Just shot some test photos with a brand new Nikon 500mm 5.6 PF lens. (Thank you Camera West in Rancho Mirage, CA www.camerawest.com) In a nutshell this thing is amazing. It is just slightly longer than the Nikon 70-200 2.8 and weighs about the same. The images are razor sharp, yes visibly more so than the Nikkor 200-500 5.6, and the color and contrast are fantastic. 

I’ve not shot in a stadium yet but there will certainly be a bit more depth of field than an f4 500mm. Whether or not that is a problem we’ll have to see. (keep in mind this lens is $6000 less than the f4 version) Lots of times shooting an f4 lens at 5.6 is common as it give you just a smidgen more room for focus error or getting that 2nd athlete in an image sharp. And with the high ISO capability of the D5, D500 and D850 bumping the ISO to 1250 is not a problem vs ISO 800. (If you shoot any of the pro body Nikon or Canon cameras you know that ISO 6400-10000 is amazingly usable.)

There are some initial limitations, the most significant being that glare and low contrast is quite significant when shooting into a backlit object. Being aware of this is very necessary as the images are not good at all. Using the lens hood and paying attention to the angle of the light in the image is critical. My understanding is that this is a limitation of the Phase Fresnel lens. It will be interesting to shoot some backlit surfing with this lens to see how it handles the spectral reflection of the water and color. On another note the 95mm diameter front element means a whole new set of filters which is kind of irritating. Being able to drop in a 52mm like the “professional” 200, 400, 500, 600 & 800mm lenses would have been nice.

Focus is as fast and accurate as the Nikon 200-400 f4. For a test I shot our black lab “Tux” in shadow with a strong backlight. The focus on the D850 was a bit slow to find him (continuous focus at 9 and 25 point were tested) but once locked on it tracked him accurately as he was running towards me until he was too close. I’ll post a sample image and you’ll see the focus point was on his nose and the depth of field is quite shallow as his eyes fall off pretty quickly. It is nice and progressive though and I like the focus fall off. I’ll be shooting soccer later in the week which  will be a good test of the continuous focus on moving objects.

I’ll continue to shoot test images but if the image quality holds up, and I cannot see how it wouldn't, this is the action, adventure, travel photographers dream lens. Pack this with a 70-200 2.8 and you are ready for almost anything. Using the DX crop on the D850 or using a D500 and you have a 750mm 5.6. 

One significant gripe is the crappy, sorry no other way to state it, tripod foot. (It is so light and compact that hand holding it is a no brainer but when the light gets low, critical sharpness is necessary or doing long exposure pans is required you’ll want this on a tripod.) Nikon makes the worst tripod foot in the history of mankind for it’s telephoto lenses and they are constantly berated for it. You would think spending this kind of money, or $10,000 for the 500 f4, they could put a nice Arca Swiss compatible foot on the lens. But no. You get this pop metal garbage foot which means going out and buying a $100+ RRS or Kirk foot to replace it. Hello Nikon marketing... anyone home?

My expectations were very high having shot the Nikkor 500 f4 quite a bit as that lens is the gold standard. While I can see the 500 PF lens having some challenges, back lit and low light / heavy shadows (regarding focus speed), the $6000 difference will certainly motivate me to figure out how to compensate for those situations!