Film Testinggreenspun.com : LUSENET : Large format photography : One Thread
I've been shooting landscapes with 4x5 Tmax (100 and 400) over the past year or so using the zone system rather loosely. I would now like to test the film and my processing to determine effective film speed, n+1, n-1, etc. My question is this: should I simply follow the procedures laid out in Adam's The Negative, then hunt around for a shop with a densitometer, or should I use the Darkroom Innovations BTZS film testing method? Are the two really "alternate" ways of determing the items noted above, or am I misunderstanding the nature of the BTZS system? Thanks in advance, I truly appreciate the benefit of your experience.
-- Mark Christopherson (firstname.lastname@example.org), December 28, 2001
I moved to the Darkroom Innovations method two years ago, relying on their testing system AND using their software on my Palm Pilot. The software supports incident readings as well as spot meter supported zone calculations. The result? My negatives are nearly always printable on grade 2 or 3 paper -- a major improvement for a person working at my level. The system neatly saves a record of the exposure for each negative indicating development time as well as other important information. No more hand written notes.
Now, if it would only help me with concept and composition...........
-- Frank LaHorgue (email@example.com), December 28, 2001.
Calumet also offers the service of determining your film speed for about $15 or $20, as I recall. Go to their site, and search for film speed test. I've used it several times.
-- John D. Clark (firstname.lastname@example.org), December 28, 2001.
You may want to check out The Ultimate Monochrome Print as well. It seems like a fairly straightforward system with no densitometer needed. I've started the process many times, but always decide I'd rather develop something more interesting and stop half way through.
-- Jennifer Waak (email@example.com), December 28, 2001.
I recently went through the same scenario as yourself and wound up using Darkroom Innovations testing "service" (after reading BTZS), for the film curve analysis, EFS, etc. As a result the density of my negatives has improved and are far more consistently printable on normal grade papers. For me it gave that little step to the "next level". You do (as you probably are aware), need to be very accurate & consistent in your temperatures, times and agitation with TMax in order obtain reliable results. I had two sets of TMax negs tested - one in TMax RS 1:7 and the other D76 1:1. The initial RS test was flawed and the info from the analysed negs was erroneous (my fault in temperature accuracy I believe). The D76 was right on. I like the service so much that I have requested a third test with Bergger and Pyro.
This works for me as I don't really want to get into converting my spot meter and plotting all the data myself. Let the experts do it and I'll pay the fee.
Hope this was of some help.
-- Matthew Hoag (firstname.lastname@example.org), December 28, 2001.
I've used the BTZS/Darkroom Innovations (now called The View Camera Store) for all of my testing in the last five or so years. I think the $30 they charge is more than worth it in terms of saving the time, frustration, and film expense involved with the traditional methods. Traditional zone system testing isn't nearly as easy as it sounds from reading about it (at least it wasn't for me). For one thing, you test for a film speed by determining a certain density above film base plus fog. Then when you do your development testing, for which you'd expect to use the film speed you just finished determining, you find that the film base plus fog reading changes as you change your development times, so you're doing your development tests at what amounts to a different film speed than you'll actually be using. You also have to make sure that the light doesn't change on you as you're doing the tests. I found that it was almost impossible to do all of the exposures for all of the development tests outdoors without the light changing several times in the middle of the tests, which ruins everything. These are just the two things I remember (hopefully accurately) from the days when I used to use traditional testing methods. The one thing I do remember for sure from the last time I did it was going through two boxes of film and still not being comfortable with anything I'd done. With the BTZS system, you use a grand total of six sheets of film for all of the testing. Plus you get all of your charts and graphs handed to you, without having to go through the tedium of doing them yourself even if you had the software to do them. All in all, I think it's an excellent service though I'm sure many people are happy using traditional methods.
-- Brian Ellis (email@example.com), December 28, 2001.
When I did several film tests, I also got different filmbase plus fog densities, but for some reason my Zone I densities were always right on with respect to these fbpf's. I was taking a photo class at school at the time so I had access to a densitometer. Unfortunately, I'm still having a time figuring out some N-1, N-2, N+1 tests. I believe these will take up the most time, film, dev, and effort. For the basic film speed test, I borrowed a set of darkslides with holes drilled in them. This allowed me to take a picture of a blank piece of matte board numerous times, changing the film speed for each shot. It was quite a genius idea. I would be interested in hearing anyone's ideas for a poorman's way of doing n-1 and n-2 dev. Perhaps, 10% less dev or 20% less dev?
