Canon EOS M Tech Info

Like most of the company's recent consumer and mid-range DSLRs, the Canon EOS M features at its heart an 17.9-megapixel, APS-C sized CMOS image sensor.

The EOS M's image sensor offers the same 3:2 aspect ratio and maximum image dimensions of 5,184 x 3,456 pixels as that seen in its sibling, the EOS Rebel T4i digital DSLR.

The 18 megapixel sensor is coupled with a DIGIC 5 image processor, a designation seen previously in the EOS-1D X and Rebel T4i. (Note that while the EOS-1Dx had twin DIGIC 5 processors plus a tertiary DIGIC 4 processor, the EOS M only includes one DIGIC 5 chip, as did the Rebel T4i.)

DIGIC 5 is, says Canon, five times faster than the preceding DIGIC 4.

The EOS M offers burst shooting at up to a rate of 4.3 frames per second. Note, though, that this speed is for One Shot AF, so focus is locked from the first frame. For continuous servo autofocus, the rate drops to 1.2 fps with the EF-M 22mm prime, or 1.7 fps with the EF-M 18-55mm zoom.

Burst depth is 17 large/fine JPEG, six raw, or three Raw+JPEG frames at ISO 100, using a high-speed UHS-I card.

Like almost all mirrorless camera manufacturers, Canon has had to introduce a brand-new lens mount for the EOS M.

The alternative would be, like Pentax's K-01, to discard the main advantage of a mirrorless camera by retaining a DSLR's bulk while throwing away the advantage of an optical finder.

The size advantage to be gained in removing the DSLR's mirror box is made clear in the two images above (shown approximately to scale.)

On the left is a cutaway of the Canon EOS M, showing the lens mount (dark green), contact unit (orange), shutter unit (light green), image sensor assembly with cover glass (light blue, red, and yellow), and LCD monitor (purple).

At right is a similar cutaway of the EOS Rebel T4i, one of the smaller cameras in Canon's digital SLR lineup.

As you can see, the Rebel T4i has to fit quite a lot more inside its body, and so is much thicker.

At top, you can see the viewfinder prism (dark blue), in front of five lens elements for the viewfinder and metering sensor. Below the prism is the focusing screen, while the metering sensor (purple) sits above the viewfinder.

In front of the shutter unit is the reflex mirror, and beneath is a secondary mirror that redirects light to the autofocus assembly (dark blue with purple sensor.)

Two lenses have been offered for the new Canon EF-M mount since launch: one prime which is included in a kit with the camera body, and one zoom that will be sold separately.

The Canon EF-M 22mm f/2 STM prime lens offers a 35mm-equivalent focal length of 35mm on the EF-M, while the optional EF-M 18-55mm f/3.5-5.6 IS STM zoom provides 35mm-equivalent focal lengths from approximately 29 to 88mm.

Thanks to STM autofocus motors, both lenses are said to provide smooth, silent autofocusing.

The zoom lens also includes Dynamic IS image stabilization, as seen previously in the EF-S mount 18-135mm STM lens. Ordinarily, the lens can offer a four stop correction, but will offer even greater stabilization capability--said to be enough for steady video when walking--via the Dynamic IS function.

Of course, an interchangeable-lens system with just two lenses would be limiting indeed, and so Canon is offering an optional mount adapter allowing use of EF and EF-S lenses on the Canon EOS M.

Lenses mounted on the adapter are fully supported; autofocus, exposure metering, and stabilization work as per normal. The tripod mount bracket is removable.

The adapter will allow use of around 70 current and historic lens models from Canon's EOS SLR series on its new mirrorless model, and is said to be capable of handling anything up to a 600mm lens.

Note though that older, non-STM glass is more likely to have intrusive noise and less-smooth focus, potentially making it less suitable for video capture.

Thankfully, the EOS M offers up a high-resolution three-inch, 3:2 aspect LCD panel with 720 x 480 pixel resolution (~1,040,000 dots), similar to those used in recent Rebel DSLRs.

As in the T4i, the EOS M's display is the current-generation Clear View II type, which removes the air gap between LCD and cover glass, reducing glare.

Unlike the T4i, the display is fixed in place, though, and not mounted on an articulated mechanism.

Like the T4i, the Canon EOS M's display is overlaid with a touch-sensitive overlay, allowing it to serve as a user interface element.

It's a multitouch-capable glass capacitive display like those found on most smartphones these days, and so can be used for intuitive functions like pinch zoom, swiping between photos in playback mode, and for touch autofocus.

Touch control is also functional for menu navigation.

Another area in which the Canon EOS M harkens back to early mirrorless models from some competitors is its lack of a built-in flash strobe. Instead, your sole option for flash is a top-mounted hot shoe, compatible with all Canon Speedlite accessories.

That includes not only the radio-controlled Speedlite 600EX strobe and Speedlite Transmitter ST-E3-RT that were announced alongside the EOS 5D Mark III DSLR...

...but also a brand-new compact, lightweight Speedlite 90EX strobe that's better-suited to the EOS M's body size.

The Speedlite 90EX has 24mm coverage, and a guide number of 9 meters (30 feet) at ISO 100.

Thanks to its small size, it's rather weaker than the built-in strobes on Rebel-series DSLRs; power comes from two AAA batteries.

Audio is recorded with a built-in stereo mic or via an external microphone jack.

As well as both wind filter and attenuator functions, there's also a 64-step manual audio level control.

As well as the aforementioned microphone jack, the EOS M also offers both Mini (Type C) HDMI high-definition and composite standard-definition video outputs. The latter port also doubles as a USB digital connection for data transfer. An infrared remote control is also supported.

The EOS M stores its data on Secure Digital cards. It's compatible with both the higher-capacity SDHC and SDXC card types, as well as the higher-speed UHS-I types.

Additionally, the EOS M is compatible with Canon's GP-E2 hotshoe-mounted GPS receiver accessory. This connects to the camera body via USB, and allows the automatic tagging of images with their capture location, altitude, and direction. It also corrects the camera's clock automatically.

Power comes courtesy of a new, proprietary LP-E12 Lithium-ion rechargeable battery pack. The battery is CIPA-rated for 230 shots per charge, or for 90 minutes of video capture, at 73°F / 23°C. That's pretty limited battery life for its class.

A dedicated LC-E12 battery charger is included in the bundle, and an optional ACK-E12 AC adapter kit is also available.