You read that correctly. The brilliant Fujifilm medium format camera that was already shooting 100 megapixels, has just had an update to the firmware that introduces Pixel Shift Multi-Shot so you can capture 400 megapixel images.
Pixel Shift Multi-Shot is a feature seen in a few cameras, including one I reviewed, the Olympus OM-D E-M1 Mark III. It was a great addition to the micro four-thirds range as it allowed for better resolution where needed, which is an obvious pitfall of MFT cameras. However, Fujifilm's GFX 100 — a medium format camera — has just received the Version 3.0 firmware upgrade which introduces the same technology, taking the maximum possible resolution from 100 megapixels to 400 megapixels. So, if you wanted to take a portrait of somebody in a neighboring village, but you don't have a telescope, perhaps you can just crop in.
Here is Fujifilm's official explanation of what the process does:
In the Pixel Shift Multi-Shot mode, the camera takes a series of 16 raw images and by using in-body image stabilization(IBIS), moves the image sensor to get a high-resolution and real color* image. The multiple images are then combined to create a Digital Negative (DNG) raw file using the FUJIFILM Pixel Shift Combiner software.* real color : As a pixel of an image sensor has one color filter from red, green or blue, we cannot detect the real color for the pixel. We need to interpolate the other colors from the surrounding pixel data for that pixel. This is called the demosaicing process. In case of Pixel Shift Multi-Shot photography, we can receive red, green and blue data for every pixel position. This means we receive real color information when using Pixel Shift Multi-Shot mode and the demosaicing process is not necessary.
Unlike the Olympus, it does require you to use external software to combine the images, but having used the GFX 100 and experienced the size of their ordinary raw files, I think I can forgive them for not having the processing power and memory in-camera!