Who says “Use half box speed for ZS”?

[MattKing]

"Shadows to the left of me!
Highlights to the right!
Here I am Stuck in the Middle with You."
(Apologies to Gerry Rafferty.)

 

[foc]

"For those who believe, no proof is necessary. For those who don't believe, no proof is possible." Stuart Chase

Sort of sums up everything, religion, politics, pre-wash, squeegees.............................................

 

[ic-racer]

Gosh, this thread reminds me of the time I was teaching the Siggaard-Andersen Acid Base theory at work. Their model, though not perfect, was designed as a teaching tool to help understand ABG analysis. I think the Zone System is the same. It is a tool to help explain, not an explanation in itself. Anyway, back to the debate...

 

[grain elevator]

Everybody knows that even if every light meter is accurate, how they are used makes as much difference as what ASA is set on the dial.

This seems to often get neglected in these discussions.
I know my metering isn't dead accurate and I consider "downrating" a measure to make sure most of the distribution of my exposures falls on the "plenty" rather than the "under" side.

 

[Vaughn]

I have to remind myself that people get involved in photography for many different reasons. I am an artist whose media is photography. There are those who just love playing with equipment and chemicals, others love the math and science behind photography, others just like making pretty pictures, others are trying to make a living, and many combinations of all of those.

A lot of fuss about 2/3 stop or stop, or whatever! Some folks need/want the precision/accuracy -- for some it just gets in the way of creating.

 

[Stephen Benskin]

This seems to often get neglected in these discussions.
I know my metering isn't dead accurate and I consider "downrating" a measure to make sure most of the distribution of my exposures falls on the "plenty" rather than the "under" side.

Here is a graph of the response of difference meter types calibrated to difference color temperatures over a range of color temperatures.

 

[Stephen Benskin]

I have to remind myself that people get involved in photography for many different reasons. I am an artist whose media is photography. There are those who just love playing with equipment and chemicals, others love the math and science behind photography, others just like making pretty pictures, others are trying to make a living, and many combinations of all of those.

A lot of fuss about 2/3 stop or stop, or whatever! Some folks need/want the precision/accuracy -- for some it just gets in the way of creating.

To me it's not so much about the 2/3 stop exposure difference, as about the fuss.

 

[MattKing]

"For those who believe, no proof is necessary. For those who don't believe, no proof is possible." Stuart Chase.

It occurs to me that if the author of that quote was identified as Santa Claus, it would work equally well.
The half box speed approach makes the same sort of "rule of thumb" approach as many of the "rules" of composition.
All of them aren't logically determinable, but they all reflect the results of experience.
So it is okay to use them, if you like the results.

 

[Stephen Benskin]

I was able to pick up a Kodak Reference Handbook when a generational mom and pop camera store closed a few years ago. The copyright is from 1946, but the book is designed to have updates inserted and replace outdate information. So there is no telling exactly how old any one piece of information is.

Found data sheets on Tri-X and Plus-X. The EI for Tri-X is 200 Daylight and 160 Tungsten, but the really interesting part is the part I've highlighted. About doubling of the film speed.

In a paper by Allen Stimson, An Interpretation of Current Exposure Meter Technology, Photographic Science and Engineering, Vol. 6, No 1, Jan-Feb 1962, he writes about the exposure meter graph uploaded a few posts back and it also relates to the two EIs, Daylight and Tungsten.

Calibration at 4700 K

With changes in color temperature, the sensitivity of selenium cells of American manufacture changes in the same direction, although somewhat less in magnitude, as panchromatic negative materials. Hence meter makers have urged film manufacturers to eliminate tungsten film rating for several years. K.S. Weaver of the Kodak Research Laboratories made extensive tests on a dozen of each of fourteen makes of meters to determine the feasibility of this elimination. His tests showed that two of the fourteen changed sensitivity with color temperature in the opposite direction from the majority. This confirmed other observations that some meters, which manifested perfect calibration in the laboratory (at 2700 K), differed markedly when used in daylight. A. L. Sorem showed that the errors could be equally divided between daylight and tungsten if all meters were calibrated at 4700 K rather than 2700 K. This calibration is now included in the standard. It will assure closer agreement between meters in daylight and eliminate the need for tungsten film speed for most panchromatic negative materials.

 

[MattKing]

The copyright is from 1946, but the book is designed to have updates inserted and replace outdate information. So there is no telling exactly how old any one piece of information is.

I have a 1940 version of the same handbook, and it is really fascinating - particularly the colour Kodachrome section!

 

[Stephen Benskin]

I have a 1940 version of the same handbook, and it is really fascinating - particularly the colour Kodachrome section!

