D76, btzs tubes, and zone system

[John Tyrell]

Hi,
I am taking an independent study course at a local community college (I get virtually private use of a complete LF darkroom!) and am about to start zone system testing ala Ansel Adams. I am shooting TMax 100 and have already shot the initial film speed negatives. I have done single sheet development in trays (too clutzy for multiple sheets) but just got the BTZS tubes, and think they will work great. The developer is D76 straight.
The Kodak data sheet recommends 5min 45 sec at 70 degrees. Room temperature has been around 68 to 70 degrees. Does this sound like a good time to start testing with, does your experience indicate a significantly different time, or should I consider using a 1:1 dilution to allow for adequate N- times? I hope this is clear enough. Any help would be appreciated. Thanks in advance.

John T.

[seawolf66]

I am a beginer here ,but I have learned that the Developer I use ID-11 if I delute it to 1-3 or 1-4 which gives the developer a better chance to get the details better ;
on HP-5 I was running up to 15min developing times: The more you shoot and develope your film, the better you get with highlights and shadow areas in your film :

I have been told that your development
time and your dilution ratio can help you get better and even developement of your Negatives, Even at my old age I am still learning stuff: Lauren

[jeroldharter]

I think you should re-do the film speed tests with the BTZS tubes because the times will be somewhat different.

If you have an extra $50, do the film test from The View Camera Store. Fred will send you 5 sheets of TMAX 100 (or any other film you want) that is pre-exposed to a step tablet. You develop for 4, 5.6, 8, 11, and 16 minutes with your developer and temp. Send the processed sheets back and they will run them through the densitometer and the BTZS plotter software to generate reams of data. He will send you the graphs so you will be able to determine the development time for each sheet of film. If you are not that particular, you will also have the development times (and corrected film speeds) for N+1, N-1, etc. I think it is well worth the $50 compared to the cost of time and materials to extract the same data on your own.

[Andrew O'Neill]

Tmax 100 and D76 1+1 will produce a lovely family of curves, waaaaay better than straight D76. I strongly recommend diluting to 1+1. It will also make your developer a little more economical.

[Brian Ellis]

I used the BTZS tubes in D76 1-1. I read a fairly convincing case somewhere that using is straight will produce slightly sharper negatives but I never tried it straight. 5:45 sounds in the ballpark for your N time, at 1-1 and 75 degrees my N time was about 7:30 IIRC. I probably still have all my times that temp and dilution somewhere, if you're interested let me know and I'll try to dig it out. It's important with the BTZS tubes to use a consistent method of constant rotation. I rolled them 10 times clockwise and 10 times counterclockwise throughout the development process. Nothing magic about that, 5 time or 15 times or some other number would have worked as well, the important thing is to do it the same way every time.

[John Tyrell]

Thanks everyone for all the info. I really appreciate it. This site is great and I have learned a great deal from it. Brian, if you do have the data handy I am interested. Frankly, your many posts helped sell me on the BTZS tubes and after a few trial runs I am very happy with them. I will probably have the View Camera Store do some tests for me in the future, but the independent study was written up and approved before I got the tubes so I am locked in for now. Also, I think DIY it will help me understand better. Thanks again.

[Brian Ellis]

Thanks everyone for all the info. I really appreciate it. This site is great and I have learned a great deal from it. Brian, if you do have the data handy I am interested. Frankly, your many posts helped sell me on the BTZS tubes and after a few trial runs I am very happy with them. I will probably have the View Camera Store do some tests for me in the future, but the independent study was written up and approved before I got the tubes so I am locked in for now. Also, I think DIY it will help me understand better. Thanks again.

Hi John - Glad you found the information helpful. Here are my times using D76 1-1, 75 degrees, TMax 100 film rated at 50, constant rotation of tubes (I see I was wrong when I said in my earlier message that my normal time was about 7:15).

N = 6' 15"
N+1 = 7' 45"
N+2 = 11'
N-1 = 5'
N-2 = 4'

These times came from the View Camera Store testing, not my own. I used to do my own and it's an interesting learning experience but also a real pain. I decided that the $35 they charged was well worth the saving of time and the cost of the many sheets of film wasted with the traditional methods. Plus I got more and better information than I could produce myself without buying the software they use.

[John Tyrell]

Brian,
Thanks for the times. I'm sure they will help me zero in on my own times. I appreciate the thoughtfulness.

John

[Roseanne]

Hello John,
How did you get on with all the zone system testing?
I have just started a MFA in Cork, Ireland, using photography.
I am using 5"x4" with D-76 and Tmax 100, and looking forward to the slow process of it all.
Hope yours went well.
Roseanne

[John Tyrell]

Hi Roseanne,
The testing is going well. A little slowly with work and kids but I work at it whenever I get the chance. So far I have gotten the film speed tests done. Made my Zone I exposures as outlined in Ansel Adams' book The Negative. I don't have access to a densitometer so I used a method to determime density without one given in John P. Schaefer's book The Ansel Adams Guide: Basic Techniques of Photography Book 2. You make a standard print tone at 10 sec. using an unexposed developed sheet and then compare print times of test negatives to match the standard. Simple and accurate. I ended up with a film speed of 64. Negs were developed in D76 straight in the tubes for the recommeded time for rotary processing given in the TMax data sheet. 68 degrees. Hope to get some development times this weekend.
I hope you like the 4x5 format. More contemplative. Good luck in your Masters studies. Keep us posted on how it is going. If you have any questions there are many people on this forum who can help. I have learned a lot on this site and I'm sure I'll have more questions as I learn. John