Chris Ross

I would suggest that your first step would be to tell us more about what you want to shoot, UW photography is different in that the focal length is chosen so you can get closer to what you are shooting and you tend not to stand back with a longer lens. The aim is to minimise the amount of water between you and your subject as it degrades the image and if you are in a natural water body usually has all sorts of floating particles in it. Also helps with lighting as UW strobes have limited range as the water absorbs the red/orange quite quickly. Even if you are doing natural light, closer is better as the light has travelled less distance through water. Another thing to consider is you don't need fast lenses generally, dome port optics means you need to stop down to bring the edges in, they are unsharp due to the optics and with rectilinear zooms you are looking at something like f11 at least if you want halfway decent corners. You can get away with less if there is no detail there of course. People use big domes as they perform better in the corners than smaller domes. Further complicating issues is that some lenses perform better UW than others, not just set by above water performance. In general terms a Wide angle zoom that focuses exceptionally close tends to do better and can be used in smaller domes. For example the Canon 14-30 focuses to 200mm, the 15-35 to 280mm and the little 15-30 STM to 130mm and some have stated the 15-30 performs best out of the 3 UW, particularly if you use a smaller dome. The lenses that tend to work well UW tend to be the ones in the port charts - but ..... just because you see an entry in the port chart doesn't mean you'll necessarily be happy with the images produced. There's various threads on here you can search about these lenses and how they perform UW. The short version is if it's not in the port chart you likely don't want to use it UW as it has issues either working behind a dome or maybe extending too much when zooming etc. Of course brand new lenses take some time to be tested and included. If you feel you need the capability to shoot wider apertures to limit DOF, a dome and wide angle zoom is probably not your best option and you may be better served by a wet optic - the WWL or one of the WACP models these tend to work a lot better in the f4-f8 range. They have specific lenses that work well with them and some of them have limitations - you need to read the fine print. They tend to be more of the kit lens variety in many cases, for example the Canon 15-30 STM lens with the WACP. The WWL and WACP have a bit of barrel distortion that gets progressively less noticable as you zoom in. The 50 f1.8 is rarely used UW and I would think you'd use it behind a flat port same as the 85mm macro lens, in fact I'd suggest make the 85mm do the work of both of these lenses. Shouldn't need a diopter with either in a flat port. Please feel free to get back with any specific questions or clarifications.

Interesting mix of usage. On the subject of fisheye vs wide angle, fisheye distortion is maximised at the a 180° diagonal fisheye and becomes progressively less as the fisheye zoom lens is zoomed in. The WWL is no different as it introduces barrel distortion that becomes progressively less noticeable as it is zoomed in. In fact the view and distortion present on the WWL family at max field of view (130° diagonal - 106° horizontal field) is about the same as you would see with a fisheye zoomed into the same field of view. it won't be an exact match of course but the overall impression is quite similar and certainly with a shot with straight lines in you would notice the difference if shot with an equivalent rectilinear lens. IF you look at the diagonal field only that would tell that the WWL is equivalent to 10mm rectilinear, however the horizontal field is probably just a touch wider than a 14mm rectilinear lens. The advantage of the fisheye zoom is it goes wider and with the right combination zooms in about as far the WWL combo. I personally use the Canon 8-15 adapted onto an OM-1 - for tropical diving it tends to stay on most of the trip unless I'm doing macro. It's like combining a fisheye and a 14-28 equivalent lens into one and is very flexible. If you search for posts on the new Laowa 10mm lens you will see people complaining that it is difficult to use as the perspective makes nearby objects look relatively huge. The WWL avoids this as the barrel distortion shrinks closeby objects at the edges. As to whether the 24-50 matches the fisheye zoom, land tests will give you some indication, the 8-15 FE is known for being very sharp and performance behind a dome is generally quite good, even small domes. The WWL minimizes quality loss and is going to better particularly at the edges of the frame compared to a rectilinear behind a dome but it can't improve things beyond what the bare lens does. If you are still set on the WWL I also had a look at the Isotta port charts, they list the the Z24-50 with a flat port and focus ring - obviously aimed at WWL use. Phil Rudin mentioned that the Marelux probably wouldn't support it as the port would need to be inside the housing - this is down to different positioning of the camera inside the housing relative to the port. You just need to confirm with Isotta that the Nauticam bayonet adapter will fit the flat port. The housing will be at least 1kg lighter and smaller in all dimensions.

