dentrock

I didn't realise you were using the 50mm N85 N120 adapter. Your dome may be similar to my 140 fisheye. Using the 50 macro and 50 adapter, the mis-alignment with the 140 is -9mm, meaning the dome is forward of the exact alignment by 9mm. That should work OK, but I also had a 34.7 adapter, which I used more often. Performance was excellent with that combo. The benefit is for travel - you might get away with one port for macro and WA. You might want to measure your dome sometime. With my 140, the optical centre is 6mm behind the port face, so I allow for that in any calculations.

Glad the firmware is sorted. All three Zeiss lenses I've owned have had problems with their V1 firmwares and required updates. 34 + 40 is 1mm < 45 +30... it's very tight but hopefully will work for you. Sadly focus in air is no help. Suggest try a large bucket of water or the bath! I don't know which dome you have but it sounds like there is some built-in extension, if the lens fits atm in a 100mm fisheye dome. Either way, I'd try it with and without an extra 17mm. You may not notice the difference as narrow FOV lenses are pretty forgiving re dome position, although if it's a long way mis-aligned, you may not get the increased FOV provided by the dome, cf a flat port.

Worth reading through the "Stop me before I buy again" thread which covers the OP's original question among lots of other stuff. Save us repeating...

-7mm should read -9mm (meaning the combo is that much too long wrt perfect alignment of EP with dome optical centre). (For Interceptor...!)

A 30mm extension is required with the kit lens 45 flat port, for the Zeiss 50, as per Nauticam port chart. It is a tight fit. Don't forget to check the lens' firmware version when you receive it. If it's the original, you absolutely will need to upgrade (free through Zeiss agent; not a DIY job). The 50 works fine in a couple of dome combos I've tried: 140 dome with 34.7 N85-N120 adapter puts it within +6mm alignment of EP and dome optical centre, which is a good result. Using the 50mm adapter, the alignment is -7mm; still very good. The lens also works fine with the old Nauticam 6" acrylic WA port plus 50mm adapter plus 50mm extension ring, giving an alignment of +3mm. But that's a bulky solution. I am currently using my 50mm with FF A7CR, using 45 N85 port plus 20mm N100-N85 adapter. The difference in length arises from the fact that the Nauticam A7CR housing port face is 15mm further from the lens flange mount compared to the A6400 housing; a total of 28mm (cf 13mm) as also mentioned by Interceptor in his blog. If I want to use a dome with it, the 25mm N100-N120 adapter plus my 'do everything' 140 dome gives an alignment of +1mm. It doesn't get any better than that! If you want to try your Zen 100mm dome, assuming it's an N85 mount fisheye dome with no in-built extension, try with the same 30mm extension for the flat port. Should be OK but 40 is probably optimal. Doubt if you will see the difference though.

Metabones V has sold - on ebay.

The OP also asked about converters. I have used the Sony APS-C fisheye converter with 16 APS-C Sony lens, but IMO while sharpness is fine for video, it's not good enough for serious stills. Stills for socials would be fine. So it depends on what the OP wants to do.

Prices negotiable. Offers considered!

Depends how it's set up. Unless your jimochi can confirm that both cams were on the same settings (can be complex to set up initially), I wouldn't take much notice. When I went shopping (in an actual shop) I took my 90 with me and spent ages fiddling with the menus on the cams, as the shop assistant wasn't familiar with Tracking set up. My wife has an A7RV and its AF is same as my A7CR. But A7RV has much better EVF and is a better cam all round, but as I said above, housing is +1kg (and larger) if you go Nauticam, and body +250g or so. So that's why I went for A7CR. Each to their own, but if AF is really important to you (as it is to me), then get to know its quirks before you buy. I had 4 years practice with my A6400. A7RV is more expensive, although price diff between the two cams not so much at Boxing Day sales. No Boxing Day sales at Nauticam!!! (I think they charge by weight, so A7RV housing is more expensive too...)

Does anyone ever handhold a big tele without supporting the lens with your other hand? As someone who shoots teles occasionally, I can't see it... If you took this fisheye underwater, the lens would be unsupported in the housing, although I suppose you could chock it in the port somehow (yuk for changing lenses!)

Correct. My mistake watching the Sony video and not seeing the scale. Internal zooming is preferable for U/W, if you have a choice.

Extends by what looks like an inch or so as you zoom in - see Sony video. MFD increase to ? 29 cm at tele end (18 cm at wide end). So needs a large radius dome to make use of full range (or just use it at wider end with smaller dome).

And the 38.5 MFD... is there a dome with a big enough radius?! Slightly off topic, but reviews of the new Laowa 10mm FF AF lens are now around. I looked at those by Christopher Frost and Dustin Abbot. Quite complimentary, except for soft-ish corners, I think only at wider apertures; and heavy vignetting, again, more at wider apertures. So... is 130 degrees "enough"? The perennial question! Price is USD 799.

