dentrock

Thanks @Craine for taking the time to post the evaluation and samples. As I suspected, the AF is probably good enough; in line with, or slightly faster than, the Sony 50 macro which I have been using a lot (with AFC) with a 140 "curved port". I forgot to mention its 35mm with FF I'm interested in. For APS-C, in addition to the 30 macro, there is the excellent Sony / Zeiss 24 (35 equiv) which focuses very close and works great behind a mini dome, such as the #36125. Too expensive new, but there are good used examples on Japanese ebay sites.

Then why not use a 60 (or a 50 for Sony)? Use a dome to calm the aberrations! Much smaller and lighter rig than what is illustrated....

This strikes me as a good general purpose lens, and good for a little light duty close-up work. It is keenly priced (c. AUD 350). Minimum focus is 15cm (1:2 mag), which makes it OK to use smaller domes (eg. 140) to calm the aberrations. Land reviews praise its sharpness, and criticise its AF as slow (a bit faster in AFC cf AFS). There is no other close-focusing AF option around 35mm focal length for Sony shooters, but Canon makes an R series 35mm macro. So, is there any Sony shooter out there using it underwater, and if so how do you find the AF (especially in low light); and are you using a dome? Thanks in anticipation...

Aside from port and lens issues, if your budget can stretch to a new camera and housing, the Nauticam housing for A7CR is 1924g and A7RV is 2806g, as measured on my kitchen scales. There is a further approx 200g saving in the camera bodies. AF performance of the two is identical, although the A7RV housing rig has a few ergonomic advantages, such as placement of the playback button, plus a joystick control, and a few more custom buttons. Design is clamshell vs removable back.

Agreed, but A7RV as tested; also A7CR. Maybe the MFO needs the A1!

In the other thread I asked if other Sony 90 / MFO users could share their settings. In particular, I was hoping to find out whether they have had any luck with AFC. But there have been no replies... In fairness to the MFO, it probably works fine the Sony 90 using AFS, which I didn't try. And the 90 is an ancient (10 year old) lens, so modern mirrorless Canon and Nikon macro lenses may work much better with the MFO. But as a fish nerd, I need AFC to best shoot small moving fish (like juvenile wrasses), so if AFC is useless with the 90 / MFO rig, then it's not for me, and I might as well revert to using the 90 behind the usual flat port.

There are now 3 threads on the MFO-1. See my comments re Sony 90 + MFO using AFC + tracking, on the thread "MFO-1 and focus limiter". I no longer own the MFO-1. As for controlling aberrations on normal focal length lenses (50-60mm), these are nicely dealt with by using a dome, although depending on your dome diameter and alignment, you may lose a little working distance and hence magnification.

I agree that there is flexibility in aligning the lens EP and dome optical centre, but that's not a reason not to try. The video could have given us the radius of the "curved port" so we could draw our own conclusions - but it didn't. By all means buy the special port, but why not first try your favourite macro lens with whatever "dome" you already have? An advantage of the 140 dome is it can be used with many other lenses. Eg. the 140 + 25mm extension works fine with the Sigma 24 and 17. So I can go from macro to wide with no port change. Or I can add extensions if I want to use a lens with a longer EP like a zoom.

Minor update: I tested the 50 + 140 dome this morning in 3m viz, overcast and under a jetty, no focus light (must be worst case scenario). Results: Out of 28 images, there were about 5 focus fails. Subjects included seastars, a 30mm goby, and 40mm mid water fish (bullseyes). I tried in order, all with medium spot: AFS, AFC no tracking, AFC tracking, AFS. I found neither AFC setting was much good in the very dime light, depending on the subject contrast. If anything, AFC + tracking worked a little better than AFC no tracking. However AFS worked quite well considering, although I would prefer not to centre the focus point (the eye for a fish) if I didn't have to (I'm not keen on focus and recompose with singe point AF). I guess with my unpleasant MFO + 90 experience, with hindsight I should have tried AFS. However, that's not going to happen now. In any case, shooting the 50 behind the dome cures the aberrations, so no need for MFO with normal focal length macro lenses... For anyone thinking of buying a Sony 50, I suggest you try it out in a dim part of your camera store first, and see if it meets your needs. Or buy a used one so you can flog it if you don't like it, without losing money. As for me, it's a keeper with the dome and some care with focusing. It's my go to rig if I want compact; otherwise it's the 20-70 with 180 dome. There is a reference in the above video to the "curved port" macro style not necessarily suiting arty photos where you want to isolate the subject. Well, I'll take overall sharpness over fake bokeh any time. If I want shallow DOF, I'll open the aperture. It's ironic really, when we don't worry about soft corners with macro, but we obsess over sharp corners with WA lenses!

I have been testing the Sony 50 macro with a "curved port" (aka a dome port) using my A7RV and A7CR with the Nauticam N120 140mm dome. I estimated the EP at 43mm at infinity and 45mm at 1:4 (behind the dome it will be always focusing close because of the virtual image). With a 25mm adapter (= extension), I calculated the alignment is almost perfect. Land tests extol the IQ of the 50 macro, and criticise the slow AF. However, almost all available tests are using older Sony cameras, and there seems to be some improvement with the latest bodies. There is no need to get the port mentioned, although it may be easier to light close-ups because of the small size. On the other hand, I have not seen a figure for the radius of this port, so we have no starting point to calculate the correct extension to best align the optical centre and the lens EP - and I believe you should always try to align a dome and lens as best you can. I have posted results in other threads, but to recap: Good: Improvement in IQ (overall sharpness right across the image) is astonishing. Not so good: There are AF issues when using AFC with tracking and medium spot (my preferred setup for all my photography), presumably because of the 10 year old lens' primitive AF motor (compared to the latest zooms). The AF adjustments required when tracking focus on the VI are minute. But it is doable - if you give the camera a little extra time to "decide" it is in focus before you take the photo. You will still get the occasional failure - but nothing as bad as trying to use the MFO with Sony 90 with AFC and tracking - see the older MFO thread. Next step is to go backwards and test AFS and AFC without tracking, and see how that compares. I would rather not, but I suppose it will be OK for subjects which are centre frame. Even so, for general use I wouldn't go back to a flat port for this lens (only for the 90 - which I haven't got to work well behind a dome).