Keep in mind that using wet optics does not restrict you to Nauticam. Isotta and Marelux have good solutions for using wet optics you can even use Nauticam ports on Isotta, though I think perhaps not the extension rings. They can advise ports to use with the recommended lenses and will either have gears or they can be 3D printed. Also Out of interest what are you planning on shooting? The WWL or equivalent is a nice solution but there are other options which may have additional flexibility with a lighter more compact package. For example on APS-c You can use the zoom fisheye lenses the Tokina 10-17 and Nikon 8-15 , though the 10-17 only works on Nikon DSLRs and also add a 1.4x to the mix . The fields of view of the fisheyes on APS-C compared to a WWL plus 24-50 on full frame are shown in the table below: The table shows the horizontal field as well as the diagonal as I feel it is more useful for comparing fields available with these lenses and also the focal length of a rectilinear lens with the same horizontal field. You can see a few of the options give you the max reach of the 24-50/WWL-C combination , but also provide much wider fields than the widest field offered by the WWL. These options are attractive as they work quite well in small 100-140mm domes and are more compact and lighter. Arguably the optics of the Nikon 8-15 are superior to what you can get from the the Nikon 24-50 kit lens. Uploading Attachment...

Plenty of people using various forms of Nikon full frame and getting results they like from the z6 through to the Z9. What is more relevant in deciding which way to go IMO is what you plan on shooting and where. I would argue that full frame is not really necessary for most UW shooters, it tends to cost significantly more for the camera, the housing and also quite likely the ports and lenses. The kit is also larger and heavier, which is mainly concern with travel with the restrictions in baggage allowances that plague dive travel these days. For most UW shooting with strobes you are down near base ISO, using strobes in fairly bright conditions, there are exceptions of course. Lots of MP only really come into play if you are printing large - think A2 size plus. I think the vast majority of UW shots these days end up as 1200-1600 pixel jpegs online somewhere, unless you sell your images. I recall you were thinking about a D500 recently -this is still a fine camera, however if you look at sensor test results it is very similar in performance to the m43 20MP sensor. Smaller APS-C sensors and m43 also have a bit of an advantage in wide angle work as you can use lenses like the Tokina 10-17 or the 8-15 fisheyes (with or without TC) to achieve fields of view between full fisheye and something like a 28mm rectilinear in terms of field of view, giving unrivalled flexibility when shooting reefs, big animals, pelagics and CFWA. To do the same in full frame you would be looking at the very heavy and expensive fisheye conversion port or for Sony combing the 8-15 with the 2x Sony TC. If you are interested in light weight and size, the Isotta housings are quite a bit smaller. I know one person using a Z6 and went with Isotta as the rig was at around 1kg lighter than the Nauticam option and more compact. Personally I use the OM-1 in Nauticam and have an adapted Canon 8-15 with the 140mm dome and I'm very pleased that. On the macro front compare this pic of the Olympus 60mm macro with a Canon 100mm FF macro lens, weights are 185 gr (Oly 60mm) vs 625 gr -it's the pic I could find with a FF100mm class and the olympus lens side by side. Price is $US550 vs $US850 for a Nikon Z 105mm macro: https://www.dpreview.com/forums/thread/4595033 Having said all that if you can afford it and can live with the weight and size, I'm certain you'd be happy with any of the Nikon FF options.

Good to know, no such luck with my OM-1

Viewfinder all the way, I find I can see the detail in the image a lot better with the viewfinder, I can't focus all that well on the rear screen. I can see it and the composition quite clearly but not tell if I've achieved sharp focus. If your closeup vision is going, it will progressively get worse, so while you might be just OK with the rear screen now, in a couple of years you may straggle. The diopter adjuster on the view finder means you can see all the detail you need in the image, whether shooting or reviewing. With mirrorless the viewfinders are different to DSLR, so be sure to get the new models which have a wider field of view to cover the full viewfinder to the corners.

Or you could look into m43, great choice of macro lenses including the 60 and 45mm macros and there are plenty of wide angle solutions that don't require pulling the port off to get the camera out. If video is you main aim then a GH5 secondhand might be a good solution, the housing are bigger at least in Nauticam but ports and lenses are a lot smaller. They get down to the equivalent framing of 2x in full frame without diopters, though I'm not sure what you refer to when you talk about not having a zoom lens UW. There are possible solutions to this in m43 including using wwl/ diopter on a 14-42 lens but the macro magnification is a little lacking. It seems the right choice is somewhat dictated by how much magnification you would like when doing video and how flexible you want to be on a dive. Though there is always the argument to stick to one type of photo/video during a dive.

converting to jpg files for Windows users:

This certainly doesn't match my experience, do you set the mini flash to 1/64 manual power? I sat at my desk today and fired off 10 shots in succession in single shot and the flash went off everytime. On my last dive trip I used the OM-1 and did 3 dives/day and had 30-40% when done for the day, using OM system battery that's about 2 years old, the body is showing 14,400 shutter count on the two batteries I have. How many shots do you take on a typical day? I seem to average around 250-300 or so over the course of 3 dives.

