After two years of black and white photography, all of it using D-76 and Tri-X 400, I've decided to jump to a finer grain film/developer combination. After much research, I settled on TMAX 400 and XTOL diluted 1:3 as the combination most suitable to my particular photographic needs. My first results with XTOL/TMAX 400 were similar to the complaints of many other posters on the boards: my negatives were underdeveloped.(posted 8779 days ago)Reading futher on this message board, I became aware that there was a minimum amount of XTOL needed for each roll of film. If you have less than the minimum amount of STOL present, and you need to either 1) increase the development time above that listed in the normal development charts or, 2) find a way to get more developer into the tank by using a lower dilution. Failure to take one of these actions, and you'll get underexposed negatives.
I therefore set out to determine exactly how much I should increase development times for my 1:3 XTOL dilution in my stainless steel, inversion-style development tanks.
Due to my inexperience (I never learned the principles of B&W development, just a recipie for D-76 / Tri-X development) and the confusing nature of Kodak's Development Notes for XTOL (they use, at various times, three different units of measurement: milliliters, fluid ounces, and rolls per liter), this took quite a bit longer than expected. I'm posting the results here to save other newbies time, and in the hope that someone else will double check my calculations!
HOW TO PROPERLY COMPENSATE FOR XTOL DILUTION IN A 16 OZ AND 32 OZ CAPACITY TANK (I think)
There are three factors that need to be considered when adjusting XTOL development times for the amount of developer present in the tank: the capacity of your development tank, the dilution ratio of your developer, and the number of rolls being developed.
I have two tanks:
a 18 oz tank that holds two rolls of film and 16 oz of developer when filled to capacity a 36 oz tank that holds four rolls of film and 32 oz of developer when filled to capacity
I've standardized on milliliters to perform the calculations; therefore my 16 oz capacity tank holds 473 ml of developer. My 32 oz capacity tank holds 947 ml of developer.
Next, we need to know how much stock developer (i.e. undiluted) we need for each roll of film to process properly, and when we need to increase development time. This can be obtained from Kodak's XTOL technical notes (I've converted from rolls/liter to ml/roll):
IF YOU HAVE: 1000 - 200 ml undiluted XTOL per roll, THEN: use normal development time
IF YOU HAVE: 199 - 100 ml undiluted XTOL per roll, THEN: increase the development time by 15%. This is the ADJUSTED DEVELOPMENT TIME.
IF YOU HAVE: 99 ml - 67 ml undiluted XTOL per roll, THEN: increase the ADJUSTED DEVELOPMENT TIME by another 15%.
All right. Still with me? Now we need to figure out how much developer is in each of my tanks at various dilutions. To do that, we simply divide the total tank capacity by the amount we've diluted the XTOL. The charts below contains the results:
AMOUNT OF XTOL IN 16OZ/473ML CAPACITY TANK AT VARIOUS XTOL DILUTIONS
DILUTION ML OF XTOL PRESENT IN THE TANK stock solution 473 ml 1:1 dilution 237 ml 1:2 dilution 158 ml 1:1 dilution 118 ml
AMOUNT OF XTOL IN 36OZ/947ML CAPACITY TANK AT VARIOUS XTOL DILUTIONS
DILUTION ML OF XTOL PRESENT IN THE TANK stock solution 947 ml 1:1 dilution 474 ml 1:2 dilution 316 ml 1:3 dilution 237 ml
Almost home. Now we simply need to divide the amount of XTOL in the tank by the number of rolls we're developing. This gives you the number of ml per roll. You can compare this with the Kodak development time recommendations (see above), and you'll know how much to increase your development time (if any). I've included the results below. Thanks for your patience, and I hope someone finds this useful!
XTOL DEVELOPMENT ADJUSTMENT TABLES
STOCK SOLUTION IN A 16 OZ / 473 ML CAPACITY TANK 1 roll = normal development time 2 rolls = normal development time
1:1 DILUTED SOLUTION IN A 16 OZ / 473 ML CAPACITY TANK 1 roll = normal development time 2 rolls = increase NORMAL time 15% (this is called the ADJUSTED TIME)
1:2 DILUTED SOLUTION IN A 16 OZ / 473 ML CAPACITY TANK 1 roll = increase NORMAL time 15% 2 rolls = increase previously ADJUSTED time another 15%
1:3 DILUTED SOLUTION IN A 16 OZ / 473 ML CAPACITY TANK 1 roll = increase NORMAL time 15% 2 rolls = exceeds max. # of rolls recommended for XTOL present
STOCK SOLUTION IN A 32 OZ / 947 ML CAPACITY TANK 1 roll = normal development time 2 roll = normal development time 3 roll = normal development time 4 roll = normal development time
1:1 DILUTED SOLUTION IN A 32 OZ / 947 ML CAPACITY TANK 1 roll = normal development time 2 roll = normal development time 3 roll = increase normal time 15% 4 roll = increase normal time 15%
1:2 DILUTED SOLUTION IN A 32 OZ / 947 ML CAPACITY TANK 1 roll = normal development time 2 roll = increase normal time 15% 3 roll = increase normal time 15% 4 roll = increase previously ADJUSTED time another 15%
1:3 DILUTED SOLUTION IN A 32 OZ / 947 ML CAPACITY TANK 1 roll = normal development time 2 roll = increase normal time 15% 3 roll = increase previously ADJUSTED time another 15% 4 roll = exceeds max. # of rolls recommended for XTOL present