Originally Posted by steveshea
I found out that 49mm filters should work with this lens, but is a different filter type required to use the hood with the filter? I read somewhere that series 7 is the filter that allows the hood to be used with a filter but a 49mm filter is the filter you use without the hood.
Is the hood cap really necessary?
The internet has the answers;
39mm filters thread in, not 49mm. Series VII (7) filters fit inside the expensive and not so good 12504 hood. Your best bet is 39mm filters (plentiful) with the (relatively inexpensive) 12585 hood. The hood cap only works when the hood is reversed, which it won't on this lens due to the aperture tab. A standard 39mm pinch type cap will fit to the lens inside the hood - I'd recommend the Voigtlander one.
It was made in (or around) 1970, as in the serial number was assigned to the lens in 1970.