I was interested to find out what the difference was between filming with and without the Yi’s inbuilt lens distortion correction, once additional correction of the barrelling from the wide-angle lens had been corrected in After Effects.
|The images on the left are taken without the Yi’s distortion correction, and all correction in the lower image in AE, using Optics Compensation effect, FOV 74, Reverse Lens Direction on.
||The images on the right are taken with the Yi’s distortion correction. Further, correction in AE, using Optics Compensation effect, FOV 48, Reverse Lens Direction on.
The result (once all barrelling is removed) is very similar between the two. However, as the correction entirely in AE means that the image is being digitally blown up, a better image quality is probably obtained by using the camera’s inbuilt correction.
Additionally, when using the camera’s distortion correction the raw footage has less distortion in more distant objects. For some footage without near objects with identifying barreling features (such as straight lines), it may be possible to avoid using the AE effect entirely.
The first Yi camera that completely stopped working in the last test is now working when both the back of the camera has been removed, including the battery. The picture above show both front and back removed, although I have since reattached the front (which allows me to use the makeshift focus ring), and it also works like this.
I have now numbered each camera (just visible on the photo in the previous post), in the order they were purchased. Each camera has a different version of the firmware, and the later two are a different model to the first.
Using the found card model on the previous post, I noted each camera’s performance. Continue reading
In order to investigate the problems with some of the Yi cameras stopping recording, and to test the use of found materials for the models, I made a quick assembly from card from a recently purchased Ikea flat pack packaging. I will discuss the model and test filming here, and the investigation into the camera problems in the next post.
I recently bought a third Yi camera to allow three simultaneous recordings. I wanted to get this while they were still available as this camera has now been superseded by a larger and much more expensive version, with round edges so it won’t stand on its short edge.
The Xiaomi Yi camera has its lens fixed to one focal length, which according to reviewers, was set up for hand-held selfie distances. For my use, this set focus was slightly too far, but for most reviewers it was too close as distance action shots were not in focus.
Consequently, there was a plethora of sites explaining how to unfix the focus length by popping off the front facia and removing the three glue spots that held the lens in its pre-set focus. I wanted to be able to manually change the focus for different shots, so I also needed to remove the bezel around the lens so that I could continue to adjust the focus once the front facia was back in place.