If the pinocchio is works with the EFS60mm only then a full frame camera like the 5D2 can use a 12mm extension tube on the 60mm. Now the issue of it working on other ports is getting adapters made for it. I'm actually wondering why Canon was chosen . Is it because of the 1.6 crop?
This sort of relay lens creates an "aerial image" which is then captured on the sensor using a conventional lens on the camera body. The aerial image appears to the lens on the camera body like it was an object within the focus distance. This is similar to what happens with dome ports - the dome is a lens that creates an aerial image that the wide angle lens on the camera then images. You sometimes need close up diopters because the aerial image from the dome can be closer than the lens normally focuses.
Inon had to chose some host camera/lens configuration to optimize this for and pretty much make it dedicated. Since Inon only makes housings for Canon 40D/50D and Olympus, they had a pretty restricted set of choices. Between the two, Canon is probably has higher sales and the 60mm EF-S lens may be a better base than the Olympus equivalent.
Presumably it will work on other housings with the same Canon 60mm EF-S lens if there is a port adapter that keeps the relay lens in the exact position relative to the camera lens as on the Inon housing.
I doubt that it will work if you use an extention tube to mate the 60mm lens onto a full-frame Canon camera. The relay lens puts the aerial image in a particular location and with a 12mm extension tube the focusing of the 60mm lens will be shifted.
If there was an adapter to use small sensor Canon lenses on full frame Canon bodies, which focussed at infinity, then that could work, but it would not cover the full sensor. That would be OK with me, but I have not found such an adapter. Surprisingly, you can get adapters to mount many other lenses on Canon cameras - including Nikon, Pentax and Leica SLR. There is very little reason to do this in most cases but people have the made the adapters anyway. Unfortunately they don't have an adapter to mount a Canon EF-S lens on a EOS body.
There are two reasons for this. The first is that an EF-S lens will vignettte on a full frame sensor. The second is that the rear part of the lens might hit the mirror. The EF-S lenses assume a smaller mirror, and there could be a physical collision. A crazy approach is to modify the 60mm EF-S lens. There are people who do this, as a sort of camera hacking - here is a thread thos shows somebody doing it. Whether this works with the 60mm is unclear, and trying it could well damage both the lens and the camera.
Using it with a different lens than the Canon 60mm EF-S is likely to mess things up. It probably will work to some degree with a different macro lenses but image quality is likely to suffer. Presumably some enterprising wetpixelers will do some experiments.
One thing to keep in mind is that a "60mm" lens from Canon or Nikon does not necessarily have a true 60mm focal length - they round the number up or down for marketing purposes. A "60mm" lens might be anywhere from 57mm to 63mm in terms of the actual focal length. This does not matter for most purposes but even small differences may cause problems with using a similar Nikon macro lens that has a different focal length and different field of view because the sensor size is also likely be slightly different. Vignetting is one risk, but that is not the end of the world. Inon may well have adapted the design to match the 60mm EF-S lens quite closely, and if so then you might see more abberations. The only way to find out will be to try it.
The quality of the Inon lens is not outstanding to begin with - although to be fair, most wide angle lenses have poor corner sharpness when used in a dome port. The dome itself is a kind of a relay lens too. Anytime we take pictures underwater we are compromising the quality compared to topside. When you start doing things like adding a teleconverter to a wide angle fisheye in a dome port (one alternative to the Inon) you're doing a lot of violence to the optical train, and you can't expect perfect quality there either, especially at the edge of the frame.
Depth of field is always an issue with macro, but when you have a narrow angle of view it doesn't come up so much. With this lens DOF will be an issue, and most of the photos seem to be taken at f/16 to f/22. At those apertures the main thing limiting the quality will be diffraction. Your fancy N megapixel sensor will actually be resolving more like a 1.5 megapixel sensor at f/22, 3 megapixels at f/16 and 6 megapixels at f/11. That is just the physics of light, and it is equally true for the the Inon, or any other lens. When we stop way to down to get maximum depth of field it hurts the resolution. That's usually the right thing to do if you need the whole subject sharp.
Anyway, I have just ordered the Inon lens, to pair with Canon 7D in Nauticam housing. Which means I need to get a 7D just for using this lens, since I normally use 1Ds Mark III and 1D Mark III. Reef is putting it together for me, and they say they have a port adapter. If this works, it should be a great set up. I'll post about it once I get it, but I am told that won't be until some point in february,
