Zen and the art of film testing

[Eric Rose]

As many of you know, I abhor film testing. Generally I have had real good luck with going by the manufacturers recommendations and then fining tuning from there.

It's not that I settle for less, I have had my negs evaluated by Les McLean and Bruce Barnbaum and both of them say they are great. In fact during the Bruce Barnbaum Black and White Workshop he made a point of getting everyone to come over and look at one of my negs on the light table to see what a good one looks like.

One reason I feel I tend to stick closer to the manufactures recommended film speed is because I am a fanatic about keeping my meters calibrated. Must be my engineering background.

I fail to see why some people get all bent out of shape trying to keep their exposures within 1/3 of a stop of what they consider ideal only to be using a meter that is out by close to a stop.

You may say, well that's ok I tested with the meter I use and everything is grand. But do you check your meter for consistency? What's ok this week may be of whack next month due to meter drift.

I use three meters. Not all at the same time, but as they came from the factory they is a stop and a third difference between them. Japanese meters are setup differently than European meters to begin with. Then you can introduce the usual deviation from factory specs on top of that.

Initially what I did was pick one as my standard. This is the one that produced the negs I like to see. Then I noted on the other two meters what I had to bias their readings by. Not a very elegant solution to say the least.

Fortunately I was able to pick up an ExpoDisk. Check it out at Dead Link Removed With this little disk I can calibrate each of my meters to a known reference.

Since doing this I have completed a round of film speed testing on my favorite film APX 100 in 4x5 size. The eventual asa I came out with is very close to 85. That's only 1/3 of a stop from the suggested asa. I used HC110 Dil B.

I have checked a few of my friends meters and in almost all cases they are out by close to 1 stop.

I think much of the prevailing notion that you should in almost all cases half the asa of the b&w film you are using is due in large part to miscalibrated meters. Of course some people just think it makes them seem special, but that's another story. My comments only pertain to using regular developers such as HC110, Rodinal, Xtol and the like. Also it goes with out saying the asa determined was for N development.

The major film manufacturers spend a lot of time and money using very fancy and well calibrated equipment to arrive at the asa's they do. Maybe if we used equipment that was calibrated a bit better we would end up agreeing with them more often.

Another issue is shutter speed accuracy. When was the last time you got your shutters checked??

Just my thoughts and ramblings. Your mileage may vary.

Eric

 

[Donald Miller]

I think much of the prevailing notion that you should in almost all cases half the asa of the b&w film you are using is due in large part to miscalibrated meters. Of course some people just think it makes them seem special, but that's another story.

The major film manufacturers spend a lot of time and money using very fancy and well calibrated equipment to arrive at the asa's they do. Maybe if we used equipment that was calibrated a bit better we would end up agreeing with them more often.


Eric, I agree with you to a point. A part of the discrepency that exists between the manufacturers rated speeds and our actual EI's is that there is a difference in the manner that they measure the film speed and the manner in which we then meter the scene. From what I understand, Phil Davis covers this in his BTZS. Certainly meters can lose calibration.

There are other factors involved here as well. For instance the developer used can have an effect. Additionally, ISO speed is not a fixed target. It is a moving target that varies in regard to development strategies. N+ will increase ISO speed while N- will decrease ISO speed.

But apart from the additional factors that you didn't address, I do agree that to arbitrarily half the mfg rating is not always wise. When we get into the arena of greater density ranges above simple silver enlarging the proper film EI will make a big difference in the ability to achieve density ranges that Azo, Pt-pd, Carbon and others require. When we add into the mix the expanding of contrast the impact of improperly rated film becomes even more apparent.

I think that your post was accurate so far as it went. I had heard of the disc before and I thank you for posting a link to their site. I may benefit from calibrating my meters.

 

[doughowk]

Phil Davis in BTZS on gray card & metering (pp.113-116): " The idea of reading a gray card in the subject area ... makes some sense... Unfortunately, its the wrong shade of gray for general purposes." He goes on how the meter calibration & film speed ratings are wrong in being based on this so-called standard, whereas in fact they should be using a 12% gray card for metering. This translates into 1 stop off when doing in camera reflectance readings, incident reading or spot metering off a gray card.

I try to follow his advice & increase exposure by 1 stop, that is when I'm not metering according to zone system. But I hope I understand him correctly (isn't the easiest of reads).

 

[Joe Lipka]

The stickiest point to all this film and exposure testing (something that is done far too much by too many people) is the absolute very first step taken by the photographer. That is, identifying the zone.

I spent the first two years of LF work doggedly pursuing Fred Picker's .01 above film base and fog. Lost two years of image making working that assumption.

