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1.3. Camera calibration and settings
Before the shooting process will be started, you should calibrate focus of your DJI X4S camera and
set optimal image settings. It is recommended to use next order.
Before the shooting process will be started, you should calibrate focus of your DJI X4S PPK camera
and set optimal image settings. It is recommended to use next order.
1.
You should determine drone’s working altitude. This value
depends on many factors: scale of the final orthophoto map,
properties of the lens, height of the obstacles, features of relief,
etc. Usually, working altitude is from 60 to 120 meters.
2.
Set correct image ratio. Go to the image menu, tap the second
tab. Use the Image Ratio 3:2 value, it allows to use all square of
camera’s matrix. Do not use 16:9 Ratio! Check another values
of this menu – all defaults.
3.
Lift off the drone to the working altitude and move gimbal to the 90 degrees (nadir). Ensure that
focusing method now is in the AF value. Then tap to the center of the screen to let the camera
focusing at the surface. After that change focusing method in the MF value - manual focus scale
will appear. Do not touch it! Now drone’s camera is focused at the selected height value. It will
not change in the future.
4.
Now it’s time to set the best camera settings. All parameters are at auto as default. In this case,
drone will change image brightness, smoothness during the flight. But this way is bad for
triangulation image processing: key points at different images will be different. To get the best
image quality during the flight it is strongly recommended to set image params as follows:
ISO
: from 100 to 200. Upper values increase image noise, and decrease ortophoto map quality
Aperture:
from 2.8 to 4. Upper values decrease stream of light, so images will be darker
Shutter:
from 1/1600 to 1/640
.
Upper values increase image motion blur
,
lower ones does not
allow the camera to use mechanical shutter, so images will be distorced.
Shutter value higher than 1/1600 will not allow to mark GNSS tags!!!
