Inspired by another thread here I am going to make a home made "replica" of Puyo-Pulligny The Adjustable Landscape Lens. I was looking for this lens for more then a year I could not find it.
I found some information on the web and in old books. Basically the lens is composed of two elements: plano-concave and plano-convex with identical focal length (10cm and -10 cm). The distance you set between the elements gives you desired focal length. My sources indicated that the lens had two diaphragms - front and rear. However, it does not say where the diaphragms should be placed. Also I have no idea why the lens needs two of them. I wonder, may be some of you, lens experts, could clarify that to me.

Regards,

Jan