Barmaglot

Yeah, after I posted that I had a thought that maybe the A7CR had its aperture drive in AF set to 'silent' - this would certainly affect AF speed, especially in low light conditions.

They have ports designed specifically for 28-60mm on FF and 16-50mm on crop, so this shouldn't be an issue. I don't own the FF version, but the short macro port fits the 16-50mm lens very well, and I'm pretty sure I've seen 28-60mm users reporting the same. I've taken to splashing down with the UWL-09F in a thigh pocket and attaching it as I descend - saves the stress on the mount threads and is actually more convenient than detaching the lens to burp it.

@jjmochi shared an interesting experience with A7CR here - it's not specifically A7CII, but it's supposed to be the same camera except for the sensor. Something weird might be going on there. You may want to test before you buy.

Aren't the tripod attachments on those big telephotos specifically there so that you don't load the mount bayonet? You mount (or handhold) the whole thing by the lens, so that the lens mount is loaded by <1kg of camera on a very short lever, instead of 3-5kg of lens on a long lever. Does anyone mount any such rig by the camera tripod socket instead of the one on the lens, when the latter is available?

I dimly recall some guy who was tossing octopuses into mid-water to take shots of them swimming that caused some commotion? Don't recall any details.

https://www.bhphotovideo.com/c/product/1812335-REG/sony_fe_24_50mm_f_2_8_g.html/specs 440g, 67mm filter size, 18cm minimum focus distance (0.33x magnification), US$1098 list price - possible higher quality alternative to 28-60/28-70mm behind WACP-C/WACP-1/FCP? Doubt it will work behind WWL-C/WWL-1 with this large front element.

It's not the tripod collar in and of itself that is the problem; it's the 1.36kg of lens cantilevered off the camera mount, in turn cantilevered off the tripod socket, not supported by anything else, and potentially bouncing around on dinghies, in rinse tanks, etc. This is no small amount of stress getting put on fairly fragile hardware.

I'm guessing it more of the former than the latter. I just went from a6300 to a6700, and although I haven't taken it underwater yet, on land the new autofocus feels like magic. Kinda kicking myself for not upgrading to an a6400 earlier; even though I could've used it in the same housing, I figured the improvement in AF can't be that great to be worth an upgrade in and of itself.

Looks like an astrophotography lens; not meant for us amphibians. For underwater purposes, Sigma's own 15mm/2.8 fisheye works much better for 1/5th the cost including an adapter. Native-schmative, autofocus with adapted lenses works fine on reasonably modern bodies; even my fairly old now Sony a6300 works quite well with a Metabones IV and a Canon 60mm macro.

What is the advantage of 28mm/2 over 28-60mm? Does it resolve more pixels?

Sigma 15mm fisheye on full-frame and Olympus/Panasonic 8mm fisheyes on M43 are probably the most widely used wide-angle primes underwater. Canon/Nikon 8-15mm fisheyes can also be considered kinda-sorta primes, as they have basically two settings - circular fisheye at 8mm and diagonal at 15mm - but most people desire flexibility, hence the popularity of teleconverters with those lenses to give them a useful zoom range.

I suppose you could use a Nauticam MWL-1/Weefine WFL09S/Kraken KRL-09S with it, but your diagonal FoV will be only about 70 degrees, similar to a 24mm lens ('m basing this off Nauticam's quoted figure of 71 degrees FoV with 12-50mm on M43 fully zoomed in behind MWL-1) - wide-ish, but not truly wide by underwater standards. Nauticam EMWL can give you up to 160 degrees diagonal view, depending on the optic, but that's $$$$, not to mention the weight and bulk.

The order page for neoprene sleeves has a menu to choose between Pro X/Prime X/Pro/Prime and Pro Max/Prime+/Pure, so there might actually be a difference. There is actually another size, that is no longer sold, from before the bumpers were released - it covers the full length of the strobe and doesn't stay in place very well; I use a pair of zipties to stop them sliding around.

If you can tolerate a little bit of lag and reduced battery life, WiFi is an option.

To be fair, at the time everyone and their dog was making a media card standard. Toshiba had SmartMedia, Olympus and Fuji had xD-Picture Card, Sandisk had MMC, etc.

Do you feel like Z7II's focus capabilities are limiting your underwater photography in any way? Like missed shots on blackwater dives, or shooting macro in imperfect conditions such as surge? If it was a choice between housing a Z7II or a Z8 I would say go for the Z8, since the difference in housing costs is marginal, but since you already have a housing for the Z7II, dropping another five thousand euros on a Z8 housing (after accounting for the import taxes) is a very hard sell - even if you were to sell the other housing, that'd still leave you a couple thousand euros on the hole, and that can easily fund a liveaboard trip as long as you're not going too far away.

So in conclusion, with Kenko Teleplus HD Pro 2x, the Canon (and, by extrapolation, Nikon) 8-15mm gives a similar, or slightly greater, zoom range than Tokina 10-17mm on APS-C/DX cameras, correct?

The 2x TC sample doesn't really look that bad. Am I correct in assuming that with 2x TC, the wide end of the zoom range is equivalent to the narrow end of the bare lens, i.e. 180 degree diagonal?

WWL-1 has options for either M67 or Nauticam bayonet mount (it's a removable ring; the lens ships with both). WWL-1B and WWL-C only use the Nauticam bayonet. Nauticam sells an M67 to bayonet adapter that you can put on a port, but it doesn't fit all ports - the M67 threading is on the inside of a narrow groove, so if your port has a wide front flange, it will not fit.

WFL05S is a very strong diopter; I tried using it with a 16-50mm on crop, and the maximum focus distance is very short. It can shoot quite small subjects, but it is difficult to use, and you'd have a fairly large window where a subject is too small for bare lens, but too large for diopter. The 90mm is a lot more flexible in terms of macro - if you want to add limited macro capability to an otherwise wide-angle rig (i.e. 28-60mm + WWL), you would need a weaker diopter, something along the lines of a +5, like an Inon UCL-165.

Maybe edit the title? Retra Pro Max is the latest model that just came out in 2024; those appear to be plain Retra Pro that started shipping in 2020.

I'd say it's a matter of are you prepared to pay for the extra pixels? A7RV has over double the resolution on the sensor, the EVF, and the screen, plus a slightly faster shutter; those are the material differences - but it also costs twice as much (body + housing, assuming Nauticam). I'm happy enough with my a6300's 24MP - I just wanted the new autofocus for macro and blackwater, so I went with a6700 and saved the price difference for more diving.

For what it's worth, I'm sitting here playing with my new a6700, and it's absolutely uncanny how it finds and tracks eyes anywhere in the frame. Granted, my comparison point is a6300, which is a far cry from D500, but still. Can't wait for the housing to arrive...

I'm not super familiar with the Nikon system, but an immediate potential problem with this plan would be a suitable fisheye - there is no Z-mount equivalent to Tokina 10-17mm thus far, and the F-mount version of that lens is AF-D and cannot focus on FTZ adapter. You'd have to use a Canon EF mount version on an EF-Z adapter...

Just saw this: https://www.sonyalpharumors.com/crazy-sigma-will-announce-a-new-15mm-f-1-4-diagonal-fisheye-lens Finally a native E-mount autofocusing fisheye? Not sure the f/1.4 aperture is of any use underwater though.