Do eyepieces in storage cases need cool down time?

[M40]

A recent topic by Pitch Black Skies has prompted me to ask a question I have been meaning to ask for some while now about storage of eyepieces, so....

Currently I keep all my eyepieces on a tray in their individual cases/boxes. The tray is open to atmosphere and I keep/store the tray local to the telescope, in a shed. Other than moving the eyepieces between shed and telescope, I don't transport them anywhere. I have long thought of a nice foam filled case but my concern is that if the eyepieces are kept in a case, once you open the case, do the eyepieces then need the cool down time to stop condensation? I ask as after having one of my eyepieces outside then bringing it inside to play with a setup, instant condensation. Any help would be welcome.

Edited May 6, 2021 by M40
correction

[Seelive]

I've always thought that the risk of condensation only occurs when a cold item is exposed to a warmer moist environment? (Hence the need for dew heaters, so unless you took it outside from an AC room on a hot summers evening, that ruins that idea 😊)

[Tiny Clanger]

1 hour ago, M40 said:

A recent topic by Pitch Black Skies has prompted me to ask a question I have been meaning to ask for some while now about storage of eyepieces, so....

Currently I keep all my eyepieces on a tray in their individual cases/boxes. The tray is open to atmosphere and I keep/store the tray local to the telescope, in a shed. Other than moving the eyepieces between shed and telescope, I don't transport them anywhere. I have long thought of a nice foam filled case but my concern is that if the eyepieces are kept in a case, once you open the case, do the eyepieces then need the cool down time to stop condensation? I ask as after having one of my eyepieces indoors to play with a setup then taking it outside, instant condensation. Any help would be welcome.

I keep my EPs in a peli-type (but not cost ..) case , plastic, well sealed . It lives indoors with the 'scopes. In use I sometimes take it outside as a whole,  but when the weather was particularly chilly and I was standing in snow to observe, I used a small padded waist bag to keep the eyepieces warm between uses. I had no problem with condensation on the eyepieces even in really cold conditions .

I don't think EPs need to cool down as a 'scope  does ... well, not the modestly sized plossls and BSTs I own anyway ! and keeping them clear of condensation in cold observing conditions actually means keeping them warm and not accidentally breathing on them . 🙂

The point when I am concerned about condensation is when I bring the eyepieces back into the warm house after being outside, so my routine is to treat them in a similar way to the 'scope, i.e. leave them to acclimatise gently with their caps off , and certainly not sealed in the case. I lie them on a bookshelf  for at least an hour  before they go back in the case, which has some silica gel desiccant pouches tucked inside. 

Once you've seen a camera lens ruined by fungus you take precautions ...

[Kon]

I have personally found if the humidity outside is high then the EPs will condensate much quicker if they are left exposed outside so i tend to cap them and put them back in my pocket. In cold frosty nights, i have found that I can easily leave them out in the cold without condensation or at least minimal condensation when i place my eye that goes away within secs.

4 minutes ago, Tiny Clanger said:

The point when I am concerned about condensation is when I bring the eyepieces back into the warm house after being outside, so my routine is to treat them in a similar way to the 'scope, i.e. leave them to acclimatise gently with their caps off , and certainly not sealed in the case. I lie them on a bookshelf  for at least an hour  before they go back in the case, which has some silica gel desiccant pouches tucked inside. 

I tend to leave mine without caps overnight including my Dob. In winter, i run my dehumidifier in the same room as the EPs and Dob o/n (both without covers); it also helps on frosty nights when the OTA is covered with ice to remove all the condensation.

[John]

I keep my eyepieces a bit above outside temperature to stop them misting / dewing up. The heat of the eyeball can mist up a cold eyepiece in seconds.

 

[JeremyS]

I keep my eyepiece in cases indoors at room temp. No cool down needed.

I definitely would not keep them in a shed, observatory or garage for fear of humidity build up.

[M40]

Thanks very much for the replies, clearly (pun intended...honest) I am doing it wrong with eyepieces. I have got to think this through a bit. Many thanks again.