Question about vintage lenses

nmasters · Jul 21, 2012

Hey gang,
So I have some old manual lenses for my Mamiya 645 1000s, and I've noticed on every lens there is a red mark to the right of the aperture selector.
Can anyone explain to me what these are supposed to indicate?

Here's what I'm talking about:

Derrel · Jul 21, 2012

That is the infra-red focusing index mark. IR comes to a different point of focus that light that makes up the visible spectrum. Focus using "white light", note the distance, then move the focusing ring until the "white light" distance lines up with the IR Index mark. Shoot IR photos!

nmasters · Jul 21, 2012

Derrel said:
That is the infra-red focusing index mark. IR comes to a different point of focus that light that makes up the visible spectrum. Focus using "white light", note the distance, then move the focusing ring until the "white light" distance lines up with the IR Index mark. Shoot IR photos!

Thanks Derrel.
Wow, that's a pretty nifty feature. I've never shot any IR photos, but I definitely want to give it a shot