder]

... However, I am still puzzled regarding my 2 second enlarger exposure time...

Well, certainly two seconds is way to fast for a manageable exposure time.

A quick photo of the negative (e.g., smart phone and using computer screen for back-light) would help us to see where the problem lies - neg or enlarger.

If the fault is not with the negative, then the first thing is to check that everything is really working properly (are the aperture blades in your lens really closing? Is there an adjustment for the condensers that you are missing, etc.).

The next is to see if there is anything you can do to adjust the light output of the enlarger (lower wattage bulb, condenser adjustment, ND filters in the light path, etc.)

At any rate, it certainly should be a solvable problem.

Best,

Doremus

[Jerry Bodine]

...changing development time changes the film-base+fog density...

Doremus, I’ve found something interesting in this regard. When I tested HP5+ sheet in HC-110B with step tablet in camera, measuring fb+fog at the rebate, the results agreed with your comment. Testing from 4min to 14min, the rebate showed fb+fog increasing from .16 to .22.

Then I read an article by Howard Bond which I copied to a pdf file (attached) in which he said on p.4 (see my red font) that he measured fb+fog under a piece of electrical tape that had a small piece of aluminum foil under the tape to make sure the measured area under the tape received no exposure. So, later when I tested FP4+ in HC-110B, I followed his method for fb+fog. Testing from 5min to 9min, fb+fog was consistently .12 +/- .01. I’ve not yet redone the HP5+ tests. I suspect this is the rabbit hole you mentioned.