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Sony a1 II

Real Sensor Data

Brand
Sony
Sensor Format
Full Frame
Resolution
50.1 MP
Pixel Pitch
4.15 microns
Circle of Confusion
0.0288 mm
Crop Factor
1.00x
Announced
2024

The a1 II, released in 2024, is a rare case on this reference of a manufacturer refreshing a flagship body without touching its core sensor at all — the 50.1-megapixel stacked full-frame chip carries over unchanged from the original 2021 a1, with Sony's updates instead concentrated on autofocus processing (borrowed from the newer a9 III), a fully articulating screen, and refined ergonomics.

Sony a1 II sensor specs

Sensor
Full Frame
Resolution
50.1 MP
Pixel dimensions
8,669 × 5,779 px
Aspect ratio
3:2
Pixel pitch
4.15 µm
Crop factor
1.00x
Circle of confusion
0.0288 mm

Full Frame sensor · DoF & Hyperfocal Calculator · Astro 500/NPF Calculator

Reusing the identical sensor means every depth-of-field, hyperfocal and astro-shutter-speed figure on this page applies equally to the original a1 — a genuine case where a full model generation passed without any change to the core imaging chip at all, unusual for a flagship refresh cycle.

Sony also carried the a9 III's AI-processing autofocus chip into the a1 II, a genuine capability upgrade over the original a1's autofocus system despite the unchanged core sensor. A real, meaningful autofocus upgrade. A real, tangible tracking improvement.

See these numbers used live in the DoF & Hyperfocal Calculator by selecting the Full Frame sensor format.

Frequently Asked Questions

Is there any reason to buy the a1 II over a cheaper original a1 for image quality?

Not for sensor performance specifically — they share the identical 50.1-megapixel sensor, so resolution, depth of field and astro shutter-speed math are the same on both. The a1 II's real upgrades are in autofocus tracking and handling, which matter for many photographers but aren't sensor-level differences.