Beyond the Zonegreenspun.com : LUSENET : Large format photography : One Thread
May we start a thread on using techniques resulting from reading the information in "Beyond The Zone".Has anyone built the adapter to use a spotmeter as a densitometer? Has It changed anyones photographic life? Is it too exacting? I,after two readings appreciate what the Author is saying but have some reservations of its practicality. Comments? George
-- George Nedleman (firstname.lastname@example.org), March 17, 1999
I think I would be interested such a discussion. I haven't yet read BTZS (I plan to soon), but have read and thought a lot about the Zone system, densitometry, and related topics. Like you, I have mixed feelings about its use.
-- Sean Donnelly (email@example.com), March 17, 1999.
I haven't read the book (yet) but I was wondering about using the spot meter function on a 35mm as a densiometer. In theory it should be fine - the only problem seems to be the minimum density step that can be measured.
If I have the maths right, the shutter speed increments will only provide 5 discrete steps over the density range of 0.3 to 0.7. For example: 1000th sec incident - 500th sec transmitted => density of 0.3 and (using the same ordering) 1000 - 400 => 0.40 1000 - 320 => 0.49 1000 - 250 => 0.60 1000 - 2000 => 0.70
Never having used a real densiometer I don't know if this a fine enough range of steps to assess negative densities. Has anyone tried to use this method for zone system calibrations.
-- Nick Thornton (Nick.Thornton@liffe.com), March 18, 1999.
I have used the BTZS approach for going on 5 years now and I like it very much. If it has a fault it is that your meter, lens and shutter all have to be properly calibrated to take the information at face value. As far as comparing it to traditional zone system calibration, this is the easiest I have found. I also use the Plotter software that Phil Davis has written so I can go from start to finish in a couple of hours. A spot meter is alright for getting you in the ball park but a densitometer is really the way to go. I have read horror stories about the inaccuracy of mini-lab densitometers but that iskind of dumb. If you are using someone elses densitometer, ask them to calibrate it for you it takes almost 30 seconds.
-- Jeff White (firstname.lastname@example.org), March 18, 1999.
Yes, BTZS is an excellent book. (I've got the third edition. I'm not sure if the new fourth edition is substantially different.) It goes 'beyond' Adams in detailing a procedure for testing films. I use a spotmeter as a densitometer, in fact I was doing this before I came across BTZS. Has it changed my life? Well, it validated some ideas that I already had. Too exacting? No, it is exactly right.
I use these methods for nailing down the effects of changed development on a film. When I measure the contrast of a scene, I can (later) look up the CI (Contrast Index) that I want on the film, and hence the development time.
If I have reservations, it is simply that the book is very technical, and may not be to everyone's taste (but I love it). Many people get excellent results without consciously using the Zone System.
Re Nick's post: this is why a spotmeter that reads in tenth-stops is recommended (I use a Minolta Spotmeter F). 0.1 stops on the meter is a density change of 0.03.
Re Jeff's post: surely the same is true of any 'nailing down' process, that all the equipment must be consistent? For example, if you only use one shutter, it doesn't matter what the actual speeds are, provided 1/15 is exactly twice as long as 1/30, etc. If you use a variety of shutters (as most LF shooters do), they have to be consistent with each other.
I haven't used the Phil Davis software, I just use a spreadshet program.
-- Alan Gibson (Alan.Gibson@technologist.com), March 19, 1999.
I agree that the BTZS doesn't really introduce anything that you wouldn't have to deal with in normal zone system testing. Testing withought using the camera doesn't automatically correct for inaccuracies that in camera testing may fix.
Alan, I like reccomending BTZS but I hesitate to suggest that someone spend $70 for the software. My use of spreadsheets is limited to basic business book keeping, can you get a graphic chart as is shown in the book for things like the characteristic curve or average gradient?
-- Jeff White (email@example.com), March 19, 1999.
>> ...can you get a graphic chart as is shown in the book for things like the characteristic curve or average gradient?
Yes, certainly. I use Microsoft Excel, which I know fairly well, because I use it for work. I would guess that most modern spreadsheet software can produce these sort of graphs.
-- Alan Gibson (Alan.Gibson@technologist.com), March 19, 1999.
Several years ago I spent many hours studying the book and since then I have attended two of Phil Davis' BTZS workshops. IMHO, the problem with the book (3rd edition - haven't seen the 4th) is that it gives you a ton of sometimes very complicated technical information that is interesting for some but that isn't really necessary for anything. I thought that the first half or so of the book could have been substantially eliminated without any great harm.
Phil has said in the workshops that he sometimes regrets the title of the book - it implies that he has a system that is very different from, and more advanced than, the zone system when that isn't really the case.
I use the Casio computer loaded with Phil's exposure program and like it very much. I had the testing done by Darkroom Innovations for $30 per film brand and type. You get all of the graphs, curves, etc. that you would get with the Plotter (or is it Matcher?) programs but without having to buy the programs or do the testing yourself so I thought it was worth the price. I only had two films tested, T Max and HP5+. If I wanted to test a whole bunch of films I'd probably buy the programs. With the Casio computer you still use the conventional zone system to get the information into the computer (unless you use an incident meter, which I don't) - the computer just does a whole lot of calculations for you so that you're free to concentrate on the image without worrying about the calculations. All in all, I think I would be just as happy if I had never spent the time and money on the book and workshops but they were good learning experiences and I do like the Casio computer.
-- Brian Ellis (firstname.lastname@example.org), March 31, 1999.