dentrock

I asked Nauticam if their zoom gear for the 24-50 would fit the 16-25, but they didn't reply. After studying the dimensions and design of both lenses, I am 90% sure it will, and may spring for the 16-25 during the black friday shenanigans.

I have been told that Nauticam has no plans to support either of these lenses, although they did suggest some port options for the Sony 16-25 including the 180 dome with 60mm extension. But we need a zoom gear for the Sony 16-25. It looks like the Nauticam zoom gear for the Sony 24-50 f2.8 G lens should fit, as these two lenses have very similar configuration and dimensions and apparently were developed as a complementary pair. Is anyone out there using the 16-25 with a Nauticam housing, and if so, what are you using as a zoom gear?

Adapter now AUD $299 (that's approx USD 200)

Hmmm... further price drop! Housing bundle exc battery packs but WITH vac valve etc now AUD $1599 (that's about USD 1100) Also N85 to N120 50mm adapter only AUD $299 (= USD 200)

Agree. Buy a used Zeiss 50 Touit. Ensure the firmware is V. 2 (has to be done by Zeiss - FOC). Better lens than Sony 50 macro in every way - except it doesn't do FF!

The N85 ID varies. The smallest I found was the 36125 dome, which was 69.5mm. I bored it out by 0.5 to accept the Samyang 12mm. Other bits are up to 73mm and perhaps even a little more. It's try it and see, or ask someone who has what you are curious about to measure for you.

A few 'drawing board' tests with the 140 N dome, which only required a dive tub of water... 1. Reduce total extension by 20mm (to 55mm comprising 25 adap + 30 ext). This aligns the EP within a few mm of the dome's optical centre, which should clean up the corners... Result: cannot zoom out the last 10mm or so! (Total zoom extension is about 40mm). Not surprising with a port with only 70mm radius, cf the 180 dome which apparently is 110mm radius. So no good. 2. Tried a total extension of 65mm (half way between Phil's 75mm and the above). In this case, misalignment of EP and optical centre is about 10mm. Result: was able to zoom out (just). But minimum focus distances (from the dome) have increased over what I got with 75mm extension, to about 120mm W and 150mm T. More to the point, I made up a 24x36mm focus target and the best I could get at 70mm was 1:4 magnification (cf lens' native mag of 1:2.6). I didn't bother to check the corners at 20mm, although they should be improved over what I got with 75mm extension. If 1:4 is enough for you, this may be a good option. So the range of useable extensions for the 20-70 lens and the N 140 dome seems to be between 65 and 75mm. Regardless, the Nauticam chart recommendation with 180 dome gives much better performance. Sadly, I have read that the widest lens you can use with the 180 is 14mm.

Check that "Setting effect" is OFF (Shooting>Shooting display>Live view display setting)

Thanks Phil. Yes, well aware you are using Marelux. I also (desparately) wanted to travel with only one dome... mostly because I will also be using the Laowa 10. I don't have your Marelux 140 dome specs, but otherwise the same ext you used (i.e. 75mm total) for Nauticam 140 seems about right in terms of trade-off between corners and MFD. Shorter ext will give better corners but longer tele end MFD and less magnification. I need good photos of gobies down to about 30-40mm length. I agree your pipe fish and shrimp pics look good. As I already mentioned, larger subjects like those (say 60mm and over) are great for the 140 / 20-70 combo, at the tele end. But I wouldn't recommend the 140 / 20-70 combo for other than occasional WA.

I test dived the 20-70 with A7RV, Nauticam housing, 140 dome and a total of 75mm extension (25 adap + 50 ext) as per Phil's rig. I really, really wanted to say it worked out well... but it didn't. Pros: 1. At approx 5440g exc arms and flashes, rig is approx 450 g lighter on land (cf 180 dome rig in my post above). Doesn't sound much, but I noticed it on my shore dive. 2. Smaller dome makes it easier to line up a small subject before you take the pic. Cons: 1. Noticeably more negative underwater. Some will want to add floatation, whereas I don't think the 180 rig needs that. 2. Max mag down. MFD at 20 still approx 50mm from dome, increasing to approx 100mm at 70. I estimate the mag at 70 MFD has dropped from 1:2.6 achieved with 180 rig, to around 1:3 - 1:4 with 140 rig. 3. Corner sharpness noticeably worse than with 180 rig; or more precisely, the central circle of acceptable sharpness viewed at 100% does not approach the centre of the long sides of the 3:2 frame (my benchmark). Even at f8, the 180 rig noticeably outperforms the 140 rig at f16. This is no doubt because the optical centre of the 140 dome is approx 19mm in front of the lens EP (just a few mm difference with the 180 rig). 4. FOV likely also affected by misalignment, but I won't try to measure this. I could use a shorter extension to improve corner sharpness, but that would drastically affect close focus ability. Verdict: hmmm. OK at 70 if your subjects are not too small (say, 60mm up). OK for shooting larger subjects you come across. Not OK if you are shooting mainly WA. If you want to use the 20-70 a lot, the 180 rig is a better option.

