Well, my shoot is over. Several important lessons learned. Man, that was a stressful morning!
I had (and always seem to have) compass calibration issues with my drones (Mavic2 and Mini2). I’ve posted here before about having to do this repeatedly- seemingly with every flight.
This time I simply could not get the compass calibrated even after 6 to 8 attempts at various locations in the middle of a field. No metal objects in the vicinity. I was going insane. My first battery was almost depleted already trying to solve this.
Then I found the probable cause.
I get cold hands. Even when it isn’t so cold outside, by hands get cold pretty quickly. And they get painful. Even wearing gloves doesn’t help much, but I had recently purchased some gloves with fold back thumb/forefingers specifically for when I am out doing photography. What holds the folded fingers back and out of the way? Little magnets in the finger tips!
Once I’d discarded these gloves the compass calibration seemed to work ok.
Next problem was litchi not doing when I expected with my carefully pre-programmed flight. I’d pre-visualised the flight using Google Earth Pro so I knew roughly what it should look like.
Litchi loaded in the mission. A simple 2x waypoint mission with the camera slowly rotating slightly as the drone flies from waypoint 1 to waypoint 2. Dead simple stuff.
I wanted the drone to get to waypoint one, start recording and hold position for 10 seconds then fly to waypoint 2 and hold position for a further 10 seconds then stop recording. Again, dead simple.
The problem was that at the first hold position the camera wasn’t pointing in the correct direction so when the movement began, the camera made an erratic rotation to where it should be pointing. It did this every time. Really weird. I needed a smooth flow from the hold to the movement.
When the drone came to waypoint 2 and held, it was absolutely fine. It was just the opening movement that would not work.
I did find a solution to this which involved pausing the mission just as it started its initial movement and starting the recording manually, then resuming the mission after 10 seconds. This seemed to work, but far from ideal.
Further issues I had with litchi were the heading setting needed correcting in the app. I can’t recall exactly what I changed but it was a bit annoying as I had pre-visualised the flight in Google Earth and it seemed fine there.
Also the altitudes were wildly different between litchi in pre-planning and the GPS of the drone when in flight. It was perhaps 10m or so different which would have taken me above the 120m restrictions. I therefore needed to manually change these in the field too. I realised there would be some discrepancy, but not this much.
So, I eventually got the shots I needed but it was hardly straightforward. I burned through my three batteries doing a simple shot like this and have now ordered another one as a backup for my next shoot!
If the site was closer to where I live I wouldn’t have been so worried, but this was a 3 hour trip and a hotel stay over so it needed to get done in one hit.
Wow, that was a long post, but hopefully useful to some?