Hi, anybody have experience with the Sigma Pantel 135 f2.8-f64 from the late '70s? Going through old issues of Modern Photography, I was reminded by the ads of this unique lens — an extra stop [beyond f22] for f64 [marked as Pan on the lens barrel in red]. The ad claimed that at f64, the DoF was from 5' to ∞ [infinity]. I was always intrigued by these ads and I now would be interested in experimenting with this novelty setting. I don't have a 135mm, having sold a Leica Hektor 135 f4.5 about a year ago because the colour aberations were quite drastic and I need the dough for m43 gear. They seem fairly cheap now. I realise the diffraction issue would be serious but I would like to experiment — after all there was the Group f/64, including Ansel Adams, Imogen Cunningham, Edward Weston and others. Am I crazy?