Ok, so I'm looking into this particular lens hood...
http://www.ebay.com/itm/161166899354?ss ... 1423.l2649
but after looking around just out of curiosity, I'm not sure if I can use this particular hood on my newly accuired Rolleicord Ia Model 3. I can't really seem to find different Rollei brand lens hoods, but with this one having the three mounting grooves on the back side and my camera not having any threads what so ever I'm just completely lost. Are there other types of lens hoods? Or are all hoods the same and require different mounting brackets with different camera models?