Numbers - Mono Monday 122

Before digital cameras my favourite SLRs were the Olympus OM series, differentiated by numbers: single digits for those aimed at a  'professional' market - 1, 2, 3 and 4 - and double digits aimed at a lower cost market - 10, 20, 30, 40. I still have one of each except for the OM3, which can still fetch as much as a high end digital.
Although they were 'automatic' to various degrees, using them successfully depended on knowing the numbers - shutter speeds, apertures, focal lengths, and of course the speed of the film.
The OM4 was almost the end of the line though there was an enhanced version, the OM4Ti, but for the theme of numbers I chose the plain 4 for the subject.
Today an adapter to use the OM lenses on the Fuji X-Pro1 arrived, so the pic is taken with a OM 50mm f/1.8 lens on the Fuji with another mounted on the OM4.
More numbers: the shot was taken at 1/125 sec at f/8 at a distance of about 0.5m. I could have made the 'OM4' sharper by increasing one of the numbers, by shutting the lens down to f/16, but then I would have had to get the tripod as I was already pushing my luck hand holding at 1/125.