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

Hi Bobby,

Roel sent me a PM asking me to help out with answering your question (nice of him I think). Now I see that Ken has already done an excellent job so all that is left to me is to try to fill in a bit.

First, as you can see in this thread, I agree with your starting point that there are situations where the fisheye effect is just what you want as well as situations where it is distracting and where it is preferable to "defish" (or more generally, change to another projection). The OP of that thread (the one to which I linked) gives you an example of partial defishing to the Panini projection. In a later post here, I also illustrate the effect of defishing to the rectilinear projection.

As to software, I personally use (at least for the time being, I am a beginner as a fisheye shooter and defisher myself) a program called Hugin which is very powerful. Among other things, it can reproject to a large number of different projections, has considerable flexibility in exactly how to do it, and can also stitch images together into panoramas, not just reproject a single image. On top of that it is free of charge. In spite of its power, I haven't found it very difficult to use. Just a few simple steps are required for basic defishing. You find more information on Hugin here and some instructions for basic defishing here.

As Ken mentioned, if you have any version of Photoshop that can take plug-ins (anything from Photoshop Elements 2.0 on), you can also use Fisheye Hemi (see here). This is perhaps the most expedient option if all you want is standard defishing to Panini (you enter Photoshop, open the image, apply a filter, and save) but Hugin is far more flexible, not a whole lot more cumbersome to use, and can also, once you get familiar with it, batch process images which is more expedient than anything else if you have a lot of defishing to do. Fisheye Hemi isn't expensive but not free as Hugin.

Those who happen to have Photoshop CS6 can do defishing without any add-ons. Google "adaptive wide-angle filter" for further information.

Finally, for those who use Lightroom and want to defish to the rectilinear projection, Ken has been kind enough to devise a profile that lets us do that from within LR. You find more information about that here and some installation instructions here. The rectilinear defishing examples to which I linked in the second paragraph above were accomplished by means of Ken's profile. Note that you need to adjust the "scale" slider in the "manual" section of "lens corrections" in LR to see the defished image in its entirety. LR maintains the 4:3 aspect ratio by default but after defishing to rectilinear, the image is more like 2:1.