-- Mark Wiens (firstname.lastname@example.org), December 28, 2001.
The Darkroom store tests are quick and rather easy. You do not need their tubes. You can process the film as you would normally--tray, jobo, hybrid jobo, etc. and produce resuklts that, used with that nifty little program they sell, will get you what you need. The step wedge, some glass to use a contact printer, etc. and you are done. Bob
-- Bob Moulton (email@example.com), December 28, 2001.
In the almost 30 years since I attended Brooks Institute I think I have read every book every written on the zone system, (and the incident system) and tried every test, including owning and using both transmission and reflection densitometers for both color and black and white films and papers. After all of that time I have become absolutely convinced that the best system of all is a visual system that starts with a paper/film test before doing any film testing whatsoever. After all, the final result will be a print on a piece of paper, not a negative film. And so, It seems prudent and works ever so well to work backwards from the paper instead of forwards from the film. Pick the paper you are going to work with, and pick the light source you are going to print with. Do not change them becasue in order for any photographic test to be valid you need to have a base from which to change (i.e. if you are changing a bunch of things at once, how in the hell are you going to know what change had what effect). The simply do the film base plus fog/maximum black in minimum time contact test, and make absolutely sure you can repeat the light and the chemicals. Once you get that done, you have a standard from which to visually test everything else you do, even if you want to also check by a densitometer. If you want to SEE what a change of a full stop more or less exposure will do, you have a standard from which to see that. If you want to see what a change of a 15 percent or a 30 percent increase or decrease in development time will do, you have a standard from which to do that. Otherwise, you are all over the place testing this and that without any knowledge of what change did what. Visual testing is the most important of all in my mind, becasue visual testing will always tell you whether something has changed better than any other tool because your eyes are so incredibly sensitive. To get a full set of zones your scene must contain white in sunlight and black in shade. ( I have had people ask me whether I thought their meter was broken because when they were testing they couldn't get a full range of zones exposing in full sunlight). Finally, I think alot of people make more out of the Zone system than it really is. When it comes right down to it, all it really consists of is the fact that film predictably reacts in a linear way to specific changes in light, and reacts in a nonlinear way to specific changes in development. For example, we can measure with a densitometer than a given film will have an increase in density of .30 for a doubling of exposure over a range of doublings.By the same token we can also measure with a densitometer that films density will increase proportionately more with an increase in development in those areas that have received more rather than less exposure, and decrease proportionately more in those same areas when they receive less development. It really is a simple as that, and it shouldn't be made any harder than it really is. I think that most people that are starting out have such a hard time with it is because they don't do the obvious, which is to visually look at what their changes are doing, and they worry too much about giving proper names to everything when in fact there are many ways to describe what is happening rather than using the terminology provided by Ansel Adams and others. Also, people worry too damn much about medium gray. Medium gray basically takes care of itself. What you really need to worry about is the maximum range of densities that will provide detail on both ends of your paper, and the effect of printing various negatives that provide less than that maximum range of density such that you might want to expand or contract that negative or use a higher or lower grade of paper. kevin
-- Kevin Kolosky (firstname.lastname@example.org), December 28, 2001.
Kevin, I agree with a lot of what you've said. It never made sense to me to test your film/development by contact printing negs with an enlarger when you shoot film with a camera, lens, and natural light in the field. OTOH, I've found that testing systems like those suggested by Chis Johnson ( Practical Zone System ) are somewhat impractical: A) I don't have 8-10 film holders to carry into the field, B) When have you conveniently found a scene with four stops range between fully textured highlights and shadow areas, AND are of even tonality for accurate metering? C) What is the likelihood that the light will remain constant within 1/3 - ½ stops throughout the scene in the time it takes to do the testing? At least for me, using this methodology I've only gotten in the right neighborhood ( not in the ballpark! ) but have only been able to center on the right EI and development by trial and error over time.
This question ( that is, film testing for EI and development ) has come up from time to time on this forum but has never really been seriously discussed. Some have responded that EI is simply a matter of finding minimum usable density on film, though this doesn't address changes to Zone III texture due to increased/decreased development. Similarly, measuring my negs with a densitometer and comparing to suggested Zone VIII densities doesn't necessarily relate to the quality of the Zone VIII area of the print. Same goes for using a gray card for comparison to measure Zone V - personally, I don't expect to match a Zone V print value since the reason we use different film/paper/developer combinations is to find a combination that provides micro/macro contrast values that we like - say, increased midrange gradation or sacrificing midrange values for better highlight or shadow definition.
