ive seen mirage referenced  in optics. just curiuos what they are reffering to.

mi·rage (mĭ-räzh')
n.
An optical phenomenon that creates the illusion of water, often with inverted reflections of distant objects, and results from distortion of light by alternate layers of hot and cool air. Also called fata morgana.

so it has nothing to do with a scope then? Its th actual mirage seen with the naked eye?

Yup!

Gotta have atmospheric heat present, which causes your "target" to "shimmer" or "shake" L-R.

Westerners get it all the time in their heat, but any place can have it with the sun beating down on cooler land. It's the old "heat rises" thing, and you can actually "see" the heat waves by observing your target object shimmer.

the scope magnifies it

You can get it from heat from the barrel or the ground.  Also if you are not focused directly on your target (like a fixed parallax scope not shooting at that range) you can focus on the air in front of the target and mirage will get much worse.

Learning to read mirage is a great bit of knowledge for a shooter to have.  If you use a spotting scope, focus on your target.  Then, back out the focus just a bit.  This gives you a really good view of the mirage near the target.  Try it,  Mastering this will definately help your long distance shooting.

Simple Rules of Thumb - remember - often simple is not the same as exact. You need to practice to become exact.

Any time you are beyond 300 - factor in the wind

Read the angle of the mirage like a clock.

There is an approximate 4x relationship between the angle and the speed - ex: 1:00 = @ 4 mph; 3:00 = @ 12 mph.  Wind speed is further refined by the length of the waves - short means faster.

Half value winds = 70% speed

Mirage will shiver and shake just before it indicates a change in wind direction

Wind factor (MOA)

0 - 500 = 15
600 = 14
700 = 13
800 = 12
900 = 11
1000 = 10

Example -

Mirage looks to be angled at 2:00 on a clock, an assumption is made that it is 8 mph, range is 700 yrds, it is a full value wind (perpindicular )

Wind speed (8) * Distance (8) / Wind Constant (12) = 5.33 MOA or (8 * 5.33 = 42.66"  // or 1.48 Mils)


Reading mirage is about practice. The above is a simple road map.

PS - if you are a BR addict - Bench Rest - pick on (learn to read)  the flags first - it is like gross data, mirage (for the well trained) is very very refined because it is real time info. Flags are easier to read at first - same deal, read the bottom of the flag (angle of the flag) as a clock, a roughly 4x relationship between angle and speed. Use the wind constants and practice.


Good luck

Quoted: PS - if you are a BR addict - Bench Rest - pick on (learn to read)  the flags first - it is like gross data, mirage (for the well trained) is very very refined because it is real time info. Flags are easier to read at first - same deal, read the bottom of the flag (angle of the flag) as a clock, a roughly 4x relationship between angle and speed. Use the wind constants and practice.

BR= Black Rifle
Thanks to all that was very informative and only hope to get to a level where I have a clue what all of it means.  It did answer my question though