Does cooling down time appley with binoculars

[Taff]

Hi' just woundering have you got to leave binoculars outside for a couple of hours to cool down' same as a telescope for best viewing results Thanks.Taff

[Ant]

I've never thought about that!

My guess is, technically yes, but as bino's have a wide field and low magnification I doubt it will ever be an issue.

Ant

[PhillyDee]

Especially since you hold them in your hands, and they are likely to be warm too.

[algol]

only thing i really do as a rule with binos is once there out keep em out until you're ready to come back in or else they tend to fog up something rotten

[SteelRat]

If the eyepieces get too cold they'll fog up when you put your face by them.

[Reggie]

cap them until they're ready for use outside and then re-cap when not using.

[Talitha]

Hmm, I'll have to look into it when the weather gets cold.

At a fixed, low magnification I'm not sure how close something would actually have to be in order for the view to be affected by internal or external currents. To be perfectly honest though, I've never noticed any visual distortions between the times when the binos were cooled down and when they weren't.. even with the large aperture of the 22x100s.

It's true about the eyepieces fogging up.. the objectives do too. Heat tapes work great on the objectives but no matter what I do, the eyepieces always keep getting foggy occasionally. Maybe because I'm looking up into them and the moist heat from my eye is floating up onto the surface?

[TheThing]

And your breath too!

I find that on cold morning, my birding bins will fog up with a combination of 'eye' heat and hot breath.

[EA2007]

Like Ant says, never thought about it, but good point.

I guess that with a somewhat smaller capacity than a scope tube then they would require less cool down time. But then again some are housed in rubber and plastic so they may require longer than you would think....perhaps this is something which needs testing...........I feel a science experiment coming on!

[argonaut]

I don't find the need to cool down my binoculars(doublet's)

I do uncap inside and recap inside and keep Silica Gell inside the case when not in use.

Now with triplet binoculars I give a 15 minute cooldown.

Hope this help's a little.

[supernova]

Thinking about it the inside would take a long time to cool down,

So my guess is with small bins 10x50 no, but big bins

If warm they will not mist up.

Bernie.

[The Warthog]

I agree. 25 x 100 binocs might have issues, but at those relatively low magnifications, I wouldn't expect it to be an issue. Still, just in case I think I'll keep my binocs in the fridge from now on.

Wife will love that!

[supernova]

I agree. 25 x 100 binocs might have issues, but at those relatively low magnifications, I wouldn't expect it to be an issue. Still, just in case I think I'll keep my binocs in the fridge from now on.

Wife will love that!

Just dont beat the door off with a golf ball

[haitch]

I do uncap inside and recap inside and keep Silica Gell inside the case when not in use.

Hmmm, this has always confused me. I always thought that the cooler outside air is drier (cold air cannot hold so much moisture which is why your breath forms mist on a cold day) so if you cap outside, so long as they're not fogged at the time, then bring them in, the relative humidity of the air under the caps would be lower than the air in the house and there would be no chance of moisture in there.

Does that make sense?

[Talitha]

Makes perfect sense, but if moist indoor air works its way under the lenscaps and fogs the objectives, there's no air circulation to help the drying process. Depending on your climate, mold may become problematic.

The best way I've found to prevent post-session equipment fogging is to place everything in large lawn/trash bags while still outside. This includes charts, atlases, notes, binos and scopes. Otherwise, everything literally drips within 60 seconds after being brought back into the house.

The bag prevents moist indoor air from coming into contact with the equipment, and it stays nice and dry. By the time the bags are opened in the morning, everything's room temperature again.

[Taff]

Thanks for your interesting comments.Taff

[ChrisEdu]

I sometimes find my sunglasses fog up in the morning just from the heat / moisture from my eyes.

[astroeddie]

I've taken 15x70 binos into the Gulf, EVERY time they came out to view the skies, FOG

Even when they've been left out for an hour or so. Very humid conditions. Even when sailing in the Atlantic its a few days either side of the equator that optics are spoilt with atmospheric conditions within minutes.

In the Artic no problems with the cold air, apart from the eyeball watering with the cold all the time.

Eddie