How do you TEST film?

[Rick Jones]

I read over and over that a poster is testing a certain film. Obviously, that means different things to different people. To me it means establishing a range of E.I.'s and development times to deal with a variety of scenes using a single developer. If that is what testing means to you I would be grateful to know how you go about pinning down those two variables.

 

[Ian Grant]

I do a series of practical zone system tests usually using 35mm film initially, finding my optimal dev times & EI to print on Gd2 Ilford Multigrade. I then interpolate this by experience for the same film emulsion in 120 & LF. The first time you do the tests is the hardest. Usually it's unnecessary to do a full set of tests for every new film/developer combination.

Ian

 

[snallan]

I follow a testing scheme along the lines of that described by AA in his book The Negative.

First off, I get an idea of the likely EI for one of the developers I use by shooting a couple of normal(ish) contrast scenes in half stop steps from -1½ to +1½, and then process for a standard time (I like dev times in the 10 minute range, so 10 minutes for the first test). I then do a contact sheet, like Ian Gd2 on Ilford Multigrade, if I am using a staining developer, I will also do a contact on an Argyrotype. After evaluating the negatives, and the contact sheet(s), I will select an EI, and development time to test further. I ususally do this first test using 120 film in a 645 camera.

Next I will tie down my EI for the selected development time by testing for a zone II exposure. I do this using 4x5 sheet film, as I have a set of four old dark slides modified for testing (see attached). Each has a 20mm hole bored in it, each one in a different position up one side of the slide. These allow me to make eight individual exposures on a single sheet of film. I do a series of exposures in 1/3 stop steps around my expected zone II exposure, along with a zone VIII and zone IX exposures. Process, and do contact sheet(s). Often I will just evaluate these by eye, though I do have a densitometer.

I don't usually do extended, or contracted development tests, as my original roll film test gives me enough info to modify my exposure/development for high or low contrast scenes. But if I do these tests, I use 4x5 sheet film in the modified holders again.

Like Ian, I don't test every format of a given film, but the first time I shoot in a different format, say 35mm, I will evaluate the results carefully in case I need to make any adjustments.

 

[Rick Jones]

Steve - when you visually evaluate your z2, z8 and z9 contacts how would you describe the density/tone you are looking for in each case?

 

[Chuck_P]

There are so many different responses you can expect from this question with folks putting their own twists on it. It's a sure way to be driven crazy. Your question is best answered by getting any one of several different references on film testing and following it. Getting support and being helpled through a known and established testing procedure is, IMHO, a more valuable use of time and resources than trying to test using multiple variations and personal twists. This is not to mean that those variations are not valid for the individual, those personal twists may come from years of experience.

I would get AA's The Negative to learn how to test, but more importantly, why you test. Or, John P. Schaefer's "The AA Guide, Book 2 (the same title with Book 1 from Schaefer is good too but does not go into testing, but does have great supporting info on the zone system). Book 2 provides ways of testing without using a densitometer, but if you can score a reliable densitometer from ebay at a reasonable price, then testing is much easier and a more straight forward process. If you are using 4x5 film, testing using the method in Book 2 can be completed in just one sheet for determining the EI and then another 5 or 6 sheets to find the developing times.

Oh, and not to leave out those Beyond The Zone System folks, you might want to explore the BTZS method of film testing, but I don't know much about that system.

Chuck

 

[steve simmons]

Fred Picker made this process simple for people in his book The Zone VI Workshop that came out in the 70s. It helps you estab. your own EI and dev. time. If you can find a copy of that book get it.

It will not meet the needs of some people for absolute, controllable science but Picker's method has been used by thousands of photographers for 30 years very successfully.

The key is to match your film, film developer, printing paper and to some extent the print developer. These are a team.

Zone 1 in the film should have a density approx .01 above film base plus fog. This will create a tone on your paper just barely perceptably lighter than pure paper black. Zone 7 or 8, whichever you prefer, will have a density between 1.25 and 1.5 and be the densist area on the film that produces a tone just barely perceptably darker then pure paper white.

