Nikon D7100 vs Pentax K-3 II — Which Is Better?

The Nikon D7100 and the Pentax K-3 II are both DSLRs with optical pentaprism viewfinders, separated mainly by their lens mounts and feature sets. The D7100 arrived in 2013 on the Nikon F DX mount, while the K-3 II followed in 2015 on the Pentax KAF mount, so native lens choice is the first commitment each purchase locks in.

Both use APS-C CMOS sensors, so focal lengths frame the same way on either system. The D7100 measures 136 x 107 x 76 mm and weighs 765 g, while the K-3 II is smaller at 131 x 100 x 77 mm but heavier at 800 g.

The Pentax K-3 II is the stronger choice for handheld shooting with unstabilised lenses, because its sensor-shift stabilisation steadies the image with every lens you attach. The D7100 has no in-body stabilisation, so shake reduction depends entirely on the lens. The K-3 II also reaches a native ISO ceiling of 51200 against the D7100's 6400, giving more exposure headroom when light falls.

For action work the K-3 II wins on burst speed, 8.3 fps against the D7100's 6 fps, while the D7100's 51 autofocus points outnumber the K-3 II's 27 for tracking off-centre subjects. Resolution is nearly matched at 24.1 versus 24.35 megapixels, so both leave similar room to crop, and both offer a 1/8000 second top shutter speed.

The Pentax K-3 II is the better pick for slow motion, offering a maximum video frame rate of 60 fps, twice the D7100's 30 fps. Fast movement like a bird taking off can be slowed smoothly for playback. Both cameras cap at Full HD resolution, and both include a built-in intervalometer for timelapse work without an external trigger.

The K-3 II's built-in GPS suits landscape and travel photographers who want every frame geotagged automatically, a feature the D7100 lacks. The D7100 counters with a built-in flash for fill light when a speedlight is left behind, and Wi-Fi for moving images to a phone. The K-3 II offers neither.

Both bodies are weather sealed, and both carry a 3.2-inch LCD with live view and support for external flash. The D7100's screen resolves more detail, at 1,228,800 dots against 1,037,000, which helps when checking focus on the rear display.

The Nikon D7100 carries the higher rated battery life, at 950 shots against the K-3 II's 720. Both hold dual card slots that accept SD, SDHC and SDXC media, so neither forces a card-format choice. Neither charges over USB, so spare EN-EL15 or D-LI90 batteries are the practical backup, and the two battery types are not interchangeable.