Lens Contrast (Part 3)
Taken with a Nikon D50 and AF Zoom-Nikkor 70-300mm f/4-5.6G lens
At coarser levels (or "for larger structures," as optical jargon might put it), say 5 lp/mm, you can have more of one than the other, and, indeed, lens designers make choices in these areas. I have one lens, the Leica 35mm F/2 Summicron-R, which has very high large-structure contrast, but not terribly good resolution. That is, if you shoot with a very fine-grained film and look at the detail under a microscope or in well-made enlargements, you may see finer actual detail in pictures made with other lenses yet the Leica lens has a very high (and very pleasing!) sense of subjective "sharpness".
To see a great visual demonstration of this, check out Canon's excellent primer on optics at the back of their book Lenswork (a must-read for any photographer interested in, but not trained in, optics). They show the same picture (of a cat) with a.) poor contrast and poor resolution, b.) good contrast but poor resolution, c.) good resolution but poor contrast, and d.) both good resolution and good contrast. This will "key" your eye in to what is meant by lens contrast better than any verbal description can. As you can see from those illustrations, it has nothing to do with overall contrast of the sort we mean when we talk about paper grades.
Labels: AF Zoom-Nikkor 70-300mm f/4-5.6G, Landscape, Nikon D50, Photography
