Did some more tests with the Phantom 4 Pro:
The into the sun shots just capture a lot of flare and the sun star is very much Samyang 14mm like. This is an issue and it reduces the image acuity for 3D point cloud modeling for object measurements as well as for the landscape panorama approach.
The against the light shots look very much like the Samyang/Rokinon 14mm lens character. The sunstar has light rays that increase in size from the center and these rays cover the full frame of the 1inch sensor when the illumination comes from one of the outer edges. It clearly degrades the full image when the lens is stopped down to f.e. f8 but gets better when the lens is driven wide open. There seem to be some diffraction effects at work that are clearly not so great. You can drive the camera to generate sharp sun stars, but as usual here the characteristics of this star make a difference to some of us. The Samyang like star is not so well received. The linked flare issue however is much more a problem because it is hard to avoid when you have the sun in your frame and when the lens is stopped down to f8 or f11. For some scenarios a lens hood may be useful but its only functional for those shooting scenarios where the sun is not within your FoV.
To be honest I am bit puzzled … this is the first affordable 1-inch sensor platform with nice resolution and better DR, but – the flare issue is likely killing some of the potential ideas that you might develop with this machine. A pitty!
Comparison shot done with the Phantom 3A, clearly shows that the lens/sensor combi wont give the same amount of flare here (again different light level and different sun illumination angle):
Multicopter Photography and Photogrammetry
Late this year I bought a Phantom 3A (Advanced). The prices went down and these platforms are so affordable now that it makes sense to test it out.
The main applications for my work are multifolded:
- Special shootings for paying clients,
- regatta event shots from above,
- very early morning misty landscape stills and
- large scale or near range photogrammetric mapping for research purposes with applications in forest biomass mapping and archaeology as well as biotop-typ delineation and fine scale analysis of vegetation structure and slope stability analysis.
Clearly 1-3 and 4 will very nicely cooperate. Its just wonderful to experience how photography and research can come together here, makes me wonder sometimes how I managed to get into that cool spot where I get payed to fly a remote controlled camera … :-)
Being not new to copter flying, I found the Phantom 3 to be really easy to fly. Once you mastered the documentation and some basic theory about controlling a quadro-copter its really a simple excercise to control these devices. This is mainly due to the perfect GPS controlled position hold of the Phantom. It just stays where you put it (in opposite to gliders) and this makes it also kind of boring to fly a copter. The DJI GO app that is used on a mobile device to check the telemetry data and to control the lifeview provides a nice overview about position, viewing angle and overall status of your copter. You can also modify shooting parameters, change the camera viewing direction and check speed, height and remaining flight time, battery status and the number of satellites. Other apps support fully automatic mapping modes with variable overlap configurations (Data Mapper or Drone Deploy).
P3 installed on a LowePro backpack fully functional with installed props and ready to fly in a minute.
Some DJI Phantom 3 A Specs:
- Image Data capturing in 12MP Adobe DNG RAWs, gimbal stabilized! & damped. 2. HDR with 5 exposures each 0.7EV under/over-ex-> RAW DNG HDR computation. 3. Sony EXMOR 1/2.3“, 12.4MP, 94°lens (20mm focal length equiv. tilt.), ISO100-3200, 8-1/8000s, single shot, multiple shot, exposure series (3/5), DNG RAW format, video: FHD upto60p, 2.7k upto30p, 4. Memory: MicroSD up to 64GB cat10.
- Control: GPS/GLONASS controlled position hold, visual Realtime-Position-Tracking (VPS – Vision Positioning System) up to 3m flight alt. (P4pro: 10m). RTH (Return to Home Funktion), Battery Low RTH, Security-RTH, software controlled flight altitude (override possible): 120m, autostart/-landing, beginner modi, (OrbitModi/anti- collision (infrared/ultrasonic)/ActiveTracking/terrain follow: P4/pro/Mavic), P-GPS – GPS controled stabilising (+/-10cm position), P-OPTI (optical position control & stabilizing), P-ATTI modi (flight altitude only (barom.) – copter could start to drift).
- Flight parameters: weight: 1280g, climb: 5m/s, descend: 3m/s, Vmax: 16m/s (ATTI) – 60km/h, flight altitude max: 6000 m (airspace above 100 m needs a clearance (approval), RC max distance: 5km, flight time: 23 min (30min: P4pro), RadioControl: 2,4khz RC with iPad/iPhone (build in DJI Lightbridge System), realtime lifeview control per DJI GO App.
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