What testing methodology do all you out there recommend or use? Is there a ‘silver bullet' test to save time and materials? Or have I already answered my own question?
-- Andy (email@example.com), December 29, 2001.
Andy I don't understand what you mean about not wanting to test your negatives by contact printing them. If you mean you would rather test them by enlargement to a standard, then I would say that is fine as well, but the absolute key to the whole thing is to find that STANDARD which you can repeat every single time you do it so that when you want to vary things you can SEE for yourself what happened using YOUR materials, and YOUR camera, and YOUR light, and YOUR way of doing things. And again, the best standard that I know of is the maximum black from minimum exposure test. That said, the next best VISUAL test is the old tried and true "corner of the white house in sun test" where you expose your film shooting a white house at the corner where one side is in brilliant sunlight and the other side is in shade. YOu make sure that there is something very dark but with good detail on the shade side, and in fact it is better if you have a few things of various darknesses (but with good detail) on that shaded side. meter your dark object for the zone you want it to be in and expose. (or, you could paint a card black, put it in the shade, and meter it for zone 1 and expose) develop normally. print/contact print at the exact time and temp you establsihed for your maximum black/minimum time test. look at the print. ask yourself these questions. did you get good detail in that dark object or did you lose all detail in that dark object, or is it too light (is the black card just a hair lighter than maximum black from minimum time -i.e. zone 1) if there is no detail you need to expose more. if it is too high (not dark enough) you need to expose less. when you get that expsosure right then then look at the detail in the white sun. if there is no detail then you need to develop more. if there is alot of detail but the white looks a little bit gray you need to develop more. Its all there for YOU to decide rather than some densitometer. But again, the key thing is that when you are doing all of this, you have to make sure you have a standard from which to start. What the hell good is testing a negative with a densitometer if you don't actually then print that negative to see what it did on YOUR paper with YOUR chemicals and YOUR light, and YOUR temperature, and YOUR method of agitation. And what in the hell good is doing a test if you are going to adjust the contact prints or the enlargements to make them look right. You need to do them to the standard so if they don't meet the standard you can figure out what you did wrong (meter possibly off, temperature too hot or cold, paper getting old, didn't set f stop correctly, shutter needs repair, etc. etc. etc.). Kevin
-- Kevin Kolosky (firstname.lastname@example.org), December 29, 2001.
I guess I wasn't clear about ‘contact printing' the negatives. I believe that with the BTZS or Darkroom Innovations method involves contact printing a step tablet onto your chosen film, under your enlarger, to expose the film for subsequent development and sensitometric testing with a densitometer. My confusion is, how does this relate to exposing your film with camera and lens, under daylight conditions ( if this is how you normally photograph )? You are testing the film in this case and excluding your camera, shutter, lenses, and light source altogether. It would seem to me that the most effective way would be to include the camera system and typical lighting conditions as part of the test. My question was more along the lines of, what methodology are all of you using to include this yet cut down on material usage, time, ( the testing in the Practical Zone System involves at least a box of film and as many papers, and a lot of time ) and eliminating as much as possible the environmental variables?
-- Andy (email@example.com), December 29, 2001.
A guy by the name of Fred Picker has taken alot of heat in this forum, but he did say some things that made one hell of a lot of sense. One of them was to go and look at prints made from different papers and then PICK ONE and stick with it. Pick one film and stick with it. Pick one camera and stick with it. Pick one or two lenses and stick with them. Get all of that stuff behind you as quickly as you can so that you can get one with the business of making meaningful photographs. I myself look at photographs a lot more than I make them these days, but in my very humble opinion, the greatness of the photograph does not depend upon the material used but rather the vision of the photographer and the excitement generated by the thing being photographed. So, just for an example, you say to yourself, I am going to pick t-max film, rs developer, and oriental paper and I am going to find out what they do and then use them. I think you probably will do just as well as if you picked ilford hp5 and d 76 and polymax, as long as you test what you have picked, learn all of it's ideosynchrocies (sp) and get on with making photographs. Kevin
-- Kevin Kolosky (firstname.lastname@example.org), December 30, 2001.