ACR is Adobe Camera Raw. It's "free" but requires a host (either PS or LR) to run in the background with it. I have LR but don't use it (the cataloguing system doesn't suit me at all). I also have an old free version of Capture One which I don't use, again partly because of the annoying cataloguing. So you use software like ACR (or LR or Capture One) to process your raw files (in basic terms, fix exposure etc etc) and output (usually) a jpg for display, sale, whatever. PS with or without ACR doesn't create a catalogue and you can save the processed result in the same folder as the raws (my preference). In the last year or so, Adobe has added so many tools to ACR that I find I can do all my post processing in ACR. The AI denoise function is very, very good. The one exception is BSXT, which operates as a plug in for PS. So when I have finished all my processing in ACR I open the file in PS and use BSXT, but only when needed, which is not that often for me. I save a copy as a jpeg and don't save the huge psd file that BSXT creates (I regard jpegs as disposable). If later I reprocess the raw file, I will need to run BSXT again, but that's simple. Well, apparenlty it's OK to spend hundreds or even thousands of $$$ on a new lens or camera which "might" give me more keepers, but not OK to buy some software that DOES give me more keepers; even fixing some stuff that I would have instantly deleted. And don't lecture me on controlling backscatter! Sometimes it's unavoidable - try diving in viz of <3m... I must say every time I use BSXT I am gobsmacked by how good it it. I read a comment that the results can be 'too clean', but I'll take clean over dirty any time!

I haven't noticed any downside to leaving IS on all the time, above or under water (Sony system). Some bird photographers say you should turn IS off if using a big tele on a tripod. A comparable UW scenario might be using a 90-100 macro for close-ups on a tripod, but that's a pretty extreme example. If that's you, try it and see! I think I also read somewhere that IS only works in two dimensions (side to side / up and down, but not back and forth). If so, Chris' comment about being shaken back and forth in a surge might be an example when IS wouldn't help (if you needed it). But presumably, still no probs leaving it on...

Image stabilisation would be handy if you are relying on available light (no strobe). But if strobes are your primary light source, the short duration of their flash should freeze the subject OK, even if you yourself are wobbling about! And don't forget, image stabilisation only helps reduce your shakes, not subject movement...

Thanks for the further comments. A couple of things: My 90 works fine on land (insect macro) and as I mentioned it was also fine behind flat ports, although I suppose I need to recheck that, as Chris suggested. I also checked for firmware updates, as I purchased mine years ago. But there are none (and none for the 50 macro). I reviewed yesterday's pics on a better monitor, and found another type of AF failure I've not seen before - a photo of the blenny with the eye perfectly in focus, but Playback on the camera showed it as a false detected eye well away from the fish (false eye detections are normally in focus). Go figure... I reckon the problems probably arise from a combination of a primitive AF motor in the 90 (compared to the latest AF lenses) which doesn't do tiny adjustments well; plus using AFC / tracking (which requires those tiny adjustments). As I already mentioned, I had similar AF failures (though not as many) using the two 50 macro lenses behind a 140 dome. But the gain in IQ is such that it's a hard call as to which way to go (flat or dome) with those lenses. And the 90 doesn't do domes at all as far as I can tell (the 90 was released a year before the Sony 50 macro). The mystery is more like why some other Sony users aren't reporting problems, but my guess is they might be using AFS with single point AF and focus / recompose techniques. I used that method for many years with various Nikons and a Nikkor 60mm micro, but it's a recipe for slightly out of focus pics in many cases. So if some of those other Sony 90 / MFO users could kindly let us know their detailed settings, that would be appreciated...!

Yes I should have removed it, but dive conditions were deteriorating rapidly and I ran out of time. It's been a while since I shot the 90 behind just a flat port, but I don't recall it behaving that bad. I know I used to use it successfully with my A6400. Lately I have been testing the 90 behind a dome, but without success - I think because the EP shrinks heaps towards as you focus in. Re the Sony 50 macro + MFO, I had intended to try that (and the Zeiss 50), but I suspect it won't work because the Sony extends 25mm as you focus in. But the Zeiss should work, since it doesn't extend. However, using these lenses with a dome makes such a huge difference in IQ, I can't see the MFO is necessary. Re settings, I tried it with subject recognition off, which seemed to improve things a little. In that case, all that's left to adjust is AF tracking sensitivity. I have previously explored those settings and concluded the default 3 is about right. I could turn tracking off (or use AFS) but that limits my ability to maintain sharp focus on even a stationary subject that is off centre. So I'm interested to hear what detailed settings people are successfully using with their 90 / MFO. One thing I haven't checked: I set the 90 on Full with the MFO. Is that correct - I haven't seen that mentioned anywhere? I may test it again (trying the above options and any others suggest), but at this stage, I'm so p...d off that I'll sell it. Anyone want a mint condition MFO? !