Originally posted by BigB BTW, where does a Kenko Vari 420-800mm Super Telephoto fit in the quality spectrum?
It does not fit into any quality spectrum, because it is so slow (small max. aperture), that you will find it completely unuseable. (Yes, I know, there will always somebody somewhere, who probably took an acceptable shot with it...)
It is a 420/8.3 - 800/16 lens! In real life you will often need to stop down a long lens to f/11 or f/16 to get a certain depth of field, but if a lens starts with f/16, you will be hard pressed to achieve correct focus, because the viewfinder is so extremely dim.Also, the aperture is fixed and will change with shooting distance, getting as low as f/21 at 800mm and the shortest distance. Even if you get correct focus you can only shoot static objects as shutter speeds get long or you need very high ISO settings with the according increase in noise.
All in all I am sure a 400/5.6 or even a 500/8 mirror lens will provide better images and is easier to handle.
Ben