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timoma

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Everything posted by timoma

  1. Folks, After more than a year of an almost total break from UW photography I finally managed to get some shooting done again this summer and published a new web gallery to go with the new images. The pages can be found at www.ahomaki.net. Be warned that the images are reasonably big and I still have some optimisation to do in the Flash department so loading times can be quite scary if you're not hooked to a big pipe. Anyway, a mix of blue and green, warm and cold in there taken between 2002 and 2010. Funnily enough, some of my best shots are still from my early days of UW shooting. Go figure. Share and Enjoy, timo
  2. Well, There are perfectly good solutions for that in the market. I myself have recently got to the habit of doing 70-90 minute dives in +3C water. Being prepared is sort of necessary in those conditions if you want to stay properly hydrated, being as it is that a sizeable chunk of those minutes is spent in deco. And yes, I know these types of dives (mostly) suck, but it's all I've got right now. timo
  3. I actually polished the inside of my 174mm dome last wekend. I basically used the micromesh pads wrapped over a piece of folded lens cloth to give a bit of padding around my fingers. As I only had minor scratches on the inside, I started from #6000 grid and worked from there. Not at all that hard to do. I still need to do the outside as well, but so far the result is looking just fine. timo
  4. I'm soooo in envy Paul! Maybe I just need to quit this local cave crap and fly south in stead. However, I wonder if the light in your middle picture is for real or if you have overcooked the WB? timo
  5. Finally my kind of a thread... I did not have the time to do nearly as much diving as I would have liked this year. One of the highlights of the season was a weekend spent anchored over the wreck of the mine frigate Ladoga in the archipelagan sea in the Northern Baltic. This very important milestone design dreadnought is out of bounds for divers except with a special permit from the war museum, the navy and the coastal fortress of Örö - All three of them separately! The wreck lies in 40-45 meters of water with 32 meters to deck. I was diving with a group I have dived a lot previously, but none of whom I have done any photography with before. Hence, modeling presented some challenges. Either the diver was in the wrong position, his posture was ridiculous or the light was wrong. Or all combined. We spent 4 dives attempting basically two different poses in two different places on the wreck and this one is probably the best picture of the session. But it was fun in a way. Especially as we had literally thousands of jellyfish floating past us in deco. Thanks to Joona, Jaska and Merkku for a fun trip despite the lack of presentable photos. timo
  6. Well, Finding the gels is not a problem as such. More finding the right combination of gels. The ccM stuff as well as standard Lee stuff is widely available both sides of the Atlantic. Kodak gels are even reasonably cheap these days. The problem is the more exotic colours like the lavender quoted above. I suppose if I had unlimited time in my hands I could start from first principles, but as I do not, I'm trying to shortcut a bit and use something I already know sort of works as a basis. Also, I'm starting to get to a point of rapidly diminishing returns and I think I'll concentrate on some actual shooting as opposed to experimenting this coming season. Which is not to say I'd not put John up for his offer... timo
  7. While I do agree that in good conditions you get pretty much the same results using a good RAW converter as you would using a filter, there are exceptions. Again, because of where I happen to reside, I end up doing some shooting in conditions I probably shouldn't. The picture below is taken at the wreck of the ship-of-the-line Kronprins Gustaf Adolf that sank outside Helsinki in 1799. She lies in 20 meters of very, very green water. Visibility on a good day can be 10+ meters, but more likely we have something like 5-6 meters due to the closeness of the site to two major shipping lanes. In this instance, the viz was around 6 meters - the lenght of the anchor shank approximately. Exposure was 30 sec, f11, ISO 400 using a D300 and 10.5mm. In this picture I have used a pretty strong filter - Kodak Wratten cc70M (cc20M+cc50M). This one is pretty much straight from the camera apart from levels adjustment and defishing. Now, I have done the same using a variety of filters as well as without. If I shoot with no filter, there's basically information in only the green channel in the picture. This in my eye tends to lead to a very low contrast image and trying to correct this using the RAW converter or channel mixer results in lots of colour noise. Even with the 70cc magenta filtration I get almost no blue! Hence, I'm currently looking for a stack of a cc50M and something bluish. I suppose what I would need is something like a Lee v98 that looks like this. Unfortunately, you cannot get it in a material suited for backmounting to the 10.5mm. So I think there are cases where filters are more or less a necessity, while in others you can definitely get away without. And while I certainly have achieved very good results with the Magics in the tropics, I have indeed sometimes lamented the inability to shoot flash on the same dive - something you might want to do if you do not have full control over the dives you do on a trip. And oh, the real reason for me to go to magenta filters specifically is that the end result of these experiments will be in B&W as in this non-defished version of above here. timo
