Mirage: Squiggly diagrams translating to real life

[BoltBandit]

You guys are talking about a lot of mirage, the most common thing we are using for wind, is NOT the mirage, but rather Heat Shimmer or Heat Haze. These conditions, while often associated with inferior mirage effect us the most as we look thru many layers of heated air and easily seen with our scope's compression, even when we can NOT detect the mirror like reflections of a mirage.

Yes, during winter on snow covered ground or across a cold body of water you'll sometimes get extreme superior mirage and on the desert floor more commonly inferior mirage, as the two most common types we might see when shooting (there are more conditions). But that is not really as common as people make it out to be at our "relatively" shorter range shooting distances.

I make the distinction, because the images of heavy inferior mirage shared online with the reflection so high you'd never see the target, are not common place, but shimmer is.

Thanks for the info! I actually did read somewhere about the distinction. The author said most shooters interchange mirage with shimmer or haze. I guess it’s one of those things. Call it by it’s proper name, or call it what most call it to easily communicate.

 

[Diver160651]

Diver can you please tell what AOF means and CEP means?? I'm guessing CEP means once your group size is bigger than the target ie you gun is 1/2moa but the target is 1/4moa??

Ya, sorry.

The angle of fire at the top of a hill and the direction of fire to the wind or azimuth where very different. But technically I should not have used AOF.

The other is circular error of probability , like displayed by AB’s WEZ tool.

 

[Laughing_Jackal]

I went out today with my wife to do some practice, and noticed some mirage when the sun came out. I took a quick video of my wife shooting, while I was filming through the spotting scope. Sorry, this is pretty shaky, and not great, but might help. It gets better around the 35 second mark.

The target ranges were:
367yds
414yds
524yds

This was shot using a 6mm Dasher at 2,890fps, with a 107gr SMK, trued to a .282 G7 BC. The wind was anywhere from 10 - 19mph and was about a 4-5 O'Clock.

The targets were bracketed with:
First target set - .5 & .8 Mils
Second target - .6 & .9 Mils
Third target set - .8 & 1.2 Mils

Actual wind holds ended up being:
First target set - .6 mils
Second target - .7 mils
Third target set - .6 mils

When tru'ing these wind holds with a ballistic calculator (Strelok Pro), the wind dopes out to about 11mph at 90 degrees (full value).

Take note of the "high level" mirage, and how quickly it's moving.

 

[Diver160651]

I went out today with my wife to do some practice, and noticed some mirage when the sun came out. I took a quick video of my wife shooting, while I was filming through the spotting scope. Sorry, this is pretty shaky, and not great, but might help. It gets better around the 35 second mark.

The target ranges were:
367yds
414yds
524yds

This was shot using a 6mm Dasher at 2,890fps, with a 107gr SMK, trued to a .282 G7 BC. The wind was anywhere from 10 - 19mph and was about a 4-5 O'Clock.

The targets were bracketed with:
First target set - .5 & .8 Mils
Second target - .6 & .9 Mils
Third target set - .8 & 1.2 Mils

Actual wind holds ended up being:
First target set - .6 mils
Second target - .7 mils
Third target set - .6 mils

When tru'ing these wind holds with a ballistic calculator (Strelok Pro), the wind dopes out to about 11mph at 90 degrees (full value).

Take note of the "high level" mirage, and how quickly it's moving.

Great video.

Here is why I like NOT to use the word mirage. Marige is going to show the reflections (usually in warm weather of the sky) and it displaces the target image, often by a lot.

The Shimmer is indicating the running wind.. they really are two different things and addressed separately if your target happens to be influed my actual mirage.

 

[Laughing_Jackal]

Great video.

Here is why I like NOT to use the word mirage. Marige is going to show the reflections (usually in warm weather of the sky) and it displaces the target image, often by a lot.

The Shimmer is indicating the running wind.. they really are two different things and addressed separately if your target happens to be influed my actual mirage.

Thanks for the clarification on heat shimmer vs mirage Diver160651. That makes sense now.

We have a PRS Skills stage (Barricade) at our range, and due to the grade of the ground, the target appears extremely low to the ground (especially when in the lowest position). I'm not sure if it's the shimmer or mirage, but I swear that one of the two significantly displace the target. I've found on those days where it's displaced, I have to add about .2 mils, and sometimes a bit of windage in order to make impacts. During one match with heavy shimmer or mirage, I shot a 1 out of 8, and I can generally clean it or close to it.

 

[Diver160651]

Thanks for the clarification on heat shimmer vs mirage Diver160651. That makes sense now.

We have a PRS Skills stage (Barricade) at our range, and due to the grade of the ground, the target appears extremely low to the ground (especially when in the lowest position). I'm not sure if it's the shimmer or mirage, but I swear that one of the two significantly displace the target. I've found on those days where it's displaced, I have to add about .2 mils, and sometimes a bit of windage in order to make impacts. During one match with heavy shimmer or mirage, I shot a 1 out of 8, and I can generally clean it or close to it.

