On 9-6-2013 11:19, scott wrote:
>
> For my sun radius calculation I used the values from wikipeda, distance
> to sun is 1.5e8 and radius of the sun is 6.96e5, dividing those two
> gives the 214.8.
>
> IMO it also depends heavily on the angle/focal length of the camera you
> are using, you can easily make the sun or moon look way too big or way
> too small (IRL and in POV). In Stellarium there's even a toggle to make
> the moon 4x realistic size because it just seems more "natural", it may
> be a similar reason why Cousin Ricky put in the factor of 2.

It is probably an unconscious tendency to 'see' the Sun (or Moon) bigger 
than they really are.

>
> Note that if you increase the size artificially and are using the sun
> sphere as an accurate light source for radiosity (or mcpov) you probably
> want to reduce the emission value accordingly (if making the radius 2x
> bigger the area will be 4x bigger, so reduce the emission by a factor 4).
>

True.

Thomas

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