I have morning mapping missions, where the light is much lower than mid day.
The app needs some way of warning the pilot that the image quality might be bad or unusable.
I flew a mission 35 minutes after sunrise and had significant blur, 50 minutes after sunrise and thought I was clear only to see the blur once I got the images to a real monitor. I ran other jobs 70 minutes after sunrise with no blur issues. Obviously guessing and timing is not always ideal and having a way know if your images are being collected without motion blur on site is critical.
I did not have the low light box ticked since there is no explanation on how that affects the settings, but it seems like this should have helped me a lot in this situation. Other posts show it just boosts ISO from 100 to 400.
There should be some way that allows the user to know if picture quality will have motion blur or not while mapping.
The simplest implementation of this would be to show your ISO and Shutter speed on the main window live so you can know at a glance what is happening and adapt accordingly instead of having to wait till after the mission completes to see.
In the case of my mission, auto settings(Mavic 3e) at 100ft altitude, 45 minutes after sunrise still results in 22mph + 1/125 shutter is still too much motion blur for “perfect” pictures. see attachment for example of blur. If I want this to be almost no blur, and 100ft mapping I can watch out for a shutter speed slower than 1/400.
Most likely there is a linear relationship(or a linear would be enough) from 100ft @ 1/400 to 400ft @ 1/100 and the app could flash an alert if the shutter is to slow. Slower shutter speeds at higher altitudes since the further away the slower the ground moves across the sensor. Your engineers most likely have a much better idea of what altitude vs speed and shutter speeds work well.
I am about to receive a Mavic 3E so I am not for sure but is the Low Light setting available? Also I know it is supposed to shoot faster with the mechanical shutter but the Phantom 4 was always limited to 16mph in my experience so running 22mph at 100ft seems very excessive, especially in that lighting. Hopefully i’ll be able to test soon and have a better answer.
Yes, I can confirm there is a low light toggle in the settings. It changes the ISO, but not the drone speed. Speed can be changed by toggling off automatic settings and it is under advanced settings for that mission. ISO toggle should increase it from 100 to 400 which is the same as dropping the speed by a factor of 4.
Regarding speed comparisons P4P vs M3E: The Mavic 3E being latest generation likely can chase a autonomous position much faster than the P4P so maybe the speed limit was related to the position planning instead of the camera quality.
I am still trying to learn the razor edge regarding shutter speed versus altitude and velocity. Theoretically the difference between 16mph and 22mph is a smaller effect than the difference between a shutter of 1/100 and 1/200 since doubling the speed will affect the motion blur the same amount as halving the shutter.
I think DJI is really pushing the time savings of the Mavic 3E hard and this increase in speed should be considered regarding acceptable shutters. In bright light the Mavic 3E does a good job even at ludicrous speeds.
Good, that is the behaviour and functionality I would expect. I think 22mph to 16mph in those conditions has a bigger affect than one might think but i’ll just have to wait for testing. Manual camera settings can be good but in 8+ years of mapping I have never had to go off auto except for darkness in which ISO 400 and/or slowing the drone down takes care of it. It adverse conditions like 50% cloudy image editing pre-processing is the way to go IMO.
The drone speed and amount of motion blur will be linearly correlated. There should be a simple equation to understand this relationship. Basically dronedeploy already calculates something similar when it gives you the pixels/inch based on height. Then using the inch/sec speed of the drone and 1/sec shutter you can calculate the amount of pixel slide an image will have.
For example a drone traveling 20mph will have a speed of 352 in/s. (Google convert)
A 150ft map will have a resolution of 0.5in/px (According to dronedeploy for mavic 3e). Other resolution vs heights below:
100ft → 0.4 in/px
150ft → 0.5 in/px → 2.0 px/in
200ft → 0.7 in/px
300ft → 1.0 in/px
400ft → 1.4 in/px
Note: for the operating ranges this is very linear, maybe it is just purely linear with round-off making it look less linear.
So for example if shutter is 1/200 and you are mapping at 150ft 20mph you get the following motion blur:
352 in/s * 2.0px/in * 1/200s = 3.52 px
Meaning over the 1/200s the image translates 3.52 pixels of motion blur. Now this might not be game breaking, but I think 1px or less should be the nominal minimum goal to shoot for.
If you ignore the shutter speed the number is just:
352 in/s * 2.0px/in = 704 px/s
Meaning a shutter faster than 1/704 would be needed to keep the motion blur to just 1 pixel.
There are other affects that unfortunately cannot be compensated for when the drone is mapping versus just hovering like for example, a picture taken at 1/60 sec shutter with a hovering drone will always be sharper than a picture at 1/2000 sec due to high frequency noise making it to the camera where the 1/60 shutter time allows these high frequency shakes to vanish. But as long as the drone is moving 8mph or 32mph your going to need a very high shutter speed to fight motion blur.
Hopefully this helps shed some light on why this feature should be easily implemented