Autochrome step 1: 1st varnish
GLASS BASE
Before I start talking about 1st varnish I have to dedicate some words to support (glass) which serves as a base on which all the layers making up autochrome are coated. Many of you probably question what is there to talk about glass? When used for autochromes it serves not just as a support but it actually plays a role during exposure. Usually at lets say wet-plate or dry-plate photography plate is turned towards the lens in such a way that emulsion is directly pointing to the light source. With autochrome the...