Canon EOS 650D/Rebel T4i In-Depth Review

Preview based on a production Canon EOS 650D with firmware 1.0.1

The Canon EOD 650D / Rebel T4i is the company's latest addition to its novice-oriented 'Rebel' series. With more than two decades of continuous success in its film and digital incarnations, these little SLRs have been improved and refined to the point that Canon's biggest challenge is finding new ways to distinguish its updated models. Place the new EOS 650D / Rebel T4i alongside its predecessor, the EOS 600D / Rebel T3i, and the similarity in design and specifications may suggest nothing more than a nominal upgrade.
Indeed the headline specifications - 18MP CMOS sensor, 9-point AF sensor, 3:2 flip-out 1.04m dot screen are all familiar from the 600D. Look a bit closer, however, and each of these has been significantly improved, with an eye both to more seasoned users who demand SLR performance and compact camera upgraders who want a familiar feeling interface. The 650D also gains significance because it forms the basis of the Canon EOS M, the company's long-awaited entry into the mirrorless interchangeable lens market.
It is largely because of the rise of large sensor mirrorless models that in today's market an entry-level DSLR must offer more than just high image quality to entice compact camera upgraders. In the age of YouTube, quick and easy access to video recording capability is a must. And for users that are far more familiar with composing via an LCD screen than a viewfinder, live view performance is of no small concern. Of course the camera must still offer users a path to a more traditional DSLR-like experience, without which, they would be hard pressed to resist the temptation of a physically smaller 'mirrorless' camera.
The EOS 650D is Canon's attempt to meet these challenges head on, with new features aimed at improving its live view and video performance. It becomes Canon's first DSLR to offer continuous AF tracking while recording movies.
This is made possible by Canon's new 'Hybrid CMOS' sensor that now includes pixels dedicated to phase detection autofocus. The Hybrid AF system uses these to quickly set the lens to roughly the correct distance, then uses contrast detection AF to fine-tune focus. In theory, this should provide faster and more certain focusing for live view and video shooting compared to previous Canon models which rely on CDAF alone. You can read a more detailed explanation of this technology and see it in action on the AF performance page of this review.
The EOS 650D also becomes the first SLR from any manufacturer to feature a touchscreen. This is of the capacitive (contact sensitive) rather than resistive (pressure sensitive) type, behaving like that of a typical smartphone. In Live View and Movie modes the screen can be used to specify the point of focus and (optionally) release the shutter. It also supports iPhone-like multi-touch and gestures. The rear screen has been redesigned with no air gap between the display and cover glass in an attempt to reduce reflections and improve visibility in bright light. There's also an anti-smudge coating which aims to reduce the impact of its newfound touch-sensitivity.

Canon EOS 650D / Rebel T4i key features

• 18MP APS-C 'Hybrid CMOS' sensor
• Phase detection AF from imaging sensor for Live View and Video
• Continuous autofocus in movie mode with subject tracking
• 14-bit DIGIC 5 processor
• ISO 100-12800 standard, 25600 expanded
• 5 fps continuous shooting
• 9 point AF system, all sensors cross type, central sensor F2.8 (from 60D)
• 63 zone iFCL metering
• 1080p30 video recording with built-in stereo mics
• 1.04m dot 3:2 touch-sensitive vari-angle ClearView II LCD (capacitive type, multi-touch support)

Additional improvements

The EOS 650D uses Canon's DIGIC 5 processor (as seen in the S100 and G1 X compacts), which helps enable a boost in the sensitivity range to ISO 12,800 (25,600 extended), and allows lens-specific corrections for chromatic aberration and vignetting in the camera's JPEG processing. The 'conventional' autofocus system for eye-level shooting is borrowed from the EOS 60D, and uses nine focus points which are now all cross-type, with the center point offering additional accuracy with fast lenses.
The camera also gains a built-in stereo microphone to provide sound for video, while retaining its predecessor's external microphone input. There are a couple of new scene modes, 'HDR Backlight' and 'Handheld Night Scene', both of which combine multiple exposures to give a final processed image. A four-exposure 'Multi Shot Noise Reduction' setting is also available in the PASM modes.
As is Canon's way, the EOS 650D doesn't directly replace the EOS 600D in the overall lineup. Instead the older model will remain in the line and effectively drop down a notch to the position currently occupied by the EOS 550D / Rebel T2i, which will be discontinued.

'STM' lenses: EF-S 18-135mm f/3.5-5.6 IS and EF 40mm f/2.8 pancake

Canon EOS 650D with EF 40mm f/2.8 STM (mounted) and EF-S 18-135mm f/3.5-5.6 IS STM

Alongside the EOS 650D, Canon has introduced the 18-135mm f/3.5-5.6 IS STM zoom and EF 40mm f/2.8 STM pancake lens. These two optics both use linear stepper motors for autofocus, hence their 'STM' designation. This type of motor is commonly used in lenses for mirrorless cameras as it offers the potential for fast, silent focusing during video recording, and is especially well-suited to working with contrast detection AF. However, this marks the first time this particular technology has been used in a conventional SLR system. Both lenses feature 'focus-by-wire' manual focus - as opposed to mechanically-coupled focus rings - and allow for full-time manual focus when the lens is set to AF mode, although only while the shutter button is held in the 'half-press' position.
The 18-135mm f/3.5-5.6 IS STM is an EF-S lens for APS-C cameras that also features 'Dynamic IS' image stabilization, designed to compensate for the different patterns of camera movement encountered when shooting video (for example when walking with the camera). It is one of the EOS 650D's 'kit' lenses, along with the cheaper EF-S 18-55mm f3.5-5.6 IS II. It's a little smaller than Canon's existing EF-S 18-135mm f/3.5-5.6 IS lens, and adds a helpful switch to lock the zoom at 18mm and prevent it from extending under its own weight when you're carrying it around. It's close-focus distance is also reduced to a pretty reasonable 39cm. Most significantly - for video shooters at least - this is the only kit lens option that is actually silent while focusing.
The EF 40mm f/2.8 STM pancake, meanwhile, becomes comfortably the smallest lens Canon makes, at about half the thickness of the EF 50mm f/1.8 II. It will also be sold as a kit with the EOS 650D in some regions (where it offers a slightly unconventional 64mm equivalent field of view), but Canon says it's aimed at least as much at EOS 5D Mark III owners. Indeed we can see it becoming a firm favorite with full-frame users, for whom it will offer a slightly wider than normal angle of view. One thing we dislike about its operation is that you can't retract the lens from an extended position without putting it on a powered-up camera, and the lens doesn't retract when the camera is turned off.


Source:www.dpreview.com

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