TMax 400 Film Testing - ISO of 500

[Ralph W. Lambrecht]

I prefer the BTZS method. I don't like their tubes, but I think that Phil Davies' process of ignoring camera and shutter works well. Another way to also ignore the shutter is to use a Stouffer step wedge and photograph it yourself. This will include your camera and lightmeter.
Don't get too hung up on including all personal variables. You can, but you don't need to. You are not forced to re-test everytime you change one piece of equipment. If you end up buying a new lightmeter, you'll see if it fits. If you have a deviation, it will be constant, and you can modify your EI without a new series of tests.

[Shen45]

I prefer the BTZS method. I don't like their tubes, but I think that Phil Davies' process of ignoring camera and shutter works well. Another way to also ignore the shutter is to use a Stouffer step wedge and photograph it yourself. This will include your camera and lightmeter.
Don't get too hung up on including all personal variables. You can, but you don't need to. You are not forced to re-test everytime you change one piece of equipment. If you end up buying a new lightmeter, you'll see if it fits. If you have a deviation, it will be constant, and you can modify your EI without a new series of tests.

I test all of my film based on the complete methods outlined by Phil davis in his book. When I first read the book I had a bit of trouble getting my head around it but when I flushed my mind of nearly 40 years of past experience and tried it as he instructs I was amazed at the results I got.

Let me say at the outset that I have been a fan of the zone system for years but never was completely satisfied with the results. There were often unexplained inconsistencies that "popped" up from time to time.

I had heard of BTZS prior to my last visit to America [September 05] so purchased a book thinking I would be able to have a go at it will on holidays. That was my first mistake as such. It is a system that demands complete attention and strict adherance if you wish to make it sucessful. That I see a very definate positive. I read the book -- and I read the book -- a few times. And a 14 hour flight back to Australia cemented my resolve to try it completely.

Once the testing is done though you can basically forget the technicals and use the system. By that I mean this -- the system does not in anyway get in the way of your creative pursuits. It frees you to be more creative.


The testing was surprisingly easy after I calibrated my enlarger using Phil's recommended test film, Delta 100 in D76. Btzs works on a known standard and all films then fall above or below that. For example Delta 100 tests in D76 1+1 at 100iso therefore if I use the same light conditions with my favourite film Efke 100 the win Plotter software will give me the most accurate "true" speed of the film.

Btzs approaches the final image based on the capability of the paper you use and step wedge tests are done and read with a densitometer to determine the Density range of the paper. This range is then used in combination with the film tests so that the capabilities of the film and paper are not exceeded

Normally 5 pieces of film are exposed at the same exposure under the enlarger [easier to do than type] and processed in the developer you normally use. The sheet are processed at 4, 5min 40, 8,11 and 16 minutes. Times suggested by Phil.

I opted straight up for the tubes to process my sheets and they are the very best [imo] way to handle film in the BTZS system.

When the sheets are read they will give you over the 5 development times all the information you need for field work.

Two points. I purchased the WinPlotter and ExpoDev programs as they tie everything together. You can use the system manually and use the Power Dial [a manual calculator] in the field but the Palm based ExpoDev is stunning.

Have I benefited from this system? -- You bet.

Is it for everyone? -- possibly not. Only those who approach it as it was designed will get the full benefit. Possible light hearted example.

" In America you drive on the "wrong-side" of the road If as an Australian I chose to drive "my way" in your country I would have a less than satisfactory outcome. But if I seat myself in the car as the manufacturer intended and follow basic instruction the wrong side will soon be comfortable if and when I drive in America "

The results you get from BTZS will amaze you. Totally consistent results over a large span of light conditions. It is really easy to do the testing and use the results. Phil davis has also done a large number of tests of common films,papers and developers as well.

This is a just a brief explaination of BTZS. If you want to know more go to www.btzs.org the forum is very helpful and the information is readily available.

Steve

[Michael Heald]

Hello! The nice thing about the BTZS is that it forces a person to objectively evaluate things in a scene that may affect exposure and development - flare, zone placement, etc. I'm not ready for such a system since I don's shoot many pictures that require such fine tuning. However, the palm program he has looks like it would work very well.

Using the film development information, a continuous curve of development times can be extrapolated to handle any scene expansion or contraction, not just the typical N+1 or N-1. For example, if a scene requires N-2/3, this film development information will allow me to change the development time.

Of course, like many things, I wonder if such precision will be noticeable in the final negative. I'll try it and see.

For now, I think I'll keep my TMax rated at ISO of 400, instead of the 500 that the test suggested. Often, I backet exposures anyway to get a feel of how the appearance of a scene changes with change in exposure, so I'll get a feel of different EIs in the future. Best regards.

Mike

[sanking]

Let me say at the outset that I have been a fan of the zone system for years but never was completely satisfied with the results. There were often unexplained inconsistencies that "popped" up from time to time.

(clip)

Once the testing is done though you can basically forget the technicals and use the system. By that I mean this -- the system does not in anyway get in the way of your creative pursuits. It frees you to be more creative.

(clip)
Is it for everyone? -- possibly not. Only those who approach it as it was designed will get the full benefit. Possible light hearted example.

(clip)

The results you get from BTZS will amaze you. Totally consistent results over a large span of light conditions. It is really easy to do the testing and use the results. Phil davis has also done a large number of tests of common films,papers and developers as well.

(clip)

This is a just a brief explaination of BTZS. If you want to know more go to www.btzs.org the forum is very helpful and the information is readily available.

Steve

I am with Ralph and Steve re: BTZS. It is not for eveyone, but it is much simpler and more consistent than the Zone sytem I previously used. You can get more information about how to expose and develope film in two hours of testing with BTZS than with 40+ hours of Zone type testing. I know a few people who have gone back to Zone after learning BTZS, but the percentage is very small.

Some hold that the degree of precision possible with BTZS is not necessary, and there is some truth to this, especially in a time when many of us are scanning negatives and doing tonal corrections in Photoshop. However, with BTZS you are free to choose the level of precision you want to work with. For example, in theory one has the ability to control develoment for contrast scenes ranging from SBR 14 to SBR 5, but in practice some people are content to lump negatives for development into SBR 8<, SBR 7 and SBR6>. However, for people contact printing with in-camera negatives for AZO and alterantive processes such as carbon and Pt./Pd. the precision of BTZS can be a great advantage in terms of productivity.

Also, bear in mind that although BTZS is primarily designed for incident type exposure readings the actual testing provides data that allow use of Zone type readins with a spot meter. This allows combination of the more versatile testing system of BTZS with Zone type exposure readings, which offer advantages in some scenes.

With regard to the original question, effective film speed depends to some extent on time of develoment. Developing to a higher effective CI will increase slightly EFS, developing to a lower effective CI will decrease it. My personal EI for TMAX-400 is about 600. The increased speed is due primarily to the fact that I develop film to a relatively high effective CI for alternative printing. i

In BTZS testing one can easily observe relative differences between different film/developer combinations, but in order to make meaninful comparisons you must first calibrate the system with what is know as a personal speed point test. Davis has directions for this at the BTZS web site.

Sandy King

[Michael Heald]

Hello! I retested TMax 400 at 1:7 dilution and 68 degrees with a unicolor drum with continuous agitation. I obtained an ISO of 500 to 575 with contraction/expansion of +/- 1.33 stops with short to long developing times.
This is similar to results that I had with 1:9 dilution at 75 degrees except the expansion/contraction was +/- 1.67. Best regards.

Mike