X-Rite 334 Sensitometer: Inspection and Analysis

[Alec246]

ISO 6 doesn't specify a developer. Manufacturers can use any developer and multiple developers if they wish. It does specify the developer needs to be listed.

If you're testing, you should use the developer you intend to use in practice.

Thank you for the clarification.

But wont this mean the reference for Ilford Delta 100 at 0.1 over base+fog will no longer match the value expected for using as calibration for the light output?

Edit:
Does this look ok? I set maximum Exposure Time, Mode 7. More than that would require me to exposure twice

 

[skahde]

I'm on my second example of this device after giving one to a friend and again finding the need to own one. My use of the seinsitometer is rather simple. I more or less ignore the absolute output and find the ISO of the film by in-camera exposure. That way I can be sure camera and lightmeter together deliver the result needed in a real-world setup.
The step-wedge in the sensitometer just tells me if I nailed the development.
That way I also do not need to worry about spectral output vs. sensitivity.

 

[Stephen Benskin]

Thank you for the clarification.

But wont this mean the reference for Ilford Delta 100 at 0.1 over base+fog will no longer match the value expected for using as calibration for the light output?

Edit:
Does this look ok? I set maximum Exposure Time, Mode 7. More than that would require me to exposure twice

Since my reply, I've read your previous posts. What you want to do requires a lot of precision and is not at all practical with the tools you are using. I agree with skahde. The best thing to do is determine a working EI and use the sensitometer for the consistency of the exposure.

Your strip looks pretty good. Maybe consider a touch less exposure. The key is to have enough toe to work with, especially with extended development times.

 

[ic-racer]

Thank you very much for these numbers!

I assume this is only true when using the ISO Standard Kodak D-76 Developer? I currently use XTOL, but I can purchase D76 just for these calibration process.

Two things from the Ilford D100 datasheet. They list ID11 or DD-X for "Best Image Quality" so you might want to use that developer. However, they also indicate the exposure indexes listed in the PDF file are:

...based on a practical evaluation of film speed and is not based on foot speed, as is the ISO standard.

So, as Steve mentioned above, you might want to determine your own working Exposure Index.

 

[Alec246]

Thank you all again!

My use of the seinsitometer is rather simple. I more or less ignore the absolute output and find the ISO of the film by in-camera exposure. That way I can be sure camera and lightmeter together deliver the result needed in a real-world setup.
The step-wedge in the sensitometer just tells me if I nailed the development.
That way I also do not need to worry about spectral output vs. sensitivity.

So you find your Film Speed like described by Ansel Adams, bracketing shooting Zone I Metering, and the frame where the exposure gives you 0.1 over b+f, that is what your film speed is set?

Your strip looks pretty good. Maybe consider a touch less exposure. The key is to have enough toe to work with, especially with extended development times.

So it would be beneficial to have more toe samples, meaning more patches with lesser density?

Two things from the Ilford D100 datasheet. They list ID11 or DD-X for "Best Image Quality" so you might want to use that developer. However, they also indicate the exposure indexes listed in the PDF file are:

About Delta 100, I only picked this film because I thought I needed a known reference ISO 100 film to calibrate my system. Usually I shoot HP5 Plus 400, and will also give Pan F 50 Plus a try, with XTOL.

 

[skahde]

So you find your Film Speed like described by Ansel Adams, bracketing shooting Zone I Metering, and the frame where the exposure gives you 0.1 over b+f, that is what your film speed is set?

That is more or less exactly how I'm doing it right now. Minus four stops correction after measuring a uniform target with constantly distrusted and frequently crosschecked devices and measure the resulting density. The optimal density is always debatable within the lower decimals. But I still have to take the time to get my Macbeth TD904 up and running again.

 

[Stephen Benskin]

So it would be beneficial to have more toe samples, meaning more patches with lesser density?

It's a balancing act. You need maintain the higher densities with reduced processing and the toe with extended development.

So you find your Film Speed like described by Ansel Adams, bracketing shooting Zone I Metering, and the frame where the exposure gives you 0.1 over b+f, that is what your film speed is set?

99% of the talk about film speed, is really about EI. In fact, an argument can be made that the ISO derived speed is an EI. Simply put EI is how you set the meter. There are too many factors involved in good testing practices and it's easy to introduce experimental errors into the process because of unknown factors or imprecise or inadequate equipment. Let's use Zone System testing as an example since you brought it up.

