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Thread: my underwater findings so far...

  1. #1
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    Default my underwater findings so far...

    only oly and sony got 40m casing, canon etc got 30m only...
    there are 3rd parties of cos but cost harm leg and the digicam.
    got snorkelling bags which is basically pvc tranparent bag... like my idea of using ziploc... these state max of 10m

    anyone can tell me what might happen if 30m rated bring to 40m? cos compression will not crack nor open the casing.. button o-rings?

    me looking at the ixus 400 n casing @ ~$1000
    or can be a crazy ******* and buy the G2 casing for 1k+
    "I'm... dreaming... of a wide... angle~
    Just like the ones I used to know~"

  2. #2

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    I think pressure will force the water into the casing, since the seal is rated to 30m, probably thru the 2 halves that clamp shut. You might be able to take it to 40 but thats beyond the spec and at your own risk.

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    this is what i was told by a fellow u/w photog:

    at 10m's depth, your casing is having 1 atm pressure (1 atm from air trapped inside), and 2 atm external pressure (1 atm from air pressure + 1 atm from 10m water depth).

    so if you take a 30m rated casing (external 3 atm water, 1 atm air) which is 4 atm external pressure rated, and bring it to 40 m (which is 5 atm already), you are increasing the pressure load by already 25%.

    see the danger?

  4. #4
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    Every additional 10m the pressure experianced will increase by 1atm, as what sehsuan has mentioned.

    From what i have known from a dive master i got to know, usually the design of those uw camera casing has certain extra allowance, this is for sure.

    Just say the label stated that it is fit for 30m and above, the factory might produced it to sustain pressure of extra 0.5atm. So most probably the uw casing wun leak at such depth, but you might faint becoz of prolonged stay at such depth.

    But all this depends on the factory and they never never ever release such info to public(unless of course you know the uncle of the mother of the niece of the factory owner )

    Again, recommended depth is recommended depth, if you wan to take the risk and add the extra metres, you should expect to see the worst should anything bad happens.
    (just like overclocking the cpu processor, but that one is still better though as i usually act innocent after i fried it and get a new replacement , not sure uw casing can do that or not )

    Happy diving and shooting

  5. #5
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    yeah I know... the main issues would be the button seals...
    cos the material itself is robust enough for 10-20 atms...

    sian leh why does canon make casings rated at 30m??? even crappy sony has 40m... *whine whine*

    caught in the frenzy of research then realised how come I was going to buy a diving set? when was that decision made?? *shudder*

    anyway I am thinking of something really daring/stupid with my oly 2100... think I'll try it anyway, then can upgrade digicam LOL...

    until the next dive!
    "I'm... dreaming... of a wide... angle~
    Just like the ones I used to know~"

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    Originally posted by denizenx
    yeah I know... the main issues would be the button seals...
    cos the material itself is robust enough for 10-20 atms...
    10 atms = 90 meters underwater,
    20 atms = 190 meters underwater!

  7. #7

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    Originally posted by denizenx
    sian leh why does canon make casings rated at 30m??? even crappy sony has 40m... *whine whine*
    According to the Canon website, the new housings for the latest range of digicams - S400, A60, A70 - are rated to 40m. Anyway, i've tried the 30m rated canon housing up to 123ft and it worked.

    Denizenx, you may want to check out the battery life of the Ixus 400 when looking for an u/w setup. Somehow underwater usage seems to drain the batteries rather quickly - my friend's Ixus 300 battery barely lasted 1 dive before going flat. And forget about buying a $1K housing for your G2 - if and when the G2 gets spoilt/flooded, the housing becomes obsolete.

    Happy diving!!

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    Originally posted by kng
    According to the Canon website, the new housings for the latest range of digicams - S400, A60, A70 - are rated to 40m. Anyway, i've tried the 30m rated canon housing up to 123ft and it worked.

    Denizenx, you may want to check out the battery life of the Ixus 400 when looking for an u/w setup. Somehow underwater usage seems to drain the batteries rather quickly - my friend's Ixus 300 battery barely lasted 1 dive before going flat. And forget about buying a $1K housing for your G2 - if and when the G2 gets spoilt/flooded, the housing becomes obsolete.

