warming filters

What's the difference between the 81 series warming filters and the

CTO half, quarter etc?

 

I should add - I'm sorting through a pile of series VII filters I got.

 

I generally use the 81 series filters for warming the super cool blue

winter light up here, not for critical colour correction of different

films/light sources. So it's an 81A or B depending on what the

weathers like...

 

thanks

The Kodak Wratten numbered filters come from the scientific end of things and are very precisely calibrated. That's why there are so many different ones. The "Rosco"-type filter gels come from the theatrical world and are equally effective, though not described the same way. Kind of like the difference between English and metric measurements. Kodak publishes a large handbook describing every one of their filters, I think it comes from Silver Pixel Press now. But you can mix'n'match as your pictures require.

I believe CTO stands for Color Transparency Orange. I've neverseen it in the form of a glass filter, only in Roscoe sheets and rolls.

We use 1/4 or even 1/2 over a strobe to simulate just-breaking sunrise light----often have to drag the flashhead w/ its 5" reflector out into the hallway to make it hard enough. :-)

Decent warming filters are calibrated in Deca-Mireds.

 

Heliopan make them and call them KR1.5, KR3, KR6 etc. for the 1.5,3, 6 etc. deca-mired filters. You can add them: 1.5 + 3 = 4.5!

 

The KR1.5 is like a haze filter, the 3 is good for overcast days etc.

 

You can take good photos on cloudy days with good colour and avoid the contrasty bright sunlight, see pic.<div></div>