Canon EOS M3 Flash

Coverage and Range
A weak flash with narrow coverage. Above average positive exposure compensation required.

Coverage. Canon rates the EOS EOS M3's internal flash coverage at approximately 18mm, though as you can see in the above shot taken at 18mm, we've found manufacturers' coverage ratings are usually quite optimistic. Peripheral Illumination Correction was on (by default) for this shots, so the fall-off seen here in the corners and vertical edges is mostly from the flash itself. We no longer test this at telephoto, as coverage is invariable better.

Exposure. Indoors, under incandescent background lighting, the Canon EOS M3's flash underexposed our standard flash test scene, even with +1.0 EV flash exposure compensation applied (and brightness didn't change from +0.7 EV). The camera's slow-sync flash mode required +1.0 EV exposure compensation for a good exposure, though the longer exposure (1/20s vs 1/60s) resulted in a strong reddish cast from the ambient background lighting.

Manufacturer Specified Flash Test. The Canon EOS M3's built in flash has a rated Guide Number of only 5 meters or 16.4 feet at ISO 100. That works out to a distance of about 4.7 feet at f/3.5, the maximum aperture of the kit lens at wide angle. In the shot above at those settings, we can see that the Canon EOS M3's built-in flash performed to specification, producing a well-exposed flash target at the rated distance.