photoman43 wrote:
For me it is not fear. It is more a change in balance and how the camera and lens is used. Change in balance becomes an issue as the focal length of the lens increases. In my case, using an adapter for a 105mm macro lens presents no issues. For a 500mm lens, balance issues need to be addressed especially if you are using a tripod or monopod.
I find just the opposite, the 500 f4 is so big I hardly notice the adapter.