Once I gave up on that and started placing shadows on zones III and IV, everything went well.

So to me, the reason behind the variation is the very first step. What does Zone III look like?

 

[Donald Miller]

I spent the first two years of LF work doggedly pursuing Fred Picker's .01 above film base and fog. Lost two years of image making working that assumption.

I thought that I was the only one that did that. Not only Fred (may his soul rest in peace) but also Ansel (who started it all as far as I can tell...and his soul also) propogated this. Never once telling us that Zone I placements are for dead people. As John Sexton once purportedly said "nothing lives on Zone III".

 

[L Gebhardt]

I am not going to say you are wrong, but I do find I need to rate most black and white films about 2/3 to a full stop less than the stated speed. This is to get good negatives for silver printing. It may be my meter, but my two Nikons agree with my Pentax Digital Spot. I get perfectly exposed slides (at rated speed) back from the Nikons as well, so they seem correct with color materials. My 4x5 transparencies are also properly exposed when I use the Pentax spot. So I don't know if it is the film or my meters, but for color the meters work, but for black and white they don't.

My film testing is usually very limited and for speed consists of shooting a Kodak gray card at Zone I and seeing which speed gives me .1 of FB + Fog. I am actually in the middle of my first real film test where i am testing the developement times for the gamma, and then testing the speed for various times as well. I will then know if all this testing is worth the hours of tedious work (which I have grown to hate).

Joe, what do you mean by:

"I spent the first two years of LF work doggedly pursuing Fred Picker's .01 above film base and fog. Lost two years of image making working that assumption.

Once I gave up on that and started placing shadows on zones III and IV, everything went well."

I have never heard to place the shadows on zone 1, but rather to place the shadows on Zone III if you want the detail to print. Is this what you do now?

 

[Bruce Osgood]

I think the manufacturers box speed can be used for snap shots. Using the cameras average metering will get you average snaps. You won't go wrong if you are looking for average snap shots.

I also think if you are trying to get greater shadow detail shooting at 1/2 the box speed will do that.

Now, if you are trying to make an "expressive" negative you must do the film test with each camera shutter (not shutter speed) and find the .01 FB+F assigned as ZI by Adams. Regardless of film type (B/W), that is ZI. Once film speed is established, then it is time to find ZVIII (1.25-1.35 FB+F) by altering your development. Once found you have N speed and development.

 

[Eric Rose]

Well nice to see my photography has been reduced to "snaps" in one fell swoop.

 

[Leon]

regardless of who wrote what about which zone and where it should be placed on any scale, surely the whole point is about making your equipment and techniques work for you and give predictable results? If Eric's technique means that he stays with manufacturers speeds, then great, if mine are different, then great.

It's only as important as someone wants to make it.

However, I can only see two ways in being able to achieve this level predictability ... trial and error, or a short period of rigourous testing - both will have the required effect, but for me, testing is clearly the the most logical way of reaching this point.

 

[Joe Lipka]

There were two ideas colliding together in my post. Fred's holy grail (as I interpreted it ) was that Zone I was fb+f+.01. Once Zone I was established, then there was a regular progression beyond that point to establish placement of the other zones. For me using the fb+f+.01 gave me really thin negatives. On the plus side, I really learned how to dodge, burn, bleach, selectively develop, use Q-tips with hot developer and a whole host of printing tricks to get a decent looking print.

The second idea is once I recognized where Zone III and IV were in the real world, I learned how to place them far enough up on the curve so that I didn't have to resort to every trick and dodge in the book to make decent print. Most modern films have a pretty long straight line section so you really have to work to hit the shoulder.

The entire "secret" of the ZS is to be able to identify any Zone at ten paces and make a judgement on the correct exposure. I think correctly identifying any zone is the key to being a true "Zonista." Feel free to disagree, that's just the way I feel after thirty years of developing film.

That being said, it's not the negative, it's the print. That's why we do this... Getting to a good print. There are lots of ways to get there. Enjoy your trip.

 

[juan]

Joe, I agree with you. I think Fred even said that the best negative was the thinnest negative that held appropriate information in all zones, or something like that. Anyway, I'm sure of the thinnest negative part. Count me among those who followed Fred's methods for years.

I find those negatives too thin for printing on Azo, so I've also begun moving shadows up to ZIV to get the required density. But I wonder if I never properly placed the zones to start with. I suspect that may be the true trouble.