That is before the fractional gradient method. Very cool.

 

[Vaughn]

To me it's not so much about the 2/3 stop exposure difference, as about the fuss.

And you are one of the ones making all the fuss about the fuss!

But, then am I. Here's to making photographs! Or at least have fun playing around numbers, chemicals, papers, equipment, or whatever floats one's boat!

 

[Stephen Benskin]

And you are one of the ones making all the fuss about the fuss!

But, then am I. Here's to making photographs! Or at least have fun playing around numbers, chemicals, papers, equipment, or whatever floats one's boat!

I'm somewhat personally invested in this subject as I was the one years ago who introduced how the Zone System had a different methodology than the ISO standard causing the 2/3 stop discrepancy in EI. Before that, there was strictly conjecture and conspiracy theories. I like to think of it as sharing information. Sure it's a lot of fuss and I have to put up with ad hominem attacks, but where would we be without curiosity and a desire for the truth?

You presented a false dilemma fallacy. A person can be both interested in theory and be an artist.

 

[Craig75]

I'm somewhat personally invested in this subject as I was the one years ago who introduced how the Zone System had a different methodology than the ISO standard causing the 2/3 stop discrepancy in EI. Before that, there was strictly conjecture and conspiracy theories. I like to think of it as sharing information. Sure it's a lot of fuss and I have to put up with ad hominem attacks, but where would we be without curiosity and a desire for the truth?

You presented a false dilemma fallacy. A person can be both interested in theory and be an artist.

Well i find yours and michael_r s contributions very interesting and helpful and firmly believe you cant be a printer without knowing what the materials are, and what they can do

 

[Vaughn]

...You presented a false dilemma fallacy. A person can be both interested in theory and be an artist.

That's covered in 'whatever'...

 

[Lachlan Young]

-Learning a little about how these things really work helped me to simplify certain aspects of the process, rather than complicate them

-I don’t think it requires a whole lot more effort on average to learn correct things than to learn incorrect things

So many photographers would work more effectively if they heeded these two statements!

I'd actually tend to go even further with these statements - I think it actually takes less effort to learn the correct information, because then the systems work as designed, making subsequent interaction with them more coherent in terms of getting the outcomes you want.

 

[Bill Burk]

Here is a graph of the response of difference meter types calibrated to difference color temperatures over a range of color temperatures.

View attachment 274622

Darn, my Kollmorgen standard light source is 2850...

 

[Bill Burk]

I'd actually tend to go even further with these statements - I think it actually takes less effort to learn the correct information, because then the systems work as designed, making subsequent interaction with them more coherent in terms of getting the outcomes you want.

So true Lachlan,

There are so many conflicting ideas that take you in different directions, that it's not unusual to make two corrections in the same direction for the same thing.

One day during the fuel crisis of 1974 they established double daylight savings time. I don't know what I heard, but I walked to school at four in the morning that Monday... Once I realized it was so early I walked all the way home and went back to bed, even though it took me 45 minutes.

 

[Arvee]

I am a perfectionist in my artistic endeavours, including photography. It was important for me to delve to some extent into photochemistry and sensitometry, because I wanted to know if I was leaving anything on the table quality-wise. I work very hard on my pictures and prints and have tried to develop as much technique as I can, but when it comes to photography, much of the process is largely a black box unknown to the vast majority of practitioners. That’s perfectly ok for many, but not for someone like me, who would always have nagging doubts, so I had to learn. Of course it didn’t hurt that I love the sciences, but the ultimate purpose for me, in this case, was for all of the technical knowledge to “serve the art”, mostly by giving me some peace of mind.

A few things perhaps worth considering (or not):

-Learning a little about how these things really work helped me to simplify certain aspects of the process, rather than complicate them

-I don’t think it requires a whole lot more effort on average to learn correct things than to learn incorrect things

+1

 

[Doremus Scudder]

... Anyway, back to the debate...

Well, as much as I value all the science about film speed, and I really do, it would seem to be of limited practical value unless there is a way to easily apply it to exposing film in everyday situations. Some way to make all that information useful at the practical level is required to actually make a well-exposed negative (transparency).

This necessarily involves somehow measuring light and determining a suitable exposure. I think that modern, highly-sophisticated in-camera meters come close to the goal of giving consistently good exposures at box speed.

Working with LF and a hand-held meter is another ballgame. One needs to read, interpret and apply readings. As precise and accurate as that can be made is great for me, but if my meter, and the way I use it (not to mention developer, etc.), seem to demand that I use a different E.I. than box speed to get excellent results, then I'm simply going to rate my film differently than box speed. Plus, since I'm using large-format and black-and-white negative materials, I don't mind erring a bit on the side of overexposure.

