Using 6x7 lens with DSLR

[Dangerous_Dave]

Hi folks, I've noticed you can pick up adaptors (about £50 on e-bay) to use 6x7 lenses with various DSLRs. Does anyone know how you calculate effective focal length of a 6x7 lens with an APS-C camera? I am guessing it's not the same as for 35mm lenses.

I'm guessing someone must have used Pentax 6x7 lenses with their DSLR? Are there any other issues to be aware of?

I reckon the flat field and large aperture might make this an attractive option for astrophotography, as well as my wife's landscape photography.

cheers

D

 

[foodpoison]

It's the same bro!

So on MF roughly 90mm is the standard 50mm on full frame.

So on APS-C 90mm will be, what, 135mm?

 

[Dangerous_Dave]

It's the same bro!

So on MF roughly 90mm is the standard 50mm on full frame.

So on APS-C 90mm will be, what, 135mm?

Cheers for that.

 

[Steve Smith]

The focal length is the same regardless of format so a 90mm lens is 90mm whatever it is on.


Steve.

 

[Dangerous_Dave]

The focal length is the same regardless of format so a 90mm lens is 90mm whatever it is on.


Steve.

Sorry, perhaps what I should have asked for is the 'effective magnification' or 'crop factor'! I now have the answer. Thanks for the response.

Has anyone used a 6x7 with their DSLR using one of these adaptors? Can I do open aperture metering or is it manual diaphragm only? I can't do any sort of automatic aperture control with my SMC/M42 Takumars, but they are fitted using a £5 EOS:M42 adaptor.

cheers

D