[Bf-vfx] Footage for Tracking

[Andrew Hunter]

Hey everyone,

On Tue, Jun 14, 2011 at 12:27 PM, Andrew Hunter <andrew at aehunter.net> wrote:
> Hey Everyone,
[...]

I had another though that perhaps Keir can answer. Does subject
distance affect the calibration? Should the calibration charts be
taken from the same distance.

The reason I ask is that with wide focal lengths, where distortion is
most likely to occur, the subject distance greatly affects the
persption of depth.

Also, in order for the chart to fill the frame on different focal
lengths with the same sized chart (say an 18mm vs an 85mm) the subject
distance would vary greatly.

Would it make sense to default to a larger chart size like 11x14 or
offer several different sizes for different ranges of focal lengths?

Cheers,

Andrew