When you start seeing the water like stuff around the targets or before them it usually means trouble.. shimmer can also move the image a bit but it tends to bounce back and forth.

You bring up a great point. The lower you are when shooting across a long flat to targets, the more optical disturbances your going to get.

Prone in the desert is a good example.. the image might be so blurry, it is hard to see... pop the gun on a tripod or back of a truck and there is almost always drastic improvement.

 

[Erno86]

The heat shimmer or mirage tends to move the target image right or left or up in a blurred motion at long distances. --- A shooter will sometimes have to compensate for that in relation to the P.O.I..

 

[Lowlight]

Crank the quality to 1080p,

 

[Diver160651]

Crank the quality to 1080p,

Great editing! Nice video

You can really see the wind closer the the firing position was greater than at the target..

BTW was he shooting Solids? The watermarks were tiny even for 2600 if the 338 had some steam behind it.

 

[Lowlight]

They were outta gas, the barrel in those rifles were terrible at those ranges

 

[Deleted member 113831]

They were outta gas, the barrel in those rifles were terrible at those ranges

What were you calling that wind in MPH?

 

[Lowlight]

Been too long I don’t recall and not sure I wrote it down,

I will say once established both Ray from TBAC and I went 4 outta 5 on the plate.

You could not shoot more than 5 rounds at a time or it would start to walk.

Might have been 8ish but it was like two years ago

 

[BoltBandit]

Great video.

Here is why I like NOT to use the word mirage. Marige is going to show the reflections (usually in warm weather of the sky) and it displaces the target image, often by a lot.

The Shimmer is indicating the running wind.. they really are two different things and addressed separately if your target happens to be influed my actual mirage.

Oh wow, I didn't realize the distinction where one displaces the image and the other as a wind indicator. Any good resources to read up on this?

 

[BoltBandit]

I went out today with my wife to do some practice, and noticed some mirage when the sun came out. I took a quick video of my wife shooting, while I was filming through the spotting scope. Sorry, this is pretty shaky, and not great, but might help. It gets better around the 35 second mark.

The target ranges were:
367yds
414yds
524yds

This was shot using a 6mm Dasher at 2,890fps, with a 107gr SMK, trued to a .282 G7 BC. The wind was anywhere from 10 - 19mph and was about a 4-5 O'Clock.

The targets were bracketed with:
First target set - .5 & .8 Mils
Second target - .6 & .9 Mils
Third target set - .8 & 1.2 Mils

Actual wind holds ended up being:
First target set - .6 mils
Second target - .7 mils
Third target set - .6 mils

When tru'ing these wind holds with a ballistic calculator (Strelok Pro), the wind dopes out to about 11mph at 90 degrees (full value).

Take note of the "high level" mirage, and how quickly it's moving.

Thanks for the video and great info! These videos really are a huge help. I definitely was way over complicating things.

 

[BoltBandit]

You could not shoot more than 5 rounds at a time or it would start to walk.

What do you mean when you say it begins to walk? Because of shifting winds? Or something else?

 

[BoltBandit]

When you start seeing the water like stuff around the targets or before them it usually means trouble.. shimmer can also move the image a bit but it tends to bounce back and forth.

You bring up a great point. The lower you are when shooting across a long flat to targets, the more optical disturbances your going to get.

Prone in the desert is a good example.. the image might be so blurry, it is hard to see... pop the gun on a tripod or back of a truck and there is almost always drastic improvement.

Diver, when you say "water around the targets", do you mean like in the movies, where it looks like there's actual water on the ground due to the mirage? Or will it be kind of like optical aberration, where it's literally around the edges of the actual target. I know it's a dumb question, but I seem to have a track record with way over thinking this stuff and missing the big picture

 

[BoltBandit]

Crank the quality to 1080p,

AWESOME VIDEO! Great editing too. And your wind call?

 

[Diver160651]

They b

Oh wow, I didn't realize the distinction where one displaces the image and the other as a wind indicator. Any good resources to read up on this?

They both will distort the image, but mirage is really, really rough and can make the target look like it is “floating” above or “sinking” below water. This huge refraction of light/image displaces the image much more than shimmer and trying to “guess” the actual shift is not something I’ve seen a good rule of thumb.

Shimmer is what we see 99% of the time and you can usual get a handle on the image shift.. or at least a good guess. Shimmer makes long range targets appear softer, less defined and a bit larger. That’s why using mil ranging at ELR distances on small targets doesn’t work. The optical distortion will make the math say the target is way way closer.

Yes, Mirage is most like you see in the movies.. with the sky’s reflection, looking like water on the ground.

For what it is worth, before LiDAR windmeters (doppler reading the wind via particles in the air), optical sensors were tried to look for the refraction effects (shimmer).

 

[sabrecross]

Watching

 

[Erno86]

What do you mean when you say it begins to walk? Because of shifting winds? Or something else?

Stringy looking groups on target because of excessive barrel & receiver heat-up.

 

[BoltBandit]

Stringy looking groups on target because of excessive barrel & receiver heat-up.

So a vertical shift, not horizontal?