Back in the 80's I was limited by my job's income to 35mm SLRs, but I wanted badly to try out a form of the Zone system. So I bought a 100 foot roll of Panatomic and sent a developed negative strip to Zone VI Studiios in Vermont to have them use a transmission densitometer to tell me what the exact film speed was. Then I would determine the optimal development time based on Zone VIII placement. It worked reasonably well for a bare basic Zone system technique for 35mm film...certainly my print quality improved a lot. I think I went through 3 100' rolls.
But then I went off to college again, got a job in Clinical Research, got married, and had kids. During this time, I would keep the bulk loader in a bag in my freezer. Until the mid-90's, I'd shoot a roll of the Panatomic every now and then, and it dwindled down.
Now 30 years later from the "Develop Before" date (printed on the box's side panel that I kept until now), last month I pulled out a roll from my freezer and shot a test roll, a la Zone VI Workshop. Now that I have a densitometer of my own, I can make my own measurements of Base+Fog density and Zone I. Plus I had kept the test shots I sent to Zone VI from the early 80's, so I could compare "then and now".
My developer for FX at the time was Edwal FG-7 (1:15) , 7 minutes at 70 degrees. But that's no longer available, so I recently bought Adox Rodinal since Freestyle Photo claims that it's an exact copy of the Agfa Rodinal formula. Looking at some charts I had, I estimated that FX in Rodinal(1:50) for 8.5 minutes at 70 degrees would come close to my Zone system-ed time of 7 minutes in FG-7.
My densitometer results: the Base+Fog level went up from 0.26 to 0.32, so the effect of age has raised the fog level. Zone VI Studios indicated 30 years ago that, based on my 5 Zone I exposures of a black card that I sent them, that my optimal film speed for this 100' roll was ASA50 (and my re-testing of the old test shots with my densitometer confirmed this), but now it appears to have dropped to ASA32, it's originally rated speed. Zone VI Studios stated that 0.08 to 0.10 above the Base+Fog reading was the proper Zone I exposure. My guess is that's the effect of the higher fog level is why the optimal film speed is now lower.
I shot a few pictures of ice and snow to finish out this new test roll. They look really good, but I haven't printed them yet (hey, my 4 kids are STILL living at home!!). But looking at them with a lightbox and lupe, the snow appears to be a bit blocked. I have 6 rolls left, so I'll develop the next roll for less than 8.5 minutes, probably 7.5.
Just thought I'd share this with the group. Comments are welcome.
But then I went off to college again, got a job in Clinical Research, got married, and had kids. During this time, I would keep the bulk loader in a bag in my freezer. Until the mid-90's, I'd shoot a roll of the Panatomic every now and then, and it dwindled down.
Now 30 years later from the "Develop Before" date (printed on the box's side panel that I kept until now), last month I pulled out a roll from my freezer and shot a test roll, a la Zone VI Workshop. Now that I have a densitometer of my own, I can make my own measurements of Base+Fog density and Zone I. Plus I had kept the test shots I sent to Zone VI from the early 80's, so I could compare "then and now".
My developer for FX at the time was Edwal FG-7 (1:15) , 7 minutes at 70 degrees. But that's no longer available, so I recently bought Adox Rodinal since Freestyle Photo claims that it's an exact copy of the Agfa Rodinal formula. Looking at some charts I had, I estimated that FX in Rodinal(1:50) for 8.5 minutes at 70 degrees would come close to my Zone system-ed time of 7 minutes in FG-7.
My densitometer results: the Base+Fog level went up from 0.26 to 0.32, so the effect of age has raised the fog level. Zone VI Studios indicated 30 years ago that, based on my 5 Zone I exposures of a black card that I sent them, that my optimal film speed for this 100' roll was ASA50 (and my re-testing of the old test shots with my densitometer confirmed this), but now it appears to have dropped to ASA32, it's originally rated speed. Zone VI Studios stated that 0.08 to 0.10 above the Base+Fog reading was the proper Zone I exposure. My guess is that's the effect of the higher fog level is why the optimal film speed is now lower.
I shot a few pictures of ice and snow to finish out this new test roll. They look really good, but I haven't printed them yet (hey, my 4 kids are STILL living at home!!). But looking at them with a lightbox and lupe, the snow appears to be a bit blocked. I have 6 rolls left, so I'll develop the next roll for less than 8.5 minutes, probably 7.5.
Just thought I'd share this with the group. Comments are welcome.
