The Canon 75-300mm USM Mark 3 lens is a pretty long reaching telephoto lens and when attached to a cropped sensor camera it is a stonking great reach. The equivelent of 450mm+
Now that is a lot of reach and for a lens that is super cheap as well.
but it is missing a few things
details after the break
This lens suffers a lot from the plague of cheap lenses and that is Chromatic Aberration. you will hear that word being used a lot in the lens reviews and a many people may think nothing of it but when you get it as bad as what this lens has it at then you really see the worth and value of buying more expensive glass. However if you are a beginner and don't want to bankrupt yourself and you are shooting in sunny locations then this lens is ok value.
The second thing to note is that this is an EF lens meaning that it will also work on full frame of any of the canon film cameras, which could be handy in the future. This lens is also a good 3 time cheaper than the more superior and IS version of the lens.
The issue apart from the chromatic aberration is its sharpness. its just not that sharp. also when you are fully zoomed out to 300mm you need a shutter-speed of at least 1/500th of a second to avoid the camera shake affecting the image too much. but even when shooting at super high shutter-speeds its not giving me images that are that sharp.
Additionally the focus is pretty slow and worst of all when i focus the barrel extends further and ROTATES.
Now again many people may not see that as a problem but if you holding your lens at the end, or have it resting on a rock, or as in my case the end of my car and you focus the lens it then suddenly slips off as it rotates and extends, this is not a good idea. It also means using circular polarisers (to give more saturation to the sky etc) will spaz up as you focus.
Sounds like this guy agrees
My advise is if you truly need a mega zoom lens then go for the more expensive lens with the Image stabilising