Inconsistent overlap, number of pictures, and flight speed

Good day to all
I have designed a flight plan used in 3 different data collection mission. I hope someone can shed light on (1) why the flight speed is not followed and (2) on the 3rd flight, the overlap was not followed.

The plan have the following parameters:
Altitude: 30m
Flight direction: 15 degrees
Flight speed: 10m/s
Front lap: 85%
Side lap: 85%
Camera: Manual (iso:100, shutter:640)

The outputs are
1st flight
Flight speed: 2m/s
Number of pictures: 129
Image projections: image

2nd flight
Flight speed: 2m/s
Number of pictures: 129
Image projection: image

3rd flight
Flight speed: 8m/s
Number of pictures: 59
Image projection: image


The flight speed is based on altitude, front lap and recovery time for the camera to be ready to take the next picture. At that low altitude, it needed to fly at 2m/s to meet that criteria.

On the third flight, I would recycle power on the drone and controller and restart the app to clear out possible conflicts.

Magandang araw

Thank you Gary for the insight. I sort of figured out that the flight speed is a function of the overlaps but have not factored in the altitude and camera recovery time. I am puzzled by the outcome of flight #3. The flights were conducted at different dates but using the same flight plan thus I am starting fresh on each flight. No other app is running in the background.

BTW, I am using DJI P4, DroneDeploy v2.55.3, Samsung Tab S2 Marshmallow