Remember when considering film speed that the ASA standards were changed in the late 50s-early 60s. The film speeds were doubled. Maybe that's why so many of us halve the film speed.
juan

 

[Dave Mueller]

Regarding rated speeds for film, I think there is a "standard" developer used for the official ISO speed test. It might be mentioned in the BTZS book, or the Film Developing Cookbook. As a few others have mentioned, I think the developer will have more of an impact on speed than meters.

I have read that the thin negatives are preferred, since for the same end result there is less light scattering by the silver grains (I can't remember the technical name for that).

 

[Eric Rose]

I think many have hit the nail on the head when they mention they either don't know what a zone looks like on the neg or took quite awhile figuring it out.

After 35 years of doing B&W I think I have a pretty good idea of what a good neg should look like. At least for me, with my techniques, my water, and my equipment it appears suggested asa's work for me. Even for trannies as well.

My main point in all of this was to stress the importance of getting your equipment calibrated so at least you are starting from a reasonable and known benchmark.

Shutter speed is just as important as meter calibration. If my shutter is 1/2 stop to slow it will impact my negs in exactly the same way whether I use it on my field camera or on my monorail. Unless you have something seriously wrong with your camera's interior there should be no difference.

IMHO there has been way to much VooDoo applied to the analysis and generation of B&W negs. Many would benefit from learning to get a great negative using suggested asa's, and developing times utilizing regular developers. This of course with calibrated equipment. Once this is achieved then fine tuning could be done. Of course they would also have to learn to print this negative as well before any fiddling is done.

This said I do use the ZS all the time and feel very comfortable with it. I can spot what zones are what in the field and know when to use N+ etc for the final effect wanted. I know of one person who has come up with very customized developing dilutions and exposure placements thru much testing. He gets the results he wants. But guess what? His meter is 1.5 stops out. I suspect he could use much more mainstream developing times and zone placements if he had is meter calibrated.

 

[Donald Miller]

In my twenty plus years of shooting and developing film I have learned a few things (still have much to learn). One thing that I have learned is that if one follows the suggestions of Ansel and of Fred of establishing .10 as the film speed point that it virtually guarantees prints that exhibit empty, flat, and unseparated shadow tones. That is I assume why some have taken to placing shadows at III and IV levels. Because a .10 density and incorrect placement will guarantee that shadows fall on the toe of the film's characteristic curve. For shadows to have separation they must be exposed up off the toe of the curve. The other thing that I have learned is that developing film to a 1.25 to 1.35 above FB+fog (per Ansel) is that the prints will exhibit very poor local contrast. The overall (general) contrast may be acceptable but the local contrast is seriously deficient. In my experience it is the local contrast within the print that brings life to the print. It is not the overall contrast at all.

Think about this for a moment, if you will. If we test and establish that a film such as TriX, for instance, is truly a EI 160 film (based on a .10 density in HC110 dil b). Then we place the low values in an exposure on a Zone III or IV. Aren't we in effect saying that irrespective of the manufacturers rating or Ansel's and Fred's edicts that this film needs to be exposed at EI 40 (Zone III placement) or EI 20 (Zone IV placement). Then when we have in our development testing placed our high value densities at 1.25 above FB+fog we have in effect shortened the entire scale of the film. This is a sure guarantee for flat and lifeless prints in my darkroom.

What I find today is that the negatives that I exposed based along the lines of Ansel's guidelines are not printing the way that I want them on grade two paper. (Not Oriental Seagull---not anybody else's). I end up printing those negatives at anywhere between a grade three to grade five filtration. What this tells me is that the density range of the negative (using Ansels guidelines) is too compressed.

The fact is that the EI of a film is a moving target. It is not stationary in the case of plus or minus developing. Nor is it a stationary number if one switches between different developers. It may be and then again it may not be. Yes we need to have some type of guideline in exposure. In my estimation the principles that Phil Davis advocates more nearly approximate the characteristics of our materials in the real world. Ansel and Fred did no testing of the exposure scale of the papers that they were using. Phil Davis considers the paper as the primary starting point for the entire photographic performance. It makes sense to me that if I am about making prints and not about making negatives that I would want to determine the paper characteristics and from that point then bring my negatives into accordance with the paper. This is because the paper is fixed in it's characteristics (in the case of a given paper at a given grade for that paper).

I think that if we didn't use VC materials nearly as much as we did today. There would be more people unhappy with their results using Ansel's and Fred's guidelines.

As others have said this is about producing prints that exhibit the tonal representation that we wish for our efforts. For myself this is not about following the guidelines of another photographer especially when their guidelines are in serious error.

