Archived posting to the Leica Users Group, 2006/01/15
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]On 13/01/2006, at 17:12, John Black wrote: > Luis: > > Is the densitometer reading for zone 5 (middle gray) that you obtained > including the fb+f or subtracting it? My best prints from any film > are made > from densities of about 0.45-0.55 at zone 5 and about 1.20-1.30 for > zone 10 > and 0.40-0.80 for zone 1 and 1.10-1.25 for zone 2. All readings are > MINUS > fb+f. Contrast index should be about 0.50-0.60 with 0.55 being > best. These > numbers are true in my hands for low to medium speed films (ASA > 100-400) but > fast films (1600-3200) will have little zone 1-3 density but normal > above > that with CI of 0.60-0.70. > > Sorry for all the numbers but I too have a densitometer and like to > play > with homemade developers and measure their performance by HD > curves. I am > interested in the D reading of the Rollei film at other zones also. I metered all the zones to figure if they were falling into reasonable values, but only noted the middle gray, which I also like near the 0.60, after having them ok. The first roll was exposed using a spot meter and placing readings into the V zone, so it was easy to read it later on the negative. My densitometer is the one incorporated into the RH designs analyzers and looks quite accurate if I set the light level to a raw reading of 370 or so. Then I start metering and this is the 0 density (usually I meter a blank exposure, so b+f). All the subsequent readings are related this first measure. My zone X also uses to fall into 1.20, but honestly I don't write nothing unless I've messed up the development. Usually it's just informative data that gives me an idea about the tones on the print. Anyway, as soon as I finish my darkroom move I will take and send complete measures of my negs. Saludos ----------------------------------------- http://imaginarymagnitude.net/blog/