What Do You Do About Dew?

[LukeSkywatcher]

If those dews were any longer, they would be in orbit. 

[westmarch]

On 20/08/2018 at 12:34, Bamo said:

Yes, the hair dryer will work fine. And as long as your powering from the car you shouldn't have much of a problem.

Good luck

Bamo

Unless you need the car to get home from a dark sky site in the dead of winter.  I was that soldier!

John

[denodan]

I would not want or recommend dew shields on 15x100 binoculars, they are allteady top heavy and adding weight makes matters worse.

 

Better off using dew straps which I am getting for my 25x100 binoculars as this minimizes weight.

[BinocularSky]

1 hour ago, denodan said:

I would not want or recommend dew shields on 15x100 binoculars, they are allteady top heavy and adding weight makes matters worse.

Not sure what you mean by "top heavy" - if you mean "front heavy",  most decent 100mm binos have some facility for longitudinal adjustment  (e.g. a mounting rail between the objective tubes) so you can adjust that out - see image (not my binos; one I was testing):

Quote

Better off using dew straps which I am getting for my 25x100 binoculars as this minimizes weight.

Are you sure about that? My "double-barrel" foam-mat shield for my 100mm binos weighs in at 37g. My single dew strap for my 102mm scope weighs 40g (not inc cable), so the dew shield weighs less than half what a couple of dew straps would weigh.

[Stbk]

On 26/07/2018 at 12:33, BinocularSky said:

I make mine at least 3x, unless it would make them unwieldy. At 4.5x, they actually work properly! (see length of primary "dew shield" on a solid-tubed Newtonian ? )

 

On 24/08/2018 at 19:43, daveintheshire said:

Um....  You sure about this, Steve?  I think I might need third party liability insurance to take these off my own property! ?

Being new to Binocular Astronomy I would have thought this would reduce field of view & light ?, So with a 10x50 what is the recomended length 

[BinocularSky]

On 13/10/2019 at 10:01, Stbk said:

Being new to Binocular Astronomy I would have thought this would reduce field of view & light ?, So with a 10x50 what is the recomended length 

Nothing like trying it out 🙂- I wouldn't usually use dew shields on a 10x50, because I hand-hold them, but I do have 26cm long (overall - they extend about 21cm beyond the objectives) for my 16x70. I've just rolled them a bit tighter and tried them on the 10x50.  Just outside the FoV at 23cm extension (a tad over 4.5x aperture). Obviously, it will depend on the design of the binocular: mine has very substantial objective tubes; lightweight ones may have smaller OD objective tubes. Also, very wide angle ones may need them shorter (mine are 6.5* TFOV, some are 8.5* TFOV)

As long as they don't impinge on the field of view, the only light loss will be light you don't want anyway. 🙂

[Fraunhoffer]

Its the eyepieces I have problems with and have to tuck the binos inside my coat or under a warm hat from time to time.
Sometimes I wondering if Im breathing out through my eyes. Maybe I should try a swimmers snorkel ?

[BinocularSky]

On 16/10/2019 at 21:19, Fraunhoffer said:

Its the eyepieces I have problems with and have to tuck the binos inside my coat or under a warm hat from time to time.
Sometimes I wondering if Im breathing out through my eyes. Maybe I should try a swimmers snorkel ?

Try folding/twisting the eyecups down, so as to get more air circulation between your eyes and the eyepieces. If you hold the binocs like this, you can keep them the appropriated distance from your eyes (and it's a heck of a lot steadier than just holding them around the prism housings, especially for high elevations).

Edited October 18, 2019 by BinocularSky