Sony FX3 II and A7S IV: Everything We Know About the New 16MP Partially Stacked Sensor

The ecosystem of rumors around Sony is in full ferment and with compelling reasons. In the last few hours, the reference site Sony Alpha Rumors published (accompanied by an explanatory video on YouTube) what could be the most important leak of the year for filmmakers and videomakers: the first technical details of a new 16 megapixel full-frame sensor partially stacked, supposedly designed for the next Sony FX3 II and, perhaps in the future, for a possible Sony A7S IV.

Why 16MP and no more?

At first glance, going from the original FX3's 12MP to 16MP may seem like a modest jump. But the logic behind the design is very cinematic: more megapixels do not always equal better video image. With 7.2μm pixels, this new sensor would offer 41% greater light gathering capacity per pixel compared to the 5.1μm of the Sony A7V, potentially making it the new king of low-light video.

Additionally, a 16MP sensor has enough vertical resolution to record the entire sensor area in 3:2 ratio, allows for better utilization of anamorphic lenses, and can deliver a RAW output close to 5K, which can then be upsampled to 4K.

DCG-HDR Technology: A Qualitative Leap

Perhaps the most interesting detail is not in the megapixels but in how this sensor manages the dynamic range. Instead of using the DGO technology of the Sony A7V, the new sensor would employ DCG-HDR, a technology first used in the Sony Lythia mobile sensors. The difference is significant: while traditional multi-frame HDR captures separate exposures and merges them (generating ghosting in moving subjects), DCG-HDR captures single-frame data using two gain settings simultaneously, eliminating those artifacts in both photos and video, even with an electronic shutter.

And the Rumor of the 33MP?

It is worth clarifying that found versions are circulating. Previous rumors suggested that the FX3 II could include a 33MP partially stacked sensor similar to that of the Sony A7V, but the source of Sony Alpha Rumors pointed out that those specifications circulating on the web are probably false. For a cinema-focused camera like the FX3 II, larger pixels are more valuable than more pixels: better low-light performance, lower rolling shutter, more affordable high frame rates, and lower processing load.

When does it arrive?

The announcement of the FX3 II is anticipated for March or April 2026, and Sony has already registered a new camera with the code WW847606 whose main declared innovation is precisely a new low-resolution partially stacked sensor. On the other hand, the situation of the A7S IV is more uncertain: the source does not confirm its upcoming existence, and there is a possibility that the "S" line will be put on hold for a while.

What This Means to You

Whether you're a filmmaker, wedding videographer, professional content creator or simply an imaging enthusiast, this sensor represents a serious Sony commitment to pure cinematic performance. It's not the race for megapixels: it's the race for the clean image, true dynamic range in video and flexibility in difficult light shoots.

The next few months will be decisive. CP+ 2026 is already underway and the market is awaiting a response from Sony compared to competitors such as the Canon C50 and the Nikon Zr, which offer attractive proposals at a lower price.