Kolari Vision Hot Mirror Filter (UV/IR cut) vs S8612

[Andrea B.]

I am thinking that perhaps something needs clarification.

 

Kolari Vision sells a UV-pass filter. It is a good one. Slightly lower trans than some, but good blocking of unwanted vis/IR.

 

Kolari also sell a blue-green glass filter which can be used to block IR when making visible photos with a converted camera.

 

So when discussing the Kolari filters, it is really good to designate Kolari UV-pass versus Kolari IR-blocker.

 

Side Note: No blue-green filter will precisely restore the original visible colour of your converted camera. Internal IR blocking filters are typically not pure, uncoated BG. I've seen internal IR blockers which are clear with a very very light pink when viewed at a certain angle. (Dichroic? Coated? Not sure.)

 

I also must note that pure BG glass passes UV. The way UV contaminates visible light is seen in long landscape photos where the distance becomes softened/hazy due to the UV scattering. Ideally the Kolari BG glass is combined with a layer of UV-blocker, but I do not know. Perhaps someone can inquire about this.

 

Anyway, to use a BG-based filter for visible work with a converted camera, you should perform an in-camera WB measurement under the BG filter against a white standard. And you should make a new color profile under that BG filter. Those two combined steps will bring your camera back to accurate visible colour.