bornish
lvl.4
Flight distance : 91447 ft
United Arab Emirates
Offline
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Howie,
I think the movements you have described should work pretty well as ICE matching algorithms are pretty good in stitching frames from such camera movement. The software is able to detect both vertical and horizontal camera movements in a set of imagery and you will end-up with a spherical projected panorama. We all can try different styles of recording and see which ones work best. So far, my experience has lead me to draw the following conclusions:
- do not move the position of the I1 during panorama recording; GPS accuracy seems to be good enough to maintain the camera in approximately same spot, which is an assumption made by all software creating spherical / cylindrical panorama
- we get less parallax in a spherical / cylindrical panorama the further we are from the surroundings, thus we can expect much better results when the I1 is at a higher altitude; being further means less details but stitching of these frames at different angles will have better results
- when panning horizontally, I prefer to rotate the I1 not the gimbal, because:
* gimbal's controllable pan range is 320 degrees, thus panned recording needs to be done from -180 to 180 for a full 360 degrees coverage; I find that more difficult than 360 rotation of the aircraft
* when rotating the I1, the gimbal will try to compensate for uneven rotation speed when set in follow mode; I consider this a great feature of the gimbal, in addition to its known 3D stabilization of the camera
* it is possible to have the landing legs appear in camera view while panning the camera through gimbal motion; even with the landing gear raised completely, wind guts may force the I1 to tilt enough and bring the lower part of the leg in front of the camera view; keeping the camera looking in front of the I1 will never be obstructed by propellers / legs, as long as the wind speed / guts are safe to fly
- when taking semi-spherical panorama from higher altitude, we may not need to horizontally pan twice; having the camera tilt at 30 degrees should cover the horizon line (vertical FOV is aprox 60 degrees) and we will only need to cover the non-visible cone of 30 degrees radius bellow the aircraft; with a horizontal FOV of 94 degrees, this cone can be covered by 2-4 camera tilt movements to 90 degrees (straight down); thus, after completing a 360 revolution of the I1 with camera tilted at 30 degrees, one may choose to:
* tilt the camera angle from 30 degrees to 90 degrees, rotate the aircraft 180 degrees, tilt back the camera from 90 degrees to 30 degrees
* tilt the camera angle from 30 degrees to 90 degrees, rotate the aircraft 120 degrees, tilt back the camera from 90 degrees to 30 degrees, rotate the aircraft another 120 degrees, tilt again the camera from 30 degrees to 90 degrees
* tilt the camera angle from 30 degrees to 90 degrees, rotate the aircraft 90 degrees, tilt back the camera from 90 degrees to 30 degrees, rotate the aircraft another 90 degrees, tilt again the camera from 30 degrees to 90 degrees, rotate the aircraft another 90 degrees, tilt back the camera from 90 degrees to 30 degrees
- using the radar in the DJI Pilot application can help a lot when rotating the aircraft for spherical / cylindrical panorama; until an SDK will be available from DJI, no automation of these movements can be achieved
- using the timeline camera mode to take regular snapshots instead of video recording may result in an unresponding camera features even when signal is lost for a short time; this happened on Android and the only way to regain control was to close and restart the DJI Pilot application
- extracting frames from 4K video proved to have the following advantages for creating panorama:
* video ISO range is 100-3200 as compared to photo ISO range 100-1600
* even extracting 1 in every 8 frames from 4K video, we still get 3 stills every second; timeline mode does not offer such frequency and manually taking snapshots without dual operator ain't much fun
* one video file is much easier to handle during post processing than hundreds / thousands of image files
- using auto camera settings is widely discouraged for panorama creation and main reason is the color correction and matching of the images that need to be stitched; with video frames though, when camera movement is slow, there is a huge overlap between frames and we have the choice to pick from multiple frames covering the same area; while the camera is auto-adjusting its settings, it is still recording a large number of frames and we have the liberty to choose the one frame that offers the best transition between them
I am looking forward to hear from others on their trials and observations.
For example, I would love to hear from someone trying to capture a spherical panorama through a spiral movement (aircraft horizontal rotation combined with a simultaneous tilt movement of the camera).
Best regards,
Bogdan |
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