The Samyang 7.5mm is a fisheye designed for M4/3 format cameras and will yield a 180 degree full frame image on a 2x crop sensor. When modded for the NEX, this lens will yield slightly more than 180 degrees in a semicircular image. This here, as far as I know, is the smallest 360VR setup you can have. So far this Samyang lens has proven to be remarkably good (from others tests online). I have yet to do any shooting with it as I just got this all setup. You can see my trimming of the lens hood was a bit crude, and I realized I needed to trim just a bit more from the top petal.
To use this lens on the NEX bodies you need to do 3 things –
1. Get an MFT to NEX adapter (cheap on eBay)
2. Remove the ring from the rear (held on by 3 screws) – inside you will find three metal spaces, just take these out and then replace the ring. This allows the lens to achieve infinite focus on the NEX.
3. Remove the label ring from the front of the lens, its just glued on (do it carefully with a very small screw driver so you can replace it later) – once removed you will find 3 black screws holding the lens hood on. You need to completely trim off the smaller side petals, and the larger petals need 2-3mm removed so they do not show up in the image on the NEX.
You can also read more on others making this lens work on the NEX here: www.panoguide.com/forums/tipsntricks/9644/