I'm hoping for some guidance as I am wanting to change into some new technology but am confusing myself and being terribly wishy-washy. I'm trying to be brief but it might drag a bit, sorry! I know that there are multiple great options and it's individual for "best", but getting some real world input may help me clarify my own thinking. I have been using dslr for over a decade, though the past year + I was only using my Oly TG series. That's been great fun, but the limitations and image quality for some types of images were starting to annoy & drain some of the fun for me so I brought the big rig out of the closet last month.

My BGC is currently Canon 7dmkii and Nauticam with Inon 240s. I have a bunch of lenses & domes/ports & dioptres for macro; I also have the Kraken KRL-90S that I think I remember having fun using, but it's been a long while. Ideally, I'd like to be able to use what I currently have with the new system with an eye on updating components as needed, so am fairly confident I'd l like to stay Canon/Nauticam. My shooting style is often wandering around the dive and taking whatever comes, versus setting out with more specific goals. My 17-70 macro lens offers great flexibility for those days; other days I enjoy the Tokina 10-17 and Canon 60 macro. I have an older Canon 100 macro and I think that is one lens I may want to update to the RF version eventually, but for now, will hopefully be able to limp along with it. Going forward, I'd like to explore shooting video & wider scenes as these are things I haven't pursued as much.

A friend let me borrow her Canon R5, but sadly I wasn't able to get it underwater as conditions were yucko. I may have another chance soon, though. I was able to see which of my lenses worked with it, so that was nice and all but the 60 played nicely. It was my first time using mirrorless and I liked it. At first I was ready to make the jump to FF, but now I'm back to not being sure if that matters so much to me; I don't think I have a strong preference either way, though when I used the R5 on land, I did miss my "extra" reach! Seems FF is more expensive, too.

I have considered everything in Canon's range, but keep flip flopping. I think the Final Four are R50 (backscatter suggested this set up and it was very tempting; love the form factor), R7, R6mkii and R5mkii. I don't think any would let me down for image quality, but I get a bit lost trying to pinpoint how much benefit I would get from moving up the chain. And, it sounds like there are new models coming later this year so maybe I should keep waiting; I don't have to have it right now, though I kinda would like it before our summer diving starts in Nov/Dec! What I want is probably what everyone else wants: excellent autofocus for both stills and video; great video - I am starting to explore this and would hate to get a body now that is too limiting (and I think I read that was an R50 issue) because changing bodies when housings are involved is just painful imho. I'm a happy cropper - I do try to get the image I want, of course, but sometimes I like/need to crop. While the R5mkii is undoubtedly an awesome machine, I do feel that choosing something else would do me just as well and any difference in costs would be put to good use on trips, lighting, lenses that would benefit me more.

Whew, is that too much info? Have I given enough info to help me narrow my choices? I hope so...i seem to be able to talk myself into anything but then fall down the rabbit hole and don't end up making a decision. I'd love to hear your thoughts. Adding a photo so this post at least has something fun to look at!

You are right there are multiple options these days, though the camera makers are gravitating towards full frame and that could be quite expensive as the housings cost quite a bit more in some cases and you tend towards more expensive wide angle solutions. Unfortunately their smaller format options are relatively limited. I would start with asking the following questions:

What are your main targets - macro - wide a mix of both? video? Flexibility during a dive?

what do you do with your images - post online? commercial sales? giant prints?

What do you see might be improved over where you are now?

The R5-II will cost about $2k (AUD) more to house than an R7. But Nauticam have gone to the N100 ports which are more limited and can need the very pricey N100-N120 adapters depending on which port you go for. Marelux also does an R7 housing and is slightly cheaper. Isotta housings are a bit cheaper still but they don't seem to do an R7. Isotta use an N120 port and any Nauticam port you have that has a bolt on lug ring can be converted to Isotta by changing out that lug ring.

The Canon 7D MkII is a pretty old camera now, so I would expect that the m43 sensors would easily beat it out in image quality, I shoot the OM-1 in Nauticam, Isotta is also available, this housing is about $1200 cheaper than the R7 housing in Nauticam. The ports are also quite a bit cheaper as are the lenses. I recently upgraded to an adapted Canon 8-15 fisheye with 140mm dome. This is an excellent wide angle setup, it goes from 180° diagonal fisheye to a 28mm full frame equivalent rectilinear field and focuses right to the dome. To have that flexibility in full frame you need the very heavy/expensive Fisheye conversion port, though in Sony you can do something similar with a Sony 2x and metabones MkV adapter. the OM-1 would also be a great solution depending of course on your uses for the images, though a lot of people shoot it professionally.

On the topic of buying a new rig, I expect that you might find it significantly cheaper to buy from the Australian distributors, Nauticam in the US has gotten quite expensive (tariffs). For example the R7 from Scubapix is $5200, while at Backscatter it is $4100 USD converting to AUD that's ~$6600, then add 10% GST plus shipping plus fees you will be looking at near to $8K landed.

1 hour ago, Chris Ross said:

What are your main targets - macro - wide a mix of both? video? Flexibility during a dive?

what do you do with your images - post online? commercial sales? giant prints?

What do you see might be improved over where you are now?

Thanks for your reply and the info on various housings/ports. Gives me more to read!

So you reckon head to FF?

1 - I quite like everything, I'm not a specialist

2 - I would to make sure that my camera can handle all of these including quality video for projects.

3 - I think pretty much everything is better on the new bodies! The 7dmkii doesn't suck by any means, but new autofocus, video capabilities, image quality, screen are all worth updating, imho.

I do not know how fast you will have to change, but Canon R6 II is a very good camera ( I know it from a friend, underwater and above water) and there is a new version of this camera in the startup line of Canon, announced with more megapixel. That could be a good choice, including good video features announced.