Upgrade Guide

Sony FX3→Sony A5100

Is it worth upgrading? Spec analysis, key improvements, and our verdict.

You own

Sony

FX3

£3799

2021

→

Upgrade to

Sony

A5100

£200 (-£3,599)

2014

⚖️

Situational

One clear hardware improvement over the FX3. Worth it if that specific upgrade aligns with what you shoot.

What's new in the A5100

Unchanged or similar

Suitability by genre

Full spec comparison

Spec	FX3	A5100
Price	£3,799	£200
Released	2021	2014	↓
Sensor	12.1MP full-frame BSI Exmor R CMOS (same as A7S III)	24.3MP APS-C Exmor CMOS
Resolution	12MP	24MP	↑
Video	4K/120p, 4K/60p 10-bit, 12-bit RAW output, S-Log3, S-Cinetone	1080p/60p
Autofocus	Real-time tracking with subject recognition (human, animal)	Hybrid phase-detect / contrast-detect AF, face detection
Stabilisation	5-axis IBIS — 5 stops	None
Burst Rate	10fps mechanical, 10fps electronic	6fps	↓
Battery Life	~640 shots (CIPA)	~400 shots (CIPA)	↓
Weight	715g body only (with XLR handle)	224g (body only)	↑
Weather Sealed	Yes	No	↓
Viewfinder	None — monitor/external EVF use only	None
Screen	3.0" touchscreen, fully articulating	3.0" flip-up touchscreen, 921k dots
Mount	Sony FE mount (full-frame E-mount)	Sony E-mount
Memory Cards	Dual CFexpress Type A / SD UHS-II slots	Single SD / MemoryStick PRO Duo slot

Compare side-by-side

See FX3 and A5100 next to each other with our interactive comparison tool.

Get a personalised upgrade score

Tell us what you shoot and we'll score the A5100 against your specific genres — not just specs.

Other upgrades from the FX3

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Camera family history