IMHO you can't do this with a densitometer. The film and paper have to be matched and so the upper end density numbers are not an absolute. I use a vc paper w/o a filter which is about the same as a #2 filter to standardize on.

steve simmons
www.viewcamera.com

 

[Mahler_one]

Chuck: Testing with BTZS is quite easy, and considering the time one can save, cost effective. I have no affiliation with Fred Newman and BTZS/The View Camera Store other then taking a course with him, and using his film testing service. Briefly, Fred will send you film to be developed in your own darkroom using your own methods. He will make some suggestions, if you desire, regarding developer and dilution. At any rate, you chose the film you want to use, and Fred will expose the film using a step wedge. The film ( 5-6 rools or 5-6 sheets ) arrives at your door, and your develop the film at various times using your standard methods for each sheet, or roll. Then one mails the developed film back to Fred, who will do the densitometer readings for you, and plot the data. From the curves one can derive the correct film developing times for the subject brightness range and exposure parameters for each expoure you make. Fred can tailor the curves for your use in either BTZS which emphasizes EV values, or the traditional Zone system. If desired the data can be entered into a very convenient program as developed by the late Phil Davis, or the data can be easily applied using a very cheap Power Dial. As needed, the program can be entered onto a hand held computer device such as a Palm Pilot which can conveniently be taken into the field and very easily used to quickly provide one the exposure needed ( including, as needed, filter factors and bellows factors ), developing times, etc. Obviously there are other methods ( as outlined here by well known and knowledgeable posters ) to derive the same data. However, BTZS certainly has definite advantages.

Rick, consider the time you have, and your level of expertise, before you make a final decision about how to proceed. Best of luck, and let us know how you make out.

Edwin

 

[BobNewYork]

Rick:

FWIW in recent years I've been film testing by setting up a black camera bag and piece of white, textured polystyrene outside in even lighting. I toss in a grey card for good measure. I run exposures from ISO - 2.5 stops to + 2.5 stops in 1/3 stop increments. I develop the film at my best guess - actually at Massive Dev. Chart!! - and proof at the usual minimum exposure / maximum black. From this I look for the best rendition of the black bag.

I then print 8x10's of the selected exposure and the one each side of it on my normal contrast paper - exposure is again min.exp. / max. black. I select the print that gives me a truly black bag with textural details. Usually one of the prints shows wonderful texture - but isn't black. Another is truly black but shows no texture. Printing the three makes the decision easier - for me at least. If I'm truly conflicted I opt for the lower indicated E.I.

Next, look at the polystyrene on the selected print. It needs to be truly white - but with visible texture. If it's dingy - increase your film development time. If it's lacking texture - decrease.

I've used this for a while and it works for me. I did "do" the ZS for a some time but it didn't suit me in the field. I also went through BTZS and again it didn't suit me in the field and I also found myself holed up in the darkroom without creativity. This, I feel, cobbles together thoughts from both, (and others) and works for me. I can shoot and develop a test roll of film in an hour or so. Once it's dried, it takes no more than an hour to print the tests. Trying a new film / developer combination now is no longer a daunting task.

Mostly, I would advise you to get to understand the underlying principles: Why minimum exposure / maximum black? Why expose for the shadows / develop for the highlights? The effects of different types of developers, different agitation etc. In this way, you can truly learn to create the "feel" you want to achieve in your work.

Hope this gives you some food for thought.

Regards

Bob

 

[snallan]

Hi Rick, the z2 I evaluate on the negatives, and I am looking for the first patch that gives me a tone that is easily perceptible against the surrounding film. I will often have a patch that I can make out if I hold the neg against the right light source, and squint at it from the right direction. But if I have to do that, it's not the right exposure

For the z8/z9. I partially mask those patches on the negative when I am making my contacts. For the z9, I am looking for a tone that is just perceptible from the masked area of the contact print. For the z8, I am looking for a definite, but very pale grey.

