Hasselblad 201f Question on CF lenses

[Andrew Moxom]

While researching the 201F, I downloaded a.pdf version of the manual and it says that in some circumstances when using a CF lens, and shutter speeds of 1/250 or faster with a CF lens, that you are under 'certain' conditions, recommended to set the lens shutter at F and use the focal plane shutter. (see page 51).. On Page 51, there is NOTHING that mentions why this is!! Anyone know why that is?? The leaf shutter can run at 1/500th, so if it's set to C, why can it not be used, and what are the 'certain' conditions?? The manual does not specify why on page 51.

thanks in advance.

A.

 

[greybeard]

Interesting question; I didn't notice that in the manual.

One possibility is that because the C shutter is an iris type, at the higher speeds it may not be as accurate as the focal plane, which is electronically controlled. It would probably be a small effect, though, if both shutters are working an calibrated correctly.

If you find an authoritative answer elsewhere, please do post it---it sounds intriguing, even if it is of little actual consequence.

 

[Q.G.]

It's about shutter efficiency, and focal plane shutters being more precise than focal plane shutters at faser speeds.
The certain conditions are a fast speed at small apertures.

You can (!) use the leaf shutter, despite of what the manual might suggest. But expect a slight but distinct overexposure (about half a stop) when using a lens at f/22 at shutterspeeds of 1/500.


There is a similar warning, but against using C lenses, elsewhere in relation to focal plane shutter cameras. That one however is based on the assumption that old leaf shutters are getting a bit slow (old grease), and might not synch perfectly with the focal plane shutter (which acts as a film shield, like the two 'barn door' flaps in lefa shutter bodies).

 

[Andrew Moxom]

thanks QG, now that explains it!