July 10, 2015 at 6:18PM, Edited July 10, 6:20PM


Which Metabones Adapter for EF lenses?

I might be quite late but not too late to make the switch from Canon to GH4 and dont want to part away from my existing EF and EF-S mount lens adapters.

Visited the Metabones website and saw quite a few EF to MFT lenses and to be honest I am totally lost.

Most of my lenses are vintage that I got it converted to EF mount (too scared of the mishaps related to the adapters) so it means 90% lenses are manual without any electronics and very few are recent purchases.

The biggest temptation regarding metabones is the one or two extra stop of light gain which is a huge plus for video but seriously too confuse.

So kindly let me know which metabones EF to MFT adapter is better and why?



May I ask which Canon camera you are switching from?

Metabones has dumb adapters and speedboosters, the latter is what will give you an extra stop of light. For the GH4, you basically have three options:

Canon EF Lens to Micro Four Thirds Speed Booster S

This one will decrease the crop factor of the GH4 by 0.71x. When shooting true cinema 4K, this will give you a crop factor virtually identical to the crop factor of APS-C lenses. For example, a 50mm lens (full frame) will become an 83mm (full frame equivalent), as opposed to 117mm without the speedbooster. It will also give you one extra stop of light, as you said, thus turning your f/1.4 lens into an f/1.0 lens.

Canon EF Lens to Micro Four Thirds T Speed Booster XL 0.64

This one is my personal favourite for the GH4. This reduces the crop factor even more than the one above (0.64x) to give you a wider field of view, which is closer to Super35 (commonly used in cinema) than APS-C; your 50mm lens will now be a 75mm (as opposed to 83mm with the other speedbooster). Furthermore, it will increase light transmission by 1.3 stops; your f/1.4 lens will now become a f/0.9 lens (as opposed to f/1.0 with the other speedbooster). Furthermore, the Metabones website says this adapter (unlike the first one) was "designed exclusively for the Panasonic GH4 and other selected Micro Four Thirds cameras" (http://www.metabones.com/products/details/MB_SPEF-m43-BT3).

and the yet to be released Metabones Speed Booster Ultra 0.71x

This one is the same as the first one except it is designed specifically for the GH4 with 4K recording in mind. I am not sure what other differences there are, and I don't know much about it because it is yet to be released. Perhaps it will be the best, but personally I much prefer the .64x crop factor and the 1.3 stop increase of the XL.

All comparisons of crop factor are specifically when using Cinema 4K on the GH4, the numbers are different using 1080p. I hope that helps!

July 13, 2015 at 8:57AM, Edited July 13, 9:01AM


Alex Rollinson first of all thank you so very very very much for such an informative reply, honestly buddy you have opened my mind and your reply is very helpful, thanks.

To be honest I have used Crop sensor camera of Canon called T4i / 650D for roughly 18 to 24 months so you can imagine that I am not so expert on such things.

From the start I was very focused on buying vintage lenses both prime and zoom (got more primes which are converted to EF mount) because the Canon Red Ring L lenses were too expensive for me to buy.

The most expensive new lens that I bought is Sigma 18 35 1.8 and after that Minolta Rokkor MD 50 1.2, both in EF mount, last one was converted to EF mount.

T4i/650D is good beginner level cam and if you are really into such stuff then it will take few months to grow out of it and some how GH4 suits my needs or better to say the over hyped 4K is too tempting for me which GH4 offers :)

S M Sabir

July 14, 2015 at 4:46PM

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