Features:

• Shutter speed 1 – 1/1000sec. (not counting bulb mode). For lower speeds you have bulb mode (through a wired remote) which you’d have to time yourself. For higher speeds you’d have to look elsewhere – the OM-3 and OM-4 go up to 1/2000sec. The available shutter speeds on the dial are: B 1 2 4 8 15 30 60 125 250 500 1000.
• Manual mirror lockup is available which is great for astro photography or other areas where very long exposures are necessary.
• Flash sync up to 1/500sec. but I am yet to test this with modern flash units.
• User replaceable focusing screens, 12 options to choose from, so you shouldn’t have a problem finding the best one for you or for a particular shooting situation.
• The finder shows 97% of the frame.
• The light meter is relatively accurate in daylight when used properly and powered by a correct battery (read more below). It can be switched off completely (and should be after metering) to save the battery.
• The OM-1 MD (MD = Motor Drive) bodies can take the optional battery powered winder without modifications.