Calibrating 4x5; gray card Zones don't match still life Zones

[Ted R]

Thanks Ted for your thoughtful and kind response. I appreciate you taking the time to write, particularly from your thirty years of experience. My response may not be adequate but it is simple: I am taking a Photography Class, Introduction to Zone. I am completing the assignments for the course. In this moment, I am trusting the wisdom of my teachers. I posted here to see if someone could help me understand the results I have been getting. Something that my teachers and I haven't been able to figure out.

I may be missing something but the Kodak data sheet for HC110 gives times for dilutions A and B but not for other dilutions. What is your development time based on?

How about using dilution A or B and using the recommended development time from the data sheet? Use the film at 400. Do everything exactly by the book to obtain a reference situation. From this you may evaluate the results and arrive at an individual calibration for your system, if needed. We have to walk before we can run, calibrating zone system is running.

Photography is a creative skill, densitometry is the measurement and control of image quality for the image processing industry where they handle other people's images and don't make images, I urge you to throw away the density meter.

[faberryman]

How are you determining what area of the negative is Zone I to measure with your densitometer if you are shooting scenes instead of an evenly lit card?

[Ted R]

PS

Ilford film data sheet for HP5+ gives development times for Kodak HC110 in dilutions A and B for 400, 800 and 1600 speeds but not for slower speeds which you used. What are you basing your film speed+developer combination on?

If you want to shoot HP5+ at 125 there is no recommended developer.

When we are trying to calibrate a system we have to start with the original specifications and test the results they give, that is the starting point, the reference. If on the other hand we start by experimenting with uncharted variables we should expect the unexpected.

Perhaps it would be a good idea to reshoot using 400 and dilution A or B for the recommended time and evaluating the results.

[Richie]

I may be missing something but the Kodak data sheet for HC110 gives times for dilutions A and B but not for other dilutions. What is your development time based on?

How about using dilution A or B and using the recommended development time from the data sheet? Use the film at 400. Do everything exactly by the book to obtain a reference situation. From this you may evaluate the results and arrive at an individual calibration for your system, if needed. We have to walk before we can run, calibrating zone system is running.

Photography is a creative skill, densitometry is the measurement and control of image quality for the image processing industry where they handle other people's images and don't make images, I urge you to throw away the density meter.

Hi Ted, thanks for trying to help me. The website Digital Truth gives development times for HC110E, 1:47, matched with HP5+.

[Ted R]

The chart seems to show 7.5 minutes for 400. Using 11.5 minutes might be appropriate if you had shot at higher speed (>400) however you shot at 125 and developed for 11.5, something is wrong here, over exposure and over development.

Kodak publish the recommended data for HC110, they are the source of authoritative information on dilution and time. When we are trying to calibrate something it is a good idea to eliminate uncertainty by only using authoritative data, use someone else's data at your own peril, it is an uncontrolled variable. Only use dilution A or B, for which Kodak gives data that can be trusted.

Ilford gives no recommendation for HP5+ at speed 125, why are you shooting at 125? You are introducing unquantified variables into a calibration procedure. Decide what you want to do, either experiment or calibrate? Don't try do both at the same time.

When we calibrate something only one variable is allowed. In your system there are four, the lens glass light transmission, camera flare, the shutter times and the aperture calibration. To have any chance of accuracy the film speed and processing need to be the nominal values, that is 400 and normal development.

[Leigh]

The website Digital Truth gives development times for HC110E, 1:47, matched with HP5+.

Based on what?

If we believe everything we find on the web, the world will be in very dire straits indeed.

For testing any photographic process, start with the recommendations from the manufacturers ONLY.
If your results don't match, the problem is at your end.

Fine-tune your process until you get results that match the documented results.

Then you can play with times, dilutions, etc to gain more insight into how the materials and chemicals behave.
But only then.

Understand that the problems you're reporting go against 100+ years of industry experience.
Are we to believe you, or several million previous reports and results?

BTW... Regarding your test exposures:
How did you set the intermediate apertures? Only f/16 is calibrated on your shutter.

250 III, VI 1/15, f/20 0.32, 0.97
200 III, VI 1/15, f/18 0.37, 0.97
160 III, VI 1/15, f/16 0.42, 1.04
125 III, VI 1/15, f/14 0.49, 1.09
100 III, VI 1/15, f/13 0.57, 1.10

- Leigh

[Ted R]

When I started in photography I learned a lot from books on a variety of topics including exposure.

I can recommend this one: Exposure Manual by Dunn and Wakefield, it is written for the photographer not the scientist and is profusely illustrated, it can be found among other places at amazon at a very low price: https://www.amazon.com/Exposure-Manu...+and+wakefield

Books are helpful in that to get a book published (a hardcopy book) the publisher choses an author who is respected for being knowledgeable and readable. Today the internet permits everyone to publish online but the quality of the author's knowledge and experience is invisible, unfortunately, so the content comes with some uncertainty.

[neil poulsen]

. . . When we are trying to calibrate a system we have to start with the original specifications and test the results they give, that is the starting point, the reference. If on the other hand we start by experimenting with uncharted variables we should expect the unexpected. . . .

This is for good reason. We begin by testing ASA, which is based on Zone 1 exposures. Zone 1 film densities vary relatively little with changing development times. So, one can begin with Mfg. recommended times and still have a successful calibration, even though the final "N" development time might be different.

[Andrew O'Neill]

Your density readings at EI 250 for zones III and VI are close to my own personal readings. Stick with EI 250 for "normal" contrast scenes. N+1 I use EI 320, N-1 EI 200. When you start printing your negatives you may find that an adjustment in EI and/or development times is in order. Just look at your results, and listen to what your images are saying to you. Keep good notes.

[Bill Burk]

In your first post you explained:

... "using HP5+400, HC-110 developer, N+1 (development time for this batch was 11'15"), ISO 125. I shot 6 frames and developed them together using tanks and hangers."...

In that test you achieved a contrast of 0.6

In my opinion, based on interpretation of the graphs, you got the development time right, because your graphed curve is parallel to the curve your teacher gave you to match, which is a curve that is similar to the standard ASA aims.

You do not need to develop any longer unless you want N+2