Some questions about filters (Hot mirror, IR, etc

[Filippo Maso]

Hello!

I have some dubts about the function of a few kinds of filters and if you could explain to me it would be great!

I've tried to check online but i haven't found a clear explanation, maybe it's because my english is terrible!

So, how a Tiffen hot mirror works an which is the difference from a PV TIFFEN HOT MIRROR IRND (infrared and ND too?)

Why in digital cinematography is so important use IR filters and in which cases they works better?

And finally what PV means? I think something about the noise reduction for digital cinematography but I'm not sure! =)

Sorry for that kind of asks! I'm a noob!

Thank you very much!

Filippo

 

[David Mullen ASC]

"PV" just means Panavision size, which is 4x5.6.

 

Art Adams has written extensively about IR filtering for digital cameras so take a look over at ProVideo Coalition:

http://provideocoalition.com/aadams/story/red_hot_mirror_shoot_out

http://provideocoalition.com/aadams/story/ir_cheat_sheet_version_2/

http://provideocoalition.com/aadams/story/red_ir_filter_test/

http://provideocoalition.com/aadams/story/arri_alexa_and_far_red_a_problem_thats_already_been_solved/

 

 

The basic thing to take away is that not only do the various digital cameras vary in their sensitivity to IR pollution, some respond to different wavelength ranges of far red to infrared, and newer models can change again based on whatever filtering they use inside the camera for the sensor.

[Filippo Maso]

Thank you Mr. Mullen.

 

I'll read the articles you've attached!