I have been using this lens for three years and I still continue to be impressed by the quality of images I can capture. It is now the only lens I use for bird photography and every time I look longingly at the top-dollar Nikon pro lenses I see trade-offs in weight, size and lack of flexibility that I don't want to make.
This is a very crisp lens. Test results show that it outperforms the Tamron and Sigma equivalents, though it takes second place to the more expensive (and heavier) Sigma 150-600mm f/5-6.3 Sport.
In the real world it has proven to be robustly built, surviving years of not very gentle handling and one fairly significant drop without complaint.
The constant f/5.6 aperture means that teleconverters can be used without problems. I have started using the Nikkor TC-14E III teleconverter regularly and it gives me that extra bit of reach with no visible degradation to the images.
There are four switches on the lens body: Manual-Auto/Manual, Full range/limited range (8m and beyond), Vibration Reduction On/Off, and Sport/Normal mode.
Vibration reduction is rated at 4.5 stops, which is particularly helpful in low light situations.
This lens will work with any F-mount body, but it shines when used with the Nikon D7XXX series and the Nikon D500.
Other things I particularly like:
- the close focus distance is reasonable at 2.2m
- there is a lock button which locks the barrel at 200mm (avoids lens creep during long walks)
- the sealing does a good job of keeping out dust
- manual focus works smoothly
- autofocus is quick and accurate, though not as quick as the Nikkor pro lenses
- the supplied lens hood is robust and does a good job of protecting the front lens element and keeping gunk off of it. (And of course it does reduce flare, which can be a problem with telephoto lenses)
Things I don't like so much:
- it is a heavy beast, and quite long when fully extended - about 17"/~43cm with the lens hood. The weight becomes noticeable after a long day of carrying it around, and after three years it has almost worn through the metal clasp on my BlackRapid strap. I hand-hold the camera 99% of the time and the weight of the lens and a D500 body gives me quite an upper-body workout!
- extending from 200mm to full zoom takes a 180 degree turn of the zoom ring
- this is not a waterproof lens. If you use it in steady rain moisture will get inside the lens body
Bottom line: This is an outstanding lens for the money, and for the enthusiast (non-professional) Nikon user it is arguably the best all-around bird photography lens.
Slight pincushion, glare when bright sky is in the view.
I bought these because I heard they were essentially a clone of the much talked about Sightron blue sky. They are a great value for the price range of under $200. they are fully multi coated, waterproof, phase corrected, and have silver prism coatings (a nice feature over aluminum in this price range).
Brightness: They have great brightness for a 10x32 roof prism in this price range
CA: Very little and only in very high contrast situations. Far better than most bins without ED glass.
Distortion: Slight pincushion, noticeable while panning but not bothersome.
Blurring at the edge: Focus is very sharp across the FOV with slight softening about 80% out, and really only bothersome right at the field stop. Brightness is also constant across the FOV.
Color: A little muted but overall natural.
Reflections: My only gripe is the glare is pretty noticeable when facing bright light sources.
Overall a great value, would definitely recommend.