I have a Lumix G7 and want to use a Canon FD lens with it (mostly because of the incredible price).

The FD lenses I have in mind are the 28mm F2,8 and the 50mm F1,4. I know that the focal length changes with an adapter, I just can't really figure out by how much.

Does the f-number change too? So from F2,8 to F4 or something like that?

  • \$\begingroup\$ I can very much recommend the 50mm 1.4 for everything you don't need auto-focus. I used it quite a bit for concert photography, great lens. \$\endgroup\$
    – pLumo
    Commented Aug 7, 2018 at 14:50

1 Answer 1


FD-to-MFT adapters do not contain any additional optics, so in and of themselves, do not contribute to any change in the appearance of the image.

The Micro Four Thirds system typically uses sensors with a crop factor of 2. This value can be used to determine the "equivalent" FOV in terms of a full-frame body. For the purposes of calculating exposure, the aperture remains the same. However, it may be useful to multiply the aperture by the crop factor to get an idea of its effect on bokeh.

  • The 28mm F2.8 lens will have a FOV "equivalent" to a 56mm lens and bokeh that looks like F5.6 on a full-frame camera, but exposure will still be taken with F2.8.

  • The 50mm F1.4 lens will have a FOV "equivalent" to a 100mm lens on a full-frame camera. Bokeh will look like F2.8, and exposure will be calculated with F1.4.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.