Are there any out there who truly check films for speed using a standardized 'model' of their own making and check for shadow detail along with highlight detail?
My 'model' is my bookcase which has 'constant' nooks and crannies (which show a very dark, shadowed rear wall wood-grain detail like A Adams' Zone I or II) along with a small white plastic drawer chest on one shelf that allows for measurement of highlight detail (ie, A. Adams' zone IX). For consistent measurement, I use a ceiling light, only this. Thus, I really get to measure a film's ability to render that slight shadow detail while retaining the highlight detail. And all this has to be present with neither too much nor too little contrast. Development time can easily mask the true speed: I scrutinize the processed negative with a magnifying glass in front of a lit light bulb while assessing shadow and highlight detail, along with overall contrast. This, I feel is a true measure of film speed.
I have NEVER purchased a roll of TMZ 3200 that showed a true 800!!! I have always seen this film to register an honest 400 like Tri-X but no more. On the other hand, Fuji 1600 and Ilford 3200 I do find to be able to actualize an honest 800. Stored in salt mines after manufacture, that TMZ must have a very short optimal life. Am I alone here? And, to make matters worse, I have NEVER found ANY color negative film to satisfy my '800' using the same determinant. I find 400 tops, no matter how fresh the film. Of course, we all know that with both of these shortcomings, a little extra development can mask reality and coddle us to come to more generous conclusions. But I am strictly going by my bookcase paradigm and can honestly say that my results bear honest fruit. Is there a marketing intention with such speeds? - David Lyga
My 'model' is my bookcase which has 'constant' nooks and crannies (which show a very dark, shadowed rear wall wood-grain detail like A Adams' Zone I or II) along with a small white plastic drawer chest on one shelf that allows for measurement of highlight detail (ie, A. Adams' zone IX). For consistent measurement, I use a ceiling light, only this. Thus, I really get to measure a film's ability to render that slight shadow detail while retaining the highlight detail. And all this has to be present with neither too much nor too little contrast. Development time can easily mask the true speed: I scrutinize the processed negative with a magnifying glass in front of a lit light bulb while assessing shadow and highlight detail, along with overall contrast. This, I feel is a true measure of film speed.
I have NEVER purchased a roll of TMZ 3200 that showed a true 800!!! I have always seen this film to register an honest 400 like Tri-X but no more. On the other hand, Fuji 1600 and Ilford 3200 I do find to be able to actualize an honest 800. Stored in salt mines after manufacture, that TMZ must have a very short optimal life. Am I alone here? And, to make matters worse, I have NEVER found ANY color negative film to satisfy my '800' using the same determinant. I find 400 tops, no matter how fresh the film. Of course, we all know that with both of these shortcomings, a little extra development can mask reality and coddle us to come to more generous conclusions. But I am strictly going by my bookcase paradigm and can honestly say that my results bear honest fruit. Is there a marketing intention with such speeds? - David Lyga
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