    Happy diving!!
    yeah yeah! the ixus lifespan cropped up when i was doing costings already! turned my attn to s40/45 then started going ARGH TEDIOUS!!

    now I think I will enjoy a few more dives before turning it into another LCD frenzy..
    "I'm... dreaming... of a wide... angle~
    Just like the ones I used to know~"

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    so conclusion is to get somethinf cheap and usable huh?
    cos at one pt my thoughts deliriously went c5050z and its $400 casing...
    "I'm... dreaming... of a wide... angle~
    Just like the ones I used to know~"

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    the 5050 and it's PT-015 casing is a very good option, but it's still highly recommended that you get a strobe - most people who do u/w photog will ask you to go for a Sea & Sea YS90DX.

    loads of u/w photog sites for you - the best i personally find are:
    www.wetpixel.com (and its forum at www.wetpixel.com/forums )
    www.digideep.com (only for its camera/casing compatibility listing)
    and www.digitaldiver.info (and its forum at http://www.digitaldiver.info/yabbse/index.php )

    the 5050 is apparently the best for u/w photography because the aperture is the largest for any compact digital camera with full manual controls over A/S/M/ISO. and the casing is rated to 40m as well, with DOUBLE o-ring seal - the next better one you have to get is a digital SLR already - now THAT'S gonna cost you one arm and two legs already...

  11. #11
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    anyone can tell me what might happen if 30m rated bring to 40m? cos compression will not crack nor open the casing.. button o-rings?
    OK I will get out on a limb here, do not kill me if Im wrong.
    But my experience with UW cameras is that you can take them much deeper than specified. Anything rated to 30m I would take to 45m and even to 50m if I was breathing anything but air.
    What normally happens is NOT that the O-rings lets in water, they actually gets better and better the deeper you go, until they gets sucked into the camera.

    The housing will NEVER open, it will be next to impossible to open it under water even at 10m.
    The plastic will not crack, the difference between 30m and 40m is so little, that they have to have bigger margins than that.

    More housings leak at 0-5m than 10m deeper than specified. It is the rinse tank that is your biggest enemy, not 40m.
    The Olympus housings that is rated to 30m has been tested to deeper than 40m without any problem by many users.

    Nikonos V is rated for 50m (I think) and works down to more than 70m.
    The cheap 3m throwaway cameras work to about 10m+ but you normally have to go up a bit to wind the film.

    If you really go to deep what will happen is either that the plastic impodes, or that a O-ring is 'pulled' in the housing and the camera will suck in water like crazy.

  12. #12

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    The recommended housing depth rating is just a rpecaution.
    Just like dive computers, they are conservative.
    So are u/w housings.

    Usually you can go deeper, just that the manufacturers play it safe and avoid getting sued :P

    30m canon housing has been down to 50m, I testify to that.
    So the 40m max depth for recreational is not a big deal.

    As stefan says, it usually floods from 0-10m, where the presure change is the greatest.

    same theory as nitrogen bubbles in your blood stream
    Kelvin
    SMS for faster response: 96622292

  13. #13
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    haha now that my cam is offically dead.. I shd get a70 and casing...
    "I'm... dreaming... of a wide... angle~
    Just like the ones I used to know~"

  14. #14
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    My experience with my PT-005 and oly 3040, is that if I go down below 30m, I cannot operate my buttons anymore. The pressure difference between the inside and outside of the housing is enough to press in all my buttons, and therefore the camera becomes un-useable. I also do not think there will be a danger of flooding at 40m if it is rated to 30m. The danger of flooding is at 0-2 m deep. I have lost 1 3040 at sipadan. It flooded as I was descending.

    I also agree, although never experienced, that if you go down too deep, the thing to give way will probably be the O-ring being forced into the housing.

    I must say though that my housing is kind of old, and the springs do not push the buttons out as well as they used to.

  15. #15

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    Originally posted by toasty
    My experience with my PT-005 and oly 3040, is that if I go down below 30m, I cannot operate my buttons anymore. The pressure difference between the inside and outside of the housing is enough to press in all my buttons, and therefore the camera becomes un-useable. I also do not think there will be a danger of flooding at 40m if it is rated to 30m. The danger of flooding is at 0-2 m deep. I have lost 1 3040 at sipadan. It flooded as I was descending.

    I also agree, although never experienced, that if you go down too deep, the thing to give way will probably be the O-ring being forced into the housing.

    I must say though that my housing is kind of old, and the springs do not push the buttons out as well as they used to.
    rem to change all the o-rings every year or at least every 6-10 dive trips or get a new casing. Not worth saving $50-80 for servcing and flood a $1000 camera.

    Like saving a $0.50 parking coupon and kena $30 fine
    Kelvin
    SMS for faster response: 96622292

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