Flight times have changed for the same flight?

Summary of Issue:
We have several flight plans that we use repeatedly (make a copy of the old flight each time). I just did an update of DD, DJI Go, and UAV firmware (Phantom 4 Pro). Flying today, the estimated flight time was suddenly different than usual (~20min vs the usual ~13-14min). In order to get the flight time down, to complete the survey in 1 flight, I had to reduce the frontlap and sidelap. I’m wondering why this might have changed?

Date Issue Began:
Today (22-Nov-2017)

Drone Model:
DJI Phantom 4 Pro

Mobile Device Model and OS version:
IPad Air 2 WiFi + cellular (A1567)
iOS 10.2.1
DJI Go 4 4.1.18
Drone Deploy 2.61.0

I have experienced the same variance in flight times. Have you also checked elevation/speed/front lap/side lap/direction? I have.

Yes, I have. Everything is identical to the way it has always been. Notably, the flight speed during capture was slower than normal (~5m/s vs the usual ~7m/s) despite a lower frontlap setting (which should result in a higher flight speed).

As far as I could tell during the flight, the capture was running at the usual 2photos/sec (hard to say for sure though), so I would think the frontlap is just being more generous than usual. Looking at the photos though, the frontlap is definitely less than usual, which agrees with the settings (having reduced the frontlap to reduce flight-time).

What I have experienced is about 2 sec / photo. My flight time will automatically decrease as I increase front-lap. I think what we are experiencing is an anomaly in the maps vs flight. I noticed the change with the updated maps. Even when I log out and back in my times are unusually high and don’t change much when I change flight parameters. Have you run any tests of proposed time vs actual?

@rosscova Thanks for bringing this up. We have not had any reports of these different (longer) flight times. I will reach out to our engineering team for more info.

Thanks, Yusuf. To add a little more detail, I noticed that there is a setting in DJI Go which I haven’t noticed before (it may be new, or I may just not have noticed it), something like “hold camera steady during capture”. That seems like something that MAY impact on flight speeds during capture, IF it adjusts the behaviour of the UAV to assist in steadying the camera (I’d guess it’s just related to gimbal behaviour, but it is possible). Just a thought; I’ll do some testing next chance I get.

I’m interested to hear what your engineers think, and am happy to provide any more detail where I can.

Noticing another issue reported on these forums, I suspect the two may be linked. The issue related to the photo format being stuck at 16:9, and not able to change to 4:3. I suspect this may be the reason for the decreased flight speeds (to maintain overlap), and therefore increased flight times. I noticed the odd photo format, and tried changing it in DJI Go, but the change didn’t take effect in DD (I wrote it off at the time, but it seems logical now).

I don’t believe going from 4:3 to 16:9 would change the flight speed. We don’t look at that setting, we assume in our calculations that it is 4:3.

@rosscova Thank you for updating us with your issue. Unfortunately, we have not been able to reproduce your issue with your longer flight times. We are currently working on a new update that may solve these issues. As far as the issue with the 16:9 format, this has been fixed in our latest update so I would suggest updating if you have not already. Thanks for being patient with us as we try to find a solution to your flight issue. We will keep you updated.

Thanks Yusuf, the latest update has indeed fixed the 16:9 issue (great work DD team!), and @chasemgray is right, that hasn’t changed the flight times back to what they were before. I’ll keep an eye on how things go in the future. For now, we’ve switched to doing a survey in 3 flights instead of 2.