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ATJ

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Posts posted by ATJ

  1. Posted

    Andrew, why not get yourself prescription lenses for your mask? Subject discussed in depth here. I have a Technisub Look 2 with small bifocal lenses, but I'm going to try the company Peter mentioned in the last post of the thread.

    Thanks, Nick. I do - well sort of. I have a Tusa Geminus mask with bifocal +2.5 diopters. Makes a huge difference, especially when shooting video with my D7000, however, I still miss a lot of the detail on small critters. Although I did "see" some pygmy seahorses in Komodo in August for the first time (other than seeing them through the viewfinder).

     

    Note that I am still able to find lots of cool stuff, I just don't get the full enjoyment until reviewing the photos later.

  2. Posted

    Jeremy, I really feel for you. I love diving and taking photos so much I hate it if I can't go for at least one dive on a weekend.

     

    Thanks, Leslie. I didn't notice the polychaete until looking at the photos. I have poor close vision (I'm an old fart) and frequently find gems like this after the dive. This particular dive I had a number of such suprises.

     

    There was this crab holding a sand dollar on its back. I had just assumed it was a flat-top crab until looking at the photo:

    Dorippid_TorpedoAlley1208.jpg

    Dorippid_TorpedoAlley1208-2.jpg

     

    A spider crab with hydroids (I saw the crab but not the hydroids):

    Majid_TorpedoAlley1208-2.jpg

     

    A dwarf lionfish with a copepod parasite on its eye:

    D_brachypterus_TorpedoAlley1208.jpg

     

    And then there were the crabs carrying upside-down jellyfish on their backs:

    Cassiopea_TorpedoAlley1208.jpg

     

    (Sorry, Jeremy if make you miss UW photography more.)

  6. Posted

    Portunid_Circus1208.jpg

     

    Shot at a site called "Circus" off Gili Banta at a depth of 5 metres at night. Looks like it is in the family Portunidae and perhaps Thalamita sp. The spines on either side of the carapace are quite long.

     

    I can post closer images of certain parts if required.

  9. Posted

    Congratulations, Randall.

     

    I still have 6 years to go to get to 40. I got my cert through FAUI (Federation of Australian Underwater Instructors) in 1978. I don't think PADI had a presence in Australia back then. We didn't eve use BCDs and we learned to put the right amount of weight on the weight belt depending on the depth of the dive. I bought my first BCD in 1981 and dived without one until then. We learned with J values but did have pressure gauges. I bought my first reg in 1980 (US Divers Aqualung Aquarius) and the second stage is my current octopus.

  14. Posted

    I get very little data for movies from my D7000. In the Info window I get:

     

    Date/Time

    Nikon D7000

    Lens

    1280 x 720 - file size

    Auto1, 0, 0

     

    If I do "Copy File & Camera Information" I get:

    File Info 1

    File: DSC_6089.MOV

    Date Created: 2012/04/28 22:46:16

    Date Modified: 2012/04/28 22:46:16

    File Size: 84.7 MB

    Image Size: 1280 x 720

    Duration: 01:00

    File Info 2

    Date Shot: 2012/04/28 18:27:33

    Time Zone and Date: UTC+10, DST:OFF

    Movie Quality: 25fps, High Quality

    Camera Info

    Device: Nikon D7000

    Lens: 10-17mm f/3.5-4.5G

    Focal Length:

    Focus Mode:

    AF-Area Mode:

    VR:

    AF Fine Tune:

    Exposure

    Aperture:

    Shutter Speed:

    Exposure Mode:

    Exposure Comp.:

    Exposure Tuning:

    Metering:

    ISO Sensitivity:

    Image Settings

    White Balance: Auto1, 0, 0

    Color Space: sRGB

    High ISO NR:

    Long Exposure NR:

    Active D-Lighting:

    Image Authentication:

    Vignette Control:

    Auto Distortion Control:

    Picture Control

    Picture Control: [NL] NEUTRAL

    Base: [NL] NEUTRAL

    Quick Adjust: -

    Sharpening: 2

    Contrast: 0

    Brightness: 0

    Saturation: 0

    Hue: 0

    Filter Effects:

    Toning:

    GPS

    Latitude:

    Longitude:

    Altitude:

    Altitude Reference:

    Heading:

    UTC:

    Map Datum:

  15. Posted

    I have a GoPro mounted on my DSLR rig and that works quite well (when I remember to use it*). I have the LCD and after using it for a few months would definitely not consider or recommend not using the LCD. It is the only way to make sure you have it pointing in the right direction.

