@stephencock987 wrote:The following stage up from the EF-S 55-250mm f/4-5.6 IS II regarding central length is the EF 70-300mm f/4-5.6mm IS, yet that is just going to pick up you half more reach from your 55-200 and just 20% more reach than the 55-250. To my eye, the 70-300 is not really worth generally double the value you would pay for the 55-250. There isn't much distinction in picture quality between those two focal points, either. So you truly don't increase much by spending twice what you would for a 55-250 to purchase a 70-300. Anything longer than 300mm will require a significant venture contrasted with your present focal point.
Hi Stephen and welcome to the forum.
I have some issues with the logic of your post.
First: Since the OP has indicated that he has a EF-M 55-200 lens, I am not sure why you are referring to the 55-250, which is an EF-S lens and would require an adaptor - was that reference a typo? Compared to the 55-200 the 70-300 lens offers a 50% increase in magnifcation, on the AP-C body he has the OP could expect a Field of View equivalent to that of a 480mm lens on a FF body.
Second: the optics of the 70-300 MkII unit are excellent - it was intended for just this situation where a user wishes to upgrade from a tele kit lens to something of better quality and magnifcation. I have gone to some lengths to investigate that in my own experiments and posted on the link in my post. I have demonstrated that it is possible to get good results from significant crops using the lens, further enhancing its tele capabilities. The 70-300 has a higher quality build with metal mount, (while the 55-250 is plastic) which has significance if it is going to be attached to an adaptor. It has 4 stops of IS and the latest tech in the use of a nano motor, giving it top end focusing performance.
Third: the 70-300 is an EF lens, not an EF-S unit, so he is assured of compatibility if the OP upgrades to a FF unit at some stage, or decides to sell the unit.
Fourth: If, as you suggest, the 70-300 is not offering the OP enough magnification, and since the OP wants a zoom, then we are looking at something like the 100-400 L lens, which is expensive and massively heavy. It would totally unbalance the M-50!
DEPENDING on what the OP wants to use the images for - i.e. if it is just for electronic and social media, he could consider going with a superzoom bridge camera. It will give him massive reach for less than the cost of an adaptor and lens for his existing unit.
The Canon PowerShot SX60HS and 70HS have zoom ranges from 21 - 1365mm equivalent, but the down side is they have small sensors - hence my comment about output. Such a camera would cope well with the outputs I mentioned, but not so well with large, high-quality prints for example. The super-zoom bridge cameras are popular with bird photographers because of their reach, and what you lose in sensor size you offset with the ability to zoom right in. Both of the latest SX units can shoot RAW, so the images can be tweaked, they have all the controls of the M50, but the SX70 has lost the flash hot shoe, which I consider a mistake - the SX60 is still available and probably cheaper.
I have the SX60, and in decent light it does a great job in capturing images at a long distance. As an example of its capabilities, all of these shots were taken hand-held.
An image taken with the SX60HS, at 21mm
In the distance, observe the dome. This shot is taken at 86mm equivalent
This shot at 552mm equivalent
The next image captures the figure on top of the dome at 1365mm equivalent
The point is the OP should easily be able to zoom in on his subject from a considerable distance away.
The SX units even have a sports mode that will automatically try to get the fastest shutter speed within an ISO range defined by the user, and it can fire off at 10 frames per second.
It has a tolerable viewfinder and a back flip rear screen.
For specs see:
https://www.dpreview.com/products/canon/compacts/canon_sx60hs along with reviews of the unit.
