Chris Ross

The PCB board I linked earlier would fit with next to two 18650 batteries I believe. I say 18650 as this would leave space for a battery holder so you can pull them out and place them in a separate charger. two by 3600 mAhr 18650s would give you just about 26 Whr in capacity. Of course an off the shelf model would be simpler to hook up if you can get something close in capacity.the right size. This could be close: Cygnett powerbank It has PD so doesn't need a separate PCB it seems, does 9V 2.2A so not quite up to spec for solo running but should have plenty of capacity for you.

Not much getting around it, occasionally you'll find an adapter second hand, I found one at about half price. You could wait and see on the Laowa newly announced but there maybe issues. If you have any interest in using it with the Sony 2x for an extremely flexible 180°diagonal fisheye that zooms to a 28mm lens equivalent in horizontal coverage then you need the I think the latest version as the Sony 2x nose will fit inside it. Requires a custom zoom gear printed which easy enough as designs are developed and available.

It seems it is reported that the 9v/3A supply is required for solo operation without a battery and if the a lesser power bank is hooked up it will just top up of supplement the battery but won't attempt to run the camera solo. One way to test is to connect a power bank of 7.2V output to the camera and see if it will operate and draw down the battery bank. Given the limitations of the space available in the housing it's likely a custom solution is needed and it only needs to supplement the main battery. The link above to the module would work but looking at the size of it I suspect you have trouble squeezing it in. I had a look and had trouble finding a lower power smaller module, maybe the wrong search terms?? I would guess a 10W module would do the job if the camera is happy just receiving a trickle charge as it runs. I found some phone charger module which I would guess might work: ali express to use you would need to wrap it it and solder on positive and negative wires and plug in a USB C cable with the right spec. A good way to start would be work out what size and how many batteries might fit in the available space. You could use a AA battery to gauge what might fit.

I can understand - there's some nice shore based diving I've been doing, you should try Walindi in PNG, not the easiest to get to but they head out on day boats to some excellent diving out in Kimbe Bay. The shore based resorts in Dampier strait also look worth exploring.

Wondering if we should be more discerning about the types of vessels we book. It seems to me that a solid timber vessel would be less of an issue, I'm thinking of the Phinisis that ply Indonesian waters built of tropical hardwoods using traditional methods. Timber will burn strongly but requires something to start it going - kindling if you are building a fire. Of course it will burn and once it gets going become intense but the ignition is probably slower. Looking at boats I've been on I looked up safety requirements for vessels plying Australian waters and while SOLAS is not required they have extensive fire safety requirements they need to meet, particularly if operating offshore - The Rowley Shoals boat comes to mind, operating 300 km offshore. I also recall the boat we did a Galapagos cruise on was steel hulled and seemed well equipped but that was 12 years ago now. Most of my dive trips have been from land based resorts in the recent past - possibly as I don't have fantastic sea legs, I was quite sick on the run out to Rowley shoals, but the return trip was much calmer seas with what swell there was behind us.

Maybe a trigger to change providers? Or maybe you keep your phone in your pocket even if it is powered down or the grab bag. With a phone in hand nearly anything can be taken care of these days.

The quality looks pretty decent into the corners in the sample photos, seems quite heavy at 650 gr, though the Canon 8-16 is no lightweight either at 540 gr.

Hi Tyler, welcome to the forum, enjoy the forums!

Welcome Craig, I'm Sydney based mostly diving Kurnell, where's your local dive site?

Do you know what the voltage limits are for your camera? I found this about A7SIII power bank requirements: Seems like it will accept higher voltages and Sony recommend 9V #A power banks and won't run the camera without battery unless it gets a handshake to show it is getting the exact voltage it wants to run the camera, but should supplement the battery if it's in place with a lesser power bank. So two parallel -two series 14500 batteries in holders (4 total) - about AA size would give you 2000 mAhr at 7.4V or 14.8 Whrs, just need to wire some holders to a USB-C cable and not worry about electronics too much and charge them in an external charger. you could use a velcro tie wrap to keep the batteries in and velcro padding on as needed. Might be a good option if you had the space. Nitecore has 1000 mAhr 14500 batteries.

It is interesting to note that even though this lens and the Canon RF100 achieve 1.4x magnification, when you add on wet lens they only achieve minimal gains in magnification over what you would get with the 1:1 lens they replaced. The Canon RF 100 with SMC-3 achieves 2.3x with 30-100mm working distance while the Canon EF 100mm macro gets 2.2x with 46-97mm working distance. The Sony 100mm gets 2.4x with 34-100mm while 90mm macro gets 2.3x with 47-103mm. This is due to the lens reducing focal length to focus in closer, this is a feature of all internal focus macro lenses and becomes particularly prominent as the magnification increases. You might initially think you'd get much more, but the shorter focal length means the power of the SMC-3 or any other wet lens is a lot lower and the peak magnification is achieved at a shorter working distance. It would seem based on theBackscatter review that a 1.4x is a decent option if you were chasing small skittish fish with Sony 100mm macro

I think the answer is with a 1.4/2x you are always further away than you would be with a bare lens and with a wet lens. With a 2x you can match nearly a 100mm macro with an SMC-3 (2x vs about 2.2-2.3x depending on which macro lens). Basically more water between you and your subject which will degrade the image. If you back off to get 1:1 with a 100mm_macro/2.0x you have the reach of a 200mm macro, so if you had a 100mm lens with 300mm focus distance and 150mm working distance at 1:1 you would double that distance with a 200mm focal length lens depending on how much the lens reduces in focal length to achieve 1:1 with and IF design. It gets worse as you progressively shoot larger subjects. A 1.4x might be a good compromise to give a bit more working distance compared to the bare lens and wet lens at a given magnification.. Also bear in mind that the longer focal length of the lens + TC combo will give you significantly more magnification than the bare lens with the same wet lens. For example the m43 Pany 45mm lens gets 1.6x with CMC-1 while the 60mm macro gets 2.0x (both 1:1 lenses) and 60mm is near 1.4x 45mm. so the new Sony macro might go from 2.4x with SMC-3 to 3.3x with a 1.4x and 4.8x when used with a 2x. So a 1.4x/2.0x locks you into smaller subjects than a bare lens/wet lens combo does and the impact would be noticeable I think in the 0.5x -1:1 range and lower magnifications unless the water was crystal clear. It may work well for skittish mobile subjects like small fish if this was the sole subject of your dive. You might also degrade AF performance with the 2x at max magnification again depending on lens/body combination

This is interesting, My old housing had 2450 cells they seemed to last forever, but my OM_1 uses 2032 cells, not sure why they would reduce the size, not exactly short of space, maybe as it's the same cell used in air tags?? The 2032 cell seems to be fine for an extended trip, I left it on for 3 days before opening at on epoint and did about 20 dives over 6 days and continued using it for local diving afterwards. Sounds like your Z8 is worse? IF you are indeed getting that sort of life it seems like a good option and worth trying out.

Welcome to the forum, good to have you here, feel free to post away with any questions.

Looks like their capacity is only 45 mAhr while a CR2032 is 235 mAhr - though that is to 2V so effectively about half of that to just under 3v where Nauticam vacuum alarms signal low battery. I like the idea of a rechargable bettery though- one solution might be to find a rechargable Li battery that you could wire in place of the coin cell holder., something with a small enough cross section.