Canon T6s Flash

Coverage and Range
Good flash range, though with narrow and uneven coverage. Average positive exposure compensation required.

Coverage. Canon rates the EOS T6s' internal flash coverage at approximately 17mm, 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. Coverage is also little uneven vertically, with a couple of dimmer horizontal bands. We doubt you'd notice this in most read-world flash shots, though.

Exposure. Indoors, under incandescent background lighting, the Canon T6s' flash performed very well, requiring the typical +0.7 EV positive exposure compensation needed for this test scene with a shutter speed of 1/60s. The camera's slow-sync flash mode didn't require exposure compensation for a good exposure, though the slightly longer exposure (1/40s) resulted in a warmer orange/yellow cast from the ambient background lighting.

Manufacturer Specified Flash Test. The Canon T6s' built in flash has a rated Guide Number of 12 meters or 39.4 feet at ISO 100. That works out to a distance of about 7.0 feet at f/5.6. In the shot above at those settings, we can see that the Canon T6s' built-in flash performed to specification, producing a well-exposed flash target at the rated distance.