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Peng62

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About Peng62

  • Rank
    Clownfish
  • Birthday 04/04/1962

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  • Website URL
    http://s32.photobucket.com/albums/d49/CPLai
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Profile Information

  • Gender
    Male
  • Location
    Singapore

Additional Info

  • Show Country Flag:
    Singapore
  • Camera Model & Brand
    Canon A95
  • Camera Housing
    WP-DC50
  • Strobe/Lighting Model & Brand
    Inon D2000s
  • Accessories
    Inon arms and base tray, UW focusing torch
  1. I am guessing it is the same as in the film Nikonos days. This works with manual focus, like with the lens set to focus at the minimum working distance. The tip of the prongs is placed to indicate where the focus is. Position the tip of the prongs to either side of the subject, with all three lying in the same plane, and the subject will be in focus. Cheers Peng
  2. Bo, I am glad to be of what little help I may be. I believe the cost is in the fact that it will be a one-off custom job. Coatings on reading glasses nowadays tends to be multilayer types and will work very well. However, there is economy of scale involved with the coating of hundreds of them. It is also likely that some special mechanical holders have to be made to hold the dome window and that is why it is not likely to come cheap. You will have to weigh whether you want to spend the money on getting that extra ~3% improvement in transmission to have the inside coated. After all, you automatically get more than that for the front side already simply by going underwater. Cheers Peng
  3. Simon, Beautiful, you gonna take photos and videos with it? Hope you share some. Have fun Regards Peng (Lembeh Dec 09)
  4. Bo, I believe you have not been given full information on how to interpret the specifications. I have worked with coatings, designing and developing them, for 7 years of my career and still is involved with it on a day to day basis after that for another 15 years. 1) You will get the better benefit coating the inside of the dome. Getting R<2% is rather correct with a single layer of MgF2. 2) The "better" anti-reflective effect on the outside of the dome is simply because of the very small change of refractive index between water and glass, not due to the MgF2 layer. Do a simple verification. Ask the local source about the amount of reflection at the front of the dome when immersed in water and without any coating. 3) If on one surface you get R<0.4% and another you get R<2% (I believe R~1.5% will be more accurate if the glass is BK7), it will not add up to being R<0.1% with both surfaces coated. You get a total transmission of (.996 x .98 =) 0.976, which means a transmission loss of about 2.4%, excluding other kind of losses. 4) Coating on the outside will help you with over-under kind of photography as the top half of the outside of the dome will then be in the exact same situation as the back of the dome, that is, both have light passing from air to glass or glass to air, which is no different, and that's when you get the benefit of the MgF2 coating giving you R<2%. It will barely have any benefit for the part of the dome underwater. 5) If someday you still want to coat your dome and you want to save on cost, just do the coating on the inside. If you want to have the benefit also when doing over-under shots, go ahead and also coat the outside, but beware the coating might not stay long on the glass surface due to interaction with the sea water. 6) "... but perhaps high reflective on the outside may increase contrast and resolution? Anybody here knowledgable on this? " No, high reflective on the outside do not increase contrast and resolution. They just look nice on sunglasses, and keep your eyes comfortable by reducing the light intensitiy to a level that your eyes can be comfortable with. It will be like putting sunglasses on your dome port, or equivalently, neutral density filters. Hope this helps you or anyone else following this. Regards Peng P.S. to Don in Colorado, I think you can stay assured with what you know and not feel that it was incorrect.
  5. Hi Mucksavage, I use the Canon 100mm f2.8 too, on a 400D in an Ikelite housing, with a single Inon Z240 strobe. Couple of weeks back was the first time I ever brought a dSLR uw for macros as I used a P&S before that, till I drowned it. I faced almost the same problem as you. After a couple of dives, I settled on the following for most of my photos. At >20m depth, mainly ISO400, 1/125s, f6.3 and strobe at full power and I even gave up using the diffuser (-0.5 stop loss). Once I move up to about 10m or so, I can work down to ISO200 and reduced strobe power, depending on natural light level. Note this. The amount of light needed from your strobes to expose properly is exactly the same whether you are on manual or TTL mode. It is just which helps you to get there quickly. I used a syn cord and work on manual strobe adjustment. Oh, and also manual (M) settings for my camera, but with AF. Just from my personal habit. Note also near to 1:1 magnification, which I imagine you will likely be trying to do with the 100mm, you are trying to collect light from a very small area to get to your sensor, so even if the strobes flood a good amount of area in front of you, only that miserable 22.1x14.8mm area at 1:1 mag is going to provide the light for your exposure, which is not a whole lot. Basically, be adventurous, move into some camera settings which perhaps you might not thought of trying so far. If the lighting conditions demand that, you just gotta do that. If it is of interest to you, here's what I got with my 100mm lens: http://s32.photobucket.com/albums/d49/CPLa...en%20Indonesia/ and http://s32.photobucket.com/albums/d49/CPLa...20And%20Snapped I did have to adjust for exposure for quite a number of them still in post processing, as they were mostly "exposed to the left". I shoot RAW all the time. Good Luck Peng
  6. Ha ha, I have a long way to go to learn about the creatures underwater..
  7. Is there enough of this pipefish to tell if it is a Stigmatopora olivacea, Gulfs Pipefish, or not since I photographed it in Bunaken, Indonesia, Apr 09. I had a macro setup so did not manage to photograph the whole fish Any help with the id will be appreciated
  8. Enje, thank you again
  9. Enje, thank you so much
  10. I had thought this might have been a sort of Phyllidia nudi but it has gills so I think not. Any help with the id will be appreciated.
  11. Is this a Fiji Clown Blenny (Ecsenius fijiensis)? I am wondering because I read something about it being local to Fiji only but this was taken in Bunaken, North Sulawesi, Indonesia on 6th Apr 09. Perhaps it is more widespread than I had read about or I have gotten it wrong and it is something else? Any help with the id is appreciated.
  12. Steve, I've made a change as above. My bad. I did not test the link when I originally posted it. Thanks for pointing out the error to me. Peng
  13. This is my first time using a dSLR macro setup underwater Previous couple of attempts were with a P&S. Hope these look like a decent effort. Suggestions for improvements are welcome *Edit : My original posted url link seems to be too lengthly. Kindly copy to your browser and then remove the opening and closing quotes or else if someone knows how to better do the link please help. "http://s32.photobucket.com/albums/d49/CPLai/2009%20Bunaken%20Indonesia/"
  14. Hi Cal, Saw your post at the office but didn't reply coz I wanted to get home to check on my strobe. Then I did a google on the net just moments ago without realizing Hal gave a follow on post. Here's what I found anyway, for anyone else's benefit who happened to drop in here as well. "The D-2000S has all the power and performance of the D-2000 strobe, but without a Focus Light or External Auto Mode, making it a more affordable option when using consumer digicams." Well, guess I gotta live with getting what I paid for Hi Hal, You've answered this question of mine for sure about your approach (and the boys and girls with the big toys) : "Or does anyone set the strobe and focus for a particular distance, and stick with that throughout the entire dive, trying to compose everything at that pre-aimed/pre-focused distance? I can understand that with macro photography and guess that might work...." I do some macro stuff with a dSLR top side and have friends who do just that, pre-focus at 1:1 mag and just move in till the subject is in focus. That's just to help make sure the mag stays at 1:1 so that we can know the real size of the critter after the outing. So I guess some folks do something like that approach too u/w but for different reasons Now you've convinced me to try that out for my next dive trip, whenever and wherever that might be. Peng
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