PS: 2 other reasons for me going with Nauticam FF A7CR vs A6700: get away from wretched N85 port system at only 200g weight penalty; and proper screw on optic fibre connections vs cheap push in ones. I was going to go Isotta so I could do my own maintenance, so I emailed them asking if they were going to produce a housing for A7CR. No reply, so I stuck with Nauticam, even though I'll never be able to dismantle (and more important, correctly reassemble) the controls!

Well, it is for me, after reading the specs, even tho I would kill for an AF fisheye. Specs: Min focus 38.5cm (!) Weight: 1.36 kgs Dimensions: D 104mm x L 158mm It comes with a tripod socket which obviously you couldn't use in a housing. How would all that weight go supported by just the lens mount? Imagine bumping it on the dive boat. So, completely useless for U/W, IMO. What do others think?

Mini review: To put a different spin on this, I recently moved from A6400 to A7CR. I chose the latter primarily so I could continue using a couple of crop lenses which have no FF equiv, and still get 26 megas. At the same time I can take advantage of any compact FF lenses that come along. Currently really enjoying a Zeiss 40 CF. Also the Nauticam housing is approx 1 kg lighter than any other Nauticam FF housing. And I could not find anywhere if you can zoom PZ lenses from the A6700 body, whereas I already knew you can with A7CR and other Sony FF cams. In my view the A7CR is thus a true hybrid camera (i.e. hybrid crop and FF)! Having said all that, the improvement in AF is not marked vs the A6400, which either demonstrates just how good the A6400 is, OR that Sony has still a way to go to improve animal eye focus (and tracking even). AF improvement from A6500 to A6400 was much more noticeable. After 10 dives or so, I have reluctantly turned off animal eye, mainly because if it does find an eye (approx 30% hit rate), the focus square becomes so small I have trouble seeing it. And even tho you can set it to pretty much avoid false positives, I just can't be certain what it has found, esp if I am in a hurry. In any case normal AFC tracking medium or small spot is so good, animal eye is not really required. On synch speed, a couple of interesting findings: 1) although rated as 1/160, I get 1/200 with no cutoff with FF lenses. 2) using crop lenses I get 1/250 (but not 1/320 which is next step). None of this bothers me as I grew up with Nikonos 1/60 max and learnt to deal with it !

Nikkor 16mm Compact autofocus rectilinear fisheye prime in VGC. Suits Nikon DSLRs with in-body AF motors (basically all high end Nikon DSLRs). It does not suit Nikon Z mount cameras using FTZ adapter, although I understand an after-market adapter for Nikkor AF-D lenses to Nikon Z mount is being developed. Coverage is 180 degrees diagonal on FX cameras or 107 degrees on DX cameras. Purchased new in the US for USD 1020. No longer available new. Works fine with nice clean optics (one tiny mark on one filter only). Includes 4 rear mount filters as standard, pouch, original box and paperwork. Reason for selling: I no longer own any Nikon cameras. Asking AUD $600. Metabones V Metabones V Canon EF to Sony E mount adapter, near mint. Includes box, case etc. Purchased new. Current new price (Georges Summer Sale) is AUD $870. Reason for selling: works well but I have recently sold the Canon lens I was using with the adapter to another Waterpixel member, who didn’t need the adapter. Asking $500. Nauticam gears and converter – new AUD prices from Scubapix Cairns Australia #19121 N60G-F focus gear AF-S Nikkor Micro 60mm f2.8G. New unused. New price $367.40. Asking $220. #19122 N105VR-F focus gear AF-S Nikkor VR Micro 105mm. New unused. New price $367.40. Asking $220. #19139 N2485-Z zoom gear AF-S Nikkor 24-85 zoom f3.5-4.5. As new, hardly used. New price $352. Asking $150. #19227 TN1017-Z+1.4 zoom gear for Tokina 10-17 lens with Kenko 1.4x teleconverter (suit Nikon, Canon etc.). VGC. New price $352. Asking $175. #83213 M67 to bayonet mount converter. Inc installation tool. New price $137.50. Asking $60.

No weight loss as proposed by the OP, assuming he stays with Nauticam. As soon as you jump up from N85 Sony, housing weight jumps up by 1 kg.... except for A7C / CII / CR housings. I struggled with same problem and opted for A7CR (waiting on housing), rather than A6700. Reason is I figured I could still use some APS-C lenses, while being open to 1 or 2 new FF lenses, such as (perhaps) new Laowa 10mm. Viewfinder is improved over A7C. Also sick of narrow N85 ports. But generally disappointed with porky nature of most FF lenses, cf. svelte APS-C lenses. Having said that, FF 28-60 although slow is compact and sharp as on land although doesn't focus close enough for serious U/W without porky water contact optics. Still, could be OK for mid-water fish pics thru flat port at 60 end... Incidentally, I seriously considered moving to Isotta, so I emailed them asking if they were going to make A7CR housing, back in December. I would have waited for such a housing, since I might have been able to service it myself from all reports (unlike Nauticam). They never replied, which has cost them literally thousands of dollars of my money. Not going to deal with a company like that.

