Hi all! I'm a totally newbie in the awesome world, and recently punched a Canon M50 with a EF-adapter and 50mm 1.4 lens. Now have just been giftet an old Takumar-f zoom 70-200mm lens by a relative, and was wondering: Is there any way I can use this on my M50? I'm thinking a similar adapter as the one I'm using for my EF-lens, but just compatible with the Takumar mount (whatever it's called)? Or is it simply just impossible to combine different branded lenses? Thanks in regards!
Welcome to the forum J, If you can get a adapter it is possible. Put your camera in either Manual or aperture priority and you will be good to go. The only drawback is the fine focus and the way around this is to put your camera in live view, press the + button to magnify the image to achieve fine focus, other than that all will be sweet.
If it is an M42 screw mount then this is the adapter, i use quite a few M42 and other vintage lenses on the M50, my stand out ones so far are the 55mm takuma ƒ1.8 and the pentacon 50mm ƒ1.8, i also have lome of the longer takumas too all my vintage ones are primes though there are quite alot of vintage lenses that can be used with mirrorless cameras, ebay is a good place to get the adapters
There are two types of Pentax mount, as Caladina mentioned the m42 or screw mount. There is also the K Mount which is widely used on pentax cameras from the late 60's forward, you will want to look for a K mount or m42 mount depending on your Pentax lenses. The adapter needs to go to EF-M Leica has an M mount as well so be careful with searching for Pentax to Ef-M mounts. Your camera will not be able to talk to the lens, so you will be focusing and selecting the aperture and all manually.
A Pentax F (70-200) lens has a Pentax K bayonet mount so you can either buy a Pentax K to Canon M adaptor or get a Pentax K to Canon EF adaptor which will fit onto your original Canon EF to M adaptor. The second option will probably be cheaper. A description and reviews of your lens can be found here: https://www.pentaxforums.com/lensreviews/Other-Pentax-Zoom-Lenses-c47.html