To add to the discussion:
I always have the 21 viewfinder in the hotshoe as I shoot more then half of my slides with it. To prevent it falling off (it is indeed a bit loose) I put a thin piece of carton (or a thick piece of paper) between hotshoe and finderfoot. It works fantastic without any drawbacks (as with tape or glue).
If you still lose the viewfinder you will be able to buy a new Voigtlander 21 mm finder from: www.cameraquest.com . It is from Voigtlander but I will assume it will work for the Contax lens as well.
Marc-paul
I always have the 21 viewfinder in the hotshoe as I shoot more then half of my slides with it. To prevent it falling off (it is indeed a bit loose) I put a thin piece of carton (or a thick piece of paper) between hotshoe and finderfoot. It works fantastic without any drawbacks (as with tape or glue).
If you still lose the viewfinder you will be able to buy a new Voigtlander 21 mm finder from: www.cameraquest.com . It is from Voigtlander but I will assume it will work for the Contax lens as well.
Marc-paul