New action camera and external battery
Posted: Mon Aug 09, 2021 9:01 am
I bought a new DJI Osmo Action Camera to replace my old GoPro Hero4 Silver. Here's a PIREP on the new camera.
The Osmo does 4K and has a very good stabilization system. The GoPro had no stabilization and it was hard to get rid of the jello effect caused by high engine power settings that transmitted the vibration through the airframe and camera mount. The jello effect is caused by engine vibration that is close to most action cameras' rolling shutter frame rate.
The Osmo has slightly longer 4K recording time than most of the GoPros at about 1:15. Like the GoPros, the Osmo suffers from a small battery. To solve that problem, I bought an Anker PowerCore 5000 external battery and mounted it securely on my home-built Manfrotto 429 ball head tie down mount. Here's a photo:
I was concerned about the cable from the battery to the action camera so I coiled up the excess cable and used a plastic tie wrap to secure it to the back of the PowerCore battery. That still left me a little concerned about the strong air flow pulling the connections loose in flight but it turned out not to be a problem. The external battery ran the camera until the 128 GB microSD memory card filled up with 4K 30 fps video in about 2:54.
The home-made Manfrotto mount turned out to be the best way to eliminate the "jello" effect with a couple of rubber washers and fender washers against the tie down ring. I have some good FlightFlix tie down ring and strut mounts but they are so tight that they amplify the jello effect enormously. FlightFlix makes a VibeX mount that is supposed to eliminate the jello but it costs $200 vs. my $50 Manfrotto mount.
Here's a 0:2:54 long video that shows the result on a test take off from my home base: https://vimeo.com/584925818/5eaf85d0cc
There's still a little jitter in the video so I'm going to add a couple more rubber fender washers around the tie down ring.
One disadvantage that I ran into with the DJI was the Mimo app on my iPhone that controls the camera by wifi. The app must be run continuously in the foreground to avoid disconnecting from the camera's wifi. If you switch to another app on the phone or turn off the display to save battery, then the app disconnects from the camera and will not automatically reconnect in flight. You have to land, stop the engine, turn off and restart the camera, then reconnect to it from the Mimo app. I suggested that DJI change this to make the app more useful. Other apps like GoPro's allow you to switch between apps without disconnecting. Also, the GoPro app will automatically reconnect to the camera using a combination of Bluetooth and wifi if it disconnects. Still, it's not a fatal flaw and I work around it by dedicating my iPhone to running the DJI Mimo app in the foreground and starting and stopping recording on the camera.
The Osmo does 4K and has a very good stabilization system. The GoPro had no stabilization and it was hard to get rid of the jello effect caused by high engine power settings that transmitted the vibration through the airframe and camera mount. The jello effect is caused by engine vibration that is close to most action cameras' rolling shutter frame rate.
The Osmo has slightly longer 4K recording time than most of the GoPros at about 1:15. Like the GoPros, the Osmo suffers from a small battery. To solve that problem, I bought an Anker PowerCore 5000 external battery and mounted it securely on my home-built Manfrotto 429 ball head tie down mount. Here's a photo:
I was concerned about the cable from the battery to the action camera so I coiled up the excess cable and used a plastic tie wrap to secure it to the back of the PowerCore battery. That still left me a little concerned about the strong air flow pulling the connections loose in flight but it turned out not to be a problem. The external battery ran the camera until the 128 GB microSD memory card filled up with 4K 30 fps video in about 2:54.
The home-made Manfrotto mount turned out to be the best way to eliminate the "jello" effect with a couple of rubber washers and fender washers against the tie down ring. I have some good FlightFlix tie down ring and strut mounts but they are so tight that they amplify the jello effect enormously. FlightFlix makes a VibeX mount that is supposed to eliminate the jello but it costs $200 vs. my $50 Manfrotto mount.
Here's a 0:2:54 long video that shows the result on a test take off from my home base: https://vimeo.com/584925818/5eaf85d0cc
There's still a little jitter in the video so I'm going to add a couple more rubber fender washers around the tie down ring.
One disadvantage that I ran into with the DJI was the Mimo app on my iPhone that controls the camera by wifi. The app must be run continuously in the foreground to avoid disconnecting from the camera's wifi. If you switch to another app on the phone or turn off the display to save battery, then the app disconnects from the camera and will not automatically reconnect in flight. You have to land, stop the engine, turn off and restart the camera, then reconnect to it from the Mimo app. I suggested that DJI change this to make the app more useful. Other apps like GoPro's allow you to switch between apps without disconnecting. Also, the GoPro app will automatically reconnect to the camera using a combination of Bluetooth and wifi if it disconnects. Still, it's not a fatal flaw and I work around it by dedicating my iPhone to running the DJI Mimo app in the foreground and starting and stopping recording on the camera.