unshootable mirage

[kzin]

First match back Saturday and I had mirage issues like never before.

At 50x on the scope the target image was dancing all around the reticle. Impossible to aim confidently because as soon as I got the reticle centered the target image would move somewhere else.

Turning power down to 24x made the effect less disorienting but it was definitely still there.

I didn't have anything worse than a 9 but a lot more of those than usual and very few x's.

How does one deal with a moving target? Pick one extreme and shoot at that?

thanks for any info or suggestions

 

[Joe Salt]

I've shot in really bad mirage at 1000 yards and thought, what do I do now! Well the answer was, hold on the bull and when it looked like it cleared I squeeze the trigger and it also helps if you have a great tracking rifle.

Joe Salt

 

[F Class John]

As the ‘blob’ in the middle is bouncing around just pick the same spot in the bounce to fire. The bounce tends to follow a pattern and while it’s not exact you can usually see it bottom out or hit the top as it moves around.

 

[ballisticdaddy]

In cool weather I prefer to shoot LR with about 40x magnification but in the summer months have no choice but to dial back to closer to 24X. Perceived moving target is bad but trying to shoot in a boil is even worse.

 

[rardoin]

As the ‘blob’ in the middle is bouncing around just pick the same spot in the bounce to fire. The bounce tends to follow a pattern and while it’s not exact you can usually see it bottom out or hit the top as it moves around.

Same here. If I decide to dial back on the magnification I will do so before I begin record shots in case I would get a change in POI from reducing magnification. It does suck when you can't see rings. I suppose I shouldn't bitch...HP iron sight shooters might be reading this.

 

[CharlieNC]

An aperature with a smaller diameter opening on the objective helps noticeably, at least a little. You could make up several different openings using paper to try.

 

[Kerry Spurgin]

Slap on those Iron sights and all is good!

 

[Turbulent Turtle]

First match back Saturday and I had mirage issues like never before.

At 50x on the scope the target image was dancing all around the reticle. Impossible to aim confidently because as soon as I got the reticle centered the target image would move somewhere else.

Turning power down to 24x made the effect less disorienting but it was definitely still there.

I didn't have anything worse than a 9 but a lot more of those than usual and very few x's.

How does one deal with a moving target? Pick one extreme and shoot at that?

thanks for any info or suggestions

I have a thread running in the Optics section about mirage and glass. May I ask what scope you were using, make, model, etc?

Also, it's called "aperture", but what it really is, it's a way to cut down on the size of the objective lens in a way that will increase the depth of field and thus reduce the criticality of perfect focus that gets messed up by the mirage. If you make a hole in a cardboard sheet or a lens cap cover to be half the area of the objective lens, you will get the equivalent of 1 f-stop reduction. It will show more mirage because of the greater depth of field but it may reduce what I called the CAI, Crazed Amoeba Index; the pulsating center of the target viewed through a scope.

I did some quick calculations and if your objective lens is a 56mm, the diameter of the hole you need for 1 f-stop reduction is 39.6mm.

The formula is S = sqrt((O ^ 2) / 2)
Where S is the smaller objective diameter and O is the objective lens size (diameter) in millimeters.
If you want 2 f-stops reduction, change the 2 to a 4 in the division.

ETA: I corrected the definition in the formula above. Age is a terrible thing to have to deal with.

 

[kzin]

I have a thread running in the Optics section about mirage and glass. May I ask what scope you were using, make, model, etc?

Also, it's called "aperture", but what it really is, it's a way to cut down on the size of the objective lens in a way that will increase the depth of field and thus reduce the criticality of perfect focus that gets messed up by the mirage. If you make a hole in a cardboard sheet or a lens cap cover to be half the area of the objective lens, you will get the equivalent of 1 f-stop reduction. It will show more mirage because of the greater depth of field but it may reduce what I called the CAI, Crazed Amoeba Index; the pulsating center of the target viewed through a scope.

I did some quick calculations and if your objective lens is a 56mm, the diameter of the hole you need for 1 f-stop reduction is 39.6mm.

