Quote Originally Posted by Nige
Another hijack...

Is there more than one 45mm lens? I bought a 45mm 'bayonet' lens shade thinking it would fit my 45/2.8 (Sekor-C I think) but it's too small. (lesson to onesself to research before buying...)
Looking at the KEH site M645 Lenses it would seem that there are at least two different filter sizes: 67mm and 77mm.