I currently have a Nauticam a6300 with a N120 dome for a ZEISS Touit 2.8/12 and a Macro port for a 16-50 kit lens.  When I bought this 4 years ago, the a6300 became my above-water camera and I sold off the Canon gear I previously used.  I recently bought a A7RV for above-water, and it is a HUGE improvement over the a6300.

 

I have a few issues with my current setup, cracks in part of my tray, a broken vacuum pump (that still works), a broken flash on my a6300, etc.  Some of these I can live with, and some I'd repair before my next trip.  I was also considering upgrading either or both lenses.  This got me wondering how much more I'd need to spend to take the A7RV underwater instead.  A Nauticam setup at $5k is not realistic, however I could probably buy a whole SeaFrogs setup for what I planned to invest in repairs and upgrades before my next trip.

 

So my question is, would going from the most expensive and best made housing for an old ASPC camera to the cheapest housing for a new and great full frame camera be an upgrade?  What do I lose going with the cheaper housing?  I am not sold on SeaFrogs either, I've just heard a lot of great things from people who've used them.  There are a lot of options priced between SeaFrogs and Nauticam, but I haven't met anyone who used them.

I'd say, the main thing you'd be losing is lens selection flexibility. As far as ergonomics go, it's kind of a wash between the two. Most Nauticam housings have nice thumb triggers for back-button focusing, which allow you to operate the housing while holding on to tray handles, using your thumb to focus and index finger to shoot, but your a6300 doesn't actually have that, so it's not a factor. Likewise, Nauticam offers nice magnifying viewfinders, but it doesn't sound like you have one of those either, so you'd be using the camera screen in both cases.

 

I don't have personal experience with the SeaFrogs A7RV housing, but I do own the A6700 housing which has a similar control layout, and the ergonomics are surprisingly good. It's not as good as a modern Nauticam or Marelux housing, but if I put my right hand on the housing (i.e. between the housing and tray handle), I can have my thumb on the AF-ON button or the top dial (aperture), my pinky on the front dial (ISO), the ball of my thumb on rear dial (shutter speed) and my index and/or middle finger on the shutter release, enabling three-dial operation and back-button focus without moving my hand at all. My left hand is on the respective tray handle and easily reaches the zoom knob. This might not work if you have especially small hands, but mine are fairly average and I have no trouble operating all the controls.

 

As far as lenses go, you'd be using Sony 16-35mm f/4 or Tamron 17-28mm behind a 180mm dome. I believe Canon 8-15mm can be adapted and used with either a 150mm or a 180mm dome, but alignment can be an issue, and you'd need to make your own zoom gear. SeaFrogs don't have extension rings - what's labeled as extension rings on seafrogs.com.hk are actually dome port bases; you can't stack them or use them with flat ports to customize lengths. There is no option for 100mm or 230mm domes either. For macro, it's basically Sony 90mm or nothing. The new Tamron 90mm macro should fit into the same port, but as it is slightly shorter, it won't work as well with close-up wet lenses for supermacro, and f/16 minimum aperture is a weakness.

 

VPS-100 vacuum system is mostly useless - its seals degrade when submerged and after 70-80 dives or so it starts leaking water. Fortunately Vivid Housings makes a version of Leak Sentinel that fits SeaFrogs housings; you can use that.

 

Since A7 series cameras lack a pop-up flash, you will need a way to trigger strobes. Avoid the SeaFrogs optical trigger - it's cheap, and actually surprisingly powerful, as it is a small Xenon flash rather than an LED, so it works well with low-quality fiber optics, but it has a major flaw - it draws power while in standby, and the battery only lasts a few hours, so basically you have to turn it on, seal the housing half an hour before your dive, vacuum it, and it's good for one dive only - you'll have to recharge it before the next dive. A Turtle or UW-Technics trigger is a workable alternative, but much more expensive. Another option is an electronic sync cable, if your strobes support that, but that means messing with a bunch of extra o-rings.

For me, this is comparing apples with watermelons, yes the Seafrogs housings work and keep out the water and certainly some people are happy to use them, but they have limitations as Barmagalot outlines above.  The lens support is limited as stated and it appears there is little attempt to optimise the dome positioning beyond making sure the supported lenses don't vignette.  Not to say that some people aren't happy using them of course.

 

I would also suggest huge improvements on land don't necessarily translate to the same benefit UW.  Especially if you are looking at using any of the rectilnear wides behind a dome that is too small or not optimised. 

