Archived posting to the Leica Users Group, 2001/06/26
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Somebody previously said: "I know that much of the Leica glass is wasted on a film like Tri-X" which resulted in the following exchange > > What is your knowledge based on? > >The fact that Tri-X Pan 400 is a very grainy film of fairly low resolution. Resolution is one thing. Sharpness is another. The basic difference between the two is illustrated on page 1 of the Developing Cookbook. You do not need resolution for sharpness. Also, a grainy picture does not need to look unsharp. Looking at pictues of real life, I think sharpness, and even more so apparent sharpness, is much more relevant than resolution for getting what I simply call A CLEAR PICTURE But then I also prefer prints showing apparent sharpness, a.k.a. edge effect, to grainless prints. That's why I shoot HP5, in the same grain class as Tri-X, at 800 and develop in Rodinal, a developer not famous for giving fine grain, but with nice edge effects. Street scences at night can look dead sharp with this combo even though resolution is low and grain is large If you like resolution, Leica glass may be of particular importance to you if you shoot Tri-X. I assume that you shoot at low light and use you lens stopped down just a stop or two. This is very Leica glass excells. The resolution on you final picture depends on the resolution of several links in the photographic chain. But it is not like a normal chain which is as weak as its weakest part. For yor picture the resolution depends on the accumulated loss of resolution from each step of the chain. (See the formula to calulate this below.) If Tri-X gives you low resolution, then it may be particularly interesting for you not to lose any more. To achieve this, use Leica glass. Fuji give the following formula in their Fact Book, but Erwin Puts say that the forgot to include the square root sign on both sides of the equation. R stands for overall resolution and r(one, two etc) stands for individual reslution, e.g. camera lens resolution, film resolution, enlarger lens resolution etc. 1/r = 1/r(one) + 1/r(two) + 1/r(three)...... - -- Christer Almqvist D-20255 Hamburg, Germany and/or F-50590 Regnéville-sur-Mer, France