I’ll keep the collected data at the top of the post and update as required. For tracking, BOTH Focal Length and Sensor Width are the main two factors required. I don’t have all these devices, so confirmation from board members who do and who have tested tracking will help validate the info here.
Model : Sensor Width (Landscape/Portrait) : Actual Focal Length : Focal Length (35mm equivalent) : ( Field Of View )
iPhone 3G/3GS : 3.39mm / 4.54 mm : 3.85mm : ??? : ( 37mm )
iPhone 4 : 3.39mm / 4.54 mm : 3.85mm : 29mm: ( 37mm )
iPhone 4S : 3.39mm / 4.54 mm : 4.28mm : 35mm : ( 43.2mm )
iPad 1/2 = iPhone 3G/3GS?
iPad 3 = iPhone 4?
To Test: When your point tracking looks good, you don’t have to re-do this part. Solving is where this camera info becomes important - it is required to convert the tracked points to 3D space. Different lenses make things look closer / further, so having a wrong focal length will really show when you try to match up eg a 3D plane with a tracked point in the corner of a room, and the source video. Correct numbers for both are key for getting this to work as accurately as possible before tweaking other settings.
Source Info ( info differs based on what sites you visit )…
The actual focal length on the original iPhone (2G), iPhone 3G/3GS, and iPhone 4 (rear-facing main camera) is 3.85mm.
The field of view (35mm SLR camera lens equivalent) for each model is listed here:
Original iPhone (2G): 37mm
iPhone 3G: 37mm
iPhone 3GS: 37mm
iPhone 4 (rear-facing main camera): 30mm
If the sensor is 3.39 mm tall (referenced to landscape mode), then half that is 1.695 mm. Focal length for the iPhone 4 is listed as 3.85 mm. atan(1.695/3.85) is 23.75 degrees from center to top, or 47.5 degrees top to bottom.
For the longer dimension 4.52/2 = 2.26 mm, atan(2.26/3.85) = 30.41 center to side, or 60.8 degrees left to right (again referencing with respect to landscape orientation).
So 60.8 degrees horizontal by 47.5 degrees vertical.
ADDED much later:
The focal length for the newer iPhone 4S back camera is listed as 4.28 mm, but with the same sensor dimensions as the older iPhone 4. So:
2atan(2.26/4.28) = 55.7 degrees, by 2atan(1.695/4.28) = 43.2 degrees
or roughly a 4 to 5 degree smaller field-of-view compared with the iPhone 4.
Seems there is a little mistake in previous calculations OV8830-G04A sensor has dimensions 4592x3450 um
Then correct angles are:
2atan(4.592/(24.28))180/pi = 56.423
2atan(3.450/(2*4.28))*180/pi = 43.903
It becomes very crucial in sensitive applications.
Focal Length (35mm equivalent):
iPhone 4 29 mm
iPhone 4S 35 mm
If any artists out there have been trying out the new Tracking and Solving feature of Blender, and using iOS devices for capturing the video, what settings have you been using for the Camera Data?
More specifically, what focal length and sensor width values are you using? If we can get this data for a number of popular handheld devices ( iOS / Android eg Samsung S2 ), we can see about getting the presets included with a future version of Blender.