Patterns

Personally (and it would be different perhaps for other people) if I'm thinking about underwater cameras my priorities (that come to mind now) are: Must have: - Manual exposure - custom white balance - Available Inon adapter for AD or AD28 mount - reasonable low-light focus capability Really nice to have: - wide zoom lens - raw - option to set the flash manually to very low power (since I use manual control for my flashes) - ability to store a couple of settings (for wide-angle, macro, whatever) - all controls by pushbuttons rather than dials - low noise sensor - long battery life (enough for 3 dives) - smaller housing, but with a bit of spare space for a silica gel pack - easy to feel the shutter half-press position with the housing Others - longer zoom - better screen - screen visible from a high angle while in the housing I'm sure I have left out lots ... -David

I don't dive much these days, but I have been thinking about buying the A570 and housing to replace my S70 (because of poor focus) and C5050 (because it uses M67 mount - see below) kits. I already have both AD-mount and M67 (threaded) wet lenses. My overvations: (1) If you want to use wet lenses, the bayonet mount is far easier to use. That's a big tick in favour of your proposed system. Problems with threaded mount (as opposed to the bayonet): - it's hard to align and screw in the lenses underwater, especially the wide-angle. You'll may be in a hurry but you still need to do this carefully to avoid dropping or damaging anything. - it takes much longer to complete this process with the threaded mount. - when you unscrew the lens you have the problem of not knowing exactly when the lens will come free, which increases the chance of dropping something. - eventually you will cross-thread the lens and housing. On my Oly C5050 systems it's the housings which eventually lose the thread. The wet lenses start to jam on the housing after a while, adn a number of times I have put a lens on gently (I thought) and have needed the tool kit to get it off again. And I think I'm not unusually weak. For this reason I have decided in principle that I will never buy a threaded mount again for underwater use. (This actually eliminates a couple of cameras which might otherwise be interesting, but low-hassle operation is important to me underwater.) I love the way with the bayonet mount that it guides itself into place, and then a quarter-turn produces a very obvious click into position. (2) I don't have the latest Inon flashes but I have 3 older ones in the same series and have found them completely reliable. (As opposed to my frustrating experiences with two other brands.) On irritation with one of them (I don't have it with me at the moment, but I think it's an older D2000) is that the power selection for manual power can rotate 360 degrees This makes it extremely difficult to work by touch at night. For night use, it's good to be able to find the end of the adjustment range by turning to one end of the range, and then count clicks back again. On the other hand, in daytime that's not needed. (3) Inon also sell a AD-mount lens caddy which attaches to your flash arm (or elsewhere with a bit of ingenuity) and allows you to safely and very quickly attach the lens to the kit when it's not in use. Well worth considering. A two-sided version lets me park both the wide-angle and the macro converter at once. (4) I'm not sure that IS will work as well underwater. As I understand it (I'm certainly not an expert on this) the IS calculates how much the image will move (in terms of angle) when the camera wobbles, and compensate for that. But I suspect that underwater, a 1-degree movement of the camera will have a different effect on the apparent postion of the subject, compared to the same movement of the camera in air (because of refraction at the air/water interface). Hence the IS may compensate incorrectly for the camera movement. Using wet-lenses will also have an effect. I don't know whether you can tell the IS system that you are using adapter lenses, and choose a setting which will work appropriately underwater with whatever external lenses you may or may not be using. Maybe someone who knows the math can work out that being underwater is equivalent to using say a 0.75x wide-angle converter on land, or something like that. (I don't know - I just made up the number as an example.) In any case I suspect that the centre of the image and the edges react differently to a given level of camera movement. Having said all of that, I am pretty sure that IS will still improve the results when underwater, but I suspect maybe not by as much as usual. (5) No raw capture on the A570 until someone manages to hack the DIGIC III firmware ... (6) I think (haven't checked back on the A570) your proposed kit would all use AA-batteries. Using a single battery type is a significant advantage for me, but some others don't seem so fussed about this. Hope that's useful (sorry I don't have time to check references, shouldn't even be writing here now but I was thinking about similar kit too and am organising my thoughts...) -David

I'm not going to have time to do a proper test in the foreseeable future; there's too much else to do. However, I loaded up with a new pair of batteries (Enneloops, as it happens; rated 2000mAH) this morning. After 50 quick shots and some review and deletions, when I started the camera again 5 minutes later the battery meter read 94% [Edit: 94% in playback mode; 74% in record mode. The meter is very sensitive to the load on the battery]. Of course this number while precise is not accurate, since I haven't calibrated the 100% and 0% points for any particular kind of battery. Still, it suggests battery life is not as bad as I previously thought it might be. Most of my other battery sets are rather old, and I have decided to replace them before the next big trip. -David