     

    I have an Ikelite rig and I made a horizontal PVC "handle" that goes between the two grips for the housing. I've had this for some years which makes it easier to hand the housing to people on boats, etc. When I got the GoPro I just made an aluminium bracket that fits the PVC "handle" and allows me to adjust the height of the GoPro. In practice it is very easy to use.

     

    * I say "when I remember" as often realise when it is too late that I could have used it. For example, on the weekend I spent nearly 40 minutes of a 60 minute dive swimming around with a 2m+ grey nurse shark trying to get still photos (which didn't turn out well because of all the particulate matter in the water). I could have taken some pretty good footage with the GoPro if I'd thought about it at the time.

  16. Posted

    I have not used Auto ISO underwater but I have above water and it does have its uses. I found it worked best when you want to set a specific shutter speed and aperture but the conditions are changing. Set the camera on manual, choose the shutter speed and aperture you want and the camera will choose the ISO to match. If you are balancing strobe with ambient light you may want to play with exposure compensation on bother the camera and the strobe to get the right balance.

  18. Posted

    They are pretty hard to spot because they look like a sponge. The first one I saw was pointed out to me and I refused to believe it was anything other than a sponge until the kept insisting I look more closely. The next one was also pointed out to me but I saw it straight away. I then found my own one a few weeks ago. It could be the same one each time, although if it is, it must move around a lot.

     

    Antennarius_Leap1109-2.jpg

  19. Posted

    Pete, I have seen the seahorses regularly at "Seahorse Rock" for over a year now. I first saw them in January last year. I think the only time I haven't seen them was when I missed "Seahorse Rock". Last weekend I was there is 5 other divers. They swam the wrong side of "Seahorse Rock" and missed them (I did manage to attract one of them over for a look but he left me while I was taking photos). I then went looking for more along the boulders at the sand line and managed to find one more further north.

     

    Interestingly, they managed to find a seadragon or two.

     

    The Leap is my second favourite site (Shiprock my favourite). The Leap almost always has cool stuff (giant and reaper cuttlefish, octopus, anglers, seahorse, seadragons, etc.) but at Shiprock I almost always find something I have never seen before, in addition to the usual cool and interesting stuff.

  20. Posted

    Shiprock is now open.

    It certainly is. I did 3 dives there over Easter (first weekend it was open) and they were all good. Found my first Sepioloidea lineolata on the Thursday night and found 2 different species of pipefish on the Monday.

     

    I love Shiprock.

     

    I also love The Leap at Kurnell. I've had some great dives there of late and found the seahorses every time.

  22. Posted

    I read some people use a diopter with this lens. Would that be a requirement, or can I get acceptable result without too?

    It is pretty much a requirement. You'll need to use in a dome port. See the explanation here: http://ikelite.com/web_pages/qdiopter.html

     

    I have found that if you use a 6" dome, +4 diopter will preserve the magnification at closest focusing distance. i.e. you'll get the same magnification underwater behind the dome as the lens does in air. I use a +5 with my 18-55mm to give me a little more magnification - and so I can get closer and reduce the amount of water.

     

    And how about the choice between the VR or the non-VR version?

    If you are only going to be shooting stills it doesn't really matter. If you can get the non-VR version and it is cheaper, get it. I suspect that the non-VR are hard to get. I actually have both and the VR bought a few months ago was cheaper than the non-VR version I bought a few years ago.

     

    If you plan to shoot video, the VR version gives you a little more stability in the image.

  23. Posted

    JimSwims makes good points, but you're being silly. The 105mm lets you get as close to some skittish creatures as you can, without spooking them at the 1:1 distance of a 60mm. If the creatures are calm, then you get get better than 1:1 with additional close-up lenses, shortening the minimum focus distance. In mirky water you're probably stuck with a 60mm. Regardless, the 18-55mm is never the best optical choice if you have a particular subject in mind.

    I'm was only being a little bit silly to make the point. A 18-55mm in a dome port with a +4 or +5 diopter can get closer that the 105mm in a flat port. Period. So, if the there is too much water with the 18-55mm there will be too much water with the 105mm.

