Trying to determine if I can create a wide angle solution. I'm not in love with anything currently on the market. (Fisheye requires you to pick before the dive ... Ikelite gives only modest improvement.) I have professional relationships with several machinists, prototyping companies, etc. but I can't source custom optics due to cost. So, the largest optics I can find have to be as large as the port to do any good. I haven't found anything yet.
That isn't the problem, port size, the problem is the distance from the primary objective lens of the camera and the rear optical element of the wet mount lens. These lenses are designed to work with a very close distance relationship between optical elements. The LONG zoom range (lens movement) required for the 6X and longer zoom ratio camera lenses requires a LONG port. The LONG port sets the front element of the camera's native lens to far aft of the rear optical element of the wet mount lens when set to their widest 28-35mm ranges. This causes severe vignetting of the image. Zooming in, depending on the particular wet mount lens, anything beyond 50mm equivalent mostly defeats the purpose of the wide angle wet mount lens.
Several people have made various adapters to mount bayonet mount AD lenses and 67mm threaded lenses. They have been able to utilize effectively various macro lenses but much less so with the wide angle end of the spectrum.
Normally folks with dSLRs do not change lenses underwater, not being able to change "mission" with a Patima or Fisheye G10 housing does not seem a problem to me. These domed lenses, the wet mount domes and wide angle lenses are large, heavy and fragile. I have not found it practical to switch them out underwater, myself.
The other issue with the G10 is that it is a LARGE P&S, the native lens has a large diameter, when the diameter of the camera's native lens exceeds that of the rear optical element of the wet mount lens vignetting will likely occur.
All in all the G10 is not very well suited to wide angle applications with current off the shelf wide angle solutions. I have several of the Inon lenses, I have made numerous measurements including taking my lenses, clamps and rulers to stores (yes--lol) and trying to simulate various housings from known and approximated dimensions.
My conclusion is that at this time with the G10 your best bet for a wide angle capability, and then just barely wide angle, is the Fisheye housing with their so called 15mm lens port. My measurements do not completely preclude the Ikelite with a custom port or the Patima for ultra wide angle but ------. I almost bought a G10 but in the end decided it could not shoot the wide angle stuff I like with current solutions.
Another problem is that the G10 has a 28 mm native lens, this means that the lens must be zoomed for most wet mount lenses because they are optimized for a 35mm equivalent. The Inon 28AD series are intended for 28mm lenses but nobody seems to make an adapter or utilize that product.
Actually, hate to say this, from an optical compatibility the Nikon P6000 sets up better but then none of the housings for it are of a correct geometry to use the lenses. It really is odd the way manufacturers simply refuse to use off the shelf equipment and offer the same tired excuses.
Now, the Canon 570/590/6-- all seem to optically mate just fine with 67mm wet lenses.
Epoque/Ikelite/Inon 100 series lenses with 67mm thread = FOV =approximately 90 degrees underwater
Inon 100-28AD lens = FOV = approximately 100 degrees underwater
Inon 105AD lens = FOV = approximately 100 degrees underwater
Fisheye 15MM port = FOV = approximately 90 degrees underwater (per a post on this board and not verified by me)
Inon 100WAL 67mm lens with Inon dome = FOV = approximately 130 degrees underwater
Inon 100-28AD lens with Inon dome = FOV = approximately 150 degrees underwater
Inon 165AD fisheye lens = FOV = approximately 165 degrees underwater.
28mm native lens through flat port = FOV = 52 degrees underwater
35mm native lens through flat port = FOV = 43 degrees underwater
28mm native lens/dome port (Ikelite) = FOV = 65 degrees underwater
I have actually measured some of the above myself and sufficiently verified other sources to believe the above numbers are fairly accurate and possible with optimal camera lens compatibility.
I have found many links, dug through books, measured cameras and lenses, gone to the library, bugged lens experts, blah, blah, I have found this particular link interesting:
Field of View - Rectilinear and Fisheye Lenses
N, if it isn't science then it is mythology
