I've been runnning some film processing tests of T-Max 400(8x10in.) with T-Max R S Dev.(1:9) using JOBO rotary processor, and I have some questions about the re sults.
First of all, Exposure Index which came out was 560. Is this pretty normal?? Here is how I found my EI. (I followed the article, "exposure test" in the KODAK book. 1. I set the manufacturer's recommended ISO film speed. That is 400. I exposed 5 sheets of film shooting a gray card (focus at infinity). 2. In the first shot I underexposed 3 stop so that the gray card is placed at Zo ne 2, and the second shot is -3 1/2 stops (Zone 1.5) , and the third is -4 stops (Zone 1), and so on. 3. I develop the films with T-Max RS (1:9) for 9 min at 75F using JOBO (rotation speed 3 1/2) 4. I read the density of the negatives. Base+fog was 0.06. The negative which is 0.16 was the one which was underexposed -4 1/2 stops. 5. I multiplied film speed(400) by the factor(1.4) on the article. 400 x 1.4 = 560 EI=560 Next, the result of the Development test shows that the normal dev. time is 10min. I set my new system-speed number(560), and shoot 4 sheets of films--whi ch were overexposed 2 stops (Zone 7)and--process them in defferent dev. times, 8 min, 9min, 10min, and 11min. The density of negative which is 1.11 was the one was deveoped for 10 min. 5. Thus, the result was EI 560 and 10 min development for grade 2 paper printing . Is this the right way to figure out?? Also, I read the article by J. Sexton ab out T-Max film ,and his current starting recommendatin for T-Max 400 in a JOBO w ith T-Max RS 1:9 at 75 degrees is EI 320 for 7.75 minutes and rotation setting o n 3 1/2. My result is very different from his recommendation. So, I shot norma l subject and processed both in my way (EI 560 for 10min) and in his recommendat ion (EI 320 for 7.75min) The negative processed by my deta looked OK whereas th e negative processed by his recommendation looked a little flat in terms of cont rast. Therefore, I thought that what he is saying in the article is that make a little flat neg. and add some contrast later when printing, which yield more be autiful print in stead of adjusting contrast when making neg. Am I misunderstanding completely?? How come my deta is away different from his recommendation?? I used sekonic meter and shunider lens --they are pretty new!! Anyone can help me?? I am beginner of large format. Thanks Anausagi