Is Konica 750nm true infra-red film?

Here is what a friend (far more knowledgeable as a photographer than

I) said to me concerning Konica 750nm IR film:

>>>...Konica. Some say its not a true infrared film, but merely

one with extended red sensitivity (in that regard, it may behave more

like an orthochromatic film than a true IR film).<<<

Does anyone know of a certainty about this and care to comment?

Thank you.

Maybe your friend is mistaking Konica 750 for Ilford SFX.

<P>

"Konica Infrared 750 film has a wavelength sensitivity range of 640nm~820nm

in addition to the intrinsic sensitivity of the silver bromide of 400nm~500nm.

The peak spectra sensitivity occurs at 750nm."

<P>

<A HREF="http://konicaminolta.com/products/consumer/photo/pdfe/pdf/

INF750.pdf">http://konicaminolta.com/products/consumer/photo/pdfe/pdf/

INF750.pdf</A>

Ortho means not red sensitive. So that should answer that part.

You might want to spend some time reading the infrared web page at:

http://www.a1.nl/phomepag/markerink/mainpage.htm

Orthographic film is indeed only sensitive to green and blue only, so it seems your friend has confused all the terms. Konica 750 is, as the name says, sensitive to about 750 nm, so the IR effect will definitely be there with the right filter.

However, the IR spectrum is much larger than any commercially available 35 mm film can capture, so "true infrared" is not a very accurate definition.