I tried to mount the Sony a7c camera on the handlebar of my bike and record a video that would demonstrate the effectiveness of the Gyroflow software stabilization. The lens I used was the Зенитар (Zenitar) 16/2.8 Fisheye, which has the widest field of view available to me.
Unfortunately, the clamp mount is quite weak for the weight, so the camera was shaking a lot. Any camera stabilization was disabled, but it wouldn't have helped either. But it is even more interesting to test Gyroflow.
Recorded at 4K/25fps.
Warning: YouTube has noticeably degraded the quality of the videos during upload.
Awful result, it's hard to watch (I get carsick watching a video like this). But the Sony a7c recorded motion (gyro) data, which can be used for stabilization with Gyroflow (great free open source software). Lens distortion (this is a fisheye lens) can also be corrected with Gyroflow.
Unlike Sony's Catalyst Browse software (native to the Sony a7c), Gyroflow is able to stabilize and correct video that was shot with a non-electronic lens.
The result of the stabilization (with the "Lock horizon" option enabled) and distortion correction:
It looks much better now. See how the original video footage has to be transformed to stabilize it:
That is why I use a fisheye lens, which has a very wide field of view and reserves for significant cropping. It's noticeable that there's a margin on the left and right, allowing for a wider video: ~21:9 instead of 16:9, for example:
However, the borders look quite blurry as result of the distortion correction.
In my opinion, Gyroflow works very well.
My experience with Gyroflow (to get better results):
1. Forget the 180° shutter rule. Motion blur will look bad after software stabilization. In this video I used a shutter speed of 1/200 (not 1/50). You could probably shorten the shutter speed even more. And the motion blur will have to be added in the post software processing to make a video look more natural.
2. You need to turn off all stabilization (OIS and IBIS). Gyroflow currently conflicts with Sony's camera stabilization.
3. The lens profile should be used. There are some, but you can build one even for non-electronic lenses. I have created a profile for this Zenitar.
4. Since version 1.5.1 Gyroflow automatically synchronizes gyro data and video from the Sony a7c. Before you had to do synchronization.
5. The Sony a7c sensor readout is quite slow, so it is necessary to enable "Rolling shutter correction" and set the correct "Frame readout time".
6. Theoretically, GPU encoding gives lower quality than using CPU.
7. The default settings work fine with the Sony a7c, but in complicated cases you can control the stabilization options: at least "Smoothness" for "Default" method and "Zooming speed" for "Dynamic zooming".
Generally speaking, post-process software stabilization based on motion (gyro) data is more controlled than software stabilization during video recording.
See also related notes:
- Gyroflow v1.6: Important update for Sony cameras (2024-12-28)
- Zenitar 16/2.8 Fisheye and distortion correction (2023-08-12)
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