I would like learn how you efficiently combine the use of b&w contrast filters with a zone-system way of thinking!
I believe I understand the basic stuff about contrast filters, i.e. that yellow filters in general have filter factors of approx K=2 and hence calls for exposure compensations of +1 stop for *average* scenes, red filters calls for 2-3 stops in general etc.
But, how to efficiently understand and apply the effect of contrast filters in zone-system work where you often use spot metering to read the EV of small regions that, more often than not, are homogeneous in color? Can I use the filter factor approach and expect that the factor only applies to areas in the scene that are in the complementary color of the filter? Should I meter the scene through the filter? One often reads that the latter approach is not recommended due to the spectral response of the meter not matching that of the film.
An example: I recently shot a landscape scene in which there was a gray stone wall, some grass, some foliage and a blue sky. The deep shadows in the stone wall read 10EV using my hand held spot meter and I decided to place those shadows into zone III. The grass and the foliage read about 9.5EV and hence fell into zone V.5, which is fine I believe. The blue sky read about 14 EV, a would fall into zone X, which is a bit too high up in the tone scale I would say.
In the example above, one could either compensate for the high subject brightness range (SBR) by applying N- development, use a contrast filter to darken the sky (e.g yellow, orange, or red), or both techniques in combination. In my case, I did not want to apply N-2 development to bring the sky into zone VIII, since I thought that would compress the tone scale of the foliage etc. I decided to use a yellow filter (K=2) to darken the sky somewhat. Due to the filter, and since the stone wall was grayish (neutral in color), I decided to apply a +1 stop exposure compensation to avoid the stone wall to drop into zone II (right or wrong?). However, I have no solid experience in how effective the filter is on darkening the blue sky, and hence do not know what to expect in terms of where the sky will fall on the tone scale, will I still need to apply N-2 or maybe N-1 development? How would you approach the problem? Suggestions are most welcome!
I believe I understand the basic stuff about contrast filters, i.e. that yellow filters in general have filter factors of approx K=2 and hence calls for exposure compensations of +1 stop for *average* scenes, red filters calls for 2-3 stops in general etc.
But, how to efficiently understand and apply the effect of contrast filters in zone-system work where you often use spot metering to read the EV of small regions that, more often than not, are homogeneous in color? Can I use the filter factor approach and expect that the factor only applies to areas in the scene that are in the complementary color of the filter? Should I meter the scene through the filter? One often reads that the latter approach is not recommended due to the spectral response of the meter not matching that of the film.
An example: I recently shot a landscape scene in which there was a gray stone wall, some grass, some foliage and a blue sky. The deep shadows in the stone wall read 10EV using my hand held spot meter and I decided to place those shadows into zone III. The grass and the foliage read about 9.5EV and hence fell into zone V.5, which is fine I believe. The blue sky read about 14 EV, a would fall into zone X, which is a bit too high up in the tone scale I would say.
In the example above, one could either compensate for the high subject brightness range (SBR) by applying N- development, use a contrast filter to darken the sky (e.g yellow, orange, or red), or both techniques in combination. In my case, I did not want to apply N-2 development to bring the sky into zone VIII, since I thought that would compress the tone scale of the foliage etc. I decided to use a yellow filter (K=2) to darken the sky somewhat. Due to the filter, and since the stone wall was grayish (neutral in color), I decided to apply a +1 stop exposure compensation to avoid the stone wall to drop into zone II (right or wrong?). However, I have no solid experience in how effective the filter is on darkening the blue sky, and hence do not know what to expect in terms of where the sky will fall on the tone scale, will I still need to apply N-2 or maybe N-1 development? How would you approach the problem? Suggestions are most welcome!
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