Zone System testing uses a different method than a sensitometric approach using a step table and curves. It states the 0.10 fixed density is four stops below the metered exposure. This method will generally generate a 1/2 to 1 stop slower film speed than the box speed because the ISO speed point is 3 1/3 stops below the metered exposure point (Hg/Hm = 10). Zone System users end up rating their film one half to 1 stop slower than the box speed without any complaints. In fact, most have no idea they are using erroneous speeds because most didn't have a way to confirm their results. And it really doesn't matter because they are satisfied with the results they obtain. So my position is why go through all that in the first place. If you're using a general purpose developer, the film will have an effective film speed close to the ISO speed. The main difference would be how you meter and your personal taste. Shoot a little and see what you like, then use that as your reference EI.

 

[skahde]

Apples and oranges. The zone system defines a different, pragmatic standard for setting the meter by defining a baseline. The photographer can and should work from there by placing areas of different subject brightness on a scale of resulting negative-densities. The placement of the zones is the subjective step where experience of the photographer comes into play: Do I agree to the suggested densities or do I prefer a lighter or darker reproduction of the scene? I'm just reading Adam's books again: The system gives you a tool to make this decisions reproducibly and defines a usable baseline, it is not scientific standard of some kind and was never intended as such. I uses the scientific basis of sensitometry and densitometry as its foundation but in application is was meant as a practical approach, regardless of what some may make out of it.

 

[Alec246]

Zone System testing uses a different method than a sensitometric approach using a step table and curves. It states the 0.10 fixed density is four stops below the metered exposure. This method will generally generate a 1/2 to 1 stop slower film speed than the box speed because the ISO speed point is 3 1/3 stops below the metered exposure point (Hg/Hm = 10). Zone System users end up rating their film one half to 1 stop slower than the box speed without any complaints. In fact, most have no idea they are using erroneous speeds because most didn't have a way to confirm their results

Very enlightening. I had no idea Zone System could shift the Film Speed so much.

I'm just reading Adam's books again: The system gives you a tool to make this decisions reproducibly and defines a usable baseline, it is not scientific standard of some kind and was never intended as such. I uses the scientific basis of sensitometry and densitometry as its foundation but in application is was meant as a practical approach, regardless of what some may make out of it.

That is also my understanding from the Zone System, and I am also in the process of reading the books. Ansel Adams makes it quite clear, it is a tool to allow the artist to transform his vision into a final print, and there are scientific but also very practical steps.

I will start with the suggested manufacturer ISO Speed, and see if I find the necessity to make it slower or not. And adopt that as my EI.


Now, I was trying to measure Density using my SpotMeter. This really didn't work at all, probably because it would require a Close Up Lens adapter which I dont own for close focus.

Instead, I have placed an order for a X-rite 331 Densitometer, Second Hand of course, and I will be continue my journey into sensitometry as it arrives. It should be well calibrated, and there will be no guess involved

 

[ic-racer]

My personal bias is ISO speed leaves little or no under exposure latitude. This is by definition; minimum exposure to produce an excellent print.

 

[Stephen Benskin]

My personal bias is ISO speed leaves little or no under exposure latitude. This is by definition; minimum exposure to produce an excellent print.

The ISO speed is a point of reference that is the same for all black and white films no matter the characteristics. It links the physical nature of the film using a limiting factor and associates it with the perception of quality. It's psychophysical. After that, it's up to the individual to determine what works for them. What the ISO speed gives you is the point to base the exposure that works for you. My point is that most personal "speed" testing is either conceptually incorrect and / or experimentally error prone leading to a false sense of accuracy. It's more a waste of time than a benefit. It's better to just base an EI on an working EI based from the ISO. A sensitometer can then used that value as a reference.

It doesn't stop there for as we know a fixed density point tends to underrate the film developed to a lower than average gradient and overrate the film when developed to higher gradients. Plus there's the question of the speed constant. 0.80/Hm is based on daylight color temperature because black and white film is more sensitive to blue light. Prior to 1960, the standard was sunlight and the constant would have been 0.95. All this adds up. Simply pick a number with the understanding it's an EI.