All, Anyone try their hand at making a meniscus lens ? Judging by the prices that the vintage ones have been going for, the considering that I want some abreviations anyway, I might give it a shot. Im not sure if Im going to just get a single element, or an an achromat. Thoughts on this ? I've been moving a large hunk of brass around my workbench for over a year, so perhaps this would be a novel application for it. Im looking for something in the 210-300mm range; which I've been able to find lenses quite easily (coated even !) for under $10. These have been around 60mm in diameter. Im not sure if Im going to try my hand at making a revolving aperture wheel, or if I will make some discs (ala imagon). One design element that I am not sure of is where to place the aperture ? I THINK it should be spaced 1/2 the focal distance infront of the lens; does that sound right ? Also, would there be any way to figure out coverage before I construct the lens ? I want it to cover 4x5, but at the moment Im just looking for the largest glass I can find, and hoping for the best. Thanks !