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Thread: drybox moisture (RH) level

  1. #21

    Default Re: drybox moisture (RH) level

    Quote Originally Posted by Valkarian View Post
    Relative humidity is the amount of moisture in the air at that point of time. Your surrounding rh might be whatever, but inside the dry cabinet, if it says 45%, it means 45%. If your country is very humid, however, it'll just be harder to get your desired setting as the dehumidifier has to work a lot harder.
    RH ( Relative Humidity) , is the amount of water vapor in the air, relative to the maximum capacity that the air would take under the given condition ( temperature / pressure) That means, the real amount of water in the air different when temperature or the pressure changes, also the RH Value stays the same. Just as an example for better understanding. At a stable given barometric pressure, 40%RH air contains around 9g/m3 water at 25 degrees celsius, but only around 5g/m3 at 20 degree celsius. If the temperature or the pressure changes, these values of g/m3 ( absolute humidity) also change. However, as temperature and pressure always change in our world, measuring humidity in absolute values is impractical. Therefore , we measure at the value, relative to the maximum amount of water vapor the air can take.

  2. #22
    Moderator Octarine's Avatar
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    Default Re: drybox moisture (RH) level

    Quote Originally Posted by Prince Photogenic View Post
    Sorry, I should have phrased my post better. Because Alphalurver said his air con is at 45%, I just wanted to see if the his dry cab 45% reading could have been caused by the low atmospheric RH when his air con his on. Just thought that if he doesn't switch on his air con for a period of time, say a week, would it be possible that his dry cab RH will rise above 55%, encouraging unwanted visitors?
    Depends on setting. But since we have learned from another thread that lower RH does not really affect the equipment it would be better to set the dry cabinet to 45% without 'aircon support'. If the aircon is working RH will drop down further, temporarily ..
    EOS

  3. #23

    Default Re: drybox moisture (RH) level

    Quote Originally Posted by Octarine View Post
    Depends on setting. But since we have learned from another thread that lower RH does not really affect the equipment it would be better to set the dry cabinet to 45% without 'aircon support'. If the aircon is working RH will drop down further, temporarily ..
    right now without aircon is 50. with aircon it's 40+ and the unit isn't running at all at both times, which i assume that's the RH of my room? and my room is actually a 'dry ROOM'???? dang i wasted my bucks.

    already my cam is less 'stiffy' on the focusing ring and the feel when i hold it. but back to my worries, what are the signs that i've damaged my cam and needs some overhaulling?

    Can anyone explain to me how 'moulding' works if it's not proportionally = RH?
    Rig: Trusty (dusty) 6 years old Sony A350, Sony 16-105 lens, Sony Flash unit
    Nokia Lumia 1020

  4. #24
    Moderator Octarine's Avatar
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    Default Re: drybox moisture (RH) level

    Quote Originally Posted by AlphaLuver View Post
    right now without aircon is 50. with aircon it's 40+ and the unit isn't running at all at both times, which i assume that's the RH of my room? and my room is actually a 'dry ROOM'???? dang i wasted my bucks.
    You can get a second hygrometer from DIY shops (e.g. Sim Lim Tower) to verify. But it's possible that your room has a lower RH, depending on overall conditions.
    Quote Originally Posted by AlphaLuver View Post
    already my cam is less 'stiffy' on the focusing ring and the feel when i hold it. but back to my worries, what are the signs that i've damaged my cam and needs some overhaulling? Can anyone explain to me how 'moulding' works if it's not proportionally = RH?
    Mould and fungus is visible as white, cobweb-like structures. In lenses it's easy to see when using a torch light to shine through the lens (just try for yourself, but don't panic about the dust you'll see probably). In cameras it sits in the corners, small white dots or balls. But it really takes a while even if you neglect your equipment.
    EOS

  5. #25

    Default Re: drybox moisture (RH) level

    In my room ( non aircon ) , I get fungus on lenses within 6 month . Higher temperature + high humidity = extremely fast fungus development . Thats why dry cabinets are an absolute must, and i check and clean them regular.

  6. #26

    Default Re: drybox moisture (RH) level

    Quote Originally Posted by Octarine View Post
    You can get a second hygrometer from DIY shops (e.g. Sim Lim Tower) to verify. But it's possible that your room has a lower RH, depending on overall conditions.

