When Canon Announced the new Canon T4i (650D) they also announced two new lenses.
These new lenses are designed to silently auto focus with the new Canon T4i and ONLY the canon T4i. They will work just fine as regular lenses and they will auto focus quickly and quietly when you ask them to but they will not add continuous auto focus capabilities to your camera. Canon’s T4i is the only camera in canon’s line-up that is currently capable of continuous auto focus during video. Sorry if I am repeating myself, I have just seen a ton of confusion on the net. The STM stands for Stepping Motor. The T4i’s on board stereo microphone will not pickup the sound of these two lenses focusing, it will however pick up the sound of other lenses. The Nikon D3200 and D7000 have this same issue.
Should you buy these lenses if you don’t own the Canon T4i?
The 40mm f/2.8 looks to be a lovely lens – 40mm is a great focal length on a crop sensor, just a little wider than the nifty fifty and you have to love the thinness – certainly makes any DSLR you add it to a good bit smaller.
The 18-135 STM is a completely different lens than the older 18-135. It’s new optically as well as having a new auto focus system. It is a much better lens in all aspects.
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