Looking at getting a Nikon with a Nauticam. The new z6III (24 mp) costs about the same as the older z7II (45 mp)—roughly half of a z8. Nauticam houses cost pretty much the same. I understand z6III is better for video, which I don’t care too much about. z6IIII (haven’t had it in my hand) seem a tad smaller and lighter. Housing a tad smaller and lighter. Like that a lot. Then 45 mp is more. Not sure how usable it will be UW. But still …

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.

If you are looking to get a Nikon/Nauticam setup the cost of the camera body is really not the biggest expense you are looking at. The housing costs nearly twice what the camera body does. Strobes are $1000 each or more. So, the difference between a Z6 and Z8 is a pretty small fraction of the purchase. With an investment like this you are usually wise to by the best, most advanced option. Especially if you plan to keep it for years to come. You can buy used bodies and lenses from reputable sites like KEH or B&H Photo. Unfortunately, a used Z8 only saves you about $300 but you can really save big on lenses sometimes.

Hi Kristian

Chris and Dave make some excellent points. Given the total cost/weight of an FF package with all the bits and pieces, the additional cost and weight difference between the Z6III and a Z8 becomes negligible. Both packages are big beasts.

Chris makes the point about what you plan to do with the images. I agree with him whole-heartedly that FF is not necessary underwater unless you are planning to produce very big prints or serious high-end commercial sales. I had a Nikon FF system (D800), really got fed up travelling with huge amounts of bulky gear (and the complaints from my partner whose baggage allowances was also being swallowed up) and switched back to APS-C and the D500.

That was 8 years ago and I'm still using and loving it. There is no way that the old technology is limiting me. I sell loads of images - as Chris writes - as JPEGs. It is much easier for travelling although there is still significant bulk. I don't regret the system downgrade (?) for an instant. And I admit to being a lover of the latest shiny toys. (I've got a Z9 and Z6III for topside)

I do think though that there is one important point the guys havn't mentioned and that is "desire"! Beware of Buyer's Regret. I'd suggest the last thing you want is to spend, say, $12k and after 6 months start to regret that you didn't spend $15k and get the system you really hankered for. Been there, done that. If cost is not the deciding factor, think about what would really give you the most pleasure to own and use. If its an FF system with all the bells and whistles and you understand the downsides, then why not......

Good luck with the choice. Not easy for sure.

Yes. Was looking into getting a second hand D500, since I come from D200 and D300. Already have lenses. But … I am now set on wet optics after some research. So a Nauticam housing. Looked at the little housing for the new DX z50II, but it has no viewfinder which might be a deal breaker for me. So tbh FF in itself not what I was looking for necessarily. But I’m more and more likely going to go that route. Have been looking at size/weight which is a concern and important to me and none of those mirrorless (z6 or 7+nauticam) FF set-ups seem to be bulkier and heavier than what I have been schlepping around for years. Already have strobes, cables … but am stretching my budget … yes.

Edited 1 hour ago1 hr by Christian K

1 hour ago, Christian K said:

Yes. Was looking into getting a second hand D500, since I come from D200 and D300. Already have lenses. But … I am now set on wet optics after some research. So a Nauticam housing. Looked at the little housing for the new DX z50II, but it has no viewfinder which might be a deal breaker for me. So tbh FF in itself not what I was looking for necessarily. But I’m more and more likely going to go that route. Have been looking at size/weight which is a concern and important to me and none of those mirrorless (z6 or 7+nauticam) FF set-ups seem to be bulkier and heavier than what I have been schlepping around for years. Already have strobes, cables … but am stretching my budget … yes.

Yeah, can understand your thinking for sure - and those wet optics sounds pretty cool and they point to Nauticam.

If you're likely heading down the Z6/Z7 route, I'd suggest a close look at the Z8. I was diving with a serious u/w photog recently who had switched to one (in a Subal housing but, urgh, with a 230 dome) and he was happy with it. It's the latest technology, as opposed to the Z7II, and has the larger file size than the Z6III (if you're going All In, go All In!). But, yeah, budget stretch.......