Hi,
I recently photographed a scene that raised an exposure question or two in my mind, and I am hoping that the wise BTZS users out there might share their thoughts.
The scene was an old condemned house in bright afternoon light. There were not any large or significant shadow areas, but I metered a shadow on the lawn just out of the frame since this appeared to be the same as the smaller un-meterable shadows under the roof line and beneath the wooden shingles that covered the side of the house. The difference between the low and high EVs indicated a SBR of 9. That was higher than I expected, but I metered it several times and each time I got identical results. So, I based my exposure on the shadow reading and indicated appropriate development. As an experiment I took another shot assuming a SBR of 7 since it felt like a 7 stop scene. (I simply took the high reading and subtracted 2 stops from it and took that as the new shadow reading and based the exposure on it). The film was TMAX 400.
I developed both negatives for the appropriate times in Pyrocat HD 2:2:100 (in this case 7.25 minutes for the SBR 9 neg and 11.5 minutes for the SBR 7 neg). I have not printed them yet, but both negatives look very good. However, the SBR 7 neg has slightly more contrast and looks to be the one that will print the best based on past experience. Still, the differences are subtle. My questions:
1. Given that Tmax 400 has a very straight line, shouldnt it be possible to take two shots of the same scene at different exposures and get essentially identical negatives by developing each for the appropriate time? Shouldnt it be impossible for me to tell these two negs apart if both were developed just right? Or is it impossible to ever achieve this since each negative has its values placed on different parts of the curve (straight though the curve may be?)
2. If it is true that one can make two identical negatives this way, would this not be a good way to test development times? I know for example that 11.5 minutes works well for scenes where the SBR is 7. If I shoot the same scene as a 7 and a 9, with adjusted exposure, would it be safe to assume that my development times for a scene with an SBR of 9 is dialed in when it looks (and prints like) the SBR 7 neg?
Thanks,
Paul
I recently photographed a scene that raised an exposure question or two in my mind, and I am hoping that the wise BTZS users out there might share their thoughts.
The scene was an old condemned house in bright afternoon light. There were not any large or significant shadow areas, but I metered a shadow on the lawn just out of the frame since this appeared to be the same as the smaller un-meterable shadows under the roof line and beneath the wooden shingles that covered the side of the house. The difference between the low and high EVs indicated a SBR of 9. That was higher than I expected, but I metered it several times and each time I got identical results. So, I based my exposure on the shadow reading and indicated appropriate development. As an experiment I took another shot assuming a SBR of 7 since it felt like a 7 stop scene. (I simply took the high reading and subtracted 2 stops from it and took that as the new shadow reading and based the exposure on it). The film was TMAX 400.
I developed both negatives for the appropriate times in Pyrocat HD 2:2:100 (in this case 7.25 minutes for the SBR 9 neg and 11.5 minutes for the SBR 7 neg). I have not printed them yet, but both negatives look very good. However, the SBR 7 neg has slightly more contrast and looks to be the one that will print the best based on past experience. Still, the differences are subtle. My questions:
1. Given that Tmax 400 has a very straight line, shouldnt it be possible to take two shots of the same scene at different exposures and get essentially identical negatives by developing each for the appropriate time? Shouldnt it be impossible for me to tell these two negs apart if both were developed just right? Or is it impossible to ever achieve this since each negative has its values placed on different parts of the curve (straight though the curve may be?)
2. If it is true that one can make two identical negatives this way, would this not be a good way to test development times? I know for example that 11.5 minutes works well for scenes where the SBR is 7. If I shoot the same scene as a 7 and a 9, with adjusted exposure, would it be safe to assume that my development times for a scene with an SBR of 9 is dialed in when it looks (and prints like) the SBR 7 neg?
Thanks,
Paul
I try to find 5 or 6 the same on ebay about every 5 years.