 

[Rick Jones]

Bob - your method makes a great deal of sense to me and pretty much mirrors what I have been doing. I never could understand the fixation with Z1 nor the target densities for the higher zones. My shadow readings are primarily placed in Z3 and 4 so I aim for an E.I. that will reproduce those areas with my paper, developer and enlarger in the way you describe your black bag using my SPT. My targets are a black T shirt, a white T shirt and a gray card. Noting where the meter reading of the white T shirt fall I adjust my development time to match my mental picture of that value be it Z7, 8 or whatever just as you judge how you polystyrene looks in print. Until you described your approach I never remember reading about adjusting exposure and development based on photographing and printing real world textured objects. I was well aware of the FB + fog approach but was hoping to hear more of the methods others have adopted to personalize their results. My method seemed too simple but it's good to know someone else apparently has come to some of the same conclusions. KISS! Maybe someone can convince me that buying a densitometer and 100 sheets of graph paper really does make sense.

 

[BobNewYork]

I had been photographing for a number of years - not getting what I wanted. Found Ansel Adams and jumped in. My problem was that in the field, I spent so much time worrying about whether I should "place" an area on Zone II, V or whatever, that the whole experience became more nerve wracking than enjoyable. For whatever reason I thought that maybe BTZS would be better. That got me in the darkroom, and at the drafting table - but the field experience was no more fun. Looking back, I'd just "grabbed" at systems without taking the time to try and understand the underlying technical aspects - not in terms of log base10 E or graphs - but really look at each part of the process and understand them, how they interacted and how it would affect my photographs. What I evolved was taking bits from everything I read that made sense to me and my work, and incorporating it. The texture thing I lifted from The New Zone System by Minor White, Richard
Zakia and someone else. Can't take credit for the thought there unfortunately!

I use a projection step tablet to test papers and keep a notebook in which the characteristics are layed out for each paper at each filtration. It tells me the speed difference from my "standard" paper, (which I actually ran out of several years back!) and the step range between "polystyrene white" and "camera bag black" at each filtration level. (Just count the steps) A new paper takes less than 2 hours to print and process and another 15 minutes to evaluate after drying.

I do use a colour analyser to set filtration levels and determine exposure - all based around my "standard" paper and I've found that my darkroom time is more constructive and enjoyable now.

Regards,

Bob

 

[sanking]

For whatever reason I thought that maybe BTZS would be better. That got me in the darkroom, and at the drafting table - but the field experience was no more fun.

Bob

I test film with the BTZS system. It took me some time to really understand and fully utilize the system, but once it fell into place I found the actual testing to be very easy and extremely efficient, and the field work to be at least and reliable as easy as any other system.

With one evening of testing it is possible to determine virtually everything you need to know to expose and develop negatives for many different processes in a wide range of subject contrast situations. You do, however, need an instrument to measure negative transmission densities, and work is much faster if you use a computer and WinPlotter to plot the curves.

Determining SBR and exposure in the field can be done with either incident or reflection readings. Either way it can be done easily and quickly. I typically use incident metering and for most subjects I simply take a shadow and highlight reading to determine SBR, and then use the shadow reading to determine exposure. This normally takes 30 seconds or less. Some subjects are best metered with reflection readings, and BTZS works equally well with this type of metering.

However, if you are new to film developing I would recommend a simpler approach to film testing, perhaps even something no more complicated than the sunny and f/16 rule, and later the Picker type testing. In this area, as in so many others, incomplete understanding of a system can cause greater problems than using no system at all.


Sandy King

 

[BobNewYork]

Yeah - I did that Sandy. It's just that for me a least, I just couldn't seem to look at a scene and translate that to my graphs. I just had some kind of mental block - don't know why. Maybe my mother dropped me on my head when I was a baby!! (It's ALWAYS the mother's fault!)

I rarely do N+ or N- . Most film today seems to hold highlight detail way beyond Zone VIII - with "normal". Film certainly seems to hold more detail than the paper can reproduce in a straight print. For the N- scenes I'll select the appropriate paper in the darkroom.

I'm a huge believer in doing what works for you and anyone who enjoys and is proud of their work should change nothing. Hell, if we all did things the same way we'd be..........North Korea

I'm a new subscriber here, and I find that the contributors to this site are not only passionate about their art, but willing to share their experiences and insights. That makes it all but perfect in my book.