  8. Typically in the control systems based on hydraulic servos there's multiple hydraulic systems (usually 3, sometimes 4) and each has a pump in each engine. Should you have a total engine failure (i.e. lose all 4 in a 747), the engines windmilling in flight will still turn the pumps to produce some pressure - provided the engines are still physically attached to the airframe (if not, you have a whole different set of issues in your hands). Additionally, you typically have one or two electric pumps per system feeding from batteries. There's no manual pump. So a total control failure is pretty improbable, although not impossible. Having a complete failure of all hydraulic systems on a 747 (or any other hydraulically controlled plane for that matter) basically leaves you stuffed as there's no way to fly the aeroplane after that. timo
  9. Not sure of how the 'puters in the A380 are set up, but as a (much) younger man I used to work on the A320 control systems when the things first hit airline service. Basically, these things typically have three computers at least one of which is different HW using an independently developed SW. The 'puters are connected via a voting logic so if one goes berserk the two others vote it out of the loop. And yes, if two go berserk simultaneously, you're basically stuffed. The voting logic is actually a bit more involving that but in principle. These things are actually pretty complex to set up and there have been multiple accidents and near misses with the A320 series that have been simple pilot errors. I.e. setting the system up to do something they did not intend to do. With that said, however, I think in relation to hours flown they stack pretty well up with their mechanically controlled counterparts. When I took my training on the A320 , we had as a trainer an older French gentlemen who - as they say - had been around. He started the lessons by stating in his pretty thick French accent that: "For years pilots have complained that flight simulators do not behave like real aeroplanes. Finally, we have solved this problem by developing a real aeroplane that behaves like a simulator". Nuff said. timo
  10. But, You will end up compensating the weight advantage in lead... timo
  11. Why not go with a backplate and wing. Or if you do not need the boyancy, just a backplate. A Draeger or Interspiro firefighting harness is what many people around here use as a non-boyant alternative with a drysuit. I changed my travel BCD to a DSS plastic plate and single tank wing some 18 months ago and I love it. Weighs about 2kg and packs really small. I dive the setup with a single piece harness which is just about as streamlined as it gets. Mind you, at home I dive 2*12/200, a steel plate and drysuit... timo
  12. Please do. To be honest, I have never tried as I do not own any suitable zoom lenses, not to mention the needed port/extension combos. My impression is that with (most) zoom lenses the focus setting changes slightly when zoom setting changes. This may or may not be material behind a dome. Dunno really. timo
  13. Speaking of which, If Mr. Carre would finally drag himself and his new glass ports to Finland next fall, we could try some of that... timo
  14. Yes indeed Paul, The crayfish are a real delicacy apparently although personally I don't touch them. Pike, on the other hand, is very good. timo
  15. Nice, Whereabouts in our beautiful land do you operate? Maybe we could set up some joint diving one of these days... timo
  16. The way I do it and the way I believe Leigh Bishop has done at one point in time at least is to use fixed focus. The optics of a dome port (a subject treated in many threads here) mean that you can actually get pictures that are sharp from a few tens of cm to infinity with a single focus setting. The way I set my system up (using Nikon 10.5mm and Hugy 180mm dome) is that I set the lens on 35cm and will get a sharp focus on anything between, say, 50cm to infinity. The best setting for the focus can be either calculated or tested in a pool. I have used the latter approach. This method, of course, is really only practical if using prime lenses I think. Have not actually ever used a zoom underwater... Otoh, focus lights are sort of difficult to use if shooting natural light (as myself and Mr. Bishop are fond of doing). Unless, that is, you go with one of the high-end trigger activated models. timo
  17. I have a Hugy and just switch it on at the surface and keep using it all the dive. Or rather would, were it not slightly unusable as I said earlier. And oh, I run the 10,5mm on fixed focus too... timo
  18. As many of you know, I shoot a fair bit of "wreckscapes" on a tripod. So, in theory, Live View should help things quite a bit without the shutter lag etc. coming into the way. But - and this is a big word, so I repeat it, But - in my typical shooting conditions (and filtering) the view on the LCD is so dark that it is even less usable than the almost totally unusable viewfinder. Which is a pity, since I had some moderately high hopes of actually being able to see what I'm shooting for a change when changing to the D300... timo
