View Full Version : schwetty lenses
Brandon H
09-15-2010, 11:40 PM
When I take my RPP's from my hometown (5 miles from the ocean) out to dryer and hotter climates, when I open up my case (the compact red lens case) there's water on top of the lenses. Is this a normal condensation thing? Or are they crying?
Pawel Achtel
09-16-2010, 12:42 AM
they're crying
Alexander Ibrahim
09-16-2010, 01:02 AM
Its normal in the situation you describe... but you should do something about it.
You don't really want that much condensation going on with your glass. Not long term. It is obviously OK so far, so short term its not an emergency or anything.
I'd suggest storing them in a dehumidified room at home. You might want to throw some silica packs in the case as well.
In fact this might be a good idea for all your gear- assuming it is or can be consolidated in an interior space with a reasonable weather seal.
Pawel Achtel
09-16-2010, 01:14 AM
I can't see how. It can't be condensation because condensation only occurs when relative humidity reaches dew point. This is possible only if you go from hot to cold and from dry to humid, never opposite. :hand:
As I said: the're crying. :cryin:
Alexander Ibrahim
09-16-2010, 03:38 AM
I can't see how. It can't be condensation because condensation only occurs when relative humidity reaches dew point. This is possible only if you go from hot to cold and from dry to humid, never opposite. :hand:
As I said: the're crying. :cryin:
I was puzzled for a minute too. Like you say it makes no sense. Of course they aren't crying.. so what is going on? Assuming the reported facts are true and accurate... there must be an explanation.
The humidity of the air in the case is reducing to match exterior conditions. This is because the air in the case is expanding, and as it reduces density, it can no longer hold water. So the water falls out of "solution." Its one of the odd effects of the triple points of water and air.
Since the case is closed, and apparently sufficiently water tight, the water comes out of the air in the case. I bet the case expands slightly too as pressure increases.
(That is a Pelican case right? If so it has a pressure relief valve. A watertight pressure release valve.)
If the case was open, there would be no condensation. Well, there might be... but probably on the windows of your vehicle. If the case was open and the windows of your vehicle were also open, then there would be no water condensation.
So... basically your lens case is acting like a dehumidifier as it exchanges air from back home with your new environment.
Its counter intuitive, but there it is.
Matthew Duclos
09-16-2010, 07:26 AM
This is possible only if you go from hot to cold and from dry to humid, never opposite.
Actually I think it's the opposite. If your gear sits in a camera truck overnight or on a plane or any cold climate and you then bring it into a warm environment, you'll have instant condensation. Similar to pulling a frosty mug out of a cooler, it cries as well. Best thing to do is use proper cases and desiccant (silica gel) packets and keep the lenses in the case until the temperature evens out a little bit.
Matt Uhry
09-16-2010, 08:05 AM
They cry because they are sad that they don't have good witness marks like the german and english kids do.
Matt Uhry
www.mattuhry.com
OptiTek
09-16-2010, 09:04 AM
Actually I think it's the opposite. If your gear sits in a camera truck overnight or on a plane or any cold climate and you then bring it into a warm environment, you'll have instant condensation. Similar to pulling a frosty mug out of a cooler, it cries as well. Best thing to do is use proper cases and desiccant (silica gel) packets and keep the lenses in the case until the temperature evens out a little bit.
Matt,
If you spend more time on sets you'd know that usually in the morning when you pull out a lens from a "warm" truck into cold morning outdoor the moisture inside (and out) the lens turns into water and sets on cold surfaces. Most of the time you'll see it on the inside of elements (and metal, really,you just can't see it so well) Thats because there is no air flow inside the lens to dry it out quickly.
Depending on the ambient temperature if you give it some time in the sun the condensation usually disappears- it is "absorbed" by the, now warmer, air inside the lens-again.
Same thing happens outside if there is enough moisture in the air inside the case- this is just a more extreme case. I'd recommend trying to keep the storage area dry with good ventilation and definitely "load" the case with silica packs and change them regularly. This is a routine with rental houses near the coastal areas...
Hope it helps....:thumbsup:
Ryan Patrick O'Hara
09-16-2010, 09:38 AM
They cry because they are sad that they don't have good witness marks like the german and english kids do.
Matt Uhry
www.mattuhry.com
Hahahaha! Love it.
Matthew Duclos
09-16-2010, 02:22 PM
Matt,
If you spend more time on sets you'd know that usually in the morning when you pull out a lens from a "warm" truck into cold morning outdoor the moisture inside (and out) the lens turns into water and sets on cold surfaces. Most of the time you'll see it on the inside of elements (and metal, really,you just can't see it so well) Thats because there is no air flow inside the lens to dry it out quickly.
Depending on the ambient temperature if you give it some time in the sun the condensation usually disappears- it is "absorbed" by the, now warmer, air inside the lens-again.
Same thing happens outside if there is enough moisture in the air inside the case- this is just a more extreme case. I'd recommend trying to keep the storage area dry with good ventilation and definitely "load" the case with silica packs and change them regularly. This is a routine with rental houses near the coastal areas...
Hope it helps....:thumbsup:
Of course. I never said it wasn't a two way reaction. But in my experience shooting outdoors in freezing temperatures, you want to avoid bringing cold lenses into a warm environment unless you want condensation.
Jeff Kilgroe
09-16-2010, 02:33 PM
They cry because they are sad that they don't have good witness marks like the german and english kids do.
Speaking of witness marks, has Mr. Duclos come up with a solution and price to dress up the RPP's a bit?
Lenses and gear can also sweat or cry with changes in altitude. Additionally, it could even be a condition brought about by the foam in the case. How much moisture is within the air inside that case foam? Altitude changes can cause it to bleed out. 50% humidity at high altitude is less water in the air than 50% humidity at sea level.
Of course. I never said it wasn't a two way reaction. But in my experience shooting outdoors in freezing temperatures, you want to avoid bringing cold lenses into a warm environment unless you want condensation.
Most definitely. But what changes is the source of condensation. In this situation, it can often be of benefit to seal the gear inside a plastic bag before entering a warmer and more humid environment and then let the condensation collect on the outside of the plastic. Remove the lens once temperatures equalize. Just be sure the humidity outside is lower than that inside before doing this.
Matt Uhry
09-16-2010, 08:47 PM
Speaking of witness marks, has Mr. Duclos come up with a solution and price to dress up the RPP's a bit?
There actually has been a bit of discussion about those very upgrades...
Contact the Duclos's
Matt Uhry
www.mattuhry.com