CanonEF-S 18-135mm f/3.5-5.6 is STM

I finally received my copy of the 18-135 STM lens. I went back and forth for a while deciding between this lens, the 15-85 and the 24-105. I eventually opted for this lens for three reasons. First, the lens is the newest available and I assumed Canon fixed the shortcomings of the previous 18-135 optically (along with the new stepping motor). Second, I really didn't need the extra 3mm on the wide end but I truly did need the extra 50mm on the tele end. Third, as a general walk-around lens, the weight was about 20% less than the 15-85 and about 30% less than the 24-105 which really does make a difference around your neck.Onto my experience(s). From what little I could read from the sparse reviews out there, this lens was suppose to be very close optically to the 15-85 (since I don't have a copy of the 15-85, I have to rely on MTF charts). There is some barrel distortion at 18mm, appox. the same as the 15-85 at 15mm, but it goes away very quickly on my copy between the 18-24 range. One thing I do like about this lens is there's plenty of space between the 18 and 24, it's not crammed together like other lenses on the wide end. The lens is a 3.5-5.6 aperture. In its progression you'll hit 4.0 in the 25-35mm range, 4.5 40-50mm range, 5.0 in the 55-80mm range and 5.6 from 85-135. On the 60D, be sure to load the peripheral illumination correction and chromatic aberration profile from Canon to eliminate any fall-off.Physically, this lens is bigger than I thought it would be (I don't know why I was expecting anything different really). It's about a 1/4 of an inch shorter than the previous 18-135 and about a 1/2 inch longer than the 15-85. Weight is about 1 oz more than the previous 18-135 and about 3 1/2 oz less than the 15-85. Diameter is roughly the same for all these lenses. The overall feel of this lens is superb. You really feel like it has enough heft to not be considered a plastic piece of junk but not so much that it creates a "boat anchor" feeling around your neck. The zoom ring is very nice and smooth along with the electronic manual focus ring. Both feel extremely upscale with the ribbing and ease of use. About the manual focus ring, you can over-ride AF anytime by half-pressing the shutter and rotating the MF ring (negating the need to flip the switch to MF each time you want to focus yourself).Performance (in my opinion) is stellar. The lens is EXTREMELY quiet while focusing and zooming (I would say audibly non-existent). Fluid is the best way to describe it. Everything flows in a way that makes you appreciate what the lens is doing, it's really a very refined, artistic, sensory appealing and tactile accomplishment (again, in my opinion). Zooming is fast. Focus is fast and spot-on. This lens focuses almost instantaneously. One thing that surprised me was the bokeh of this lens. I was expecting a kit lens 18-55 type of bokeh but I have to say this lens is VERY good (when I say VERY, I mean VERY close to prime). I am truly impressed! This lens is extremely sharp in the center, I have found it is sharp throughout the focal range and exceedingly sharp in the 35-85mm range. The lens profile will correct for any fall-off you might get in the corners. I have not found any color fringes yet although I haven't "pixel-peeped" a lot of the close-ups and I haven't had it for that long to begin with. Color balance is VERY good. I truly enjoy the warm/vivid colors this lens captures.In closing, this lens has exceeded my expectations in every way. I think this lens is a bargain in the $400-$500 price range (although the MSRP is $549.00). With the optics, build quality, and performance I believe it is probably the best value for a lens with it's focus range. Obviously prime lenses and L glass are going to trump this lens but for the price/performance/ergonomic ratios, good luck. Canon really has produced a winner here. Feel free to comment or ask if you have any specific questions about the lens...

I got the EF-S 18-135mm STM to use with my EOS M. It really is an awesome lens -- super quiet AF, great focal length range, good size and weight, and superb quality even compared to my heavier/more expensive "L" glass. It's got good contrast and color, and I haven't run into any distortion, fringing, or vignette issues that couldn't be fixed via Camera Raw.One thing I've been having trouble finding online is information on performance of various lenses when coupled with the EOS M. For that reason, I'll say that this lens performs just as well as the 22mm f/2 kit lens. That is to say the AF is still slow, but no slower than what you're used to. The picture quality is on par as well, except you of course sacrifice between 1 2/3 to 3 f-stops for the increased zoom range. Maybe I just got lucky with a good copy, but I've been able to achieve tack sharp images wide open above 35mm, and reasonably sharp images from 18mm.As others have mentioned, this lens is awesome for video. I tend to not use the continuous auto-focus feature very often, mainly because the EOS M AF isn't very speedy. But the IS, zoom range, sharpness, and color reproduction of this lens lead to some great video. I mount the EOS M with this lens in my car when driving on the freeway, and you wouldn't know how bumpy the ride was by watching.

The short version: If you plan on shooting any video with the Rebel T4i, this is the lens you want to buy first.The long version: While the new video autofocus feature on the Rebel T4i will work with any Canon autofocus lens, the 18-135mm STM focuses quickly and silently, unlike the 18-55mm lens in the other kit. The 18-55 has a noisy, slow focus motor that constantly 'hunts' for focus while taking video, and the whirring of the non-STM motor is easily picked up by the built-in microphones. It doesn't sound so bad in the field, but once you playback your video clips, it's magnified a great deal, making the audio nearly useless for any serious work. But even with recording Audio separately, the constant focus blur makes the video completely useless anyway, so you may ask yourself why the T4i has any video capability at all.Enter the 18-135mm STM. Not only is the STM motor virtually silent, it's fast enough to keep focus while you shoot (well, depending on the speed of the target, of course. No lens can work miracles.) This is the lens all those gorgeous sample videos on the Canon website were taken with, and with good reason.Now, there are certainly better Canon lenses for still photography--this isn't even an "L" series lens--but for video work on the T4i, it's hard to beat. It is also both quicker to focus and quieter than the other STM lens currently on the market, the 40mm STM pancake. (I can barely hear the 40mm focus, but the 18-135mm really is next to silent.)My recommendation for anyone looking to purchase the Rebel T4i/650D is to insist on the 18-135mm kit and forget the 18-55mm kit. I wish I had. Not that the 18-55 is a horrible lens--it's a decent starter kit lens for still shots. But at the time of this writing, the 18-135mm STM lens is nearly impossible to find by itself--and it lists on the Canon site for $549 when they do have it in stock. So you can either pay the $250 premium for the 18-135 kit over the 18-55 kit, or pay $550 later when you realize the 18-55 won't "do for now" until you can afford the 18-135 STM lens, if you want to take advantage of the video autofocus of the T4i. I suggest the 18-135 kit, plus another $199 for the 40mm STM pancake. That will give you a good solid pair of lenses to get started with, while you save up for an L-series telephoto.