No 33MP partially stacked sensor for the Sony FX3 II? New 16MP rumors emerge

Launched in 2021, the Sony FX3 is long due a replacement. However, its 12.1MP sensor may not be getting the resolution boost expected.

Earlier rumors suggested that the Sony FX3 II might feature a 33MP partially stacked sensor, similar to the Sony A7 V. However, recent talks point to a 16MP partially stacked full-frame sensor as the more likely candidate.

As previously reported by trusted source Sony Alpha Rumors, "probably fake FX3 II specs [are] making their rounds on the web" – the biggest headline being the 33MP sensor.

While other cameras have 32-33MP sensors, the partially stacked Exmor RS sensor is specific to the A7V and FX2 lineup – making the 33MP rumor questionable.

The previous FX3 II rumors also highlighted 4K 60p and 4K 120p in crop mode, a tiltable EVF similar to the Sony FX2, 8.5-stop image stabilization with anamorphic lens support, and 32-bit float audio with an XLR accessory.

These specs, however, were marked "likely not true".

Now the website has shared that there's solid evidence Sony is working on a new 16MP partially stacked full-frame sensor. While it remains unclear whether this sensor will actually appear in the FX3 II, the talk is gaining traction among industry insiders and rumor trackers.

Sensor specifications (unconfirmed)

• 16MP (partially?) stacked  sensor
• Near 5k recording
• 240fps readout
• Active stabilization
• HDR video
• 2 PDAF system with 120fps

What does it mean in practical terms?

More megapixels are not always better (as more pixels = smaller pixels).

For a cinema-focused camera like the FX3 II, bigger pixels – like those on a 16MP sensor – deliver cleaner video, better dynamic range and more practical high-speed performance. Even if, on paper, a 33MP sensor sounds more impressive.

In the real world, this means better low-light performance (due to larger pixels), faster readout (reducing rolling shutter and enabling high frame rates), efficiency for 4K/5K oversampling, support for active stabilization with minimal crop, along with less heat and lower processing load for high-resolution video.

How realistic is the rumor?

Multi-layer sensor technology is designed to provide fast readout speeds while keeping resolution moderate, which in turn allows for larger pixels that excel in low-light shooting and deliver cleaner images – a key aspect of the original FX3, which was explicitly designed with a lower total pixel count to allow for larger individual pixels.

Supporting the rumors, Sony has registered a new camera under the code WW847606. Cameras with such codes typically belong to Sony's premium lines, including the A1, A9, A7S and FX3, making it plausible that this is indeed the FX3 II.

In the registration, the camera's main innovation was stated as a new, partially stacked, low-resolution sensor....

While the development of a 16MP partially stacked sensor seems credible within the rumor ecosystem, whether it will appear in the FX3 II remains uncertain.

With the FX3 II announcement widely anticipated around March or April 2026, we may not have to wait much longer to find out if this new sensor will become the heart of Sony's next cinema camera.

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