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Member Since 31 Jul 2022
Offline Last Active Aug 07 2022 07:38 AM

Hey from Cambridge, UK

02 August 2022 - 12:03 AM

Hi everyone. I think I'm posting this in the correct place. Jeremy from Cambridge, Uk here. Would love to get to know some like minded people

Nikon 600mm f4 prime stops autofocusing intermittently

31 July 2022 - 05:09 AM

I shoot with a Nikon D850 and a Nikon 600mm f4E FL ED VR AF-S Lens

I sometimes use a 2 x teleconverter (AF-S TC-20E III)


April 2022 I was photographing at a Peregrine site and all was fine. 

I put on the teleconverter and took a few shots then removed it. 

From that point the 600mm lens would not autofocus.

I checked all settings, removed and re-set lens, removed battery, cards......... I tried everything. 

Autofocus worked fine with another lend with and without the teleconverter therefore issue seems to be with the lens. 

Next day I tried it again and still no autofocus. 


I drove and dropped all the kit to "Advanced Camera Services" 

​Next day they tried the lens and couldn't;t find any fault with it. It worked fine. 

They checked everything and nothing was stuck, dirty or faulty. 

I collected it and used it occasionally through the summer with and without the teleconverter. No problems. 


27 July I was in a hide photographing birds. No problem. 

Woodpecker landed a way off so I put on teleconverter and took some shots. 

Teleconverter off and then same thing again. No autofocus. 

I tried everything and nothing worked. 

I put the 600mm lens on someone else's D750 and it would not autofocus on that either. 

I put another lens on my D850 and it auto focussed perfectly. Issue is with the lens. 

That evening... still not working

Next morning... Still not working


29 July I tried it just on the off-chance and it was and is now working as normal 

Called ACS who said it "may" me an intermittent fault with the DC/DC ???? but they aren't really sure. 


​31 August I tried it all again with and without the teleconverter and it's working perfectly. 

My issue is that I drove 4 hours to get to this hide to photograph birds in flight. 10 minutes into this shoot it stopped working. That was a very expensive wasted trip. 


The kit is clean. It has not been bumped. 


Any sensible suggestions?