Hello boysos and girlziz.. I have this super antique yet well working Vivitar 3900 flash gun auto thyrister thingy..
I like to strap it to the side o my 4x5 fieldy and go out stressing.. Trouble is its been a few years since I humped the chunk and now I can't find my manual.. Anyone got a few words of guidance re using this little lollypop..