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Pentax K-3 Mark III · with 50mm kit — APS-C DSLR · 2021
Pentax

Pentax K-3 Mark III · with 50mm kit

APS-C DSLR · 2021

80
/ 100
From $2,299
VS
Sony FX3 wins by 10
Sony FX3 — full-frame · 2021
Sony

Sony FX3

full-frame · 2021

90
/ 100
From $3,898
Specdex verdict

Sony FX3 takes it — here’s why.

In our weighted Specdex score, Pentax K-3 Mark III · with 50mm kit lands at 80 and Sony FX3 at 90. That puts Sony FX3 ahead by 10 points — a decisive margin driven mostly by its strengths in the categories below.

Pick Pentax K-3 Mark III · with 50mm kit if…

  • ✓Mature system, great used market
  • ✓Proven lens lineup
  • ✓Often on sale

Pick Sony FX3 if…

  • ✓Current-gen AF system
  • ✓Proven lens ecosystem
  • ✓Strong video + stills balance
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Winner by scenario

Derived from the sub-score breakdown · not a separate test

Ergonomics

Tie

Compared on the ergonomics sub-score

Effectively tied — neither pulls a 2-point weighted lead.

Photo

Sony FX3

Compared on the photo sub-score

Sony FX3 leads on photo (90 vs 80).

Autofocus

Sony FX3

Compared on the autofocus sub-score

Sony FX3 leads on autofocus (88 vs 76).

Value for money

Pentax K-3 Mark III · with 50mm kit

Specdex score per dollar at MSRP

Pentax K-3 Mark III · with 50mm kit more score per dollar ($2,299 vs $3,898).

Pentax K-3 Mark III · with 50mm kit 80
vs
90 Sony FX3

Score breakdown

Pentax K-3 Mark III · with 50mm kit
80
photo 80
video 72
autofocus 76
ergonomics 86
Sony FX3
90
photo 90
video 86
autofocus 88
ergonomics 86

Specs side-by-side

Pentax K-3 Mark III · with 50mm kit versus Sony FX3 — full spec comparison
Spec Pentax K-3 Mark III · with 50mm kit Sony FX3
Format
APS-C DSLR
full-frame
Release year
2021
2021

Pentax K-3 Mark III · with 50mm kit

Pros
  • +Mature system, great used market
  • +Proven lens lineup
  • +Often on sale
Cons
  • −Older AF system
  • −Heavier than modern mirrorless
  • −Firmware updates trailed off

Sony FX3

Pros
  • +Current-gen AF system
  • +Proven lens ecosystem
  • +Strong video + stills balance
Cons
  • −Body price excludes lens
  • −Heavy for travel (flagship)
  • −Learning curve on menus

FAQ: Pentax K-3 Mark III · with 50mm kit vs Sony FX3

Which is better, Pentax K-3 Mark III · with 50mm kit or Sony FX3? +

Sony FX3 scores 90 on our weighted rubric — ahead by 10. Your best pick depends on the sub-scores above.

Is Pentax K-3 Mark III · with 50mm kit worth the price? +

At $2,299, Pentax K-3 Mark III · with 50mm kit delivers a Specdex score of 80 — strongest in ergonomics.

Is Sony FX3 worth the price? +

At $3,898, Sony FX3 delivers a Specdex score of 90 — strongest in photo.

Does Pentax K-3 Mark III · with 50mm kit or Sony FX3 last longer? +

Based on our long-term update and support ratings, both ship with multi-year support. Battery and reliability scores are visible in the breakdown above.

Which is better for photo, Pentax K-3 Mark III · with 50mm kit or Sony FX3? +

Sony FX3 — leads on photo (90 vs 80). Compared on the photo sub-score.

Which is better for autofocus, Pentax K-3 Mark III · with 50mm kit or Sony FX3? +

Sony FX3 — leads on autofocus (88 vs 76). Compared on the autofocus sub-score.