The formula is S = sqrt((O ^ 2) / 2)
Where S is the smaller objective radius and O is the objective lens size in millimeters.
If you want 2 f-stops reduction, change the 2 to a 4 in the division.

Sightron sIII 10?-50x

 

[kzin]

Slap on those Iron sights and all is good!

I shot first relay in Modern Military with 4.5x scope. that wasn't so bad

In hindsight I should have shot my 50x scope at 9am and the 4.5x at noon instead of vice versa.

 

[kzin]

As the ‘blob’ in the middle is bouncing around just pick the same spot in the bounce to fire. The bounce tends to follow a pattern and while it’s not exact you can usually see it bottom out or hit the top as it moves around.

This is about what I was thinking in hindsight.

At the match I was trying to pull the trigger any time the center and reticle coincided(like my offhand) but I'm thinking now that was dumb.

If I always aim at where the target image is at the bottom point in the bounce then it doesn't even matter where the image is in the bounce when I release, right?

 

[F Class John]

This is about what I was thinking in hindsight.

At the match I was trying to pull the trigger any time the center and reticle coincided(like my offhand) but I'm thinking now that was dumb.

If I always aim at where the target image is at the bottom point in the bounce then it doesn't even matter where the image is in the bounce when I release, right?

Yes that’s exactly the theory. But again you have to be consistent in your release to match the bounce of the blob.

 

[Dusty Stevens]

2 things- everybody else has the same view at the same time. And denying its there doesnt make it go away. You have to decide which is the correct position of the aiming point (a good tracking gun is important for more than speed). Dialing the scope back so you dont see it didnt make it go away- you just have less information to go by then.

 

[JFrank]

Mirage gives me fits also so when you get it figured out - share

First match back Saturday and I had mirage issues like never before.

At 50x on the scope the target image was dancing all around the reticle. Impossible to aim confidently because as soon as I got the reticle centered the target image would move somewhere else.

Turning power down to 24x made the effect less disorienting but it was definitely still there.

I didn't have anything worse than a 9 but a lot more of those than usual and very few x's.

How does one deal with a moving target? Pick one extreme and shoot at that?

thanks for any info or suggestions

 

[Liven The Dream]

http://www.kreativ-solutions.com/mirage-caps.html

This Guy Make those Caps for scopes I have Two for my Sightron 8-32 and 10x50 they help some ?

 

[Turbulent Turtle]

Ok. Sightron scope. I don't know anything about those and since you didn't specify the exact model, I looked at the online specs for the SIIISS1050X60LR series. Since they didn't mention ED glass, I'm assuming the glass in those scopes is the regular kind.

My hypothesis, as described in my running thread, is that ED glass tames the mirage, reduces or eliminates the CAI. When I switched from regular glass to ED glass, the crazed amoeba covering the target got really placid.

 

[JohnKielly]

I shoot on the rise.

 

[Sandstorm]

So on my side of the pond it would be on the drop.

 

[XTR]

Shooting F class at Laurel MS one weekend and it was horrible. There was no way you could say you held the same spot twice. I came to the decision that if I ever had to shoot in mirage that bad again I was going to back off to 25 or less and dial.

It happened at Connaught last yr. I was shooting the Canadian Nats and the mirage was just abysmal. Dialed the whole match and held center. Shot the highest score I shot all weekend.

 

[kzin]

Ok. Sightron scope. I don't know anything about those and since you didn't specify the exact model, I looked at the online specs for the SIIISS1050X60LR series. Since they didn't mention ED glass, I'm assuming the glass in those scopes is the regular kind.

My hypothesis, as described in my running thread, is that ED glass tames the mirage, reduces or eliminates the CAI. When I switched from regular glass to ED glass, the crazed amoeba covering the target got really placid.

As far as I know the SIII model differences are only in reticle design.

How does this relate to spotting scopes?
The other problem with mirage was that I never saw a bullet hole in paper all day.
Usually at 200 with a white target I can see them easily.