     

    Yes, I very much agree that for certain subjects the 105mm is the only choice because you can't get close enough. In that case you compromise to get the shot you want. That's what underwater photography is all about. You very often have to make a compromise.

     

    I don't believe anyone suggested that the 18-55mm was ever the best lens. But that doesn't mean it isn't a useful lens. Yes, it is a compromise, but I find over and over again when I take my 18-55mm lens on a dive I'm able to take a shot that would not have been possible with either the 10-17mm or the 60mm.

     

    Going back to the origin of the thread the answer seems simple: if you have an 18-55mm you could use it, but it isn't the lens you would buy with underwater photography in mind. There is pretty much a consensus (with which I have some disagreement, in fact) that the two most useful lenses for underwater photography with Nikon cameras are the 60mm micro and the Tokina 10-17mm fisheye. Jef doesn't need this lens!

    I don't fully agree. Yes, the 10-17mm and 60mm lenses are fantastic lenses and my 60mm is by far my favourite lens. However, there are times, particularly when diving around Sydney where the viz is often pretty poor where neither the 60mm or the 10-17mm can do the job. In fact, I don't even bother with the 10-17mm in Sydney as I found it next to useless. It can't handle small to medium subjects and the water is not clear enough for large subjects. It is just usable at 17mm. Now, perhaps that's because I have it in a 6" dome and I should go for a mini-dome.

     

    The 60mm is perfect for small subjects like nudibranchs and if the water is clear enough can be used for medium subjects (up to around 10-12 cm) anything larger than that, e.g. a Port Jackson shark, wobbegong, ray or giant cuttlefish and you don't get a the shot - or you take a shot of the eye.

     

    This is where the 18-55mm lens comes in - for me at least. Obviously I lose the ability to go to 1:1 so for really small subjects I can't get a good shot - although I can get a shot and crop in post. It can do 1:2.5 and so it can handle anything from 4cm long and greater. As the subject gets larger, you zoom out which allows you to keep the amount of water between the port and the subject small - certainly much less than if you were using the 60mm. In fact, if you took a shot of a 4cm fish with the 18-55mm there would be less water than taking the photo with the 60mm. As the subject gets larger, you have to pull back with the 60mm but with the 18-55mm you just zoom out and maintain the distance.

     

    I used the Nikon 18-70mm underwater for a while, but stopped: I posted some positive comments at that time, but other lenses were better. I know that the 18-55mm is regarded as an improvement over the older lens, but the drawbacks are still there. It's not a novel concept, but "jack-of-all-trades, master-of-none" seems applicable, particularly as we are asking lenses optimised for terrestrial use to perform behind ports, with all the optical compromises that entails.

    I started with the 18-70mm, too and was constantly disappointed. I have a few keepers but I found it just wasn't that good. The very inexpensive 18-55mm does a significantly better job. It focuses closer and seems to be optically better. By the way, all lenses are optimised for terrestrial use and underwater use would only be a small percentage of actual use.

     

    I dive around Sydney almost every weekend with a club. In many cases I don't know where the dive will be so I can't even guess what I might encounter. Even when the site is known, there's no guarantee what might be found and most sites have a range of subject sizes. I have to take a punt when I set up the camera. Many a time the 18-55mm has turned out to be the best lens for the conditions and encountered subjects. Sometimes it isn't and I live with the fact that I can't do as good a job as I could have done with 60mm. Often when I take the 60mm I miss larger subjects.

     

    Sure, if the goal of a dive is to take photos of a specific subject and nothing else matters, it make sense to take the right lens for that job. If you're diving for fun and want to document what you see on the dive, the 18-55mm is a good compromise - yes it is "jack of all trades, master of none", but getting an OK shot is better than no shot, at least in my thinking. Yes, it is a compromise but if you understand and accept that, you can go on and use it well. I have loads of shots I've taken with my 18-55mm that I'm very happy with. I have even sold them, so it is doing its job.

     

    One final point, if you're shooting with a D7000, you have the option to shoot video. I have found the newest 18-55mm works well for video, especially with the VR which helps stabilise the video.

  24. Posted

    I'm sorry to pop your balloon, but that means it will never take a top-flight underwater image as there will always be too much water between lens and subject.

    Based on this generalisation, the 105mm lens will never take a top-flight underwater image as there will always be too much water between lens and subject.

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