Nikon Announces a New 70-300mm/f4.5-5.6 E AF-P ED VR

[Sandy Vongries]

Overall the compatibility situation in the Nikon mount is getting very complicated.

Seems, so, but I can recall when Nikon first expanded from Pro oriented toward consumer. In the decades that followed, that strategy served them well, though many criticized at the time. It is useful to be able to use every Nikkor I own, pre AI on up on either the DF or D 750. If there are challenges on newer lenses, I can stand pat or buy an additional camera when / if the advantages of the new lenses become significant.

[Matthew Currie]

I had a question about how this lens would behave with AF-ON, given that it seems to need current to focus at all. I got a partial answer, I think, today. I went to a store (clerk a little busy so not able to do too much trying out), and he handed me a D500 with the AFP-DX 70-300 lens. I would have liked to switch on back button focus but did not have time. However, this is what I found: If you start it up with the AF turned off at the camera, no focus of any kind occurs including manual. If you start it up with AF turned on at the camera, then turn off the AF, AF holds, and manual override still works. My guess is that this will mean AF-On will also work correctly, including manual override when AF is disengaged, if you have woken up the AF first. I also don't know what happens if you have back button focusing on and the camera goes into standby. I think it's likely to stay focused, but I don't know how it will behave when it comes back on.

[Andrew Garrard]

Thanks for experimenting, Matthew. I guess I should have expected that manual focus behaviour, but it's interesting. I believe it's the case that Nikon's digital rangefinder AF confirmation light has "more slack" when in fully manual focus mode (presumably to make AF "easier"), so I guess this might mean it's in precise mode only. Not that I have any objection to that (and the position of the AF mode switch on cameras since the D700 has made me largely stick to using AF-C/AF-On anyway), but it's a difference.

[ilkka_nissila]

AF-P is needed to get acceptable contrast detect AF performance especially if the subject is moving. CDAF is the only AF that is currently available during video and LV in Nikon DSLRs. AF-P seems also quieter which can be important if using an on-camera microphone. I believe video is the primary reason for introducing AF-P lenses, not that they are low cost. I am sure Nikon understand the negative ramifications due to compatibility issues but they decided to go with AF-P nonetheless.

 

I don't believe AF-P will be the solution for large lenses however. For wide aperture lenses with large elements, if Nikon wants to improve LV and video AF, they will probably need some kind of phase-detect sensors or dual-pixel AF implemented in the sensor. However, stepper motors may still have some advantages where they are applicable.

 

I think most Nikon lenses introduced will continue to be AF-S (and USM for Canon).

[ShunCheung]

Imaging Resource had an interview with Nikon's Masahiko Inoue during Photokina last year (2016), It is quite clear that AF-P is mainly for smaller lenses only (at least at the present time). It cannot generate enough torque to drive superteles: Nikon Q&A @ Photokina 2016: Can KeyMission break out of the action niche, who needs AF tuning & more

 

That interview also covered many other topics.

[rodeo_joe1]

Another "foot-shooting" exercise by Nikon IMO.

 

My limited experience with focus-by-wire is that it's jittery, noisy and slow, making it a "feature" I would never want to see in widespread use. I further fail to see its need for manual focussing. After all, you have to twist or twiddle something to focus manually, so why not just move an old-fashioned focus ring?

[Andrew Garrard]

> so why not just move an old-fashioned focus ring?

 

Usually a combination of it being mechanically awkward to get at the focus units (possibly because they're buried behind the zoom, and possibly because they're weather sealed) and the throw required for the focus unit being incompatible with the amount of movement suitable for fine tuning by hand (recall all the complaints about how manual focus lenses are easier to focus because of the trade-off between short throw, fast-to-focus AF lenses and long throw, precise MF lenses). I've no objection to the AF ring on a big prime being located for ergonomics, without compromising the internal lens design to link it to the AF group (70-200 mk 3, I'm looking at you). Technically, if the lens has close range correction and moves multiple focus units differently, I don't dislike the idea of controlling this electronically rather than with some big helical sliders. It might mean that AF fine tuning gets some more parameters in the future. And we might be able to get an accelerated manual focus system as, I believe, some other cameras have (turn the ring fast and the AF moves further than it otherwise would to reduce the overall throw, while still giving precise fine tuning - like mouse acceleration on a computer).

 

I'd be surprised if any of that other than the mechanical convenience argument applies to this particular lens, but I, for one, welcome my fly-by-wire overlords. Though it would be nice if Nikon had found a way to make it play nicer with manual focus mode on the body.

[Andrew Garrard]

It's been pointed out that this lens does change the optical formula, apparently (if you believe the MTFs) for the better. Both ends of the range look better according to the MTF graphs, although the long end does look quite astigmatic (which I guess might make for nice bokeh, according to at least one heuristic I've heard). I'll be interested to see whether it's actually much sharper in the corners in one orientation than the other, or whether there's different field curvature for each axis.

 

Which, for a lens I'm not particularly interested in buying, says I spend way too long on this forum...

[ilkka_nissila]

Generally low astigmatism is thought to result in nicer bokeh.

[Andrew Garrard]

Ah, sorry - clearly I was mis-remembering. (A strong astigmatism - and field curvature - is responsible for the unusual bokeh of Petzval lenses, which I suppose should have clued me in.) I'll look out for bokeh issues at the long end when I see sample images, then.