Please select Into the mobile phone version | Continue to access the computer ver.
Mavic Pro 8 Sec Exposure Drift
1328 12 2019-8-17
Uploading and Loding Picture ...(0/1)
o(^-^)o
wash81
lvl.1
Germany
Offline

Hello everyone,

i have a question regarding stability of the Mavic 2 Pro itself or the Gimbal with long exposure. I never made any nighttime shots before and thought the Tripod Mode will give me good results on a night with no wind. Unfortunately all images i took looked the same. I see a constant drift with 8 Seconds. Has anyone seen similar results with their Mavic 2 Pro? Im running the Latest Firmware!

Best
wash
DJI_0219.JPG
2019-8-17
Use props
gnirtS
Captain
Flight distance : 5712575 ft
United Kingdom
Offline

You;re asking something which is impossible on any drone.

Firstly, tripod mode does NOT increase stability in any what what-so-ever.  All it does is reduce the sensitivity of control inputs and reduce the max speed so it wont do anything.

8 second is a very long time.  We have a lightweight chunk of plastic in the sky at the mercy of wind, turbulence, thermals and everything else.  Even a "still" night the air moves.  The IMU/Gyro does an amazing job of keeping it in the right area as does the gimbal but it cant work miracles.
In addition the GPS is only accurate to within 3m or so meaning the craft will drift around a circle roughly that size as well.

8 seconds is only ever going to be clean with a proper camera on a proper tripod.  No drone in a real world environment is going to be able to remain totally still for that large amount of time.

Ultimately in perfect conditions you can get an acceptably sharp image in the region of 1-2 seconds at most with the drone.


Just to prove the point, on a calm night launch the drone and hover it close to you and low.  Now look at it, you'll see it constantly correcting in 3 dimensions to maintain its position.  Its not utterly solid and unmoving - it cant be.

2019-8-18
Use props
Tollytastic
Second Officer
Flight distance : 30932 ft
France
Offline

Hi wash81,


I am always amazed how stable the video from my Mavic 2 is but to get an 8 second exposure from a drone will be impossible unless NASSA build their own.  Any movement at all will be recorded as blur, so don’t worry your drone doesn’t have a fault.

Looking at your photo I’m surprised how good it is. I am also into astrophotography and to get long exposures of the stars taking account of the rotation of the earth I have to use a camera/ telescope mount which costs many time the amount of my Mavic 2 pro and weighs 45kg.

Hope this helps

Tolly


2019-8-18
Use props
hallmark007
Captain
Flight distance : 9812789 ft
  • >>>
Ireland
Offline

Using tripod mode will do no harm, tripod mode will only preform in very good gps, what you actually have is a pretty heavy mass in the sky , don’t forget if it fell on your head no one would be calling this light lol,  not a light plastic object.
Yes you can see drone moving very slightly in no wind , and a little more in stronger wind, but you have to take into account while the drone moves this doesn’t necessarily mean gimbal is moving, I can move my Ronin S 90 degrees up left and up right and it will cause almost no movement in my camera. GPS yes back when we had P3 P2 3 metres was about right, but much has moved on since and gps is much more precise in M2.
So while you should not expect to get perfect 8 second exposures, this machine can cope with up to 4 second exposures on a good day, I have posted many clean photos taken at 3/4 seconds on this forum.
This forum is full of well read self called photographers, it’s only when you view their work you realize that all they are is well read hobbyists.
Don’t be discouraged by first attempts, don’t expect this drone to preform miracles, but as I said it’s quite possible to get up to 4 seconds exposures, I have also seen many excellent fireworks images which usually take higher exposures than 3/4 seconds, so trial and error take as many shots as you can fly in tripod sport or P mode, whatever suits you, and good luck .

These photos were taken at 3 seconds, because this river was extremely dark because of almost full tree cover and they were taken with a Mavic Air .
2019-8-18
Use props
gnirtS
Captain
Flight distance : 5712575 ft
United Kingdom
Offline

Using tripod mode will do no harm, tripod mode will only preform in very good gps

No.  Tripod mode is absolutely nothing to do with GPS.
It reduces control sensitivity and maximum speeds.  GPS has absolutely nothing to do with it.  It'll "perform" exactly the same as P and Sport mode in that respect.  It simple allows you much smoother, finer control as you move the drone around (and side sensors to reduce the chance of hitting something in a confined space).

