Filtration Question

[Jesse Aragon]

Hello All,

I have a question regarding irnd's. In the past Ive used schneiders irnd's and have noticed the green color shift. I was wondering however if I was to use a non IR nd9 on camera with a tiffen pola have the same color shift as say a 1.2 schneider irnd?

 

[Nick Morrison]

Try the Firecrest...they appear to be the cleanest/most consistent ND's on market....with seemingly minimal shift...

 

[Jesse Aragon]

Nick, thanks for the tip, I have heard of the firecrest but at the moment they are not an option, my question is whether the tiffen pola will shift the image the way the nd does.

 

[Will Turner]

From my understanding using a ND.9 and a pola will give you the same color shift as using a 1.2 (give or take depending on the pola). What you're doing is cutting out visible light and not altering the infrared light coming in to your sensor, so the infrared is starting to overpower the visible spectrum and that's what gives the pink cast.

The green cast is from the filter attempting to correct out the pink cast with dye in the filter, and because just like the visible spectrum infrared light can always vary in intensity sometimes you get a green cast and sometimes you don't depending on the light and time of day. In my own experiences I've seen a green cast looking one direction and had perfect tones looking the other, just depending on how much infrared was coming in at those angles.

The best solution I've found is to use a hotmirror. That way the infrared is just bounced away rather then absorbed by the sensor. Format is my prefered brand for hotmirror + ND combos.