A few months back I asked a few questions on another thread about some of the practicalities of making an underwater housing for a K-01, and I promised that if I did get around to making something that I would create a separate thread for it; so here are some pics of the build, the final result, and my thoughts about its use thus far.
I described my idea as being a "simple box", but it turned out to be a little more elaborate than what some people may have expected! The plans were drawn up from a set of measurements I had taken of the camera and selected lens, and most of the planning was done sketching in 1:1 size on a piece of A4 paper. I made it out of stainless steel, as I would sooner trust TIG welded stainless over any sort of plastic welding that I would be able to do, and the fact that at my workplace has most of the tools and equipment to fabricate it out of stainless made the decision easier. The stainless sheet itself was an old electrical/pneumatic instrumentation box that I salvaged from a scrap bin. The box was in a pretty corrosive area, so there was plenty of scaling I had to buff off and plenty of pitting underneath that, but the parent metal was in good enough shape all-in-all. The sheet is approximately 1.2mm thick. The housing body is made of one piece of sheet that I folded into shape to minimize any welds that were necessary. It's far from perfect, since all I had to bend it was a workbench, two F-clamps and a length of angle iron. The end result is a little out-of-square, but good enough.
The flanges on both ends of the box are 3mm stainless ( again salvaged from the scrap bin ), which hold a 3mm rubber gasket and a 5mm Plexiglass sheet with 6mm stainless steel bolts. I glued some bits of rubber on the inside of the housing to space the camera body and lens away from making contact with the steel. I also glued some black rubber sheeting around the inside of the front of the housing to cut down on any annoying light reflections from the stainless steel that might affect the lens.
The only moving part of the setup is a lever that operates the shutter button; I had no other controls in place that could manipulate the camera once it was sealed inside the housing. The lever that triggers the shutter button is a piece of bent 5mm stainless rod that passes through a small housing with 4 x O-rings sealing against it. The O-rings are held and compressed inside their housing by a 12mm stainless grub screw that has a hole drilled in its centre to allow the rod to pass through. This setup allows for a very high amount of finesse and feedback when depressing the shutter button since you aren't fighting against a spring in the lever.
I didn't have much of a chance to actually field test the housing before going on a dive trip to the Great Barrier Reef last month. A couple of mates and I spent 3 days on a live-aboard boat and I made a total of 11 dives on the reef down to a max depth of 18 metres. I first took the housing down without the camera in it for a couple of dives until I had tested it at our max dive depth. I then decided to use it with the camera and my [I]second[I] ( and much cheaper ) choice of lens, which was an older Sigma 105mm f2.8 macro. This precipitated an unfortunate event, as I had not designed the length of the box to accommodate the full length of the lens barrel when it focuses at a close object. I didn't expect this to be a problem, and I ( foolishly ) didn't set the focus limiter either; with a little earlier testing I found I could still focus on objects about 300mm away without the lens barrel needing to reach its full extension. The problem was that the lens didn't know that. Once I was underwater I tried to focus on something, and the lens racked through its entire focal range. The barrel hit the inside of the front Perspex panel and pushed the camera body back against the rear Perspex panel. It must have hit the Playback button, and so I had a bricked camera at 18 metres that I could do nothing to fix!
After that I put the lens on the K-01 that I had actually designed the case for - the Sigma 18-35 f1.8. I was a little weary of having a relatively expensive lens in there, but it performed really well. The only other issues were my use of Auto mode, which doesn't seem to allow you to select the preferred focal point? After that I put it in Av ( in hindsight, Tv might have been better ) and used the centre focal point. The camera bricked up on me again on one occasion, but I had left it on standby inside the housing overnight and it may have objected to that.
I got a lot of curious looks from fellow divers. The finished product looks pretty butch, but it's a WWI tank compared to the sleek Icalite case my dive buddy was using for his Nikon. The weight of the case wasn't a problem, as it was only slightly below buoyancy in the water. Since I was probably slightly under-weighted with my kit in the water anyway, the little bit of extra weight actually helped me control my buoyancy in the water.
As for my underwater photography experience, I have mixed feelings. The GB Reef is beautiful, but you lose colour very quickly at that depth and most of the fish there are so small that shooting with a 28mm FF equivalent makes it hard to capture marine life that isn't much bigger than a matchbox. The Sigma 18-35 close-focusing ability does help, but getting close to fragile coral formations is difficult for a new diver. Capturing photos of fellow divers ( since they are bigger and slower than the fish ) is much easier!
I'm already thinking about a Mk.II case, but the only features I think I'll change/add will be a geared setup for being able to control the lens' zoom function, perhaps a better way to seal the back of the housing ( tightening/undoing all those nuts/bolts is a bit of a chore ), and ( probably more importantly ) a way to use an external strobe with the camera, as that would make all the difference for capturing colour in the coral and fish. A change in lens would be handy as well; something like the Sigma 17-70 would probably be more ideal with the extra reach. Or maybe I'll just buy another camera that already has underwater housings available! That's all someways down the path in the future, though!
Originally posted by hcc 
Post #2 by Focusrite
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