Wouldn't a diving pool be deep enough? Well the test chart would be best but since you are using a fisheye, I doubt it'd be easy to read the results. I guess sunballs are a great way to test but you need a normal D300 to compare with. Maybe it's time to visit Wolf's or Fry's?

I think a diving pool is deep enough provided it is outdoors of course. The water will be especially clear which worries me. Can't hurt to try.

Without a regular D300, wide angle test charts or brick wall shots would be kind of useless I think. I've done the macro shots mostly to show the diffraction and moire issues.

I think 10-17 fisheye pool shots will be interesting if I can get some sun in the picture. I'll look into that. This will be with the Seatool dome which Ryan says is good. It would be more fun to have different domes to try out.

I had minor throat surgery about 2 weeks ago and the infections have been killing me. It may be a bit longer before I can get in a pool.

Ok cos I'd like to see what sort of resolution loss a domeport has underwater. A few more months won't hurt.

I've created a gallery of test images here.

There are three sets of images all shot in a shallow pool, evening ambient light, Seatool done and 10-17. Each set consists of shots at f/4 - f/11 in 1-stop increments.

The first set is of my strobe test projection screen. I don't think that set is useful because the screen doesn't have any sharp details. I need to figure out how to get all the air out of it before I start shooting strobe patterns with it. The screen has a 6 stop ND filter embedded so that I can fire strobes directly at the lens and measure undistorted beam patterns. In that set there's a starburst pattern taped onto the screen in the upper right corner. The lens is zoomed to 13mm.

The other two sets are 10mm shots of the pool. Focus in all cases is on the center point. Conversions are done in Lightroom with 0 brightness, contrast, and linear tone curve. Clarity is boosted but noise reduction and sharpening are disabled. Sharpening in SmugMug is turned off.

For those curious about white balance because of the removed hot mirror, settings varied from 5500,-35 for close shots to 7500,+35 for far shots. No filter was added to the lens.

Drew, would you like to see some sort of resolution test chart shot underwater through a dome port? If so, I will work on that. I don't think a fisheye is the best choice for that, though, so I'll work with Ryan on something else. I've asked Ryan for a midrange zoom solution and we should be getting close to receiving my Nexus port parts. I haven't made a rectilinear ultrawide (weitwinkel) a high priority.

Nice toes!

Thank you Toes smashed two ways

Looks good but only you know if there is an improvement over a normal D300. That's the problem with a one sided test. Not that I'm not appreciative of you doing all this with a bad throat and smashed toe. Thank you for that. I think when I get back I'll send my 1D in to mod the AA filter. All I want is about 20% increase in resolving power so I can keep my rig for another few years.
And yes, the other issue is the dome port losing detail. How much is lost through a dome port? Is it worth the extra work if the dome port kills the increase anyhow? Things we all want to know.

I think it has to be a pretty bad dome port to make the AA filter removal unnoticeable. Remember, I expect benefits from the ICF removal as well.

Short of buying a second D300 I don't know how to do comparative testing. All I can show is whether IR, UV, and aliasing can be controlled. If I expected to use the D300 for several years I might be tempted to get a second. If what I suspect is true, it would end up converted as well.

I've done some testing and am completely convinced that IR is managable underwater. The gels I've bought for the purpose are effective enough considering the D300's lack of fundamental IR sensitivity. The UV-IR groups are good for confirming that the D300, and all CMOS sensor cameras, just aren't that sensitive to UV or IR to begin with.

I saw a simple IR test performed in one of the forums and followed it. Basically you use a black fabric that reflects IR and turns colors, then you use an IR remote or a lighter. I confirmed that the camera responded to IR radiation and that both my lens and strobe filters effectively eliminated the problem.

UV I'm less convinced of but I haven't spent as much time on it. UV filtration on strobes is a cakewalk---just add diffusers. UV in ambient light is possible but I don't know that it's a problem. You can always filter it at the lens since they are available as gels for the fisheyes. I don't plan to do that. As was said already, the lenses we use may not pass UV well anyway.

I would love to think that 20% was possible. Thom Hogan is saying it is but tt seems optimistic to me. I've done what I consider pretty good (not perfect) slanted lines shots and I'm still beaten by a guy at dpreview testing a D3. I think it's because he is one stop less sensitive to diffraction than I am. Our results are nearly identical but mine should be better without the AA.

Ok Craig... I'm sending my old 1D2 in for AA removal I'll have a similar camera to do a before and after.

Any follow up on this topic? Any test results? Saw Peter Scoones a few weeks ago , he highly recommends removing the IR filter.