I have been looking at the cheep macro options for my Canon 20d and as I have one of these in the house http://cgi.ebay.co.uk/MC-Pentacon-1...goryZ707QQssPageNameZWDVWQQrdZ1QQcmdZViewItem I then came across an adapter that fited the lens the right way round onto the body.!! http://cgi.ebay.co.uk/M42-Lens-to-c...ryZ30059QQssPageNameZWDVWQQrdZ1QQcmdZViewItem A perfectly good quality prime lens for vertualy no spend, then the options of same screw fitting lenses bolting onto my 20d. Sounds great. Yes it will only work in manual but I use mine like that any how. AND THEN, This open the possibility of adapting all sorts of very good quality cheep lenses? BUT are there any pit falls with this ?