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Question: is this is the only piece that i would need to trigger my flash?. my camara is nikon d5100?
Document: (as long as you use on channels 1 to 16)Another drawback: I need a VERY expensive cable to trigger my Nikon D90. almost the same price tag ofVello Wireless ShutterBoss Timer Remote (Nikon DC-2 Connection)which is also a intervalometer too.
The two PocketWizards Plus III I received recently seemed to work well in all modes when syncing remote flash units using a D700 or D200 Nikon cameras as masters. However, when the time came to operate the D700 remotely, problems started. It is regretable that PW is not specific about the cables or the cost of the cables required to trigger the camera. After spending $139 each for the two units, I discovered I had to invest another $85-$95 for the correct cable.
II had gone the cheap way many times before and using different triggers for my flash (Nikon SB-910 and strobes)  but something always went wrong. I am mostly shoot on location, weddings, engagements, fashion shoots, outside portraits...I shoot Nikon so a while back I decided to cough up about $300.
Several people have asked and you should know that you will need TWO of these. One for the camera and one for the flash.
1)  You can remote trigger a camera with two of these. You will need the appropriate cable to connect the one on the hotshoe to the camera.2)  You can remote trigger a camera and fire flashes at the same time. Use a channel above channel 21, set the ones on the flashes one channel higher than the ones on the &#34;trigger&#34; and camera.Awesome tool. These are probably the most essential part of my lighting, and they work flawlessly.
The PW III has set a very high bar for off-camera manual flash photography. Nothing out there beats it for reliability and ease of use. I own four of them (you need two to make them work) and I also have a PW X (cheaper, fewer features) that I keep as a back-up. The battery life is great and, if one goes flat, they use AAs so they are easy to replace.
I plan to buy many more of these. I would recommend to anyone not needing a TTL-based flash triggering system. You will pay more for a similar PocketWizard product featuring TTL. I generally shoot manual with flash and camera, and generally do not use the TTL features.
These transceivers are finally at a more affordable point. They don't support high-speed-synch, at least not on my 7D. While cheaper than other models from the same company it would be nice to have support for high speed synch. I have not really tested the boundaries of the range on these, as long as the batteries are fresh they trigger every time. The battery indicator BTW is a very nice feature.
Works as a remote trigger with the correct cable. check their website or give them a call. also remote triggers flashes from quite a distance.cons? I wish it would pass TTL, I wish the cables were cheaper, and I wish it would auto power off after a predetirmined time of non use.and re awaken with a remote signal.
It all seemed to work... but only one one direction: when switching the two PWs I found that one of them would not work in pre-trigger mode. I have since returned the bad unit to Amazon and they have promised to have a unit at my door steps tomorrow. Shame on you PocketWizard for the poorly written manual and defective unit... and thank you Amazon for the great service and customer care!
Answer: You would need two. One to act as a transmitter and one as the receiver. The unit can act as either one but not as both at the same time of course. Make sure you get the correct flash sync cable for your flash. http://www.pocketwizard.com/products/cable_accessory/flash_sync_cables/