https://www.lenstip.com/531.4-Lens_review-Nikon_Nikkor_AF-S_180-400_mm_f_4E_TC1.4_FL_ED_VR_Image_resolution.html
TL/DR version -- it's brilliant ...provided you don't use that 1.4x (bold below is my emphasis):
"If you decide to use the teleconverter, though, the situation is quite different and MTFs - distinctly lower. Resolution decrease is noticeably sharper than in the case of other contemporary, expensive, high quality telephoto lenses cooperating with a teleconverter. I admit the performance fell short of our expectations; we thought that such an optically complex teleconverter, designed to cooperate with just one model of lens, would perform much better than traditional, external devices which, after all, are supposed to fit many professional telephoto lenses of a given system.
As a result, even if the performance at 550 mm cannot exactly be called weak, as the results allow you to enjoy fully useful, good images, it is not something we expected from such an expensive lens."
Ouch. They don't typically report T/C results and we have no Canon 200-400 1.4x review at LT to compare to, but they went so far as to say above that traditional modular T/C use on a good telephoto lens does better, not worse, than this dialed-in and fixed T/C does. That's somewhat shocking.
- A
TL/DR version -- it's brilliant ...provided you don't use that 1.4x (bold below is my emphasis):
"If you decide to use the teleconverter, though, the situation is quite different and MTFs - distinctly lower. Resolution decrease is noticeably sharper than in the case of other contemporary, expensive, high quality telephoto lenses cooperating with a teleconverter. I admit the performance fell short of our expectations; we thought that such an optically complex teleconverter, designed to cooperate with just one model of lens, would perform much better than traditional, external devices which, after all, are supposed to fit many professional telephoto lenses of a given system.
As a result, even if the performance at 550 mm cannot exactly be called weak, as the results allow you to enjoy fully useful, good images, it is not something we expected from such an expensive lens."
Ouch. They don't typically report T/C results and we have no Canon 200-400 1.4x review at LT to compare to, but they went so far as to say above that traditional modular T/C use on a good telephoto lens does better, not worse, than this dialed-in and fixed T/C does. That's somewhat shocking.
- A