jimbarcelona

1. I think any lens formulations are kept pretty secret, but are pretty easy to reverse engineer. The Leica Glow is a result of 2 things: spherical aberration which the Leica engineers were quite ashamed of, and the micro contrast already present in Leica Lenses. The newer Leica lenses (ASPH ones) do not have this glow. Micro-contrast is perceptible but really hard to measure. You need photo samples of a spectrum from light to dark to see it. There are some clear comparisons of high and low micro-contrast on line. 2. I think the trick of spherical aberration has been pulled off in lots of lenses. Micro-contrast is hard to reproduce, but the Nikkor 50mm 1.4 has the Leica glow, too, because of the flaw of spherical aberration and high micro-contrast. The newer lenses that are sharper actually looks less 3D! Try the 50mm 1.4 Nikon lens wide open and I'm sure you'll get that glow. Make sure it's the version that doesn't correct for spherical aberration. Anyways, I created this account just to say there is no mystery. It's just spherical aberration + high micro-contrast. Lots of 2000-ish lenses will do that, but not the newer ones that remove the aberration.