As mentioned a little time ago and mainly for its video potential, I bought a Lumix G90/95 which is a micro four/thirds camera and totally unlike my other Canon kit. The main problem with the 4/3rds system is the crop factor which is x2 so that a 50mm becomes a 100mm focal length when used. Obviously this is of great benefit at the telephoto end of focal length but a big problem when it comes to wide angle photography which is the main use in video work.
Because of some good fortune, I was able to pick up a very wide angle 7-14mm which in 35mm terms is equal to a 14-28mm focal length at a good price second hand so I solved my wide angle issue. However and unexpectedly, I did find myself needing a decent zoom lens for certain wildlife situations and this hits the main problem with using M4/3 cameras which is the price of high quality glass whether wide angle or telephoto.
To be fair, just because the hardware is physically smaller, given the nature of optical designs, there should be no real reason to expect good quality lenses for M4/3 to be any cheaper than those for larger full frame bodies. But the reason that I walked away from M4/3rds back in 2017 was simply because I didn’t want to spend money on building up another expensive lens collection alongside my Canon L glass back then.
Things have changed for me in terms of the creative direction and reasons I bought back into M4/3 recently. However and today there still were shades of this when I contemplated buying a native good quality telephoto lens for this system. Why spend £400 or £1,000 second hand on a M4/3 lens when I have some high quality Canon glass that could be used via adaptation ?
Adapted Lenses

It is easy to adapt most lenses from one system to another via purely mechanical means and indeed it was this back in 2016/17 that led me to acquiring a collection of Canon FD glass from the 1970/80s to use on my original M4/3rds camera. These are purely mechanical, there being no electrical linkage to connect the settings of the lens and camera body. I did earlier this year pick up a ‘speedbooster ‘ connector for my Canon FD lenses to use on M4/3 and that was fine, still totally manual in terms of focusing and setting the aperture but it did brighten up those lenses and pulled some of the focal length back.
Then a few weeks back, I noticed that Viltrox also had an EF to M4/3 speedbooster except this included an electrical connection that promised to deliver autofocus plus aperture control which if it works and at around £130 would be a total steal compared with buying a native and good quality 4/3rds telephoto lens ! After all I really don’t want to acquire just another bit of kit for “occasional use” .
An Explanation

Just as with my Canon M series cameras which are physically small, whilst you can mount any 35mm lens to them, there are constraints and handling limits in practical terms. So as far as my G90/95 is concerned, there were only two of my Canon lenses I was interested in mounting, my f2.8 200mm prime and my f4 70-200mm zoom.
Because of the x2 crop factor, this would mean that the 200mm prime would be 400mm equivalent on the G90/95 and the zoom 140-400mm. On top of this I have x2 multipliers for my Canon lenses so that even 400mm could be boosted to 800mm. In fact the Viltrox speedbooster would reduce these focal lengths by a factor of 0.71 which means that the theoretical 400m would equal 281mm and 800mm would be 563mm but in return, I will get an extra stop of light which for wildlife can be very handy !
The Result

The Viltrox speedbooster turned up the other day and although I had initial struggles with it working the way I wanted, once I sat down and worked it out, I soon found that it worked perfectly with both my targetted Canon lenses and multipliers.
The Lumix G90/95 is nowhere near as fast as my Canon M6 MkII but that won’t matter too much for its intended use. The important thing is that using this adapter the Canon glass acts as if native, giving autofocus and full aperture and shutter control which is brilliant. The most flexible setup will be using the 70-200mm zoom rather than the 200mm prime but in both cases because they have tripod mounts which I can use as my main grip/pivot point so physical handling of the body lens combination works extremely well. What I call a bit of a result !