Scope sunshade question.....

Discussion in 'Scopes, Optics, LRFs, Spotters, BoreScopes' started by NDAR15MAN, May 26, 2018.

  1. NDAR15MAN

    NDAR15MAN

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    Question ..... Any need for target shooters to run 2 three inch long sundshades back to back on their scopes ? I have noticed some shooters doing this and they do make the sunshades with threads in them were you can install them back to back. Just wondering if I am missing something or if one sunshade will do the job ? Thanks. Marty
     
  2. LA50SHOOTER

    LA50SHOOTER Gold $$ Contributor

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    Marty, - I've ran two 3" shades back to back but didn't really see big gains in doing it. - Heat coming off the barrel is just that and we don't want it to interfere with our view of the target when we look through our scopes. - Solutions that help reduce the heat are a proper mirage shield run the length of the barrel & I've heard that a small portable electric fan also helps. - I've purchase a couple of fans to try this but have not done much at this time to see if & how much it helps. - If the fan(s) works then I'm all for it.
     
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  3. Bart B.

    Bart B.

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    I don't think barrel heat bends the light from targets enough to matter.

    Has anyone actually measured how much refraction light from targets is bent from barrel heat and separated that from what downrange mirage moves target image?
     
  4. Rob01

    Rob01

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    I only run one 4" sunshade and it works fine. Protects the objective from debris and keep sun out well enough.
     
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  5. LA50SHOOTER

    LA50SHOOTER Gold $$ Contributor

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    Sounds pretty much impossible to do, as the variables of heat from the barrel & the changing mirage condition are not something we maintain a whole lot of precise control over.
     
  6. Bart B.

    Bart B.

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    A cup shaped mirage band 10% wider than scope objective will divert barrel heat waves to the sides of scope field of view.

    https://www.google.com/search?q=heat+waves/around+mirage+bands&client=tablet-android-samsung&prmd=isnv&tbm=isch&tbo=u&source=univ&fir=fw_r3WzFzUU0UM%3A%2CUD6yILvLShUSwM%2C_%3Bg_g6L3xPDrPKKM%3A%2CUD6yILvLShUSwM%2C_%3BDL1Q8vbM9p5dHM%3A%2C28CJNaUWtgZA5M%2C_%3BghEIQyejv1oTqM%3A%2CEq7slyi2E37E8M%2C_%3BUYv8YzkZqHo9iM%3A%2CKCW4P3ZH0CM3fM%2C_%3BTq9_Yi9tOZwmPM%3A%2CUD6yILvLShUSwM%2C_%3Brnyc7UFf9c2HAM%3A%2CvHOX7biACY2bkM%2C_%3BOaxem7MQkJpFvM%3A%2CUOyRVeegUc121M%2C_%3BcH0qSHtCc-FTlM%3A%2C0FNx2U2NNMzZyM%2C_%3BrYKYpkS6FDtkpM%3A%2C28CJNaUWtgZA5M%2C_&usg=__XGrfTIxuVVJpFeQJlY2r_g3eaKA=&sa=X&ved=0ahUKEwikooj7saTbAhVKulMKHfOfA_UQ7AkIJQ&biw=911&bih=683#imgrc=UYv8YzkZqHo9iM:

    Once the wind blows, barrel heat waves are moved sideways. Take the mirage band off as it catches the wind like a sail and can move point of aim.

    On the range at break of dawn, anchor a scope on a concrete bench focused on something fixed 1000 yards downrange. Look through it during the day to see how much mirage shifts target position.
     
    Last edited: May 26, 2018
  7. LA50SHOOTER

    LA50SHOOTER Gold $$ Contributor

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    Yep, - we use these mirage shields all the time. - But not really practical for all shooting applications - great for Bench Rest though.
     
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  8. Milo 2.0

    Milo 2.0 Gold $$ Contributor

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    I like a 4" sunshade myself, do notice about an hour before dark for about 1/2 hour, it'd be a good time to remove if the sun is behind a guy somewhat.
    Not certain what mirage has to do with a sunshade though.
    Other than trying to look badass, I question screwing 2 together.
     
