AF-C 100-400GM + 2.0TC on A7riii

[bwud]

I recently received the SEL20TC and paired it with a 100-400GM on my A7riii. AF-C is very strange.

 

1) When the lens IS enables, I see weird visual disturbances in the EVF. Is this common?

2) Focus acquire is lousy with a propensity to go into a pulsating hunt. My suspicion is that PDAF isn't enabled on the A7Riii with f/11 maximum lens combinations (unlike A9, per reports).

 

AF-S works very well, but isn't applicable to anything which move much.

 

Is my situation unique or have others experienced this? Is it a bad combination?

[tinplater]

based upon performance reviews, I'm surprised anyone would want the 2x (whereas the 1.4 seems to be excellent)  Hope you can make it work for you.  It is an expensive add on.

[bwud]

I have a functional 600mm option already (EF mount version 1 tamron 150-600), and was looking for something longer. I’m thinking it might go back to BH, however. It’s very limiting for, as you say, such an expensive accessory.

 

The combination is nicely sharp, though. Maybe it’s just not right for action.

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[Chrissie]

I recently received the SEL20TC and paired it with a 100-400GM on my A7riii. AF-C is very strange.

 

1) When the lens IS enables, I see weird visual disturbances in the EVF. Is this common?

2) Focus acquire is lousy with a propensity to go into a pulsating hunt. My suspicion is that PDAF isn't enabled on the A7Riii with f/11 maximum lens combinations (unlike A9, per reports).

 

AF-S works very well, but isn't applicable to anything which move much.

 

Is my situation unique or have others experienced this? Is it a bad combination?

 

I've looked this up on Sony's web page: There is a compatibility limitation for the A7Riii when using your quoted combination:

 

 

When a Teleconverter (SEL20TC) is mounted, focal plane phase detection AF cannot be used.

 

http://support.d-imaging.sony.co.jp/www/cscs/accessories/compatibility.php?area=us&lang=en&mdl=SEL100400GM&cat=3&loc=en_US

 

Click on the ILCE-7RM3 "Detailed info" link on the above page to view.

[bwud]

Thank you.