Camera Calibration

[charliej]

When I hover my MPP and point the camera down so that it is pointing directly over an object I note that in fact the MPP is NOT directly over the object but a meter or so to one side. Is this normal?

 

[MAvic_South_Oz]

Hmm, not 100% sure.
With my MP, I've occasionally landed straight down with camera pointed directly down, and it seems to come down directly onto whatever was in the centre grid square (grid option turned on).
I'll have to check this next time I'm flying.

I wonder, does it really matter, or are you just checking to see if it's reasonably common ?
With camera calibration at start up each flight, I'm not sure there are other adjustments or finer calibration that can be done with that.
You can do a manual camera calibration, but that is just the same as the start up one I'm pretty sure.
It could make a difference if you were doing a forced landing to a clear area, but then as you get close to the ground the different should decrease markedly as it nears the ground, yes ?

Not sure if related in some strange way, but have you ever noticed / done a RTH with precision landing point recorded ?
(Not just the home point, but where you log the precision point after ascending straight up 10m.)
It should land within inches and orientation of where it took off from.

 

[WithTheBirds]

How far above the object are you? How do you know it is a metre out?

 

[old man mavic]

the best way to check if it is indeed out of line is to take off, put the camera all the way down come down over your take off mat get it centered, and then slowly gain altitude and see what happens as you go up, ideally you would need a calm day for this as the mav will move slightly in any strong wind dont forget that it is very difficult to accurately judge if you are directly over something as the distance and height that you are away from an object gives a false perspective, you could as you are directly over the mat at say 50ft altitude, walk away from that point and see how the perspective changes the further away you get

 

[THE CYBORG]

At what height do you notice this ?

If you descend to your landing pad (assuming you have one ) with the camera pointing directly down at what height dose the mat disappear from view ? At a meter out you wouldn't see any or only a little of the pad.

If you are a meter to the side by doing the above you should be able to tell how far out the camera is.

I can land on my pad using the camera pointing down even if I am some distance away.

 

[charliej]

Hmm, not 100% sure.
With my MP, I've occasionally landed straight down with camera pointed directly down, and it seems to come down directly onto whatever was in the centre grid square (grid option turned on).
I'll have to check this next time I'm flying.

I wonder, does it really matter, or are you just checking to see if it's reasonably common ?
With camera calibration at start up each flight, I'm not sure there are other adjustments or finer calibration that can be done with that.
You can do a manual camera calibration, but that is just the same as the start up one I'm pretty sure.
It could make a difference if you were doing a forced landing to a clear area, but then as you get close to the ground the different should decrease markedly as it nears the ground, yes ?

Not sure if related in some strange way, but have you ever noticed / done a RTH with precision landing point recorded ?
(Not just the home point, but where you log the precision point after ascending straight up 10m.)
It should land within inches and orientation of where it took off from.

Not sure it really matters except if you are doing a POI then you would need to take this 'error' into account in the radius.
I have done a precision landing and it pretty OK - in fact better than that!

 

[charliej]

the best way to check if it is indeed out of line is to take off, put the camera all the way down come down over your take off mat get it centered, and then slowly gain altitude and see what happens as you go up, ideally you would need a calm day for this as the mav will move slightly in any strong wind dont forget that it is very difficult to accurately judge if you are directly over something as the distance and height that you are away from an object gives a false perspective, you could as you are directly over the mat at say 50ft altitude, walk away from that point and see how the perspective changes the further away you get

I'll try this thanks.

 

[charliej]

How far above the object are you? How do you know it is a metre out?

10mts high - I walked under the drone and it was not where the camera was pointing!!

 

[Lowell Crabb]

Was there a wind that the MP was pitched into? I know when I hit the RTH button and watch it return, it seems to be off until it gets very close to the ground. Are you using a landing mat? I find that it (the drone) is much more accurate when using a mat with some sort of design on it rather than a spot on the concrete.

 

[old man mavic]

while the camera on the front shows what it sees on the screen and takes a snapshot of its surroundings when doing a precision take off, its the ones underneath that actually tell the drone where it is that is why as it comes down in a RTH as it nears the ground it will reposition itself and if it does not like what it sees it will refuse to land, regardless of where the main camera is pointing of course it is all combined with the compass, and satellites locked and all the info is stored in the IMU

 

[THE CYBORG]

10mts high - I walked under the drone and it was not where the camera was pointing!!

If your drone is 10 metres above and you think it’s camera is 1 metre out how can you possibly accurately know you are directly under it ?
I don't intend to sound condescending but either I am missing something or I don't think you have a problem.

 

[MAvic_South_Oz]

Was there a wind that the MP was pitched into?

If your drone is 10 metres above and you think it’s camera is 1 metre out how can you possibly accurately know you are directly under it ?

These are 2 definite possibilities.
Wind could cause pitch towards the direction of force and tilt the camera too.

To check for sure, try a very still day, take off from a point on the ground, and check again as it rises, or do a hand launch and watch yourself on the device as it rises to a similar height.

 

[Brevanskc]

Am reading this thread with much interest as I have the same condition. I have had my MPP 3 weeks and and have used a 2.5' painted board as a landing pad until recently and never checked to see if this condition was evident out of the box.

Charliej did you ever resolve the issue and if so how did you do it?

 

[charliej]

Am reading this thread with much interest as I have the same condition. I have had my MPP 3 weeks and and have used a 2.5' painted board as a landing pad until recently and never checked to see if this condition was evident out of the box.

Charliej did you ever resolve the issue and if so how did you do it?

Not resolved yet. But need to do more 'scientific' research!!

 

[Brevanskc]

It is a little annoying but the unit seems to fly well and all the other camera settings seem to be working fine. I will also do a little more research and post if I find anything useful.