My Camera Equipment
I started my underwater photography with a Nikon Coolpix 3100 in a Fantasea housing, which produced very good pictures provided available light was good, which was not that often. I moved on to a Canon Powershot S70 which brought 2 major benefits.
Being able to use RAW gave me the power to do my own post dive white balancing, plus greater exposure latitude, and its manual mode made an external strobe a possibility. My first strobe was an Ikelite A35 Substrobe which produced vastly better pictures in poorer light conditions, but only when the camera managed to focus, and this was a problem in low light conditions. As a result I changed my strobe to a Sea&Sea YS-110 which has a built in focus light which turns itself off when the strobe fires. This improved the focusing no end and so very satisfying pictures resulted. However, the shutter lag typical of compact cameras, meant taking fish was very difficult as they had moved by the time the camera shutter opened. I limited my pictures to slow moving creatures such as nudibranchs, but lusted after an SLR, though the price of these was beyond me as housings were several times more expensive than the camera itself. Olympus changed this when they started to produce their own acrylic housings for their E-range of cameras. The first ones had some problems but by the time the E-520 was out they seemed to have solved them and I am currently (2009) using an Olympus E-520 in the Olympus housing specifically for it (PT-E05) using the standard 14-42mm lens in the dome port made specifically for this by Athena.
The same Sea&Sea YS-110 serves me well. It is only able to use manual mode, but this is what I would use most of the time anyway. Synchronisation is via a fibre optic cable (half an audio one costing only a few pounds, with home made connectors, rather than the much more expensive Sea&Sea one) and is as near foolproof as you can get. My latest addition is a home made adapter to fit a wet diopter in front of the lens (Athena do one but charge several hundred pounds for it!) and this gives me great versatility from moderate wide angle through to a moderate macro. While specialist lenses for each would be better still, they can't be changed underwater as my set-up can, so I don't think I will change things for a while now.
Famous last words! Inevitably things have grown while I have failed to update this page (It is currently 2019!). I still use the E520 camera, and I have a spare body in case of floods (which has happened once) and which used to double as my land camera, though that function has been replaced by an Olympus OM-D E-M1 Mark I. I also now have a two handled tray with an Olympus UFL-3 strobe on each which give full TTL exposures, and a Big Blue focus light on the cold shoe which has improved focusing speed. More ports and lenses have accumulated, so I have been using a 50mm macro and port quite a lot, and also an 9-18 wide angle zoom and port, though only when the vis is good. The standard lens has been replaced with a 14-54mm f2.8 lens, at first with a flat port which was soon replaced with the modified dome from the standard lens (the internal restrictor being removed on an industrial lathe to allow the larger lens to fit through it) and extended with a PER-E01 Lens Port Extension which seems a perfect combination. I have also just invested in a couple of dome diffusers for my strobes for the 2019 season and these seem to produce a very pleasing softer light.
The Olympus OM-D E-M1 Mark I with a M4/3 12-40 f2.8 standard lens, a M4/360mm f2.8 macro and an old style 4/3 50-200mm 1:2.8-3.5 zoom, a wonderful lens for which there is no M4/3 equivalent (I use it with a MMF-3 converter and usually a 1.4 teleconverter) has given me much more scope on land, though as most of the improvements would not be used underwater and the cost of a new housing and potential loss if it flooded has meant that I have not been tempted to take it underwater. However, after using it for a couple of years the temptation of the Mark II proved too much and I upgraded again. The main improvements are better low light performance, better focusing with my 50-200 lens and at last, a function I have not seen since my Olympus E-100RS 1.5 megapixel camera back on the year 2000, which is a rolling buffer that stores pictures while the shutter button is half pressed and saves them when it is fully pressed when it continues to take pictures in real time, so you end up with frames both before and after the button is pressed, removing any problems with reaction times when trying to take pictures, for example, of birds taking off or landing, and I love it :-) I also now have an Olympus Pen E-P5 with a Panasonic 12-32 lens which makes a small versatile M4/3 unit which also doubles as a backup for the E-M1 as I can use all my other lenses with it, though it struggles to focus with the big zoom!
When I only need a small point and shoot I still occasionally take the Canon Ixus 70 which was a free replacement from Canon for an early Ixus I bought on eBay which had a faulty sensor. I also have an underwater case for this which has proved useful when snorkeling in Australia. This camera continues to produced some excellent shots, and when combined with CHDK software to enable it to take RAW images, leaves little to be desired when weight and space are at a premium and I want underwater shots. However I find the pictures from my phone (Samsung Galaxy S5 Mini) nearly as good (though no RAW available), but I can't take that underwater.
My pictures are named yymmdd_hhmmss_camera so you will be able to see to the second when a picture was taken and with which camera, and many of the more recent galleries allow you to click a map button to see where it was taken.