It doesnt change how it flies or hovers in the slightest.
GPS accuracy is also determined by physics and the satellites not the drone.  Without WAAS type corrections its about 3m and has been for ages.  That wont change without more satellites and differential corrections.
Its determined by the geometry of satellites available, the view of the horizon and atmospherics.  You cant change those and assuming a modern level, good receiver simply changing hardware wont do anything.

2019-8-18
Use props
hallmark007
Captain
Flight distance : 9812789 ft
  • >>>
Ireland
Offline

I’ve never heard so much tripe around here, now we’re told a better better gps satellite receiver will not give more accuracy, tell that to companies who pay thousands for their sat receivers.

The receivers are the most important hardware in a GPS operation. Their characteristics and capabilities influence the techniques available to the user throughout the work. There are many different GPS receivers on the market. Some of them are appropriate for surveying, and they share some fundamental elements. Though no level of accuracy is ever guaranteed, with proper procedures and data handling they are generally capable of accuracies from sub meter to centimeters. Most are also capable of performing differential GPS, real-time GPS, static GPS, etc., and are usually accompanied by processing and network adjustment software and so on.
2019-8-18
Use props
gnirtS
Captain
Flight distance : 5712575 ft
United Kingdom
Offline

Reading not your strong point or are you simply choosing to selectively ignore statements?
Which bit of " You cant change those and assuming a modern level, good receiver simply changing hardware wont do anything." do you not understand?  Would google translate help?

You might want to read up on something called "Physics" and then look up how GPS works.  They all have a base error determined by physical constraints such as atmospherics and importantly, geometry.  That error is known and calculated mathematically.  No matter how shiny a new receiver you have you are not going to get to or better than that error.  And that average error circle is roughly 3m.  You can pay 20x more for a GPS receiver and guess what - its not going to change that.

Having completely failed to understand that point you then move on to completely fail to understand how differential corrections, augmentation and everything else works and mentioning GPS for surveying which again you dont appear to have a clue how it works.  Without external calibrations, external corrections you are not going to increase any accuracy at all.  A survey or highly sensitive device to measure movement to within millimetres isnt a case of buying a really nice expensive receiver and pressing the "on" button. It requires substantial external setup and equipment.

There is no accuracy guaranteed but its mathematically possible to give a level where its impossible to get more accurate then.  A circle of probability.  Defined by those physical characteristics which the person has no control over.  And this changes as the satellites move.

The US Government (who know a thing or two about GPS as they actually created it) quote a 4m RMV accuracy for GPS without augmentation.  They attempt to guarantee a URE of <7.8m with 95% confidence.  The best its ever been in recorded history is 0.716m.  Maybe they should just "buy" better receivers to get around that problem?

IF you have WAAS and EGNOS you can get it down to sometimes 1-2m depending on conditions but thats it.  No amount of money on hardware is going to improve on that.

And back to drones, as DJI themselves and the manuals state there is NO "enhanced" gps mode.  Trpod, Sport, Position is all the same GPS hardware, same GPS error, same gyros and same position stability yet you persist on saying otherwise.
The drones are going to move around the same in ALL modes (assuming no visual positioning in use) and that wobble is going to be in a circle of 2-3m radius or up to 4 or 5m depending on physical conditions.  So for long exposures in several or tens of seconds, forget it.  Its not happening.

2019-8-18
Use props
hallmark007
Captain
Flight distance : 9812789 ft
  • >>>
Ireland
Offline

gnirtS Posted at 8-18 11:00
Reading not your strong point or are you simply choosing to selectively ignore statements?
Which bit of " You cant change those and assuming a modern level, good receiver simply changing hardware wont do anything." do you not understand?  Would google translate help?

