Olympus's waterproof cameras have a long history of high rankings--and for good reason. It's not unheard of for even a professional to pick up the top camera in this line-up so they don't have to damaging risk their pricier gear for an off-duty trip to the beach. The TG-4 has everything we loved about the TG-3, but adds RAW--that's great news for anyone who likes to edit their shots.
The TG-4 (and TG-3) gets a high ranking over other similar cameras for one big reason--it has a bright f/2 lens, while still offering respectable features all around. Lighting is much more limited when heading underwater, so that bright lens is a big deal for this category. The Ricoh WG-5 also has a bright lens--but offers a disappointing burst mode where the TG-4 at least hits average at 5 fps.
The TG-4 also has an excellent crushproof rating (220 lbf), where many other manufacturers don't even specify this trait. It's also still sporting the 50 foot depth rating and 7 foot drop rating of the older TG-3.
The TG-4 adds RAW files to allow for a greater range of possibility when editing shots. Most (if not all) cameras with RAW though have full manual modes--the TG-4 does not. It does offer aperture priority and programmed modes to offer some control over the settings, but the camera still doesn't include full manual mode. Since most consumers looking for RAW are also looking for manual modes, this is a bit disappointing.
While RAW is the biggest addition, there's also a few other minor tweaks over the TG-3. There's a new underwater HDR mode as well as a live composite mode which will combine multiple images (often used for night landscapes or shots in dark conditions). Oh, and there's two custom slots on the mode dial, so users can save their favorite settings and return to them quickly.
We're glad to see Olympus continue to make improvements on our favorite tough camera. While we'd like to see additional improvements in the future like the addition of manual mode, the TG-4 looks to be an excellent camera that can withstand some pretty tough conditions. If you don't edit your shots (and don't plan to in the future), watch for a price drop on the very similar TG-3.