completely newbie's question about filters

[gratings]

Being a red/green/blue/yellow filter, will the filter block out or transmit this colour's light? It seems the articles on the internet conflict each other.
Thanks a lot in advance!

 

[FuddyDuddy]

Hello

Yes, a filter will allow light of its own colour to transmit whilst blocking its opposite colour. So a yellow filter, for example, will transmit yellow but will reduce transmission of blue. A red filter will transmit red, while blocking cyan (blue+green).

F. Duddy

 

[ksmattfish]

Here's a color wheel.

A colored filter blocks the colors on the opposite side.

 

[Hertz van Rental]

To add to that:
For example, a green filter will make magenta come out very dark. Red and blue will also appear darker. Yellow and cyan won't be affected. Green will come out lighter.
Only works with B&W film, remember.