#1. "RE: Vivitar 283 Flash" In response to Reply # 0
Very possibly. The 283 has enjoyed a spectacularly long run, with somewhere north of 5 million units in the field. Unfortunately, some of the oldest samples used a very high 250v trigger voltage, and this is utterly incompatible with modern digital SLRs, which use a trigger voltage of around 6v. Most of the 283's use a 6v or 12v trigger, but I don't know of any way to tell the types apart visually. There are ways of identifying which is which using electronics tools. If it runs on a low trigger voltage you'll be fine.
_____ Brian... a bicoastal Nikonian and Team Member
My gallery is online. Comments and critique welcomed any time!
#2. "RE: Vivitar 283 Flash" In response to Reply # 0
Welcome to Nikonians! It depends on the age of your Vivitar 283. The sync voltage can range from a safe 5V to as high as a 600V which is almost 3 times greater than the maximum sync voltage of your D5100 and enough to destroy the camera. Check Photo Strobe Triggering Voltages .
Personally I would not mount it on the camera. That said you can find out How to Check Trigger Voltages about 1/4 of the way down the page. On occasion, I use my Vivitar 285HV as a remote slave with a Wein Peanut Optical Slave. Good Luck and Enjoy your Nikons!
#4. "RE: Vivitar 283 Flash" In response to Reply # 0
Oak Foest, US
It will damage your camera I have an old 283 and 285 Vivitar flash I used with my 35 mm Olympus the voltage is too hight for the 5100 but you can by an adaptor by Wien that you put in hot shoe and mount the flash on it. This will reduce the voltage You can get one on Amazon