I'll keep the story short.. I needed a shutter for my new 210mm lens and didnt have the $500 to spend for a SKgrimes mounting job so i made my own studio shutter. the accuracy depends on my reflexes.. but so far i am pleased with it ths is the first prototype later versions maybe a little sleeker looking.
it accepts upto 77mm filter on the front. It doesnt vignette with the 210mm lens, and acts as a lens shade in bright sun!!
I may custom build one for anyone that needs one.
Its made out of maple and basswood so its not heavy but plenty strong
in the photos its mounted on a sinar/horseman board on my 8x10 tachihara