The Earth's Rotation Can Limit IBIS Performance

A lot of aspects of digital cameras get better with each new model, but a feature that consistently improves with almost every new generation is in-body image stabilization (IBIS). It’s a significant area of focus for camera engineers, as it benefits photographers and videographers alike by making it easier to capture sharp photos handheld and smooth, stable video without a gimbal or tripod. But did you know that IBIS performance can get so good that the rotation of the Earth itself actually limits it?

A recent discussion on Reddit’s r/photography subreddit brought up a 2020 article from The Center Column, a dedicated tripod testing website that has been inactive for the past few years.

In the 2020 post by David Berryrieser, he recalls Olympus Camera (now OM System) announcing the E-M1 Mark II in 2016. At the time, as PetaPixel wrote, Olympus noted that the camera’s 6.5 stops of IBIS performance was limited not by technology or engineering but by the very rotation of the Earth.

“The in-body stabilization itself gives 5.5 stops, and the Sync IS gives 6.5 stops with OIS lenses. 6.5 stops is actually a theoretical limitation at the moment due to rotation of the Earth interfering with gyro sensors,” Olympus Deputy Division Manager Setsuya Kataoka told Amateur Photographer in an interview in 2016. By the way, Kataoka continued with OM System as the company’s Chief Technical Officer.

In theory, if a stabilization system and its accompanying gyro sensor worked perfectly well, there is no limit to how many stops of correction IBIS could deliver. However, beyond six stops of correction, the Earth’s rotation adds a sort of noise to the system. Given the Earth’s rotation, a stationary subject on the Earth’s surface is rotating at 7.27*10^-5 rad/s.

A camera’s IBIS system compensates for camera movement in the photographer’s hand and helps keep the camera stable when pointed at a specific subject in a particular direction. Even if the camera is kept stable for an infinite amount of time, a stationary subject on Earth is always moving. In Berryrieser’s equations, beyond 6.3 stops of shake correction, the Earth’s rotation itself will cause visible blurring, even if the camera is perfectly stable.

While the 6.3-stop limit Berryrieser reached was based on a 24-megapixel full-frame camera, the results “will be consistent” across most cameras.

Many cameras since the E-M1 II have boasted IBIS performance beyond the 6.5-stop performance Olympus said in 2016 was limited by Earth’s rotation. As Reddit commenters quickly noted, the recent Hasselblad X2D II 100C promises 10 stops of stabilization, at least in the center of the frame when using the XCD 120mm f/3.5 Macro lens. Hasselblad admits that stabilization is eight stops at the edges of the frame. In either case, that’s more than 6.3 stops, so what’s going on?

As Berryrieser alluded to back in 2020, a camera can calculate exactly where a photographer is on Earth using GPS, an accelerometer, and a compass. Armed with this info, a camera’s stabilization system could calculate how to precisely compensate for the Earth’s rotation.

That is what the Hasselblad X2D II 100C does. As Hasselblad explains in its X2D II 100C Frequently Asked Questions, photographers must jump through some hoops to actually achieve 10 stops of stabilization.

“Each time X2D II 100C connects to Phocus Mobile 2, it obtains current latitude/longitude position,” Hasselblad writes. “Using location and compass information compensates for Earth’s rotation effects on stabilization.”

The company adds that this location information is valid for about four hours, but when a photographer’s location changes “significantly,” they should reconnect to Phocus Mobile 2.

While not related specifically to IBIS, it is also worth considering how Pentax has utilized its Astrotracer technology in DSLR cameras. Pentax combines its camera’s Shake Reduction (SR) IBIS technology with an external GPS module to compensate for the Earth’s rotation to capture sharp long-exposure photos of the night sky. The principle here is the same. Pentax uses global positioning data and its sensor-shift IBIS to adjust the sensor to counteract the Earth’s rotation.

A more recent Astrotracer Type 3 technology, introduced in 2023, removed the requirement for the GPS module, instead using a preliminary calibration frame to achieve the same results. This is useful because magnetic fields can affect the accuracy of a global positioning system. The downside of the new Type 3 method is that it requires visible stars, so if clouds roll in while shooting, the accuracy is reduced. This is similar to a solution Berryrieser posited, too, which involves a camera measuring rotational movement during test frames.

Camera manufacturers go through extensive engineering to improve IBIS systems, and it’s a complex matter that relies on improved hardware, more accurate motion sensors, and sophisticated software working in perfect harmony while taking up as little space as possible inside a camera. It is easy to take good stabilization for granted, but recent achievements in IBIS have been hard fought. Cameras have never been so stable, even if it can be very difficult to reach the results CIPA ratings suggest. But that’s a matter for a different day.

Image credits: Header photo by NASA