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  9. Bart B.

    Bart B.

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    The primary reason to use sun shades on rifle scopes is exactly the same as lens hoods on camera lenses. They block light rays entering the optics at greater angles that can cloud the image and reduce contrast. Some scopes have light baffles in them that minimize the effects and shades aren't needed.

    I've seen foot long plus shades on some scopes in matches wherein best scores were shot with scopes without shades in heavy mirage conditions.
     
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  10. NDAR15MAN

    NDAR15MAN

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    Yep. I use one but I was just wondering if any benefit of using 2 Sundhades back to back on there scopes ? Most are 3 inches to 4 inches long each. That would be 6 to 8 inches total. I guess it is common because scope companies make them so you can stack them. It seems like about 3 in 10 target shooters from what I noticed have 2 sunshades on their scopes . Thanks. Marty
     
  11. LHSmith

    LHSmith

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    It is rare to find scope sunshades affixed to scopes at sanctioned SR BR matches. This is what we use to shield the objective lens from direct sunlight:

    http://internationalbenchrest.com/photos/gallery2/pages/Don Cameron.htm
    To minimize mirage from the barrel we use these:
    http://bulletin.accurateshooter.com/2013/03/mirage-shields-not-just-for-benchresters-anymore/
    Years ago there was a transluscent aftermarket mirage tube (Saunders Mirage Shield) which was seen on the BR circuit. They were short-lived as it was found to actually induce heat waves from air inside the tube heating up. I believe your adding multiple sunshade extensions will do the same- especially if used in direct sunlight.
     
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  12. LHSmith

    LHSmith

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    I don't know what discipline you shoot, but in SR BR it is a big deal. At 45x you can see it.
     
    Last edited: May 27, 2018
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  13. LHSmith

    LHSmith

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    From a SR BR perspective -If the wind blows your rifle off target due to the mirage shield -you either have a very poor rest set-up or you're being forced to shoot in a thunderstorm in which case you have a death grip on the rifle and are just praying to hit the scoring portion of the target to avoid being DQ'd.
    If you shoot with a mirage shield in matches, it will be wise to practice with it in place also.....BR rule #1 -eliminate the variables.
     
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  14. danny

    danny

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    Afraid I can't answer that directly, but the reason for a sunshade is simply; shade the front lens elements from receiveng a direct sun hit, which is something that degrades the image quality. A lot would have to be considered in answering your question, such as your position relative to the sun, the time of day, etc, and maybe other issues I have not thought of. There would be a certain length required
     
  15. Rob01

    Rob01

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    Having shot in a bunch of rain, snow, dusty conditions and mud splatter, the sunshade also protects the scope objective. It does do a little more than keep sun out.
     
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  16. NDAR15MAN

    NDAR15MAN

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    I use a sunshade. I think they help.
    My question is ..... Is there any value putting 2 sun shades together
    I have been see guys shoot with 2 on there scope , some are 8 inches long total ? Thanks Marty
     
  17. JRS

    JRS Gold $$ Contributor

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    The longer the sunshade, the less light you have entering the objective lens.
     
  18. NDAR15MAN

    NDAR15MAN

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    Ok. Maybe I will just stay with 1 sunshade. Marty
     
  19. Bart B.

    Bart B.

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    Sunshades can be any length as long as they don't block light from the scope's field of view at target range.

    If the field of view at 100 yards is 2 yards, the scope objective lens is 50mm diameter, a 100mm long shade needs an inner diameter 2% bigger than the objective lens: 51mm. An 8" (200mm) long shade requires a 52mm inside diameter at its front; 4% bigger. A100 yard long shade needs a 2 yard wide inside diameter up front on the shade plus another 50mm to be technically correct

    Calculate for the scope lowest power field of view.

    Yes, as long as the field of view is not blocked.
     
    Last edited: May 31, 2018
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  20. walker2713

    walker2713 Gold $$ Contributor

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    If one is good, why shouldn't two be better? o_O
     

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