DXO Optics Pro Rocks!
I have written about how to correct Fisheye images in this blog before. Now the team behind DXO Optics Pro have built support for the combination of Canon 5D MarkII and my Canon 15 mm f2.8 Fisheye.
And look no further. The best fisheye correction you can get is here. DXO analyze the different lenses in detail. On the specified camera. So you need to check if they have a module for your lens / camera combination. But if they have, DXO does the best corrections possible.
My original image
Corrected with DXO Optics pro
Corrected with DXO Optics Pro with new aspect
All sorts ...