[Marc B.]

Instead of buying individual Bay-1 filters, you can also obtain Bay-1 - to screw mount filter adapters.
These adapters will allow you to use common screw mount filters that you may already have, and
with the use of step-up/step-down rings, you can fit just about any filter and rubber hood size you have.

An example of Bay-1 adapter-to-screw mount w/round hood:
http://forum.mflenses.com/userpix/271_IMG_7147_1.jpg
http://forum.mflenses.com/userpix/271_IMG_7148_1.jpg

Bay-1 to 30.5mm:
http://www.bhphotovideo.com/c/produc..._Ring_Bay.html

Bay-1 to 46mm:
http://www.ebay.com/itm/230892668328...84.m1423.l2649

Bay-1 to 49mm:
http://www.ebay.com/itm/310526950651...84.m1423.l2649

Bay-1 to 52mm:
http://www.amazon.com/52mm-Adapter-R.../dp/B0079QRP7Y
http://www.ebay.com/itm/230892668327...84.m1423.l2649

Marc