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SaltyDog

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What causes a mirage in the view of a scope?

I use a leupold Vari XIII 4-14.5X50. It has an adjustable objective. I tried adjusting the objective and it helped at times but it seemed difficult to adjust a clear visability of both the cross hairs and the target down range (100 yards). I eventually found a happy medium for the visibility but there was still somewhat of a mirage. I have never seen this before. Atleast I never noticed it before.

Thanks
 
Salty,

You will see two forms of mirage:

  1. The mirage caused by air movement between you & the target is there to live with. Nothing that won't be detrimental to accurate shooting can be done to avoid it. Focus you parallax adjustment (objective) so the crosshairs don't move across the target when you move your eye behind the scope, & that's the optimum sight picture you'll get.
  2. The mirage caused by barrel heat wafting up in front of objective can be avoided or reduced by either using a mirage tube on your scope as long as the barrel, or by fixing a mirage band onto the barrel. This type of mirage is normally seen when there's little breeze to blow it away.
Many (me included) will say that it's beneficial to see the first type of mirage, as it gives you an indication of changes in the breeze. A whole lot believe that it is a real pain & use low(er) magnifications to avoid seeing it as distinctly.

Take your pick.

John
 
John Kielly said:
Salty,

You will see two forms of mirage:

  1. The mirage caused by air movement between you & the target is there to live with. Nothing that won't be detrimental to accurate shooting can be done to avoid it. Focus you parallax adjustment (objective) so the crosshairs don't move across the target when you move your eye behind the scope, & that's the optimum sight picture you'll get.

  2. The mirage caused by barrel heat wafting up in front of objective can be avoided or reduced by either using a mirage tube on your scope as long as the barrel,

    [Not recommended. The TUBE actually traps the air in the tube where it heats up and compounds the problem. BETTER TO USE A MIRAGE SHIELD / SHADE to divert the heat coming off the barrel and allow whatever flow of air is around the barrel to disperse it.]

    or by fixing a mirage band onto the barrel. This type of mirage is normally seen when there's little breeze to blow it away.
Many (me included) will say that it's beneficial to see the first type of mirage, as it gives you an indication of changes in the breeze. A whole lot believe that it is a real pain & use low(er) magnifications to avoid seeing it as distinctly.

Take your pick.

John
Click to expand...

Picture of a mirage shield/shade. Looks like a slat from a venetian blind. Available from Sinclair International for a few bucks: http://www.sinclairintl.com/prod_detail_list/s.
 

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  • Mirage Shade.jpg
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I'm anal.

I use old full size xray negatives & cut one strip diagonally out of each using my 3' Stanley level as a guide. They do the job just as well & will oack into a soft or had case afterwards, or even roll up to fit a gun box.

They're just long enough for a 34" barrel.
 
John ...

John Kielly said:
I use old full size xray negatives & cut one strip diagonally out of each using my 3' Stanley level as a guide.
Click to expand...

I used to use a piece of an old x-ray too ... until the image of someone's bones started messing with my head. :eek: It just didn't give me a warm fuzzy feeling each time I unrolled it and attached it to the barrel. :)
 
If you've never used a scope that has more than 8X or so you may well not noticed mirage although it's still there. The higher the scope's power the more you'll notice mirage too.

Mirage shields help with mirage off the barrel. Sometimes when it's really bad not much helps with mirage coming off the ground that I've ever found anyway. When the target goes invisible it's hard to shoot. :eek:
 
Thanks guys

I'll pick up one of those shields from Sinclair. There wasn't even the slightest hint of a breeze while this was going on. Thanks for the information.
 
If you ever get tired of the hard type shields, Champion Choice sales one that is an elastic cloth material. They work just as well and can stay on the rifle without being damaged.

Here's a pick of it on one of my rifles....

100_2802.jpg
 
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