Bob

 

[stillsilver]

I too use Bob’s method. I think I got part of it from Davis Vestal. I use a black terrycloth towel and a white one with a gray card in between. These are clipped on a piece of cardboard and placed in the shade.

Mike

 

[hal9000]

Zone 1 in the film should have a density approx .01 above film base plus fog.

The target density should be 0.10, not 0.01 above film base plus fog for Zone I.

 

[BobNewYork]

Mike:

I forgot David Vestal. Like I said none of my method is really mine, poached it. Never met David Vestal, but I always felt I'd love to be at a party he was at!!

Bob

 

[Chuck_P]

KISS! Maybe someone can convince me that buying a densitometer and 100 sheets of graph paper really does make sense.

Rick,

When I finished my ZS testing using a calibrated step wedge (i.e., I calibrated it myself with my own densitometer, I did not buy a calbrated wedge), I only used three sheets of graph paper. I used one to graph the curve for the film speed test and then I used another one to graph the curves for the 7 sheets of film I exposed at the working EI found from the speed test. So, the second sheet had 7 curves on it, each representing a different developing time. From that set of curves, I was able to determine the developing times for N-1, N-2, N, N+1, N+2. I just re-drew the final family of curves on a third sheet of graph paper, although it wasn't really neceassary----I just wanted to eliminate the dev time curves that did not hit the correct mark at the upper end of the scale.

It takes only a few minutes to graph a curve from the results of a test. Reading the results with a densitometer takes less time than it takes to actually graph the curve---still, only talking minutes. The most time consuming phase of the testing is developing at different times the individual Zone VIII sheets that I exposed at the working EI found in the speed test.

For me, I got all of my testing done with T-Max 100 using 1 gallon of D-76 at 1:1. I have 8 16oz bottles of d-76, so one bottle for the speed test, and the remaining 7 bottles for the individual sheets. It was really quite very simple and quite illuminating.

 

[BobNewYork]

I think the the difference in methodology used by Sandy, Chuck and myself fundamentally arises from attacking the same problem from two different directions.

Personal EI testing is a means of taking into account our different meters, shutters, film developing techniques etc. As such, it is mandatory if we are to avoid a "point, shoot, pray" approach and just live with what we get. It is from this point that the directions diverge.

It seems to me that BTZS approaches the problem by tailoring the negative to the printing paper, whereas the approach that I have taken tailors the paper to the negative.

Opposite approaches to the same goal I guess.

Bob

 

[Chuck_P]

I think the the difference in methodology used by Sandy, Chuck and myself fundamentally arises from attacking the same problem from two different directions.

Personal EI testing is a means of taking into account our different meters, shutters, film developing techniques etc. As such, it is mandatory if we are to avoid a "point, shoot, pray" approach and just live with what we get. It is from this point that the directions diverge.

It seems to me that BTZS approaches the problem by tailoring the negative to the printing paper, whereas the approach that I have taken tailors the paper to the negative.

Opposite approaches to the same goal I guess.

Bob

Bob, Just to be clear, the method I am using is not my own and does not contain any personal twists or variations. It comes straight out of John Schaefer's Book 2---it's very simple but does require a densitometer.

When film is tested via zone system methodology, then the negative density range becomes a constant by which to achieve each and every time film is exposed and developed. Historically, with contemporary films, and from AA's writings the range is 1.2. Thats a zone 8 density of 1.3 and a zone 1 density of 0.1 for a range of 1.3 - 0.1 = 1.2. So, tailoring the expsoure scale of the paper to the constant density range of the negative via choice of paper grade or filtration with VC papers is correct in the ZS method.

Just an aside--------If you go to Allan Ross's web site you'll see where he is flirting (or actually doing, IDK) with the idea of a longer negative density range with the basis of the range geared toward zone 9, rather than zone 8. I believe, from memory, that all development times would be targeted toward a zone 9 density of 1.45, which establishes is a longer negative density range and I guess "fits" within the exposure scale of todays papers. I just recently came across this and find it pretty interesting.

