Archived posting to the Leica Users Group, 1998/12/27
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]>Dan wrote: >When you mention using a CC40 filter with Tech-Pan because of its red >sensitivity- I am assuming a minus red or cyan filter, n'est-ce pas? Dan, you are right: I should have stated CC40C. I had one custommade by B&W. Eric wrote: >Contrary to some opinions, Leica lenses do very well with both >films. You don't need 100 speed film to see the benefit of Leica lenses. >Maybe in terms of sharpness, but that's not all that makes Leica special. Many wide ranging and broad covering expressions are true and not true at the same time. The image quality of Leica lenses is tightly coupled to film technology and its derived image qualities. Leica lenses (at least the latest generation) excell in edge contrast, excellent clarity of very fine detail to the limits of film resolution, excellent colour hue separation, fine representation of solid blacks and clean highlights and the subtle gradation in shadows and specular highlights. To see this we need the best contemporary films we can buy at fairly big enlargements or magnifications. Whenever we use higher speed films we get soft but fine grain, low gradients to cope with exposure latitude and low edge contrast and bad colours. There is a definite diminishing return when using the highest speed films and the superiority of Leica versus others is also diminished. Leica lenses also excell at giving image quality over the whole image field at full aperture, and medium to high contrast and neutral colours and flare suppression etc. This you will see on any film, but the very fine and soft edged grain structure of the higher speed emulsions reduces contrast of fine detail, if it is represented at all. Recent films are advancing though in this area. And an amazing level of detail is visible with finely graded colour hues. But if you look at the Kodak figures for Print Grain Index for the new Portra and Ektapress films you will see a fairly soon breaking up of grain structure killing the image quality of any lens, but specifically Leica lenses. So it still is best to you the largest aperture and slowest speed film you can afford per opportunity. The discussion around the 1.4/80 and 1.4/75. These lenses are not the same, even when the lens view looks the same. Both lenses do not exhibit at full aperture the contrast we are getting from the new Apo 2/90 for the M. Comparatively speaking the 75 is at full aperture visibly better than the 80 which is a bit softer overall and loses out in the field when having to record fine details. But here we see my point made above. On low contrast film with soft grain the overall contrast difference will vanish as do the fine details, giving comparable image structure. Basically the 75 is the better lens. Erwin