 

[Jim Chinn]

If I am shooting 35mm I have a standard ei for each film and developer combo. But I still bracket one under and one over my ei. Film is cheap and if I don't have a spot meter or am shooting street stuff that ensures i get one good negative with normal developing. If I think I have something really special, I might record the exposure number, pull the canister and clip use tailored developing time for that specific neg and sacrifice the rest.

With sheet film I always use a spot meter meter highlights first and then set the shadows on IV and determine development from there. One thing I noticed right away when i strated using staining developers is that you can really open up shadows mtering for IV and not worry where the highlights fell because the compensating effect would tame the highlights. Then it is up to the paper and developer combo. I think this is why contact printing and AZO have become the rage. The more people move to PYRO based developers the more you need a paper that can record the information. Once you use a paper that produces a greater range of tones, you need to go back and adjust the exposure and devlopment regimen to take advantage of the materials.

I guess what I am getting at is it doesn't really matter how you determine exposure, but you need to consider all the materials as part of the equation.

 

[lee]

Don wrote this:
"Think about this for a moment, if you will. If we test and establish that a film such as TriX, for instance, is truly a EI 160 film (based on a .10 density in HC110 dil b). Then we place the low values in an exposure on a Zone III or IV. Aren't we in effect saying that irrespective of the manufacturers rating or Ansel's and Fred's edicts that this film needs to be exposed at EI 40 (Zone III placement) or EI 20 (Zone IV placement). Then when we have in our development testing placed our high value densities at 1.25 above FB+fog we have in effect shortened the entire scale of the film. This is a sure guarantee for flat and lifeless prints in my darkroom."

Lee wrote this:
"the way I interpret this is that the zone III is really at 80 and the zone IV is 110. Maybe I am not understanding properly. Certainly would not be the first time.

If one is slavish to the zone system, one can expect some of the problems that Don has stated. I disagree with the number he used for zone VIII. I like 1.35 for zone VIII. The 1.2 or 1.25 would be about zone VII in my book. I use PMK pyro and without a color densitometer I can't tell exactly what the zone really is but I have exposed and developed and printing a lot of those negatives. My times do not reflect what Gordon H. uses or recommends.

lee\c

 

[Donald Miller]

Don wrote this:
"Think about this for a moment, if you will. If we test and establish that a film such as TriX, for instance, is truly a EI 160 film (based on a .10 density in HC110 dil b). Then we place the low values in an exposure on a Zone III or IV. Aren't we in effect saying that irrespective of the manufacturers rating or Ansel's and Fred's edicts that this film needs to be exposed at EI 40 (Zone III placement) or EI 20 (Zone IV placement). Then when we have in our development testing placed our high value densities at 1.25 above FB+fog we have in effect shortened the entire scale of the film. This is a sure guarantee for flat and lifeless prints in my darkroom."

Lee wrote this:
"the way I interpret this is that the zone III is really at 80 and the zone IV is 110. Maybe I am not understanding properly. Certainly would not be the first time.



Don wrote this:
Lee, you raise an interesting point. Maybe my calculations are in error. This is how I arrived at the EI's that I originally posted. If we start with the EI of 160 for TriX, then each zone will be a doubling or halving of light reaching the film and consequently a doubling or halving of the EI. Thus I calculated Zone I as 160. Zone II as 80 (since the exposure is doubled), Zone III as 40 (again redoubled), and Zone IV as 20 (again redoubled). The EI is halved when the exposure is doubled.

Yes you are correct in that Ansel said 1.35 for diffusion sources and 1.25 for condensor sources. I did my originally testing of TriX according to those parameters. My experience still stands. The overall contrast is acceptable and the local contrast seriously sucks.

 

[L Gebhardt]

Didn't Ansel say to place the shadows on Zone III? In which book did he say to place areas with shadow detail on Zone I?

 

[Bruce Osgood]

Didn't Ansel say to place the shadows on Zone III? In which book did he say to place areas with shadow detail on Zone I?

I don't think he said where to put the shadows, except that placing the shadows rather than the highlights would be easier to do accurately. There is more room for error when placing the shadow than there is in placing a highlight and still getting a desirable print from it. I don't think he felt it necessary or desirable that every image have maximum black or white.

 

[juan]

But, interestingly Fred Picker did believe almost every picture should have a bit of maximum black and maximum white (or at least Zviii).

In the last years of his newsletter he was advocating determining exposure by picking the high value and placing it on Zviii. (He also advocated making a second exposure with the high value at Zvi1/2 so that one had choices when printing. I believe this was after he began selling multi-contrast paper and heads.) Anyway, when I started putting the high value on Zviii and letting the shadows fall where they may, my pictures really went to hell.
juan

 

[Donald Miller]

Interesting to me was the fact that Fred Picker, in the later Newsletters that I have, advocated a "key day" approach to photography. In these he alluded to and advocated more the "intuitive" practice that Edward Weston followed then to the more technical approach of Ansel Adams. I think that there is a great deal to say about the difference in approaches.