Last time I checked (2 weeks ago) I couldn't find any indication anywhere that someone has succeeded yet with the DIGIC III chip. Others (especially if they speak Russian) may have more luck. I have tested the hack on my A710IS. Nothing scientific, but: - The hack is loaded from a file on the SD card at bootup. It can be enabled and disabled by locking and unlocking (respectively) the write protection on the SD card before turing the camera on. The hack loads at startup, and remains running until the camera is turned off. There is no change to the camera's firmware. Note: locking the SD card does not prevent the camera from writing image files. - It seems (from my reading elsewhere) that the raw file is 10-bit not 12-bit. This is consistent with my observation that it's quite hard to do better with the converted raw file than the camera does itself in producing its jpg. - It is possible in Adobe Camera Raw to rescue some minor overexposure. I think this would be useful for underwater, where I find it really hard to avoid occasional overexposure when one part of the scene turns out to be more reflective than I realised. - However my impression is that battery life with the hack running is really dreadful. That may turn out to be because I'm not using the camera much and the NiMH batteries may be discharging before I actually get around to using the camera. I'm hoping to test that in the next couple of weeks, but it's hard to find the time. - The additional capabilities include: -- real time RGB histogram -- raw -- better exposure bracketing -- control of display of all on-screen information elements I decided not to get the housing for the camera as it seems that Inon does not make an AD-mount adapter for it. -David

Well, not everybody ends up wanting to move to a DSLR system. It's true that you can get shots with a DSLR that would not be possible with a digicam. The reverse is probably also true, especially for critters in awkard positions. I'm not sure that I would recommend anyone to start underwater photography with a DSLR unless they were already pretty comfortable with using a DSLR topside. The task loading might be too much. A digicam may be safer initially. There are also issues around convenience, size & weight. But for me personally, the biggest single reason I don't have a DSLR for underwater use is that I prefer composing picture on the LCD rather than through the viewfinder, even for topside. I think I remain more aware of my surroundings this way, and that's important to me as I'm a diver first, and a photographer second, when I'm underwater. In any case, depending how much diving you do, by the time you move from digicam to DSLR (assuming you do) the DSLRs will have moved on a little, so it's not clear that you would be wasting money by buying a cheaper digicam system first. Do make sure that your flash will be compatible with a future camera & housing upgrade. Good luck with the new hobby! Whatever system you get, u/w photography can be very satisfying. (Until your friends start saying, "What, more nudis?!?") -David

Indeed, I'm eagerly awaiting the release of this new lens. I already have the done unit on my M67 wide-angle lens, and (with a spacer which Inon will provide for a no-doubt modest fee ) it will attach to the new lens. I don't think the geometry of the dome allows this kind of reflection (if that's what it is) - I certainly haven't seen any when using it with my C5050z setup. I was hoping to have it in time for this weekend's trip, but ... will have to wait until next time. Thanks for your thoughts -David PS more of the Manta shots - the ones she liked! - are here: More manta pics Vis was really bad, as you can see! This was her first dive with this lens. This is a good, very lightweight camera/lens combination for this sort of work.

And incidentally, apart from this occasional effect, I completely agree that it's a GREAT lens! Won't get into the water without it (provided I've got a camera with an AD mount, of course).

A couple more comments - 1. although in the last shot above it looks as if the bottom is black, in fact it's not black - there's detail of the sandy bottom visible. 2. I just had a bit of a rummage on my disk, and here is one which my girlfriend took (not one of her best, by the way!) with the same camera/lens combination. This is at full wide setting of the S70 lens (ie 28mm). It shows what the vignetting looks like (when it's visible). In this picture, I can see that the edge of the reflection is visible even at the bottom edge where the vignetting should mask any other effects. Again, I think it's a reflection that causes this. But there might still be a better explanation. (Have been quite wrong before about optical effects!!) -David

Hi Trevor My picture was zoomed a little to avoid the vignetting which otherwise definitely occurs with this lens combination. Here's one where the effect is more obvious: With guide: The same guide line (at the bottom right) *seems* to me to correspond to a minor discontinuityin the light gradient in your picture, which suggests to me that the effect really is something generic. And here's one in portrait orientation, where the effect has moved to the short edge of the frame - to me this is the clincher, more or less proving that I'm dealing with a reflection of light rather than a vignetting effect. In spite of these shots, I also have very many where no such effect was visible. It tends to show up in shots with very different amounts of light at top and bottom, especially where the sun was overhead at the time (although well out of shot). -David

Hi Trevor I'd be interested to knwo whether you have any problems with reflections of light inside the dome of the fisheye. On my shots, at the bottom of the picture there's sometimes a dark area intruding from the bottom edge of the frame. My investigation suggests that actually, the part of the shot above this has superimposed a faint reflection of the lighter water (with silhouettes of fish or whatever) abvoe the camera. So the dark part of the shot is "correct" as the reflections from above are blocked by the upper petal of the lens shade. You can see it a bit in this shot: S70 / WPC-DC40 / 165AD Fisheye At the bottom right corner, there's a strange lighter patch, with a fairly sharp edge (the edge of the reflection of the shade petal). Have you seen any such problems? I'm trying to figure out whether there's a general problem with this lens, or whether mine is defective (did they forget to coat the lenses or something??). -David

