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Sony a6400
Sony · a6400 · Free lesson

Common fixes

What fixes the Sony a6400’s known problems — a shutter that won’t fire, missing animal Eye AF, greyed-out tracking?

camerasdecoded.com/camera-select/sony/a6400/common-fixes
The answer — share this
Manual lens won’t fire: Release w/o Lens on. No Animal detection: firmware 2.00 or later, and Subject Detection set to Animal. Tracking greyed out: it needs Continuous AF, and it steps aside while Animal detection is on. 4K stops: a U3 card for 100M, and heat headroom.
Lens: Camera Settings2 → Release w/o Lens → Enable  ·  Animal AF: Setup → Version (2.00+) + Camera Settings1 → Face/Eye AF Set. → Subject Detection → Animal  ·  Tracking: Camera Settings1 → Focus Mode → Continuous AF  ·  Heat: Setup → Auto Power OFF Temp. → High
Cameras Decoded — Camera Select
Fix 1

It won’t fire with a manual lens

MENU→Camera Settings2→Release w/o Lens

A fully manual or adapted lens has no contacts, so the camera believes no lens is attached and refuses to fire. Set Release w/o Lens to Enable. Sony’s guide adds the honest trade: correct metering cannot be achieved with contact-less lenses, so judge exposure on the recorded image.

Fix 2

Animal eyes that aren’t there

MENU→Camera Settings1→Face/Eye AF Set.

Two gates. Firmware: the Face/Eye AF Set. menu, Animal detection included, is documented for firmware Ver.2.00 and later — Animal Eye AF arrived with that update — so check Setup → Version. Setting: Subject Detection must be on Animal; Human detection never produces an animal eye box. For animals the camera detects eyes only; faces are not detected.

Fix 3

Tracking that won’t select

MENU→Camera Settings1→Focus Area

Two conditions. The Tracking focus area requires Continuous AF. And Sony’s guide states that with Subject Detection set to Animal, [Tracking] cannot be selected — for animals, Wide or Zone plus Eye AF is the working pair on this body.

Fix 4

4K that stops

MENU→Setup→Auto Power OFF Temp.

Card first: 4K at 100 Mbps wants a U3 SDXC card by Sony’s own table; a Class 10 card under a 100M stream stops predictably. Then heat: Auto Power OFF Temp. set to High raises the shutdown point for planned long takes — on a tripod, per the guide’s warning.

Try it now

Rehearse three fixes now: find Release w/o Lens, read your firmware under Setup → Version, and check the card in your slot against the rate you shoot.