In the "key day" method of determining exposure he advocated a series of three, as I recall, basic lighting conditions. The first is a high key day in which there is bright unclouded sky. The second would be a hazy overcast day with indistinct shadows. The third would be a heavily clouded day.

In the first instance, lets assume that we determine a proper exposure for a typical luminance scene would be 1/2 second at F32 (or equivalent) for the film that we are using. In the second instance we would open up one stop. In the third instance we would open up still another stop. If we photograph in open shade we open a stop. If we photograph in deep shade we open another stop (at least).

By incorporating the development by inspection practice that Michael Smith advocates, we free ourselves from a lot of the technical hinderances that can get in the way of seeing and making meaningful photographs.

When I began to trust my eyes, I learned that I can see when a scene is low contrast, normal contrast, and high contrast. I can certainly determine whether there are clouds in the sky. I think that meters are wonderful devices. However they do not make meaningful photographs. Photographers do that.

 

[Bruce Osgood]

But, interestingly Fred Picker did believe almost every picture should have a bit of maximum black and maximum white (or at least Zviii).

In the last years of his newsletter he was advocating determining exposure by picking the high value and placing it on Zviii. (He also advocated making a second exposure with the high value at Zvi1/2 so that one had choices when printing. I believe this was after he began selling multi-contrast paper and heads.) Anyway, when I started putting the high value on Zviii and letting the shadows fall where they may, my pictures really went to hell.
juan

With all respect to every member of APUG, I hold Picker in the lowest esteem possible. This is only my opinion and I will not get into a flame over it, but he represents the lowest form of commercialism in photography that there ever was. I've seen his books, they are printed on lousy paper stock that will not begin to accurately reproduce an images' fine line or tones. I think this was done on purpose. The images I saw that he sighted as 'good' were muddy and banal. He would take something from Adams and turn it around. Where Adams would say "place the shadows" Pecker would say "Place the highlights". He came up with a print washer that was supposed to revolutionize print washing. It turns out his concept was entirely wrong and opposite to what really happens when washing a print.
He was a man without vision, imagination or talent, but he sure could sell snake oil.

Again, I mean no disrespect to anyone who finds him a god (small g). I just start ranting when his name is used in the same sentence with Adams.

 

[lee]

I totally agree with you Bruce. I own a zone 6 washer and a zone 6 washing machine and they do work and own an Oriental 20x24 washer and they all do the job. The concept that fixer is heavier than water was his mantra. This may not have started at Picker but may actually have started with Adams. This was a very effective sales tool for him and I don't remember anyone taking him to task for it. That said there is a theory that if fixer is heavier than water, then fixer would not mix or at the very least STAY mixed for very long. It does stay mixed together, but some of the non-acid fixers do separate after several months and that is another story.

lee\c

 

[Donald Miller]

While this has gone afield from Eric's original post, I think that all of the names that have been mentioned (Ansel Adams, Edward Weston, Fred Picker, and Phil Davis) have their points of view. They have certain strengths and weaknesses. I think to fall at the feet of any of them is to rob oneself of the experience of photography in a meaningful and genuine manner.

I would say that if anyone was commercialized then Fred Picker certainly was...but then again I can say the same thing to an even greater extent about Ansel Adams both prior to and after his death.

Phil Davis certainly has his disciples. I imagine additionally that he earns something from his software, his book(s), his tubes, etc. Certainly anyone that has a genuine benefit to offer deserves to be reimbursed for their efforts.

I did not ever get the impression from the writings of Fred Picker that he espoused exposing for the highlights. In fact he made mention of the need for proper exposure based in the full knowledge of one's materials and the example that I recall him using was Weston's unmetered exposure and resulting print of the Church Door at Hornitos. In this example he indicated that had Weston relied on a meter he would have underexposed this image by over four stops.

The only one of these that didn't seem to gain much monetarily from his efforts while alive is the one that worked the simplest. He had a vision that was a million fold finer tuned then Ansel Adams or Fred Picker. He was an artist in the truest sense in my opinion.

 

[lee]

Don,
Picker did espouse that zone VIII exposure. I have done it and to some degreee it worked. He also later in life said he had never made a N+ exposure and saw no need for a N+ development. Maybe he just got weird in old age. It happens.

lee\c