  19. So Paul, What's it going to be? Something with nice, expensive glass, I recon. timo
  20. Yep, I'm using a 10 sec timer. So the process is: setup tripod, aim, squeeze the nipple, move back and relax. I generally do not keep my eye on the finder while triggering in order to avoid shaking the tripod so the finder is exposed to ambient during metering regardless of when that happens during the process. Going forward I will set up a wired remote (I have a third bulkhead already fitted) using an on/off switch to allow me to do Bulb exposures. I'm using fixed focus (as the AF would be useless anyway) so a simple flip switch does the job just fine. Good idea But joking aside, I had naively hoped that live view would have helped me in this as aiming through a 2+ stop filter in low light with the camera on tripod is not exactly easy as you have found out yourselves. If it was of any use, I would actually do just that. timo
  21. Will do. It lives in my home 'puter (homputer?), but I'll try to remember to send it when I get there tonight. timo
  22. Thanks Paul, That would explain it, especially when I just realised that although I do frame the image with my eye in the finder (live view, unfortunately, is pretty much useless in the dark), the metering actually takes place with the finder exposed. Now I just need to rig a cap to the finder. Fortunately the Hugy housing has a nice round protrusion where the finder exits the housing so this should be reasonably straightforward to remedy. At least to the point where it should not be a significant problem any more. Overall, though, I have to say that the D300 performs admirably in these conditions. Compared to the D70(s) the high ISO noise is very low indeed, although starts to be really visible at ISO800 and above. The image below was taken in bright sunny conditions in about 20 meters of water and 4-5 meters of viz using the Nikon 10.5mm. Exposure was 30 sec@f11, ISO400 and using in-camera NR. Filtration is Kodak Wratten Magenta 70cc (stacked 50+20) to get the contrast way up in the green water. The anchor shank is actually longer than the naked eye could see in the visibility of the day. I have not done any significant editing to this one, just set exposure and WB and tweak the contrast a bit. So I think after 18 months of trial and - mostly - error, I'm starting to get somewhere. timo
  23. To continue, It has been suggested that I'm getting some light onto the meter through the viewfinder. In film (TTL) cameras this would be the problem (and Nikon even supplies the little plastic cap that you lose within weeks of purchasing the camera), but my understanding was that in (most) digital SLRs, there's no metering going on when the shutter is open. Is this correct also for the D300? Of course, any light leaking in through the viewfinder is bad and I suppose I need to rig a plug on the housing viewfinder. If the housing-camera joint was lightproof (which I doubt it is) this would stop any light leaking in. Oh, well, at least there will be less of it.... timo
  24. I have noticed the a strange behaviour in the D300 exposure metering and thought of picking the collective wisdom of the forum to see if there's simple solution. As some of you know, I have a serious perversion towards shooting wreckscapes in the murky Northern Baltic waters. In our conditions (and especially when using strong filters) exposures tend to run in the tens of seconds. Historically, I have used manual mode for my shots but last night I felt lazy and selected aperture priority in stead. Now, the correct exposure should have been in the 25-30 second range @ f11 (aperture selected to keep the exposure under 30 sec) and ISO 800. But - and this is an important word so I repeat it: But - the camera for some reason elected for 15-20 sec, resulting in grossly underexposed pictures. I tested this further at home by putting a lens cap on and shooting in aperture priority and program mode and guess what, the metering was all over the place. Basically, when in aperture priority, the meter shows f11 and LO but the camera exposes for anything between 3 sec and 15 sec with no apparent change in anything. And with two different lenses too. So I called my father who has a D200 and he tested the same and got more or less the same results. So it's a feature. And I do not like it. I seem to remember my old D70 in similar conditions always exposed for the max 30 sec and then gave up. Which was infinitely better than an erratic behaviour. So my question is, is this metering behaviour for example configurable somewhere? The manual was not very helpful in this respect. In the end, I have no problem shooting manual and will soon end up rigging a remote release to go Bulb for the deeper stuff anyway, but somehow I feel that paying good money for all this fancy software shoud give me something in return. Puzzled, timo
  25. Great stuff Alex. I tried filter shooting across the light last year at Bunaken. Partly because I had no real choice of sites and partly because I wanted to see if it could produce results. On that short trip I did not get the chance to really experiment, but I think the initial results seemed promising. timo ps. Kodak Magenta 50cc is showing some real promise for B&W in the Northern Baltic. More on this when I get some proper tripod shots together...
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