I read that chinese scientists defends to produce micro lenses with exposing dichromated gelatin and make an positive or negative element .

What could be the limit at thickness , relief height or depth and total diameter ?

Its possible to produce free form and non spherical ones also and as Hexavalent reported , it would be possible to add alum and make hard rock pieces.

This is very interesting because wide angle domes or cylindrical lenses are veryt possible to be produced.

I am thinking loud , we can pour gelatin to glass box and expose from two sides

I need to know the dimensional limits of these parts as I asked above.

I think photopolymers could use a mask than appear a relief and clean with a solvent.

I think acrylics are very suitable to uv exposure and a photomask

Mustafa Umut Sarac