I don't think I'm blindly following advice that I've read (although following advice from know authorities with proven expertise is probably a good idea, especially for a starting point), nor am I taking things on faith (I test, keep notes, compare results, etc.). Nor do I think that I'm discovering the film's "true speed" by rating it differently; I'm fully aware that I'm compensating for whatever inaccuracies and weaknesses I have in my system.

So, if the metering and visualization system (Zone System) and equipment/methods I use (Pentax spot meter, pyro developers, darkroom printing, etc.) provide better results when I change the film-speed setting on my meter by 1/3-stop (for my favorite film, 320 Tri-X) or 2/3 stop (for TMY), then I'm just going to do it.

I'm interested in making expressive photographs, not doing sensitometric science, which, if it hasn't become obvious by now, are two different (albeit related) disciplines. I'd love to have a meter and a metering method that just let me take one reading at box speed and get great, easily-printable negatives. It would seem to me that, although some sophisticated in-camera meters do a heck of a good job, we aren't there yet with hand-held meters. Since I'm using one of those rather less-sophisticated meters that requires me to interpret and apply the readings, I have no qualms about changing a film-speed setting if (and only if!) it gets me better results.

Furthermore, in my experience, a lot of beginning photographers, who are trying to expose using hand-held meters and the Zone System, and who are developing and printing their own work, end up underexposing their film at first, for whatever reason. So, it seems pretty apparent to me that there is a systemic flaw in the hand-held-meter-Zone-System-metering method that ends up needing an exposure compensation so as not to underexpose. If so, then I still think the tool is valuable enough to simply downrate film speed to compensate for the shortcoming, being aware, of course, that by doing so, I'm simply compensating for the "system" and that the film speed is what it is, regardless.

Making excellent prints is the goal; whatever I have to do with the stuff I use to get them is fine with me.

Best,

Doremus

 

[pentaxuser]

So true Lachlan,

One day during the fuel crisis of 1974 they established double daylight savings time. I don't know what I heard, but I walked to school at four in the morning that Monday... Once I realized it was so early I walked all the way home and went back to bed, even though it took me 45 minutes.

Clearly your internal clock was set to the wrong colour.

pentaxuser

 

[Bill Burk]

Haaa pentaxuser so true.

I am in some senses a perfectionist but in most senses I like when things work. I like to make prints that look good.

The 2/3 stop though.. I wonder of the Zone System practitioners who meter and place shadows low… do you (they) generally place them on Zone II or Zone III? Just that alone makes a stop of difference, and I think there isn’t a standard accepted low zone placement.

 

[Vaughn]

But we do not place shadows anywhere. That statement alone makes talk about 2/3 or whatever a bit silly.

There are shadows with no detail or no texture, shadows with detail, and so forth. First one has to decide what type of shadow one wants where before one can to do anything with a light meter reading.

 

[Doremus Scudder]

But we do not place shadows anywhere. That statement alone makes talk about 2/3 or whatever a bit silly.

There are shadows with no detail or no texture, shadows with detail, and so forth. First one has to decide what type of shadow one wants where before one can to do anything with a light meter reading.

Exactly.

The trick is to get the shadow placement to match your visualization of how the shadow should be rendered. Adjusting E.I. ends up being a part of this process and has little to do with film speed; much more to do with getting what you expect in the way of shadow tonalities.

Then there are those pesky highlights...

Doremus

 

[Adrian Bacon]

Furthermore, in my experience, a lot of beginning photographers, who are trying to expose using hand-held meters and the Zone System, and who are developing and printing their own work, end up underexposing their film at first, for whatever reason. So, it seems pretty apparent to me that there is a systemic flaw in the hand-held-meter-Zone-System-metering method that ends up needing an exposure compensation so as not to underexpose. If so, then I still think the tool is valuable enough to simply downrate film speed to compensate for the shortcoming, being aware, of course, that by doing so, I'm simply compensating for the "system" and that the film speed is what it is, regardless.

a lot of beginning photographers have only ever shot digital before trying film and have “don’t over expose” ingrained in them. They don’t generally know that film doesn’t have miles of under exposure latitude until they experience it AND have the benefit of someone explaining it to them. Usually they experience it and go “man, this sucks” and give up. At least that’s been my experience in dealing with processing other peoples film. Casual shooters are almost always under exposed by at least 1 stop. Hipsters almost always over expose by at least one stop, then ask, “can you pull process this for me? 2 stops., oh, and I want a flat tiff file”. Sure. I then proceed to process it normally and just pull the exposure down in LR before exporting the TIFF file. “That looks so great!”. Thx. All in a days work.