This is great! I was just getting organised to sell my M67 WA lens with the dome. Time to change my plans a little ... -David

Hi John A couple more things to consider if you do go the compact route ... - There's a substantial price difference (last time I checked) between the Canon housing and the next-cheapest option. - For cameras with small lenses such as these Canons, the obvious way to go for wet lenses (should you decide you want a wide-angle lens) is the Inon AD-mount. These lenses are much easier to deal with than the M67 (67mm thread) mount lenses. But Inon do not support the Canon S60/S70, apparently because the native lens is so wide already that the adapter would vignette, and they don't want people to compain about that. (Having said that, I got an Inon AD_mount adapter from a website in Austria, and it works, although it does in fact vignette unless you zoom in a bit; but the result is still much wider than the native lens alone.) - If you house an expensive camera, make sure your insurance is appropriate! Occasionally people DO flood these things. - My observation on live-aboard trips is that dealing with the housing is much more fiddly with the DSLRs. But since I have never housed one, that's a bit of conjecture. - I have personally resisted the DSLR route because of the size and weight of the whole setup (I already usually have to fast-talk my way out of weight penalties when I check in for dive trips!), and my presumption that's it's more complicated than what I do now. - My other - equally important - reason for resisting the DSLR route is that I so much dislike the idea of not having a view of the whole scene - including whatever's happening around me - while I'm framing a shot. Different people obviosuly have very different preferences in this area. Without knowing your level of diving skill, I'd just suggest to be sure you don't initially give yourself too high a task loading in what is afterall a potentially lethal environment. My observation - based on watching other divers - is that a housed DSLR leaves you less spare attention for your dive situation. I have a few S70 shots (only did a few dives) in the 200411 Bali Diving gallery here: http://www.fototime.com/inv/36B23AC6067E711 Some of these used the Inon w/a lens or macro lens. Wherever I used flash it was a pair of Inon Z220s. The "S70 Manta" subdirectory has shots taken by my girlfriend on her one-and-only dive (of that trip) with the S70 - she had ear problems and couldn't descend as recommened, so she was right up there with the Mantas. She used the Inon W/A lens. Otherwise, in the "diving" subdirectory, the others are all my shots with the S70 (except the Mantas were taken with my old Oly5050, without a wide-angle lens) (All the previous diving directories were taken with the 5050.) HTH -David [edited the embedded link]

Thanks again, this seems to produce quite realistic results, for 2 versions: (1) what it's actually like down there at around 10m depth, for eyes adjusted to land conditions, which I can confirm by comparing with pictures taken with my old Sony P5 a couple of years ago. I can get there on average (or close enough for my purposes, for green water conditions) using approximately saturation -50, levels (red output range 0-63, blue 32-223, green 64-255), contrast -40 or so. (2) what it looked like when I was there, with my eyes adapted to the conditions, which I can get to using similar settings to the above except that red range is 0-191. Of course I'm relying on my memory ... The difference between the two is the adaptation of the eye ... Just confirms that there really is no right answer as to what is the "correct" colour for most of the things I see in those conditions, because the eye's adaptation fools me. -David

Hi Craig, thanks for the explanation - there's a lot more to it than I first thought of. Will start experimenting now ... -David

Hi all I have somehow been talked into doing a slideshow of my diving pics after a dinner next week. I have 15 minutes. It's a gathering of a professional society (of actuaries), and I'm part of the entertainment. I think it's the first of a series of "what actuaries get up to when they're not exercising their professional judgement" talks. (No need for any smart comments, thanks! Let's keep the board clean.) There's no particular reason to suppose the average actuary here knows anything much about diving. It's all very well showing pics of all sorts of things, but I'd also like to point out that some of these gorgeous critters don't look so brilliantly coloured in natural light. However, I have no good examples of natural light (with or without approriate white balance) vs flash exposure of the same scene. I'd particularly like to be able to point out that some things which show up brilliantly in the pictures are really hard to spot in natural light. I tried reducing the red channel in photoshop, but I didn't seem to get what I wanted. Maybe I was doing it wrong. Or maybe it's impossible to give an accurate impression of what things look like in conditions of very low red light levels, but with the eyes adapted to those conditions. Does anybody have a reliable method of doing this, suitable for a not-very sophisticated Photoshop user such as myself? I'm willing to mess around for a while adjusting settings, but I don't yet know which controls I need to play with. Any thoughts appreciated. Thanks -David