Defishing

Not Fisheye, but the good old 17-40 @17mm

No its not about putting fish back in after catching them, I read on a forum a discussion about normalizing or correcting the fisheye look from photos taken with a Fisheye. I have a 15mm Canon Fisheye and though I appreciate the effect and try to use it sensibly, sometimes I have thought “Hey thats a good photo, shame about the Fisheye look”.