Ernie Misner wrote:
Converters, especially the 1.4x work great with fast, prime lenses. The series III converters are the latest versions as compared to the older II converters. People using the 300mm f4 PF lens say it is equally sharp when using the 1.4x III converter.
What people? You say the people using the 300 f4 PF say it is equally sharp using the 1.4x III converter. Who are these people? Are they rating this system some where? Is there documentation? Or is your comment about people just more here say or what you have heard without seeing resulting images.