Hot Mirror Filter

[CMoore]

I was looking through all my miscellaneous filters, and there is one, a Tiffen, that says "Hot Mirror". I have never used one, did not even know i had This One.
But anyway.....it has been my understanding these were some kind of "Protective" filter. They protect the Lens, or maybe Film from an excess of one extreme of the non-visible light spectrum..... maybe?
What are these for exactly.?
Thank You

 

[MattKing]

They are an infrared "cut" filter - designed mainly for digital cameras, many of whom have high sensitivity to light at that end of the spectrum. Yours may also have neutral density built in.
The long exposure digital crowd would be the target audience.
Most film is not particularly sensitive to infrared, although the neutral density might be of use to you.

 

[CMoore]

Thanks Matt......Assuming there is no ND aspect with this..... What would "happen" if a person used this on a Film Camera.?
Maybe on your "typical" daytime, street photo, scenario with Ilford HP5 for example.?
I gather then, from what you are saying, there would not be much affect with "normal" Black and White film.?
Thanks Again

 

[bdial]

As Matt said, most films aren't especially sensitive to infrared, in fact, some newer cameras have infrared sensors to detect whether the film is loaded correctly or not. It probably would have little or no noticeable affect with your HP5.

 

[Kino]

I was looking through all my miscellaneous filters, and there is one, a Tiffen, that says "Hot Mirror". I have never used one, did not even know i had This One.
But anyway.....it has been my understanding these were some kind of "Protective" filter. They protect the Lens, or maybe Film from an excess of one extreme of the non-visible light spectrum..... maybe?
What are these for exactly.?
Thank You

Useful for photographing any industrial process that generates a lot of IR and heat; like steel production.

 

[CMoore]

Interesting info.
Thanks everybody.

 

[M Carter]

The big market for these is digital cinema cameras, particularly some of the Blackmagic line - they really can have an issue with shadows going very red when using ND, and those guys regularly use from 3-5 stops to get wide apertures outdoors. They're pretty freakin' pricey as well, and are probably unnecessary for most film shooting - so you might eBay it and get a few bucks.

 

[CMoore]

The big market for these is digital cinema cameras, particularly some of the Blackmagic line - they really can have an issue with shadows going very red when using ND, and those guys regularly use from 3-5 stops to get wide apertures outdoors. They're pretty freakin' pricey as well, and are probably unnecessary for most film shooting - so you might eBay it and get a few bucks.

Thanks......I have no idea Where/How i git this thing, and i am not sure i could "testify" to it being in good shape.
It is in a box with my other Never/Infrequently Used filters.....it will probably live there for the rest of my life.

 

[M Carter]

Thanks......I have no idea Where/How i git this thing, and i am not sure i could "testify" to it being in good shape.
It is in a box with my other Never/Infrequently Used filters.....it will probably live there for the rest of my life.

I'd guess if it's clean and free of scratches it's good.