I agree with Curtis
The JTL Versalight units (which were inexpensive but, fairly decent lights) each have an optical slave. When one light goes off, all the lights will fire.
You can attach one light to your camera with a P/C cord but, that is not necessarily the best way to fire the JLT units. I am not sure what the sync voltage of the JLT units are but, they "may" exceed the maximum allowed by your camera. If that is the case, then the electronic circuitry of the camera may be fried.
A solution to this is a Wein Safe Sync which also provides a PC cord outlet in case your camera is not equipped with one. However, the Wein Safe Sync will cost about $50 and there are better ways to trigger your flash.
I use an infrared trigger which was once available in great numbers on eBay for well under twenty dollars each. I have used the same one for about five years now and am on my third set of AA batteries. The IR trigger fits on your camera's hotshoe and fires a burst of IR which is picked up by the built-in optical sensor of the JTL. The only drawback to firing your strobes this way is that if anyone else in the vicinity is shooting a flash, the JTL units will fire. This doesn't pose any problems for me because I am the only one using flash in my studio.
I have not seen the specific IR trigger that I use on eBay lately. However, here is another IR trigger which should work.
http://cgi.ebay.com …ZWDVWQQrdZ1QQcmdZViewItem
Smith-Victor distributes their own Smith Victor PGIRT-20 Infrared Flash Trigger which is a bit more expensive
http://www.adorama.com/SVPGIRT20.html
There are also radio controlled triggers available but, often the less expensive triggers don't work as well as expected. My el-cheapo infrared trigger has worked flawlessly for years.
NOTE: There are many units which are advertised on eBay and the general Internet as "Infrared Triggers" but which are not triggers at all but, are optical slaves. These units are good when you desire to attach them to a hotshoe flash so that the flash will be triggered from another flash. However, they will not trigger a flash themselves.
http://www.724deal.com …al-camera-syk-3-5192.html
Set your camera to manual 1/60 second and fire a set of test exposures at one-stop intervals from f/4 to f/16. View the images on a calibrated computer monitor and decide which is the best exposure. Make a note of this exposure.
A variety of test exposures at different distances and with different light modifiers will provide enough exposure information that you will not really need a flash meter.
