If you've early-adopted to Canon's new STM motors, then you've probably been wishing there were a few more lenses available that you could make use of. Canon is releasing new STM lenses at a steady pace, and today announced the 55-250mm f/4-5.6 IS STM, expanding the lineup of STM lenses to six total models. The new 70D will have STM compatibility, so this is certainly an area to keep an eye on.
The EF-S 55-250mm f/4-5.6 IS STM telephoto zoom lens offers high magnification in a compact and lightweight EF-S telephoto zoom lens with an Optical Image Stabilizer for up to 3.5 equivalent stops for shake correction. The lens' stepping motor and newly-designed focus mechanism support Canon EOS Movie Servo AF (available on select EOS cameras) to provide smooth and quiet continuous autofocusing during video shooting, as well as when shooting photos.
The EF-S 55-250mm f/4-5.6 IS STM telephoto zoom lens features one UD lens element, reducing chromatic aberration throughout the zoom range for excellent image quality with high resolution and contrast. It features enhanced lens coatings to help ensure superb color balance while minimizing ghosting and flare and a 7-blade circular aperture creates beautiful, soft backgrounds. For outstanding performance, a new compact six-group zoom system provides a maximum magnification of 0.29x at the telephoto end. Full-time manual focus is available in AF mode. The front element does not rotate during focus, which is beneficial when using polarizing filters. Minimum focusing distance is 2.79 ft./0.85m. The lens' rear focusing system, high-speed CPU and improved AF algorithm allow for high-speed autofocusing.
The EF-S 55-250mm f/4-5.6 IS STM telephoto zoom lens is scheduled to be available in late September for $349.99.
Interesting we haven't seen this STM motor introduced into L series or consumer level glass. It seems to be reserved for entry level only, with maybe an exception of the 40mm 2.8
What's the difference between STM, USM and just a regular autofocus?
STM has the ability to automatically follow a focus point. So if you select a face during video, the lens will automatically focus to that face regardless of their movement. Sort of. I tried it with the 40mm pancake and it worked just ok.
STM is meant for video, that allows smooth focus transition, while USM is fast, but jitters when for video. STM is silence as well. At least thats how it is advertised..
I want to shoot motorsport (stills) would this be a good starting point or should I keep saving for the Canon EF 70-200 F2.8 L IS USM? Or is the 'L' worth waiting for?...
For motorsports, save for 70-200. This is way too dark, way too unsharp and probably not fast enough to focus. The L is worth of waiting for and you don't need to upgrade it for a while...maybe never unless you break it :)
Thanks...