John E

I agree with the comments above. As someone in reef tourism I'd emphasise that the Olympus TG6 or TG7 have advantages. It can produce good shots on its own with no strobe, tray or wet lens if you need to go as small as possible. It doesn't need anything like as much preparation or care for a dive because it is a waterproof camera in a housing, so you can focus your attention on customers. The TG6 or 7 have really good jpegs when used underwater and if you take photos of customers you can share them straight after a dive eg using Olympus-share onto your phone and airdrop. You can also potentially use the camera as a rental and hire it to customers. The quality for social media or website use is fine. For Canon, the Nauticam R50 looks really interesting but with the wet lenses added I suggest it is too bulky and heavy for a divemaster diving with inexperienced customers (I have a WWL-1B but not handled a WWL-C) . For any compact camera in your situation I would be tempted by a less expensive second-hand camera in an aluminium housing and not be too set on particular model, but get one that has been looked after (even older G16's in a Nauticam housing can be good). Depending on your own needs, a simple less valuable small camera for diving with customers and a larger one like the one you have for diving without customers might be preferable to a half-way solution.

I wonder if anyone knows what is special about the S+S correction lens or is it like other low power achromatic diopters? My limited understanding is that single lens diopters (filters) impact image quality whereas achromatic ones are much better. Both just act to reduce the minimum focus distance, helping the lens focus on the virtual image which is close to the sensor and curved. So if the S+S is not available, or is not a suitable size for a particular lens, another weak achromatic filter would likely do the same thing? There are several high quality low-power achromatic filters including the Canon 500d close-up lens, Nikon 5T diopter, and Sigma close-up lens AML 72-01 (which I have and is 72mm threads) which seem to do the same thing but are in different diameters due to sometimes being intended for specific lenses.

I'm thinking of boat compasses. These are filled with a transparent mineral oil and it is not unusual to get bubbles, especially with age. But a reason oil is used in that case is to dampen the motion of the compass card. I agree it would be odd to have oil in an optical instrument but the only potential reason I can think of would be to help make a complex shape pressure proof. Seems weird to get droplets in something before it goes in the water even if it has been knocked, unless as Dave wrote, some drops of liquid were already inside but not on glass and moved?

I don't know how viewfinders are made but it seems logical that if the "droplets" arrived before submersion they could indicate the viewfinder is oil filled and the droplets are actually bubbles. If it is oil filled maybe the knock has caused a tiny bit to be lost or dislodged so there are now small bubbles on glass. Maybe it is possible to get these to move off the glass possible by something like warming the viewfinder slightly such as putting it in the sun so the oil gets less viscous and the bubbles rise.

I think a few people use this lens as it has a versatile zoom range for mixing wide-angle and close-up on the same dive. I mainly got it for fish and people portraits but it seems a good lens for dives when I don't know what to expect. I have been using it with a close-up achromatic diopter lens. (Sigma AML-72-01) which 72mm diameter, matching the lens filter threads. I think it is 1.75 strength. To be honest I am not sure how important the diopter is, but it certainly seems sharp using it. Maybe someone else has the calculations on what it does to the minimum focus distance. I have a photo of the top of my Sony A75 with the diopter and without which shows the minimum focus distance looks slightly reduced, but not by much. I assume it helps corners at the 20mm end and maybe helps to be able use a larger aperture with an 8 inch dome. I haven't tried it in a smaller dome. Isotta have a zoom gear and port extension for this lens although it is not yet listed on their Sony port chart. The replicated close-up pictures are just crops of the original frame. Of course for wide angle it is not as possible to get as close as an ultrawide lens to the subject but in clear water it is still effective.

Thanks. I have wondered the same thing with this lens. I have the Kenko 1.4x teleconverter, and on my Sony the 4k60 has a 1.2 crop too, so I am guessing the resulting field of view is pretty good. I also wonder if using the additional advanced stabilisation means the 4k60 is not necessary for smoothing footage? And wow the reefs filmed look so sad. Can you say how patchy this was - just some areas of reef with extra local warming due to water flow or was it very widespread?

Fantastic .. and the music choice works so well.

Thanks for a great article and raising this topic. Also, Tim please do your article on neutral spaces. I took the attached photo this week which I personally really like because it did involve a some effort to try try to create a certain feeling and memory of the moment.

If you are willing to use APS-C mode when you need faster sync speed it is possible to get faster sync with the Sony A7R5 as that means the dark band at the top of the frame is not in frame. I haven't tested it thoroughly but tried it when I first got the camera and, from memory, I think 1/400s is fine. This is bearing in mind that the APS-C mode is 26MP and that the pixel size is the same as the Sony A6700 and larger than the OM System OM1.

Hi Chris, Are you now using your OM1-1 underwater? I know you previously had the OM-D EM 1 ii underwater and the Om-1 above. If so I am interested in your thoughts, maybe on a different thread. Thanks John

Thanks Chris and Phil. By the way Phil, in case anyone else looks for it, I found the review in issue #132. I'll try the Sony 20-70mm.

Thanks Chris, The Tamron 35mm has a close focus of 15cm. I can't see a slightly longer prime for Sony from them. I have wondered about the 20-70 and am tempted. I wonder how is does in an 8 inch dome? I see 9 inch is recommended. I am fussed about centre sharpness but not overly fussed about the extreme corners as this is mainly for photos with a central subject.

I am thinking more of close up coral colony and medium sized fish pictures that suit this focal length rather than pure macro. Just wondering what the conclusion is between the Sony 50mm macro and the adapted Canon 60mm macro on a late model Sony like A7Rv? Maybe a different prime is better like a close-focusing Tamron?

Obviously camera systems suit different people's use requirement so the title of this thread is silly. But the point that crop sensor lenses and suitability for reasonable size domes often work better for a particular person or underwater use is correct. That is not news, and all the advice I've seen given on this forum when people ask questions about new gear reflect that. Pooley hit it spot on when saying the photography is not about test graphs. Striving for technical perfection in a picture but not putting the same attention into creativity easily ends up with photos that are fairly boring other than a personal connection for the actual photographer. This is more true now than ever with the development of AI.

It doesn't look like you can assume you are getting the colour the diffuser claims when you take a picture underwater... Re Inon diffusers... From Driefish "The S-220 for example measure as 6650k without diffusers and 5400k with the Inon '4600k' filter." I am intrigued why the manufacturers may be off. Is there a reason or is it, say, the way the measurement is taken in water? I don't see any marketing logic for a manufacturer to incorrectly state a diffuser colour. The may not want their strobe to appear to customers as too high Kelvin, and that may be a trade-off for power, but if they make a range of diffusers why not be accurate?