Originally Posted by
Mike Buckley
The file format being used doesn't affect whether flare is present in the image; flare is an optical issue that will be recorded using any file format.
I actually haven't done much with capturing flare, so I don't know the ideal situation other than that the direct rays of the sun must not be blocked by a lens hood or other object. Different apertures will have different effects on the style of the flare and perhaps even the shape of the aperture will be apparent when using certain aperture settings, but I don't remember which apertures produce which effects.