Vivitar 283 is a very good flash for macro - especially as it has a manual module - I made up a reflector card, with the manually-flashmeter-checked exposures, F-stops, & distances written on the back of it it = PERFECT EXPOSURE EVERY TIME (essential for pro industrial work with E6 slides)
While the Vivitar 283 was a great piece of kit (I had one) owners of digital cameras need to be cautious of using old flashguns as they can damage some DSLR's