I don't think there is too much more beyond being on Manual flash at 1/64 power. Looking in the menus RC mode is off, X-sync 1/250, slow limit of 1/60 flash compensation off. red-eye reduction off, first curtain. At 1/64 flash power I get at least 10 exposures clicking the shutter one after another in single shot mode. This is with an OM-1, I previously used the EM-1 MkII and I remember it being quite similar. The mini flash gets its power from the camera, so maybe check if the hotshoe contacts are clean?

I'm not sure that's the only reason it's so popular for macro, in addition there's a complete range of macro lenses including the 90mm macro which goes to 2x by itself and at that magnification has the equivalent framing of a FF at 4x. The in-body IS is also highly regarded, the smaller sensor is easier to accelerate to compensate for shake. I have taken shots with the 300mm f4 lens at 1/13 and they have come out tack sharp and can use ridiculously low shutter speeds with the 90mm macro. It's also what allows hand held focus stacking and super resolution shots. Probably not so useful UW, but it does compensate for any movement except for in and outwards and helps hold the AF point on your target. In addition the smallest AF point in the OM-1 is smaller still and uses a single AF point, while the small option uses a group of points and the camera selects which to use in that area. You can set the number of points the AF point will move with each click of the controls, here is the relative size of the targets: The OM-1 has 1053 covering the frame quite effectively and they are closely spaced. The only issue with such a small point is it needs to be placed over some contrast, though often a small movement is enough for the AF system to grab. The AF system also works quite well in low light, I found with my old EM-1 MkII it could gab focus on mandarin fish at dusk without a focus light. Having used this system on land the limitation when hand holding is how stable I can hold the camera to stay on target at maximum magnification. Even with the IS I have to take extra care to stay stable and moving subjects adds another layer of complexity. UW I mostly shoot around Sydney and the surge and current places limitations on how much magnification I can use not to mention the ability to actually find ultra small subjects UW. For this reason I use only the 60mm macro UW and find it has plenty of magnification.

Seems like a camera issue - I certainly don't see this with the OM-1 and seems like others don't see it with that model. Seems like it has tracking turned on even though you didn't set it.

I use the same mini flash to trigger my strobes I have never run into recycle time issues, I shoot only manual and set the the mini flash at 1/64 power manual flash. Admittedly I don't shoot rapid fire, but often squeeze off single shots in fairly quick succession. The Nauticam manual LED trigger is reported to work well and has the bonus of allowing shooting at up to about 1/400 and maintaining flash sync. If you are shooting TTL, you'll have these slow recharge issues with any of these small flashes and the only solution is an LED trigger. In fact I think most of the small accessory flashes are manual only.

It seems the issue is the difference between AF-C and AF-C plus tracking. I just played with my OM-1 and it was quite capable of using a very small AF point in AF-C, however for AF-C + tracking it draws a box around what it thinks you want it to track and this is where algorithms for choosing a subject come into play. It will lock onto what the system thinks you want and generally it will be the body part or object with the best contrast, but it depends on how it is programmed and it seems it chooses to use a bigger box when tracking is used. Subject recognition is the same deal it depends on how well it recognizes your subject. Another aspect of this is how well the Image stabilisation works- it can be particularly helpful in keeping the AF point stable on the subject if you sway a bit. If you move in and out in super macro you will be adding in the the AF speed and whether it can keep up as well. I find I'm not so stable as when I was younger and the IS on the OM-1 is a godsend. It really helps keep you subject framed properly - the smaller sensor is easier and quicker to accelerate and seems it quite stable enough to do hand held focus stacks. It seems to me that how well you like a particular AF system is a little personal and depends how well it can compensate for your instability. Water should slow things down a bit (unless you are dealing with surge or current) and again I think trying out some systems on land would be a good starting point.

Seems like the best thing you could do if it is available is to go to a physical camera store and try a few candidates out, Bring along a small model of some type which would allow you to test for precise AF placement. I know my OM-1 has a very small AF point available, the limiting factor is probably if the subject has enough contrast and beyond that holding the camera sable enough at high magnification. The stabilisation is a big help here. The OM-1 seems to be a favourite among macro bug photographers.