I finally had a chance to test out my new 5.4mm Lens that I put onto my GoPro Black+. The results are interesting! First of all, it makes flying FPV way more difficult because you lose all of your peripheral vision, so be careful if you are flying low. It also ampliifies the effects of wind (I was flying the video below in about 15-20 mph winds). It also amplifies every little movement that you make with the drone and the gimbal. Despite these limitations and drawbacks, the output is pretty good and opens up lots of new opportunities for filming stuff that would not look good with a fish eye lens. I only have the 2 axis gimbal but I think the 3 axis one would make this fly better in the wind, so you might consider upgrading to that as well if you want to use this as your primary lens.
The still pictures are going to be much better for showing off the views and things in the distance. This is something I covered in my book on aerial photography and this might just be the inexpensive solution for those shots! Use the stock fish eye for shooting the actual structures and switch to this lens if you need to show the structure and the view. This way you do not need to fly a huge hexacopter or larger camera drone to get the different shots - you just have two GoPros that you swap out. Note that the horizon is NOT curved or fish eye, just a nice normal looking picture.
If you want to modify your GoPro Black + (this is the only one that seems to work easily with this mod) you need to know that you will void your warranty. I would recommend having two different cameras, a stock one and the modified one for serious aerial work. For most people the regular GoPro will be fine, but if you really want to add to your photo toolbox, it is so much easier to just add another GoPro than to build a different copter to fly a different camera. This is a great solution for me because although I might actually need an S900, I really want to avoid getting one if the phantom can get the job done. It is cheaper, simpler, and safer.
I bought the actual 5.4mm lens from here OSTRC.COM for $155
I also bought a dust ring cover and hood from PeauProductions.com who also sells the same lens. The dust ring cover fits over the lens when you screw it in and covers all the electronics underneath. I really needed this because I can fly in some pretty dusty and wet climates and I did not want my GoPro black+ to get all that gunk inside. The lens hood prevents lens flairs and I would recommend it. Both parts are very inexpensive and worth the extra trouble to get them.
Installing the lens is pretty straightforward, just watch a few different videos on Youtube to get up to speed. The focusing of the lens is critical and you should watch this video as well as some others before you try it. The GoPro LCD backpack is a great tool to help with focusing .
If you need more specific information or you have questions, please ask in the comment section of this blog post so others can benefit.