GIZMOS & GADGETS
Some random (but important) things that also have a place in our kit.
The world's most advanced light meter. We upgraded from the L-478DR-U to the new L-858 for one main reason: HSS/Hypersync metering. Many of our main lights are HSS or HyperSync capable, an additional bonus is flash duration analysis, and a built-in reflective/spot meter (which was an additional attachement for the L358 and L478 we had before). This one doesn't come with a built-in trigger, but transmitter modules are available for PocketWizard, Elinchrom, and Phottix.
While light meters aren't as popular as they used to be, it's an important part of a strobist's kit in order to create precise, repeatable results or lighting ratios, as chimping can be deceptive at times (so learn how to read your histograms!). We like the Sekonic L-478DR-U for its extensive feature set, large color touch screen, simple controls and built-in PocketWizard radio triggering. They also offer versions with built-in Elinchrom Skyport and Phottix Strato triggering.
Canon WFT-E8A Wireless File Transmitter
Aside from its outrageous price, The WFT-E8A is a nice bit of kit to have on location. It allows us to shoot wirelessly to a tablet, smartphone or laptop and shoot "tethered" without being restricted by cable length and keeps things safe on location. For "everyday" shooting, the camera can be controlled via the Canon Camera Connect app, and files can be transferred. File transfers are surprisingly quick and live view is very responsive.
Tether Tools USB 3.0 Cables
Pricey, yes -- some may even say overpriced -- but their eye-catching orange color is more than just aesthetics -- the high visibility makes sure people are aware of it on set. We're partial to the Right-Angled cables that don't stick out as much when connected to the camera.
Tether Tools TetherBoost Pro
The TetherBoost Pro allows us to have longer cable runs for tethered shooting without degrading the USB cable's signal or having annoying frequent connection drops with longer runs. The TetherBoost Pro is an improvement over their previous solution which required bulky battery packs and hubs.
Peak Design Slide SL-2
While there's no shortage of different camera straps available, we've really fallen in love with the design and ease-of-use of Peak Design's products. We like the Slide camera strap in particular because of its width (best suited to larger DSLRs), and flexibility in configuration. The latch-system they use of length adjustment is extremely fast and effortless. The kicker is their use of "anchors" to attach your camera to the strap, making removing your camera from the strap entirely quick and easy. We also recommend their "Leash" and "Slide Lite" straps for smaller DSLRs or mirrorless setups.