Jack, In absolute terms, the negative emulsions have finer grain than positive. Indeed, Agfa's best negative, Portrait 160 with it's granularity of RMS 3.5 is obviously better than the RMS 10 of their best positive - RSX 50. The difference maintains more or less at all other manufacturers. In real world though, the thicker layers of the positive emulsion accounts for higher densities that translate to finer gradations in all three colour channels. This comes at the expense of the reduced exposure range compared to the negative emulsion, but given a subject whose exposure range is covered by the positive emulsion latitude, the positive delivers a richer image than the negative and the continuity of tones hide its higher granulation giving the overall better appearance. In the digital era, this becomes even more obvious with the post processing level of the scanned image: the lack of tones of the negative emulsion image is immediately apparent as noise, sometimes after as little as level adjustment and curve manipulation to open the shadows. Despite its smaller grain, the noise gives the negative film the contrary appearance. In my limited experience, the only negative film that comes close to various positives (like Provia 100F, CT Precisa 100, RSX 100, etc.) in terms of rich image in tones is the Kodak RG50. Too bad it became "obsolete". [Flame disclaimer: note that I don't discuss other criteria like exposure latitude, colour linearity, etc.; it's not the end of the world if I cannot capture all the subject's details, to me a good picture should also suggest, not just depict). Servus, Alin
Jack wrote: JD> I had a lab owner emphatically contend that.."positive JD> film of the same ISO has finer grain than negative JD> film". Didn't address b&w. JD> We happened to be reviewing a b&w print at the time JD> and their existed a situation wherein the subject JD> couldn't be pursued (customers waiting). JD> I've since emailed him for a follow-up on his JD> recommendation that "b&w film be scanned as positive JD> film". JD> If his answer (if received) is at all decipherable, JD> I'll forward it. JD> Does anyone know or suspect what he may be talking JD> about? JD> I've, also, read the RMS charts but, their results JD> don't appear to be comparable. JD> __________________________________________________ JD> Do You Yahoo!? JD> Tired of spam? Yahoo! Mail has the best spam protection around JD> http://mail.yahoo.com
