Complete tutorial for building a device that allows you to make sun exposures with the same amount of UV radiation even at different times and atmospheric conditions. Useful for cyanotype, gum bichromat, salted paper, van dyke brown, platinum, palladium, carbon and other historical photographic printing processes.
Link for complete project: [ Ссылка ]
![](https://s2.save4k.ru/pic/42rwjuU4VrQ/maxresdefault.jpg)