# DSLR lenses for Mirrorless



## dilby (Oct 4, 2015)

I have a canon 600d and am looking to upgrade soon, probably to a gh4 or a7sii. 

My question is how would my lenses translate to either camera in terms of fical length, would the auto focus still work and would i need a speedbooster? I've tried reading about it but im confused!

Two example lenses I use a lot are the nifty fifty canon 50mm 1.4 and the sigma 10-20 4-5.6f wide angle tele.

Thanks!


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## jaomul (Oct 4, 2015)

50 gives fov of 80 on your Canon, 100 on the Panasonic and 50 on the Sony.

10-20 gives fov of 16-32 on Canon, 20-40 on Panasonic, 10-20 on Sony but will likely give massive vignette on Sony


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## Ido (Oct 7, 2015)

dilby said:


> how would my lenses translate to either camera in terms of fical length,


The focal lengths won’t change, because you’ll be using the same lenses. What will change is the angle of view they give, and jamoul gave a good roundup on that.

Since you’re used to thinking about focal lengths for APS, I’ll give a slightly different take on it than jamoul:
If you mount the 50mm lens on the GH4, the angle of view will be similar to what you'd get with your current camera at 62.5mm, and if you mount it on the α7S II, expect an AoV similar to what you’d see with the Canon at 31.25mm. Round the numbers out, of course.
Same drill with the 10-22: on the GH4 it looks like 12.5mm–27.5mm, and on the Sony — 6.25mm–13.75mm, probably with a large portion of the image being completely black (only on the Sony).



dilby said:


> would the auto focus still work


Depends on the adapter. Metabones Smart Adapters retain autofocus, and I think most Metabones Speed Boosters do as well. It won't be nearly as quick as it is on the Canon DSLR, though, as the lens is optimized for an autofocus system that isn’t present in those cameras. With your lenses, it would be like shooting in Live View, perhaps even slower.



dilby said:


> would i need a speedbooster?


The Metabones Speed Booster adapters are what’s called a “focal reducer.” It takes the light coming through the lens, and centers it onto the smaller sensor to reduce the focal length. Because the focal length is changed but the aperture diameter stays the same, the maximum aperture increases accordingly.
That only works for an adapted lens that’s made for a bigger sensor. It definitely won’t work on the Sony camera. On the Panasonic, it should work with the 50mm lens, but I’m not sure the Metabones Speed Booster adapter from Canon EF to Micro Four Thirds supports EF-S lenses, so I’m not sure it will work with the 10-22.


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## beagle100 (Oct 28, 2015)

dilby said:


> I have a canon 600d and am looking to upgrade soon, probably to a gh4 or a7sii.
> 
> My question is how would my lenses translate to either camera in terms of fical length, would the auto focus still work and would i need a speedbooster? I've tried reading about it but im confused!
> 
> ...



the focal length stays the same and the "auto focus" works, ... speed booster?

50mm 1.8 on the Canon M


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