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Not a huge fan of my GoPro

Discussion in 'Underwater Photography' started by bvbellomo, Mar 13, 2021.

  1. bvbellomo

    bvbellomo Contributor

    # of Dives: 50 - 99
    Location: United States
    283
    44
    Thanks! I bought 2 of those cables now, as they will take a while to ship.

    I am not sold on the idea of a perfectly neutral rig. A floating or sinking rig is easier to recover.

    I also have trouble hovering horizontal without moving. I know I need to work on this skill, but any extra weight in my hands will make this easier. Maybe buoyant arms are the way to go, I just wish I had more time to play with this system before my trip.
     
  2. tursiops

    tursiops Marine Scientist and Master Instructor ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
    Location: U.S. East Coast
    11,857
    9,782
    Slightly heavy is OK, but even slightly positive is difficult to manage. Anything more than slightly, either + or -, gets tiresome really quickly. Take care of the "dropping" by using a tether.

    Many suggest getting control of your own buoyancy before taking a camera underwater. In any case, counting on the camera as part of your personal buoyancy control is not a good idea. You really don't want to be tilting fore-and-aft every time you bring the camera to your eye.

    Can you play in a swimming pool prior to your trip?
     
  3. bvbellomo

    bvbellomo Contributor

    # of Dives: 50 - 99
    Location: United States
    283
    44
    My buoyancy is not bad, it is just the 1 specific scenario (horizontal and motionless) that gives me trouble. I can stay horizontal without going up or down if I go forward and I can stay in 1 place vertically.

    Unless the camera is truly neutral, it will affect my personal buoyancy whether I want it to or not.

    Pre-Covid getting into a pool would be easy but it is probably not an option now. I plan on at least 1 quarry dive before I go once it is warmer, which only gives me 1 chance to make adjustments before the trip.

    I am not so worried about "arm fatigue". Holding the camera all day on land is easy, so 1 hour underwater should be easier.

    Nauticam mentions their housing as "slightly negative" in their manual. A big glass dome is heavy, but also holds lots of air, so it could go either way. An Inon 330 is 48 grams in fresh water. By my calculation, it will be 25g in the Red Sea. The rest of my rig, such as arms and clamps are probably negligible.

    I will have a chance to try this in the fish tank once I get my SD card and get familiar with the camera and housing.
     
  4. tursiops

    tursiops Marine Scientist and Master Instructor ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
    Location: U.S. East Coast
    11,857
    9,782
    But that is exactly the position for taking a picture!
    Right, that is why you are striving for neutral.
    You might be surprised....
    48g in fresh water, but 25g in the Red Sea? I don't think so....the RS is only about 3% denser than fresh water. You are not the first person to try and estimate these things, so do some more searching. Best of all, just put the full system together and weigh it with a luggage scale in your fish tank.
    You don't need an SD card to get your buoyancy right.
     
  5. bvbellomo

    bvbellomo Contributor

    # of Dives: 50 - 99
    Location: United States
    283
    44
    Inon says a Z330 is 789g in air and 48g in fresh water. This means it displaces 741g of fresh water. Using your 3% figure, it displaces 763.23g of Red Sea water, so it weighs 25.77g in the Red Sea.
     
  6. Barmaglot

    Barmaglot Contributor

    # of Dives: 200 - 499
    Location: Israel
    970
    421
    IME, negative camera buoyancy is relatively easy to manage when shooting wide-angle and holding the rig by both tray handles, but it's considerably harder when shooting macro, steadying yourself on some rock outcropping with your left hand and trying to manipulate and shoot the camera with just the right hand. Positive buoyancy is always a major annoyance.
     
  7. tursiops

    tursiops Marine Scientist and Master Instructor ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
    Location: U.S. East Coast
    11,857
    9,782
    OK, I had no idea it was that heavy in air!
     
  8. bvbellomo

    bvbellomo Contributor

    # of Dives: 50 - 99
    Location: United States
    283
    44
    I placed what is hopefully my last order today for the strobes and arms, after a successful test run in the aquarium last weekend. I may post a few pictures, but I can say that a huge dome and wide angle lens is not appropriate for home aquariums. Images are technically good, but the composition just doesn't work.

    I was hoping for some pointers on camera settings. Does autofocus work with a dome? Or am I better off manually focusing before I get in the water and leaving it where it is? Do I want to shoot everything at 1/160s shutter speed? I assume I want a narrow aperture, but should I go all the way to f22? Should I set ISO to auto? What should I really be adjusting underwater?
     
  9. Barmaglot

    Barmaglot Contributor

    # of Dives: 200 - 499
    Location: Israel
    970
    421
    Autofocus works just fine with domes. Manual focus is only really useful for supermacro, where you set the lens to minimum focus distance and then rock the camera back and forth to get the tiny subject in the right spot.

    Shutter speed, aperture and ISO are generally tweaked to give a good background exposure, with flash power tweaked to illuminate the foreground. The actual settings are highly dependent on dive conditions - bright noon sun at ten feet is one thing; cloudy morning at a hundred feet is quite another. 1/160s, f/11 and ISO 200 is a good starting point - if your background water is too dark, then raise ISO and reduce shutter speed while reducing flash power to avoid blowing out the foreground. You can easily go to ISO 800 and maybe 1/60s; slower shutter speeds than that and you start getting blur. If that is still not enough then start opening up the aperture.

    I don't recall ever using f/22 for wide-angle except when shooting directly into the sun; it just comes out too dark, and diffraction starts limiting sharpness at these very small apertures. I do use it quite often when shooting macro though, for additional depth of field. For supermacro (i.e. greater than 1:1 reproduction, I use Sony 90mm lens with Weefine WFL05S +13 diopter) I don't bother with any apertures other than f/22.
     
  10. Chris Ross

    Chris Ross Contributor

    # of Dives: 200 - 499
    Location: Sydney Australia
    686
    249
    What did you buy again? APS-C Sony and what lens and dome are we talking about? Wide angle with APS-C is generally shot around f11-13 depending on dome size.
    Use AF, MF is not practical you are focusing on a virtual image close to the dome - so you can't do the hyperfocal distance thing, AF should be good and snappy.
    Start simple, use base native ISO - the lowest one. If you want blue water in the BG meter that at your chosen aperture and adjust shutter speed to get a nice deep blue, a tad under exposed. The exposure will depend on how deep you are and how high the sun is. In clear tropical water 1/125 @ f11 ISO200 would be a starting point
    Once you have you shutter speed sorted out - leave aperture and ISO at the starting point and then adjust your strobe exposure to get a good histogram, use auto WB. Stick with your aperture/SS for a while and play around with your strobe positions and getting shots well lit.
    Only start playing around once you get your lighting right - leave your aperture and ISO and only move them if you need to keep shutter speed within your sync speed limit. Crawl before you walk and only start trying other values once you've mastered your base settings.
     

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