It seems without Wikipedia you wouldn’t have a clue, I can tell you as someone who has both built and flown gps drones for a long time now, that you claim of accuracy ONLY being within 3 metres for this drone is pure rubbish, as someone who has both owned P2 and P3 drones I can tell you that receivers have been upgraded in all dji drones since then, and all new gps systems offer greater accuracy.

I noticed you also choose to ignore the fact you clearly said drone moving in the wind being corrected by CPU command to IMU somehow moved the gimbal, you also ignore the FACT that there is no difference with flying tripod mode when taking long exposures, but think you have some job pointing out to others that somehow according to you they shouldn’t rich coming from an idiot.

This is about someone looking for information on how to take long exposures with his drone, I’m certain he wasn’t looking for the Wikipedia book to be thrown at him.
Stick to these drones, many have accomplished long exposures at higher values than 1/2 seconds, you might not have but no one needs to know your inadequacy towards long exposures, they’re  looking for opinions, not to be told they can’t do something by someone who just can’t manage it himself, maybe check with the founders of gps how they manage long exposures and keep your drivel and diatribe to yourself.
2019-8-18
Use props
hallmark007
Captain
Flight distance : 9812789 ft
  • >>>
Ireland
Offline

I think this video will show you it’s quite possible to get good photos between 5/8 seconds, contrary to what others would make your believe.

2019-8-18
Use props
Tollytastic
Second Officer
Flight distance : 30932 ft
France
Offline

hallmark007 Posted at 8-18 13:46
I think this video will show you it’s quite possible to get good photos between 5/8 seconds, contrary to what others would make your believe.
https://youtu.be/eb4GaxAeyBU

Wow, thanks for posting this video as I didn't think that this would be possible, just shows its live and learn
Cheers

Tolly
2019-8-18
Use props
wash81
lvl.1
Germany
Offline

Hello everyone,

thanks for the explantations! I have to admit that i asked a little innocently with a purpose. I started digital photography in 1996, so i have some knowledge about using Digital Cameras, but i have no experience with Cameras on drones, and i assumed that if 8 Seconds are on the Menue, i can use it and get acceptable results. I just want to make sure my drone is working correctly and the performance is similar with other Mavic 2 Pros. If someone would tell me that such a drift was never experienced on their drone, i would ask DJI to check my drone. I recalibrated Gimbal and IMU after this and will test in the next days if i see and improvement.

Best
wash
2019-8-19
Use props
hallmark007
Captain
Flight distance : 9812789 ft
  • >>>
Ireland
Offline

wash81 Posted at 8-19 01:19
Hello everyone,

thanks for the explantations! I have to admit that i asked a little innocently with a purpose. I started digital photography in 1996, so i have some knowledge about using Digital Cameras, but i have no experience with Cameras on drones, and i assumed that if 8 Seconds are on the Menue, i can use it and get acceptable results. I just want to make sure my drone is working correctly and the performance is similar with other Mavic 2 Pros. If someone would tell me that such a drift was never experienced on their drone, i would ask DJI to check my drone. I recalibrated Gimbal and IMU after this and will test in the next days if i see and improvement.

There was a time with GPS receivers in dji drones that gps accuracy would be somewhere in the region of 3 metres this was pre 2015/16 receivers now in dji drones are much more accurate down centimeters, it’s very easy to test holding power of gps in your drone, just fly above VPs height and hover you will see then how incredibly steady your drone is and how gps holds its coordination.
We may see drone moving slightly while hovering but this slight movement has little or no effect on yout gimbal, this is a testament of the exceptional gimbals on dji drones, I have taken many shots with my drones at very low shutter speeds with great sharpness in pretty high winds and this is due to fat that dji make great gimbals .
2019-8-19
Use props
KerryG
First Officer
Flight distance : 11736709 ft
  • >>>
United States
Offline

Conditions have to be pretty much perfect to pull off an 8 second exposure. Just because there is no wind at ground level doesn't mean there isn't any wind or other turbulence at higher altitudes. I have done it numerous times, but more often than not, it doesn't work out. Its just a matter of having the ideal conditions.
2019-8-19
Use props
Advanced
You need to log in before you can reply Login | Register now

Credit Rules