All lenses and also battery packs for A6400 housing now sold. Price drop on housing bundle to $1800 without vac valve or $2000 as listed exc battery packs. That's AUD....

Phil Rudin has posted plenty of WA photos for this lens. Here is a close-up of a 40mm male Nesogobius pulchellus, moderate cropping and minor processing (I tried and failed to upload uncropped version), at 70mm. Not too shabby for a do-everything zoom, so might satisfy fish nerds and perhaps blackwater dudes:

Finally got to test mine this morning with A7RV and Nauticam, and following the N port chart recommendation (35 adap + 35 ext + N120 180 dome). In addition to Phil Rudin's positive reports: Positives: 1. At 20, focuses to within approx 50 mm from dome. 2. At 70, approx 65-75 from dome. Specs say 1:2.6 max mag; MFD 30cm at 20 to 25cm at 70, so N recommendation is sound. 3. Heavy rig on land but quite well balanced UW. 4. Successfully shot 40mm gobies as well as a bit of boring WA in the conditions. 5. Very sharp for close-ups and fast focus. As sharp as my macro lenses on gobies. 6. Corners pretty good (no complaints from me, but obsessives can obsess). Besides, for WA I rarely shoot with smaller ap than f8. 7. Zoom is operated by the housing knob and gear. No need for adapter with knob. 8. Terrific lens for general use on land. Negatives: 1. As above, rig is very heavy on land at 5913 g, excluding strobes and arms. Actually, shocked me coming from APS-C A6400 rig. Not ideal for shore dives, depending on difficulty of entry. Options to reduce weight include: a) shoot with A7CR (1.1 kg lighter, comprising 200 less for body and 900 less for housing) b) try with 140 dome (save another 500g). Will do so weather permitting. 2. 35mm adapter used as recommended, but adapter knob gets in the way of housing knob. Because of the profile of the housing face (not flat), cannot mount upside down to get the knob out of the way. What was Nauticam thinking?????? If I was buying the bits to use this lens again, I'd use the hideously expensive 25mm adapter (no knob) + 50mm N100 ext. Or if I owned the N100 version of the 180 dome, no need for adapters. Just use extensions... 3. For close-ups of small, slow moving or static subjects, I like to sight the camera in externally first, then move to the EVF, focus, recompose and shoot. This is fine with a comparatively narrow macro port, but impossible with the big 180 dome. Using 140 dome may help.

Phil, in earlier posts this distance (lens flange to port flange for your Marelux) has been quoted as 43mm. If it is in fact approx. 30mm, that is good news and makes perfect sense. It also means that whatever best extensions you come up with for your Sony FF Marelux rig, we can apply to Sony FF Nauticam rigs, as the measured lens flange to port flange distance for the latter(26-28 depending on who measured and which model) is close enough to the Marelux figure. No need to add that 15-17mm extra for Sony / Nauticam, as quoted earlier in this thread. Perhaps the 43mm is for sensor to housing flange? The only remaining variable is where the optical centre lies for the Marelux 140 dome. I'm making the (bold) assumption that this is also close enough to the Nauticam 140 figure (6-7mm behind the dome port flange) as to not make any further difference, for the purposes of calculating necessary extensions. I am keen to see how you go with reducing your extension from 35 to 30. Perhaps we can get to a compromise where corners are sharp enough with a shorter-than-theoretically-ideal extension - and we don't need to remove the 140 port shade! Apologies for all this measurebating, but I can't dive my Laowa 10 until next week at the earliest. Still, we have a great starting point!

Kenko sold (ebay). Will (politely) consider all offers on adapter!