How wide(angle lens) is recommended to be used without creating image distortion?

Question

How wide(angle lens) is recommended to be used without creating image distortion?

Answer 1

You can get extreme wide angle lenses without any distortion accross the frame, i.e. not a fisheye effect, however lenses wider than 40mm in 35mm camera terms will distort the perspective (so that foreground items appear relatively bigger than the subject) whereas lenses above 40mm will start to compress the foreground and background around the subject, the distortion will increase the further you deviate from the 'standard' view.

Sigma do a 12-24mm lens (in 35mm terms) that doesn't not distort the subject other than by perspective.

Answer 2

all lenses have a distortion because the picture is taken from a point source.  but a good 28mm (in 35mm format)  is considered the widest you can go before incurring distortion