Chuck

 

[BobNewYork]

Bob, Just to be clear, the method I am using is not my own and does not contain any personal twists or variations. It comes straight out of John Schaefer's Book 2---it's very simple but does require a densitometer.

Chuck: I'm sorry. I didn't mean to imply that you'd claimed credit for devising the system you use. When I said it was yours I should have described it as the system you use. The system I use is not mine either. It's cobbled together from everything I've read over the years. Effectively my "calibrations" are the same as yours, it's just that I assess my shadow values visually rather than using a densitometer; and then in similar fashion, I visually assess the highlights to determine development time. I only do this because I find in the field that I can visualize "camera bag black" and "polystyrene white" better than I can Zones.

My real departure is that I don't change film development to account for different subject brightness ranges. My reasoning is that film holds detail in a greater range than any paper can reproduce. In fact I was re-reading AA's The Negative and noticed that several of the film curves he uses for illustration show the straight line portion extending beyond Zone XI. I feel assured then that normal development will assure details on the negatives whatever the subject brightness range. In the darkroom, I just meter the highlights and shadows and select paper and filtration or grade to suit the negative.

I did notice Alan Ross' adjustment posted on his website. I don't know whether he has elected to use a different paper grade for "normal" or what the reasoning is. I'm going to have to think it through - and I can already feel a headache coming on!!

Again, sorry for my previous inadvertent implications.

Regards,

Bob

 

[jgjbowen]

You could always check out Bruce Barlow's Film Testing Kit. The kit is available through www.circleofthesunproductions.com The kit is inexpensive, easy to use and matches your film development to your paper of choice. Highly recommended. Also, you don't need a densitometer with Bruce's kit. While you are at his website, check out his "Finely Focused" book. If you buy the book, you also receive the Kit.

Good Luck

 

[Chuck_P]

My real departure is that I don't change film development to account for different subject brightness ranges. My reasoning is that film holds detail in a greater range than any paper can reproduce.

No offense taken regarding method, I just wanted the OP to know that he has resources that can clearly work for him without a lot of confusion from outside sources like us.

Yes, that's a huge departure and a fatal one at that, IMO. The idea is to be able to expose those higher SBR's on the film and then to develop the film to keep their densities low enough so the paper can respond to it during processing, while maintaining the shadow detail you require. Take a look at the graph on page 249 with "highly dilute" developer. It shows that N-4 was achieved----that means he was able to expose a highlight on zone XII and then develop it so that that area of negative density is "held" to a density that can be printed on the paper. So, there is a Zone XII luminance value developed to a Zone VIII negative density of 1.3-----thus, that highlight is now within the negative density range of 1.2 required for detail on the paper.[/QUOTE]

Believe me, I understand using a "visual" reference when doing testing as I have had to do that too. And it can work to a degree that can satisfy a lot of people, no question.

Chuck

 

[MurrayMinchin]

I found the max-black time (shortest exposure that is just shy of max black using a clear negative) of the paper/developer I am using at normal contrast, then found which ASA on my light meter resulted in a negative that printed a Zone I print density at the max-black printing time. I usually hang a darkish towel across an open doorway to a dark room so it's easier to tell the difference between Zone I and the complete black of the dark room beyond. This is done with daylight coming through an open window, not under tungsten light.

Once my personal film speed is found I go outside and photograph something like a smooth, painted concrete wall (something without a lot of texture) and using the new film speed found earlier rattle off a few 'just a bit out of focus' exposures which would place the wall on Zone IX...I use Zone IX because sometimes I want to place things like open, bright light blue skies there, and sometimes I want a small area of pure white paper base to shine through an area of Zone IX. Then I develop these one at a time at different times until Zone IX prints as Zone IX at the max-black time to find my normal negative development time.

Once these extremes are found, I go out and find some full range subjects and see if everything lands where it should, and so far they have. Once I have my personal film speed set and my normal development time it's easy to find the plus and minus times. Not the fanciest way of doing it, but it works for me.

Murray