So I currently have a TC-14 1.4x TC on an older Nikon 300mm f4 AF lens.
I presume if I want a 2x teleconverter I'd get a TC-20 and be done with it. Optically is that much worse than stacking two 1.4x and related, is using less teleconverters, if you had to use it, a lot better or are results similar?
Effectively I know that adding a TC reduces quality. Is the quality loss dependent on the magnification or more on the amount of glass between the lens and sensor?