Very Early Leica Slip-on No.1 Yellow Filter For Elmar

In black and white photography, colored filters are used to bring out the different shades of gray and get the desired contrast.

Yellow Filters - Black and White Photography
Most used filter
Ideal for beginners as yellow filters can be used in all types of photography
Good for separating the different shades of green, good for shooting plants
Landscapes: Produces a very subtle effect, darkens the sky slightly, balances lighting in darker areas.
Portraits: Produces warm, natural skin tones

Lightens: yellow, red, pink, orange, lime green
Darkens: Blue, Violet, Purple