Summary: The camera on the Mavic Air is advertised with an 85° field-of-view. A careful test shows something very different!
I was puzzled to find that shots I'd carefully composed offline (using Virtual Litchi Mission) were not framed as I'd expected in the field. It became apparent that the advertised 85° field-of-view is not accurate. So I ran an experiment to measure the true field of view for the Mavic Air. Some walking and simple trigonometry gave the answer. Was I surprised! ?
Free to wander the campus of a local high school, and using a 50' tape, I measured a long baseline segment of a pillared wall (see below). I made sure each end of the baseline was the outside edge of a pillar, to make framing easy. The baseline--red in the diagram--came out to 220'. From the center of that baseline, I measured a perpendicular line--yellow in the diagram--out to 200', with stakes at 100', 150', and 200'.
I started the MA (without props) so that I could see and capture images hand-held. I put it into video mode, and walked along the yellow line, facing the wall, until the ends of the 220' baseline--the outside edges of the end pillars--barely touched each edge of the frame. I marked that spot on the yellow line, and then switched to photo mode. With its wider FoV, I had to move toward the wall to get the two pillars at the edge of the frame. Then I measured the distance of each.
The sketch below is based on a perspective view (from Litchi Mission Hub), so the yellow line is somewhat foreshortened and the proportions don't look quite right. Sorry; anyway, the numbers are what matters.
Here's the still image. Note the small yellow stake in foreground, with the tape measure attached to it and extending toward the camera; that stake is 150' from the wall:
And a frame of the video. (I'm actually a couple of feet too close, cutting off most the actual end pillars, so the true FoV is slightly less than I've calculated, closer to 58°). Here, note again the measuring tape that ends at that yellow stake. Neither the stake nor the tape were moved between images, but here--because of the narrower FoV in video--the stake is much farther away.
However DJI calculates FoV for the MA, it bears little relevance to reality. I'd be surprised if this is not true in varying degrees across the DJI lineup.
- When shooting video, the measured FoV is about 59° (actually, more like 58°, see below).
- When shooting still photos the measured FoV is 69°
I was puzzled to find that shots I'd carefully composed offline (using Virtual Litchi Mission) were not framed as I'd expected in the field. It became apparent that the advertised 85° field-of-view is not accurate. So I ran an experiment to measure the true field of view for the Mavic Air. Some walking and simple trigonometry gave the answer. Was I surprised! ?
Free to wander the campus of a local high school, and using a 50' tape, I measured a long baseline segment of a pillared wall (see below). I made sure each end of the baseline was the outside edge of a pillar, to make framing easy. The baseline--red in the diagram--came out to 220'. From the center of that baseline, I measured a perpendicular line--yellow in the diagram--out to 200', with stakes at 100', 150', and 200'.
I started the MA (without props) so that I could see and capture images hand-held. I put it into video mode, and walked along the yellow line, facing the wall, until the ends of the 220' baseline--the outside edges of the end pillars--barely touched each edge of the frame. I marked that spot on the yellow line, and then switched to photo mode. With its wider FoV, I had to move toward the wall to get the two pillars at the edge of the frame. Then I measured the distance of each.
The sketch below is based on a perspective view (from Litchi Mission Hub), so the yellow line is somewhat foreshortened and the proportions don't look quite right. Sorry; anyway, the numbers are what matters.
- The point on the yellow line where the outer edge of the end pillars spanned the frame in video mode (pink) was 195' from the center point of the red line.
- That yields an FoV of very nearly 58.9° for MA video.
- The corresponding point in photo mode (blue) was 160' from that center point.
- That yields an FoV of almost exactly 69° for MA photos.
Here's the still image. Note the small yellow stake in foreground, with the tape measure attached to it and extending toward the camera; that stake is 150' from the wall:
And a frame of the video. (I'm actually a couple of feet too close, cutting off most the actual end pillars, so the true FoV is slightly less than I've calculated, closer to 58°). Here, note again the measuring tape that ends at that yellow stake. Neither the stake nor the tape were moved between images, but here--because of the narrower FoV in video--the stake is much farther away.
However DJI calculates FoV for the MA, it bears little relevance to reality. I'd be surprised if this is not true in varying degrees across the DJI lineup.
