The Formatt 58mm Yellow 12 Glass Filter is used for minimal contrast in black and white photography. It can give a simple boost to your images and is generally used for a slightly noticeable increase in contrast.
When used with color film, this filter will give everything a yellow tint creating a somewhat surreal image.
Especially useful for clear contrast between blue sky with clouds and foreground
Recommended as a basic filter for use with Kodak Aero Ektachrome Infrared film