Nikon Teleconverter TC-20 III On a AF-S Nikkor 500 f/5.6 PF ED VR, With AF Issue

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AtTheLake

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Santa Claus brought me a Nikon Refurbished TC-20 III teleconverter. Using a D500 and the 500 f/5.6 PF ED VR lens I installed the TC-20 III. Now I had a very hard time focusing when using the auto focus. I tried to focus on a Canada goose, for every time it focused it did not focus 10 times, seemed to be in a continuous hunting mode. I could manually focus. I have used the same D500 and lens with a TC-14 III teleconverter with good results. I then put the TC-20 III on a AF-S Nikkor 300 f/2.8 and focusing was not an issue. I tried the same combinations but now with a D850, with the 500 f5.6 lens and the TC -20 III, with the same issues of very poor focusing in the AF mode.

In Nikon's Compatibility Chart they shows that the TC-20 III is fully compatible with the 500 f5.6.

I believe it needs to go back to Nikon Service. Am I missing something?

Thanks In Advance
 
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The 2.0 TC makes the lens f8...and that generally limits you to AF points that are in the center. In addition to that...individual AF sensor performance might be limiting you even more. Take a look at the manual or google to see whiat the AF points are limited to...or if you have Steve’s AF book I’m pretty sure it is discussed in there.
 
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AtTheLake said:
Using a D500 and the 500 f/5.6 PF ED VR lens I installed the TC-20 III.
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Adding a TC-20 to a 500mm f/5.6 lens turns the lens into a 1000mm f/11 lens. Nikon DSLRs will only auto focus properly with lenses up to f/8 in through the viewfinder mode and then only using the center most AF points as Neil posted above. You should be able to get the camera to focus in Live View mode but AF will not work very well if at all in through the viewfinder phase detect AF mode.
AtTheLake said:
I then put the TC-20 III on a AF-S Nikkor 300 f/2.8 and focusing was not an issue.
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Yes, adding the TC-20 to your 300mm f/2.8 lens turns that into a 600mm f/5.6 lens and that's well within the AF specs for your D500.
AtTheLake said:
In Nikon's Compatibility Chart they shows that the TC-20 III is fully compatible with the 500 f5.6.
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I'm not sure what version of the TC compatibility chart you're looking at but if it shows an f/5.6 lens as being fully AF compatible with a 2x TC then that's a typo as all the Nikon DSLR manuals clearly show that AF performance is limited to lenses (including TCs) with a wide open aperture of f/8 or better. Here's the TC compatibility chart I found on Nikon's site that doesn't list the 500mm f/5.6 lens but shows that the 200-500mm f/5.6 is not compatible with the TC-20 iii: https://cdn-5.nikon-cdn.com/Assets/...eleconverter-Compatibility/EN_Comp_chart.html
 
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If you go to the Nikon Lens on their web site and go to TC-20 III teleconverters and go the "More" tab on that page and click on it and then go to Compatibility it shows the AF-S 500 5.6 as being compatible with the TC-20 III. How ever, it does does not mention if the AF will work at F11.

Thanks for the help.
 
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AtTheLake said:
If you go to the Nikon Lens on their web site and go to TC-20 III teleconverters and go the "More" tab on that page and click on it and then go to Compatibility it shows the AF-S 500 5.6 as being compatible with the TC-20 III. How ever, it does does not mention if the AF will work at F11.

Thanks for the help.
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Yeah, that's very misleading on Nikon's part. Sure the TC-20 iii is compatible from a mechanical standpoint (it will mount) and from a pure optics standpoint but it won't maintain AF compatibility with the 2x converter attached, at least not in through the viewfinder mode which is a different AF system than what's used in Live View mode.

The Nikon mirrorless cameras should maintain proper AF performance with this lens and TC combo as they use the sensor itself for AF detection much like the DSLRs in Live View mode but for a DSLR in through the viewfinder focusing mode a f/5.6 lens plus 2x teleconverter just pushes things too far from a wide open aperture standpoint.
 
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The good news is the 2.0 teleconverter and 200-500 will AF on the Z cameras. But If it were me, I'd return the teleconverter. You can try a Nikon 1.4 teleconverter (TC14E II or III) and it will work better, but it's difficult. For birds in flight, it is marginal but for static or perched subjects, it's an option. If you are trying a combination that is f/8 wide open on a DSLR, limit your effort to the center AF point. Depending on the camera, you may have a few other points that work, but AF will not be for all AF sensors.
 
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AtTheLake said:
If you go to the Nikon Lens on their web site and go to TC-20 III teleconverters and go the "More" tab on that page and click on it and then go to Compatibility it shows the AF-S 500 5.6 as being compatible with the TC-20 III. How ever, it does does not mention if the AF will work at F11.

Thanks for the help.
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I think that being compatible does not mean will give you all functions. I think that compatibility means 1 it won't damage the lens or TC if you try to mount it and 2 it will focus either with AF or manually. In the compatibility charts I've seen in the past they have mentioned that no AF is available with some TC/lens combinations.

In this compatibility chart for the 2x TC iii it lists the 200-500 f5.6 but has *1. When you look below, *1 is *1 Autofocus cannot be used. The 500mm f5.6 is not listed.

 
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This combination (Nikon 500mm PF and Nikon TC-20E III) does work well with
Geese for web 27Dec2020.jpg
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the Nikon Z50 mirrorless camera. I tried switching focus to several subjects at different distances and it it even worked well on some yard birds that were in the shade. Here is a photo using it on flying Canada Geese.
 
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I struggle with this as well especially with birds in flight with a 1.4. I don't think Nikon wanted this lens to be used in this way. I struggle with my D4s using a 1.4 with birds in flight and I end up getting a soft focus that's not near as sharp as I wanted.
 
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robertrear said:
I struggle with this as well especially with birds in flight with a 1.4. I don't think Nikon wanted this lens to be used in this way. I struggle with my D4s using a 1.4 with birds in flight and I end up getting a soft focus that's not near as sharp as I wanted.
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Birds in flight with 500mm and a 1.4 teleconverter can be very challenging. It's reasonable photographing sandhill cranes or other large wading birds in open areas, but in a wooded area with songbirds the hit rate is probably very low. I was using a 600mm lens with 1.4 yesterday to photograph songbirds and even hopping on the ground, images were at times a challenge.
 
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With the 500mm PF and even the TC-14 teleconverter I will use manual focus and a monopod to get a sharp in focus shot. Part of the problem is the very shallow depth of focus with a 700mm or 1000mm focal length. I prefer to use manual focus or AF with manual ovrerride with stationary subjects as I know what part of the subject is most important to have in focus.
 
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I just used this same TC on some moose and about 1 out of 20 images was in focus. It happens sometimes, but rarely. Not a great combination, sadly.
 
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