The Cokin Warm (81C) Colour filter is for use with a film camera using daylight colour film or a digital camera in "automatic" mode. Same purpose as Warm Filters 81A/81B, but with stronger effect. The Warm 81C filter decreases colour temperature from 3600ºK to 3200ºK. The 3 filters 81A / 81B / 81C can be combined with each other for maximum effect.