I'm trying to determine out the actual focal length of the Mavic Air camera, not the 35mm equivilent focal length.

Does this help??
Lens        FOV: 85°
35 mm Format Equivalent: 24 mm
Aperture: f/2.8
Shooting Range: 0.5 m to ∞

Simmo1 Posted at 2018-5-27 15:41
Does this help??
Lens        FOV: 85°
35 mm Format Equivalent: 24 mm

I am trying to figure out what the physical focal length is - not the equivalent.

Ahh sorry.

Should be 4.27046 mm at f2.8 (crop factor 5.62 with a 1/2.3" sensor size)

Keule Posted at 2018-5-27 23:05
Should be 4.27046 mm at f2.8 (crop factor 5.62 with a 1/2.3" sensor size)

Thanks, Keule! Can you share how you calculated that focal length? I found a conversion equation in a Pix4d article:

FR = (F35 * SwR) / 34.6 (mm)

where:

F35 = focal length that corresponds to 35 mm equivalent [mm]
FR = real focal length [mm]
SwR = the real sensor width [mm]

For the Mavic Air:

FR = (24mm * 6.17mm) / 34.6mm = 4.27977mm =  4.3mm (2 sig figs)

Our numbers are in agreement, but I'm curious if there's another way to get at the focal length. Also curious why DJI doesn't list it in the specs.

I just looked up the crop factor of an 1/2.3" sensor. That's 5.62.
The AIR has an 35mm equivalent focal length of 24mm.

24 / 5.62 = 4.27046263

That was my lazy approach ;-)

For what it's worth, DJI does attach focal length to the image Exif. For the Mavic Air, it's 4.5mm.

NITER Posted at 2018-5-28 11:07
Thanks, Keule! Can you share how you calculated that focal length? I found a conversion equation in a Pix4d article:

FR = (F35 * SwR) / 34.6 (mm) where:F35 = focal length that corresponds to 35 mm equivalent [mm]

hi, im reading all forum , can you send me the link with PIX4D article where they show the equation?

thanks for your help

kind regards carlos

fans0b2d57d2 Posted at 2019-10-31 03:35
hi, im reading all forum , can you send me the link with PIX4D article where they show the equation?

thanks for your help

Check this forum treat. It contains the Pix4D calculator. Hope this helps.

Search in google:
How-to-select-Camera-Focal-Length-and-Flight-Altitude-considering-the-desired-Ground-Sampling-Distance-and-Terrain-to-map

fans0b2d57d2 Posted at 2019-10-31 03:35
hi, im reading all forum , can you send me the link with PIX4D article where they show the equation?

thanks for your help

Search in google:

Pix4dENGusermanual.pdf

equivalent focal legnth = (crop factor) x (actual focal legnth)   and the crop factor is (43.27mm / diagnal distance of respective sensor)