Comparing Fish-Eyes : Rokinon 7.5mm vs Zuiko 8mm (FOV and look)

I'm sorry that I cannot help on that subject.

Because I never use de-fishing software.

But I wonder if such software would discriminate between lenses used.  I think it would use optical information found in the image itself.  Or is the process of de-fishing purely mathematical, regardless of actual content, and are the algorhythms written to match with specific lenses?

Really, I would not know.

But you could ask in one of these threads, where people are talking about de-fishing in a very informed manner :

http://forums.dpreview.com/forums/post/50722127

http://forums.dpreview.com/forums/post/40689446

Or maybe ask KenW or AndersW.

--
Roel Hendrickx
lots of images: www.roelh.zenfolio.com
my E-3 user field report from Tunisian Sahara: http://www.biofos.com/ukpsg/roel.html