Hi, some feedback on the 45 degree viewfinder that I just tried out on my Ikelite housing. First, to install it your need the Nauticam 33103 viewfinder mounting ring for Ikelite housings. Mounting the ring with the viewfinder is rather easy, and in this respect I found the instruction video by Kelli of Bluewater very useful.
My first opinion is that this viewfinder is a nice improvement (compared wth the Ikelite standard finder) because of its clear enlarged view of the object you are focused on. I think it can be very useful, not only for macro but also for fish-eye shooters that like to focus of very close subjects (like in CFWA shots). If you decide to switch back to a standard (flat) viewfinder during your diving trip its better to stick to the Nauticam standard model (Optical Viewfinder 0.66x) instead of re-installing your old Ike viewfinder.
The negative part concerns the ergonomics after you have attached the viewfinder to the housing, First, handling of the push buttons left and right of the viewfinder can be somewhat problematical, if you rotate the viewfinder. Second, inspection of of the full LED screen on the back of the housing (e.g. to inspect the result of your UW shot) is only possible if you tilt the housing in a slightly forward position. See the pics for clarification.


