Compatible off camera flash for the Nikon D7100?

I'm going to be purchasing some pocket wizards for my skateboarding photography. The off camera flashes I have been using are only lighting half the image. I don't want to spend a but load of money on a few Flashes. WHERE?!

Are you using a shutter speed faster than 1/250 second? That could explain half the image receiving no flash. Normally with the flash on the camera in TTL mode the camera knows there's a flash there and won't allow faster than x-sync shutter speeds. With some off camera connections that might not work.

Your Nikon D7100 supports CLS with the Nikon SB700, SB800, SB900 and SB910 flashes. Forget the pocket wizard and use the supported CLS flash units. Those flash units can be controlled from the camera using CLS (Creative Lighting System)

The flash sync on your D7100 is 1/250th second or 1/320th in the Auto FP mode

Ahh… The old high speed shutter problem.

Flashes are one thing you get what you pay for. The best flashes for the D7100 are going to be either the SB700 or SB910 - neither of which are cheap. You don't need pocket wizards for these flashes with the D7100 if you maintain a line-of-sight fro the camera to the flash as they have built-in IR communicators.

If you don't have line-of-sight, then of course you will need radio triggers; pocketwizards, Yongnuo, etc.

If you are only lighting half the image, then your shutter speed is too high. You can only use up to 1/320sec before this happens. The reason for this is that at high shutter speeds, the shutter begins to close (rear curtain) before it is fully open (front curtain) - so you never actually get a full opened shutter. At shutter speeds below 1/320, there's a short period of time when the shutter is fully open, and that is when the flash normally fires.

It is hard to explain, but there are several good YouTube videos that demonstrate this phenomenon a lot easier than can be explained.

However, with the Nikon SB-700/SB-910, there's a special mode callled FP Auto High Speed Sync, which allows you to use up to 1/4000th of a second shutter speed. Only the Nikon speedlights fully support this mode, so you have to buy one of the Nikon units.

FP Auto sync "stretches" the flash output over time by multiple bursts, which prevents shutter speeds higher than 1/320sec from "banding" the image, such as you are experiencing. Of course, this takes more flash power and more batteries, so if you are doing this heavy duty, you will probably want the SB910s.

Also, I'm not sure if any of the aftermarket flash triggers (pocketwizards, etc) will support FP Auto High Speed Sync or not - so you may have to use the Nikon IR controller (CLS) built into the D7100 and Nikon speedlights for this option to work off-camera. You may have to research this.

This is probably one time you are going to have to just buy Nikon gear vs. 3rd party. I have read that one of the Yongnuo flash units supports FP Auto High Speed Sync, but I can't recommend it as I have not used it (I have a Nikon SB-700 and SB-900, so that is where my experience is).