Turning the focus ring simply sends input to the computer electronics - and the electronics interpret and focus the lens.īut the lens has a few very positive things going for it: You can think of it as a "focus by wire" lens in that there is actually no mechanical linkage between the focus ring and the movement of the focusing elements inside the lens. STM is Canon's new "STepper Motor" technology. That EF-S 55-250 has been updated to an "STM" version. it's a mid-range lens which means it's more expensive than the entry-level zooms. The EF 70-300mm f/4-5.6 IS USM has a fairly good reputation. it's perhaps the least favorite lens in the lineup. The EF 75-300mm (and there are a few) does not have an impressive reputation. Mostly I found the contrast disappointing and the "sharpness" (detail resolving) was a bit soft & mushy. I owned this lens and actually gave my copy away to a nephew - I was never nuts about it. I'm going to assume you probably want a "telephoto zoom".Ī very common companion zoom lens in the consumer price range (priced to not break the bank) is the EF-S 55-250mm f/4-5.6 IS.
There are standard zooms (like the EF-S 18-55mm f/3.5-5.6 which likely came with your camera if you bought the camera as a body + lens kit) which provides a little room in the wide angle plus a bit of telephoto focal length.Īnd then there are the telephoto-zooms (which go from moderately enlarged telephoto image to a more strongly enlarged telephoto image.) There are "wide angle zooms" (like the EF-S 10-22mm f/3.5-4.5) which has a range from wide to very wide. "Zoom" simply means you can change the focal length within a range. Also keep in mind that if you want to test a lens, you can always rent the lenses you are considering before deciding which one to purchase.Īll lenses have trade-offs - which is why the camera allows you to swap lenses (you can swap to the lens which is best for your needs.) You might want to head over to and read some of the reviews.