I am having a lot of trouble getting accurate and trustworthy information about the effect of convertors on the following setup:

  • Nikon D800

  • Nikon AF-S 80-400mm F/4.5-5.6 ED VR

  • Nikkor AF-S 105mm F2.8 G IF-ED VR Micro

My primary requirement was to get more reach on the 80-400mm, whilst keeping the AF ability. Then I realized a convertor could also be beneficial to my macro lens. Now I am looking for the proper convertor that finds the sweet spot:

  • Is compatible on both of the above lenses

  • Maximal magnification up to the point where AF keeps working

Let us assume for now that I accept the loss of light, and that cost is no issue. What would be the sweet spot? i have tried looking for this answer myself but get very different answers. Here's on source I'm using:


That overview suggest that AF is not possible on the macro lens, not on any of these convertors. Yet I see many users in forums reporting that it works just fine.

Furthermore, regarding the telezoom, it only mentions "AF limitations", with this foot note:

"Autofocus is available only with cameras that offer f/8 support. These include the D4, D800/D800E, D600 and D7100."

Since I have a D800, and if I would be naive, this would lead me to conclude that even up to the TC-20E, auto focus would work. Yet other information mentions that AF isn't possible at all for a F4.5 lens like this.

I'm struggling to find that sweet spot, a convertor to work on both lenses, with the maximum magnification possible for as long as AF works on both lenses, yet there is conflicting information all over the place.

Care to help?

  • 3
    \$\begingroup\$ Your 80-400 is an f/4.5-5.6 lens. It's only f/4.5 at the short end of the zoom range. At 400mm it's f/5.6 wide open. A 1.4x converter makes that f/8 (compatible with your camera's centre PDAF); a 1.7x makes it f/9.5; and a 2x makes it f/11. At 80mm and f/4.5, the 1.7x makes it about f/7.6, so you can use the TC17, but only at the short end of the lens's range. It's not the amount of light that matters so much, it's the angles at which the light hits the AF detectors from the edges of the lens. The macro is just weird at the rear, for want of a better phrase. \$\endgroup\$
    – user2719
    Jan 22, 2014 at 23:37
  • \$\begingroup\$ @StanRogers Thanks! So that would mean the 1.4 convertor is the only safe option to use on the telezoom, correct? \$\endgroup\$
    – Fer
    Jan 23, 2014 at 10:46
  • \$\begingroup\$ Since you're talking about AF a lot I feel I should point out that just because the camera/lens can still turn the AF on does not mean it will perform the same as without the TC. It may take longer to lock focus, or may not lock focus at all. \$\endgroup\$ Jan 23, 2014 at 14:17
  • 1
    \$\begingroup\$ On Monday I'll be able to try both lenses with both converters on a D800, so I'll write an answer with what I find. \$\endgroup\$
    – mpr
    Jan 24, 2014 at 21:03

2 Answers 2


I've tried out the TC-17 and TC-20 with both the AF-S 80-400 and the 105VR Macro on a D800. The short version is that the TC-17 is probably the best match given your requirements.

First, the AF-S 80-400: with the 2x teleconveter at the longest end of the lens, where it's at f/11, the D800 could occasionally manage to focus with the centre point in medium-bright daylight light. But only occasionally. With great reluctance. Under duress. (At the short end, where it's at f/9, the camera had no problem with the centre focusing point.)

The AF-S 80-400 with the 1.7x teleconverter is f/9.5 at 650mm, and the D800's centre point AF was able to produce reliable results outdoors and in lower light indoors. None of the other focus points were any help, though.

The 105/2.8VR will autofocus with the 2x converter, both with the central and the corner AF points. (At minimum focusing distance the bellows effect has the lens at f/9.5, so I'm not sure why it worked with the macro but not the 80-400G.) Naturally AF is fine with all points at longer focusing distances, where the aperture drops down to a relatively bright f/5.6.

  • \$\begingroup\$ Thank you, this is by far the most useful information I have seen so far, covering exactly the combination that is relevant to me. \$\endgroup\$
    – Fer
    Jan 28, 2014 at 16:56

As you said I would believe only the f/8 limitation whatever Nikon said on one of their site.

I checked the same information on the Nikon.ch and nikon UK sites and here is one extract:

Teleconverter compatibility note

As you can see the 80-400 f/4.5-5.6 is only fully compatible with the TC-14E converter (footnote *3). For the Micro-105mm, there is just no AF whatever the converter used.

The original UK document is here and the Swiss one (in French) is here

Apparently marketing is more aggressive in USA (what a suprise) but the finality can make customers unhappy.

Tip: when checking information on a Nikon site, it is often useful to see what they say for other countries. As a french speaker I like to have my information in my native language but sometimes I prefer to have it in English (the nikon.ch site is only in French and German) then I go to see USA or UK sub-sites. Apparently they are a bit messy for having the same content (which is not the case). It is the same for the hardware registration sites (I was able to register my devices on both Swiss and European sites)

  • \$\begingroup\$ Thanks! By now it is clear to me that the TC-14E is the only option given my needs. The only unclarity I have left is the lack of AF on the macro lens. I see the official info, yet have seen several forum users on the dutch Nikon site saying AF works just fine on their 105mm. Either way, I can live with MF on macro. \$\endgroup\$
    – Fer
    Jan 23, 2014 at 10:48

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