AFS and AFC

Tracking is useful when the eye is not centre frame, and you need to recompose. Locking focus on the eye at the edge of the frame with single spot and recomposing without tracking (or some kind of focus adjustment) is a recipe for slightly out of focus shots (of the eye).

As someone who specialises in fish photography for IDs, and who is busy fooling around with an A7CR (same menus and AF capability as A7RV) while I wait for the housing to arrive, some quick comments: 1. Play around with focusing on the pics in a fish ID book. This will speed up the experience curve, and give you an idea of what the various tracking sensitivity settings do. 2. If you need to turn off (say) animal eye AF tracking, just cycle to human (eg. via Fn menu), and unless a diver pops up, false positive is pretty unlikely. Or customise a button etc. 3. After years of spot focus on various Nikons when I used a 60mm micro 98% of the time, after moving to Sony A6400 and Zeiss 50 I only use tracking with medium spot. I put the spot over the part I want to have focus priority (usually the eye) and let the camera track it as I recompose or the fish moves. You don't need animal eye AF to do this, and my little book tests suggest a very sensitive animal eye AF setting (with the A7CR) may be counterproductive for fish. (Animal eye setting does not work for fish with the 6400, and is best turned off, as it appears to slow down the AF. I leave it on human all the time). 4. Pretty sure the focus motors in the 90 limit what you can do. My Zeiss 50 is a bit faster, and I expect to continue to use it in crop mode on the FF camera. Sony 90 may not be the best choice for constantly moving fish like juvenile wrasses and damsels, since it may not keep up or successfully lock on in the first place. 90 could be good choice for fish which perch (like birds), such as gobies. But for the midwater stuff, better to back off and perhaps use a non-macro lens with terrific AF motors. 5. Check how close you are actually getting to the midwater species. They present the greatest challenge, and no harm in shooting from further away and later cropping extensively. If the focus is spot on, you should still be able to get a pic which allows scale or fin counts on some species. 6. Skill, knowledge of fish behaviour and practice are as important as tech advances. After 50 years I'm still learning and dare I say it, improving, aided by advances in AF technology and sensor resolution.

Interceptor, My point was that Nauticam should provide the info up front to assist dome choice, rather than via instructions that come with the port. I read your dome calculations article carefully and you pull together lots of info which makes an interesting read - for those interested in the detail. Sadly, I think there are not many such people who like to go 'off piste' from the port charts, like you and me! You also make a couple of points which don't tell quite the whole story, but it's not my job to critique. Regarding the N180 which I never intend to buy (and have never even seen one) I was only interested in the detail to be able to cross-check Nauticam port chart recommendations against other possible solutions, using bits and pieces I already have. I accept your measurement of 25mm required extension, and thank you for that. I guess the built-in extension will be in the order of 20-25mm then.

Chris, Aha! Thanks. That explains it. I didn't see the built-in extension in looking at the photo on Nauticam website, and of course they don't bother to mention it, just as they don't bother to mention radii on their website, and are happy to misquote port weights.... Makes you wonder what is their aim. Perhaps push buyers towards those expensive water contact optics?

Chris / Interceptor: clarification requested re amount of extension required for Nauticam 180 WA dome port: 1. The calculator as mentioned by Chris delivers a dome height of 43 if you input R=105 and C=170 (inside dimensions; height is 40 if R=110). 2. Interceptor states in his interesting article on dome port calculations: "I have access to the 180mm dome and I know that the port is actually 8.5cm tall from mount to glass edge because I measured it. This means I need to add 25mm to the extension required." [subtracting 85 from R=110] Now I fully realise that you have to add the thickness of the port mount to the calculator's answer (c. 14mm with my N140), but that is a big discrepancy. 85 vs 43 (+ say 14) =57. Subtracting 57 from R=105 = 48 as the required extension, before you start accounting for EP position etc. So can either of you confirm that only 25mm ext is needed (to account for the 180 WA dome being less than a full half hemisphere), or is it actually quite a bit more ? Thanks!

Thanks again. Wasn't aware of that one. Pleased to see my crude measurements for my N 140 are spot on. Curious about 62mm figure for N180 as it is the same as I calculated for my (now discontinued I think) N 6 inch acrylic WA dome. Will recheck that one. Anyway, great to have the N180 figure and radius as you can then cross-check Nauticam port chart suggestions against any other combos of stuff you might have handy and want to try with a particular lens. And you could use my drawing method if you can't find a published radius for your dome.