This is something I put up on cavediver.net where we discussed housings.
I have tested three different brands of aftermarket housings/lenses. Backscatter, Eye Of Mine, and Snake River Prototyping. All of them are very nice. I give the advantage to backscatter personally. The one flaw we have found in the Snake River is the screw in lens. That acts as a flat lens. Ours cracked. Now this did not allow water in, as you still have your factory lens in place. According to Snake River, this happens in approx 1% of their lenses, but they do replace them free. The Eye of mine seems well made. I am currently ordering a Mako lens to try on my factory housing. It will be the first lens I try. I expect some vignetting in 1080 wide, but in medium I should see none. It was this way with the first backscatter housing we tried, which was the same concept as Mako. Backscatters new housing is made much different now, and we get no vignetting.
Just to give some clarifications on my last post.
The Snake River Prototype housing itself is very well made. It consists of a the factory housing with a flat lens adapter screwed in place. The flat lens comes from the filter that is screwed in place with an o-ring seal. The entire unit is rated to 180". The problem is not with the housing, but with the lens. They purchase the lens from a different manufacturer. What happened with ours is at a depth of 85' the lens cracked from the pressure. You could hear it when it happened. Snake River did send a new one that same day that it was reported to them. They said that around 1% of the lenses have that issue. The lens it happened to was a red filter lens. The clear lens has not had an issue as of yet, and has been to 80'. Another Snake River setup that we tested was the do it yourself kit. We have had it to 40' without issues, but have pressure tested it down to 200' without issue. So I would have to believe Snake River that this is a very isolated issue.
The Back Scatter housings we have tested have worked great. One is the new style with a glass lens and then either an option to screw on filters or use an o ring retainer to hold filters in place. This one works great. Buying screw in filters can cause vignetting, but very minimal. The ones sold by backscatter have none to very litle vignetting. The oring setup has none. The other style is their older style that they quit producing in December of 2011. It is an acrylic port and has slight vignetting in 1080 W, but none in the medium FOV setting. However, the acrylic lens scratched easy. Very easy. You can buy polishes to remove the scratches though. The other fall back of this housing is if you want to use filters. In OW a red filter is a must in most cases. You have to use a product called Magic Filter and cut filters to fit. Cut the filter even a hair to small, and it will show in your video.
The Eye Of Mine has worked good so far, but you either need to order a red filtered housing that is not removable, or use the Magic Filters as well.
These options are not cheap. I just ordered some flat lenses from Mako. They are acrylic, so they can scratch easier then glass, but I want to try to find a cheap option to recommend to folks. Once I have them here, 2-3 weeks, I can let you know what I think if you like.
I hope this helps in some way. And just to add one more update. The Eye Of Mine that we are testing is the one that does not have a red permanent filter. We are now wanting to add a filter to it, but are having avery hard time doing it. The way it is designed, getting a magic filter to fit is downright impossible. Also, the top if the lens area has broke. It has not let water in, but I don't trust it anymore. My buddy is still using it.
I have not got the Mako lens yet to try.
As for filters, I have used the Magic Filter sheets, one by Intova, and the one that snake river sells. I think the Intova one provided the best color at depth. The Magic Filter gel started to lose color around 30 feet. The Snake River one is the one that cracked, but it held color until about 50' or so. The Intova had color to about 60' and that was on a homemade flat lens setup that I made. I currently use a L&M SOLA 1200 light with all my video, day or night. This has brought out the color better than any filter. I still use the filters, but supplement them with the lighting.
I hope this helps in some way shape or form for you. If I was to order all over again, I would go with the new backscatter setup first, and the Snake River next. Next up, the 3D setup!!!