I was on my Droid earlier and it is hard for me to type on that thing, so to continue my first point. The larger diameter of the G series lens coupled with the long zoom ratio forces the port to be very long. The Inon lenses and all wet lenses/accessory lenses are designed for an expected operating distance between the camera lens and the rear of the accessory lens. When that expected design distance is exceeded several things happen and the one we complain about most is vignetting but also edge distortion. This can also be made worse by a lens that is very large in diameter compared to the rear element lens diameter of the accessory lens (this is concern with the G series).
I have read that Inon built their lenses with an expectation of a 3X zoom ratio, with small cameras like the tiny little S90/95 which has barely a 4X zoom ratio and a small lens diameter they work fine because the (zoom) rack distance is very small despite the slightly longer than optimal zoom ratio. This even despite having to zoom to 35mm on some accessory lenses, which brings up a second point, that being that most of these lenses are designed for a native camera lens of 35mm with the exception of the Inon WAL100-28AD and the Fisheye UWL-04 which are designed for native 28mm camera lenses.
So now at point three, if I understood you asked if you could use the G9 lens on the G11, no, you can not remove the G11 lens and install a G9 lens and there are no adapters to do so. While on the subject, didn't the zoom ratio on the G series grow over the years as did the camera?
If you want to use a wide angle lens with the G11 you need to purchase the Patima housing which has a short port option and a zoom lock to use the available Zen wide angle lens. Or you can purchase the FIX G11 housing if still available and use their dry port wide angle lens system.
Your other choice is to get the camera that currently works best with all accessory lenses via a wide selection of adapters which was the FIX90 and currently sold as the Recsea95 housing. The G series is just not a good choice for wide angle shooting, the S series is and the new Oly ZX-1 might also be a good choice.
I have done pretty extensive testing with multiple accessory lenses over the last few years on multiple cameras and housings, what I say is not just a guess even if sometimes I extrapolate from one to another, it is based on my testing and similarities and dissimilarities I have noted. I do not have any information on the Dyron products, their operation or compatibility but the "bubble" lens choice, IMO, I do not like the concept or care for the results gotten with the "bubble" lens concept and I would not waste my money on one.
If wide angle is really what you want, you have the wrong camera. The G series is better at macro than the S series, the S series is better at wide angle. This due to the physical design of the cameras and as well the housings that are provided for them and the design of the lenses available on the market.
There is a new lens, the Inon LD series lens. It has a new bayonet mount design, a larger rear lens element for use with cameras with larger lenses. It still needs a short zoom ratio as optimal. It is designed also for camera lens of 28mm (35mm equivalent). I do not know if this lens might work with a G series camera as I have only seen photos of it, but, it looks like a possibility.
No, at this time, Inon does not make a kit adapter for any of their products for the G series camera or OEM housing.
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