Canon introduced the EF mount in 1987. Since then there have been a series of non-L, enthusiast-grade mid range telephoto zooms in the catalogue.
At various times Canon has offered versions of 75-300, 90-300 and 100-300mm optics each clearly aimed at the same user demographic.
The EF70-300mm f4-5.6 IS USM was released in 2005 to a favourable reception ensuring its popularity. This is a full frame lens designed to cover a 24x36mm sensor but it can also be mounted directly onto Canon EF crop sensor DSLRs..
I used one of these for several years on a succession of EOS crop sensor DSLRs with decent results, marred only by the unreliable autofocus of Canon’s DSLRs at the time, which caused me to abandon Canon ILCs for 10 years.
Now Canon’s mirrorless RF and recent EF-M cameras use on-sensor dual pixel AF which is very accurate and reliable.
A Mk 2 version of the EF 70-300mm was released in 2016 (together with the EF-M 18-150mm by the way) with Nano USM, improved IS, a UD lens element, new styling and an information display showing in sequence focus distance/focal length/shake amount.
Canon offers an EF-M to EF adapter with the promise that EF lenses will focus just fine on EOS-M camera bodies.
As it happens the longest native EF-M lens is the 55-200mm which is equivalent to 88-320mm in full frame equivalents.
This lens
a) gets some bad reviews and some good reviews so maybe sample variation is an issue as is the case with some other EF-M zooms
b) does not deliver much reach for bird/sport/wildlife photography
In the early days of the EOS-M system the bodies were really just compacts with interchangeable lenses which few users would have considered for telephoto work.
But now we have the EOS-M6.2 which has a super AF system and runs like a rocket.
I refuse to buy the M6.2 because it does not have a built in EVF, does not have a fully articulating monitor and does not offer electronic first curtain shutter so I still have the M50.
So I bought an EF 70-300mm and an adapter and tried the combination out on the M50.
It works !
In fact it works surprisingly well and performs better than my old EF 70-300 ever did on one of the crop sensor DSLRs.
Description
By EF-M standards the EF 70-300 with the adapter attached is a big thing and looks a bit out of place on the diminutive M50 body.
A detachable tripod mount can be fitted to the adapter and should be used for tripod work.
Length with adapter, 67mm filter and front and rear caps is 198mm. Total length when zoomed out is 267mm.
Diameter 80mm
Mass with adapter and tripod mount 937 grams.
On the barrel are a zoom lock switch, mode toggle button for the display, AF/MF switch and Stabiliser ON/OFF switch.
There is a large zoom ring and a smaller focus ring near the front of the barrel. The zoom action is very smooth.
No lens hood is supplied although aftermarket ones are readily available.
Operation
The lens works well on the M50 with no problems that I have noticed.
In particular both single and servo AF work quickly and accurately
I ran several tests photographing moving subjects with a very high percentage of sharply in focus frames even in high speed continuous drive mode which gave me about 5 fps.
The native EF-M 18-150mm runs a bit faster at around 6 fps.
The stabiliser works well.
Sharpness/resolution
I can read every word in my standard test target at every focal length and aperture to f11. Not many lenses can better this.
Contrast at the short end is a bit low but that is easily rectified in post processing.
The lens is sharp at close range and at distance.
Overall this is an excellent performance with evenly high resolution.
Distortion, color fringing and peripheral shading
A mild amount of each of these can be seen in some conditions but each is easily rectified in post processing if required.
Flare can be induced if one sets out to do so deliberately but is rarely an issue in practice.
I use the lens without a hood.
Downsides
The only one I can identify is the size and mass, which are much greater than any native EF-M lens.
This is not really a problem in use as one’s left hand takes the weight of the lens anyway, but is definitely a consideration when looking for a suitable carry bag.
Summary
The EOS-M user looking for a tele zoom with a decent reach has to turn to the EF catalogue. I Chose the 70-300mm as it has a good reputation, is modestly priced and is not impossibly big.
The lens works well on the M50 and delivers consistently very good results.
Recommended.