 

A good alternative for an upgrade might be to see what is on offer second hand through the classifieds.

5 hours ago, Chris Ross said:

I would also suggest huge improvements on land don't necessarily translate to the same benefit UW.  Especially if you are looking at using any of the rectilnear wides behind a dome that is too small or not optimised. 

While in general I would agree with you, I have met several people using the 16-35mm f/4 Z lens behind a SeaFrogs 150mm dome and the results seemed adequate. IIRC someone posted, either here or on Wetpixel, tests showing this particular lens being more tolerant to smaller domes than most rectilinear ultrawides. Canon 8-15mm is also an option, and I'm pretty sure that a SeaFrogs dome will give it better positioning than, say, Ikelite compact 8-inch - if nothing else, it's a much deeper section of a sphere.

 

6 hours ago, Chris Ross said:

A good alternative for an upgrade might be to see what is on offer second hand through the classifieds.

If it was something like an A7 III then maybe, but A7R V is a current-gen body with no replacement in sight. A quick search shows none to have been posted in the classifieds here thus far, and only a single offer each on Wetpixel and Scubaboard, both over a year ago and with no price stated. A new Nauticam A7R V housing is about $4500, compared to SeaFrogs $566. A Nauticam setup with a 180mm dome set up for 16-35mm f/4 and a flat port for 90mm, per Backscatter, runs about $8300, whereas a SeaFrogs setup for the same is about $1500, both including a vacuum system and a manual strobe trigger. The $6800 difference buys a lot of air/nitrox fills...

Even though the A7 R 5 is an incredibly good camera, if you have a limited budget I would consider which is the best way to go for underwater.
I personally have had bad experiences with Seafrogs and have actually flooded one camera and almost flooded one camera. I would personally only consider the established durable housings: Isotta, Sea&Sea, Marelux, Nauticam, Ikelite.
To build a system on a limited budget I would go more in the direction of A6700 in Nauticam. You can reuse a lot of your existing equipment. Read my A670 thread.

 

4 hours ago, Barmaglot said:

 

 

If it was something like an A7 III then maybe, but A7R V is a current-gen body with no replacement in sight. A quick search shows none to have been posted in the classifieds here thus far, and only a single offer each on Wetpixel and Scubaboard, both over a year ago and with no price stated. A new Nauticam A7R V housing is about $4500, compared to SeaFrogs $566. A Nauticam setup with a 180mm dome set up for 16-35mm f/4 and a flat port for 90mm, per Backscatter, runs about $8300, whereas a SeaFrogs setup for the same is about $1500, both including a vacuum system and a manual strobe trigger. The $6800 difference buys a lot of air/nitrox fills...

Not what I was trying to suggest - the suggestion is to look for full setups possibly including the camera, Sony A6xxx series that is a bit newer or branch out into other camera makes potentially.  A6700, you'll probably only get new, but the 6600/6400 might be a possible choice.  There's a 6400 on wetpixel now dropped to $1050.  I know you like yours, but I feel you get what you pay for, though the returns are diminishing of course.  A new ikelite setup is also an option.

23 minutes ago, Chris Ross said:

Not what I was trying to suggest - the suggestion is to look for full setups possibly including the camera, Sony A6xxx series that is a bit newer or branch out into other camera makes potentially.  A6700, you'll probably only get new, but the 6600/6400 might be a possible choice.  There's a 6400 on wetpixel now dropped to $1050.

Problem is, that will require another new camera. A new a6400 is $900, so just the housing + body is approaching $2k, and the jump in capability from a6300 is very incremental. It's got somewhat better AF, but not the big boost found in A7RV/A1/a6700, and the rest is basically the same - same 24MP sensor, same small battery and so on. Might as well just get a camera repair shop to replace the flash on a6300, get a new tray and keep using it.

 

23 minutes ago, Chris Ross said:

A new ikelite setup is also an option.

I'm actually very unimpressed with Ikelite's a6700 housing. It's got a thumb trigger for AF-ON, yes, but no access to front dial, making three-dial operation impossible, and the knobs that are there are located in such a way that you have to reach for each one individually. There are no M14 or M16 bulkheads, and no provision for optical triggering - electric sync cords only. I suppose a UWTechnics converter can be installed in place of the electric bulkhead, but that's a $650 part on top of a $1200 housing.

Edited February 24Feb 24 by Barmaglot