Nikon D7100 Flash

Coverage and Range
Decent flash range but narrow coverage at wide angle. Our standard shots required an average amount of exposure compensation.

Coverage and Exposure. Flash coverage was rather uneven at wide angle (18mm), with very dark corners. Coverage at telephoto (105mm) was much better, but still somewhat uneven. (Some of the corner shading is due to the lens itself, though.) There was also a slight magenta tint near the center of the image. For our Indoor Portrait scene test, the Nikon D7100's flash required +0.7 EV exposure compensation adjustment to get bright results in normal Auto flash mode with a 1/60 second shutter speed at ISO 200, which is about average for the DSLRs we've tested. The camera's Slow-Sync flash mode at 1/13 second produced bright results without any compensation, though with a stronger pinkish-orange cast from the room lighting.

ISO 200 Range. With the kit lens at wide angle, the Nikon D7100's flash exposures started out bright at 6 feet, and brightness remained good out to 12 feet before dropping off rapidly. At the telephoto end, flash intensity started out a bit dim at 6 feet but remained consistent to 8 feet, then dropped off from there. We'll call the range 8 feet at full telephoto.

Manufacturer Specified Flash Test. The Nikon D7100's flash guide number is 12 meters in Auto iTTL mode at ISO 100. At ISO 200, that translates to about 15.8 feet at f/3.5 and about 9.8 feet at f/5.6, the maximum apertures of the kit lens at full wide angle and telephoto respectively. In the shots above, the D7100 appears to underperform by a small amount relative to Nikon's specification, producing slightly dim exposures at the rated distances. The flash target was underexposed compared to the ideal exposure by almost a full stop at wide angle, and almost 1/2 f-stop at telephoto. Our standard test method for flash range uses a fixed setting of ISO 200, to provide a fair basis of comparison between cameras. We've now also begun shooting two shots using the manufacturer-specified camera settings, at the range the company claims for the camera, to assess the validity of the specific claims.