OK that makes sense... according to this UWL-100 chart (
http://www.camerasunderwater.info/optics/inon/uwl100.html) the coverage of the UWL 67mm screwed onto the 20mm pancake port would be ~85 degrees or ~115 degrees with the Inon dome port - any thoughts on how the quality of that may compare with the 7-14mm + 7-14mm dome port? It would be more modular and you could change all the way to wet mount macro underwater, not to mention save the cost of the dome port......
Rob
I don't think that is correct. The Inon 100WAL with dome is a semi-fisheye lens, the diagonal FOV underwater with the Oly pancake lens, which is a 35mm equivalent, should be around 130 degrees, maybe slightly less, when fitted with the Inon 100WAL with dome. I took my dome equipped 100WAL to a friend who owns an EP-1 with the pancake lens. In fact, I was able to use the camera for an entire day. Holding the Inon lens in place indicates to me that the combination has potential and that a very wide FOV was achieved similar to the lens on my 570 and S90. Now, will it really work, I cannot say, it looked promising if the port is very compact for the fixed focal length pancake lens.
You cannot directly compare a rectilinear lens to a fisheye type, the Inon 100WAL is a fisheye lens, it has barrel distortion and the image wraps back quite a bit in the corners. The focal length calculations will not work with a fisheye lens, review the below site:
http://www.bobatkins.com/photography/techn...ld_of_view.html