    Mould and fungus is visible as white, cobweb-like structures. In lenses it's easy to see when using a torch light to shine through the lens (just try for yourself, but don't panic about the dust you'll see probably). In cameras it sits in the corners, small white dots or balls. But it really takes a while even if you neglect your equipment.
    wow thanks for the extra info. haha i guess you've misinterpreted my worries. My dry box has been on 25% for the past 3 years and someone said earlier in this thread the lub and rubber could dry up and crack. What are the signs and symtoms this has happened? I use my A350 frequently, well quite, does this prevents the above from happening? right now i really feel like sending it down to sony and have them check it but i have no idea how much it will cost. if it's really ex i'd just stick with it cause the pictures' are still great.
    Rig: Trusty (dusty) 6 years old Sony A350, Sony 16-105 lens, Sony Flash unit
    Nokia Lumia 1020

  7. #27

    Default Re: drybox moisture (RH) level

    Quote Originally Posted by AlphaLuver View Post
    wow thanks for the extra info. haha i guess you've misinterpreted my worries. My dry box has been on 25% for the past 3 years and someone said earlier in this thread the lub and rubber could dry up and crack. What are the signs and symtoms this has happened? I use my A350 frequently, well quite, does this prevents the above from happening? right now i really feel like sending it down to sony and have them check it but i have no idea how much it will cost. if it's really ex i'd just stick with it cause the pictures' are still great.
    Basic check-up and cleaning may cost about 80 plus GST, as you can see here:

    Service Charges - Visual

    However, quite frequently you pay less (sometimes even F.O.C.) if the tech didn't see anything wrong.
    Alpha

  8. #28

    Default Re: drybox moisture (RH) level

    Quote Originally Posted by Rashkae View Post
    Basic check-up and cleaning may cost about 80 plus GST, as you can see here:

    Service Charges - Visual

    However, quite frequently you pay less (sometimes even F.O.C.) if the tech didn't see anything wrong.
    cool, thanks.
    Rig: Trusty (dusty) 6 years old Sony A350, Sony 16-105 lens, Sony Flash unit
    Nokia Lumia 1020

  9. #29

    Default Re: drybox moisture (RH) level

    Quote Originally Posted by Octarine View Post
    Depends on setting. But since we have learned from another thread that lower RH does not really affect the equipment it would be better to set the dry cabinet to 45% without 'aircon support'. If the aircon is working RH will drop down further, temporarily ..
    Thanks for (sort of) giving me the chance to clarify, bro. I was trying to warn AlphaLurver that the air con might have caused the RH in his dry box to decrease, and if for some reason he doesn't switch on his air con for some time, it could result in higher RH and might encourage fungus growth. I wanted him to monitor his RH when he doesn't on air con and wanted to leave gaps for thoughts, but i guess i should have just said out.. sorry for any misunderstanding and thanks for the useful info though.

    Quote Originally Posted by AlphaLuver View Post
    wow thanks for the extra info. haha i guess you've misinterpreted my worries. My dry box has been on 25% for the past 3 years and someone said earlier in this thread the lub and rubber could dry up and crack. What are the signs and symtoms this has happened? I use my A350 frequently, well quite, does this prevents the above from happening? right now i really feel like sending it down to sony and have them check it but i have no idea how much it will cost. if it's really ex i'd just stick with it cause the pictures' are still great.
    Yup, i may have misunderstood you, but my stand stays. You should try and monitor the RH and keep it below 45% without the aid of the air con, just in case. =)
    Alpha
    Want to get back to photography

  10. #30

    Default Re: drybox moisture (RH) level

    Quote Originally Posted by Prince Photogenic View Post
    Thanks for (sort of) giving me the chance to clarify, bro. I was trying to warn AlphaLurver that the air con might have caused the RH in his dry box to decrease, and if for some reason he doesn't switch on his air con for some time, it could result in higher RH and might encourage fungus growth. I wanted him to monitor his RH when he doesn't on air con and wanted to leave gaps for thoughts, but i guess i should have just said out.. sorry for any misunderstanding and thanks for the useful info though.



    Yup, i may have misunderstood you, but my stand stays. You should try and monitor the RH and keep it below 45% without the aid of the air con, just in case. =)
    W/o aircon it went up to 50+. im trying to put it at 40ish w/o aircon but its hard with the control my dry box has. A turn knob with just HI, MED, LOW marking. Anyway i've read another thread by Achim. i think my cam should be fine. *fingers crossed
    Rig: Trusty (dusty) 6 years old Sony A350, Sony 16-105 lens, Sony Flash unit
    Nokia Lumia 1020

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