Optics 'misting' at higher mag

Eric the Red

Well-Known Member
I have a scope (6-24 x 56) that is crystal clear at low mag, but becomes 'misty' at higher mag. It's still useable, but somewhat limiting in low light. It's also a pain as eye relief is that bit shorter at high magnification. It's as if a small amount of light is being reflected across the objective. It's not an issue I've had before - anyone else come across this/got any bright ideas? I am wondering whether it is as simple as atmospherics at the moment - but this would be too easy an explanation - isn't it the law that these things have to cost you money?!
 
Eric

What make is the scope and how old is it? Sorry - ignore the first part as I've just seen from your signature that it's a Nighteater.

Could it be that it needs re-charging with Nitrogen, presuming it's Nitrogen filled? Though perhaps in this case you might have expected to see misting throughout the magnification range.

Alternatively, maybe one of the lenses might be dirty and it's only obvious on the higher magnifications.

Either way, you might want to try Glasgow Binocular Repair (seach on the SD site and you'll find it).

For a nice article on how a riflescope works, look here:Shooting Voodoo :: Anatomy Of A Tactical Bolt Action Rifle: The Riflescope

Good luck!

willie_gunn
 
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When you say “misting” do you mean that you have moisture in the tube? I suspect not as you mention only at higher magnification, I suspect you mean a lack of clarity at high magnification. I too have seen this with “cheap” scopes. I have one that is fine up to 18/20X power but looses it after that. If you are running high magnification scope you need the quality glass or it will be found out.

ATB

Tahr
 
Actually my view is that it's the poor quality of the lenses. You will also find that eye position is critical at higher magnifications another sign of cost cutting and being cheaply made. Sorry but you need to get a better scope.
 
Hi all,

I have to agree with Brithunter i had one of the same scopes which suffered with the same problem on high mag it just looses sharpness and seems to be a bit misty but its down to the quality of the glass, you can get used to it but i tended to leave it on a lower mag to avoid the problem.

ATB

Rob
243Sako
 
While I remain open to the obvious quality statement, I raised the point as it was something that had not occurred until recently. The image is still in sharp focus and there is no chromatic aberration, just a view as if one were looking across a misty field. There's no moisture in the tube itself - this would show at all magnifications and if one looks down the scope slightly off centre, one can see the walls of the scope are clean. The lenses are clean - as a camera freak, I keep them clean and protected like my camera lenses.
 
Eric

Given your statement I would still think that one of the internal lenses might be the problem. The fact that the problem is only appearing at higher magnifications would lead me to think that it's one of the erector lenses (see my earlier post), since they are the only things that should change as you change the magnification.

I am also a camera buff and have had lenses where the internal coating has failed - even in my Leica :eek:

willie_gunn
 
Thanks Willie - sounds like a plausible cause. Off to see what Nikko CS is like.....time to mount the Nikon.....

From my experience with Highland Outdoors..................................... very poor. Sorry to have to tell you that. Brought a new Nikko Sterling scope for range use. A 4.5-14x50AO and found out that the whole fast focus eye piece wobbled about in the occular housing. They told me that ALL fast focuse eyepieces do that :eek:. The scope was sold for someone to use on pre charged recoils air rifle and it seem ok on that but anything more than a .22 L/R the recoil would move the POI.

Good Luck as I feel your going to need it :(. .............................. Of course we hope i am wrong.
 
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