The Cokin Warm (81B) Colour filter is for use with a film camera using daylight colour film or a digital camera in "automatic" mode. The Warm (81B) Colour serves the same purpose as Warm (81A) Colour filter but with a stronger effect (warming-up more). The Warm (81B) Colour filter decreases colour temperature from 3500ºK to 3200ºK. The 3 filters 81A / 81B / 81C can be combined with each other for maximum effect.