Reticle changing direction on target over time.

[dickn52]

90's? I thought you were talking a long time ago. When I did my cornfields we used good old K&E's and paper notebooks. Probably early 70's.

 

[memilanuk]

Years ago, when I was just getting serious about F-class, I ran into a situation where I was shooting @ 600yds in July, and the last two relays of the day I was having to hold down, almost to the bottom of the 9 ring, to put the shots in the middle. The mirage was boiling almost straight up. Then, as I was lining up for another shot, I saw a puff of breeze come thru and the flags just flicked up for a minute... and I watched the target image suddenly *drop* right down to where my crosshairs were just about centered in the X-ring. As I continued to watch, the breeze died, the boil came back... and the target image slowly rose back up to where it was before, with my crosshairs at about 6:30-7 o'clock on the bottom of the 9-ring.

Very much an eye-opening and educational experience as to the effects of mirage on what you think you're seeing out there. It's not often that you get the opportunity to see the effects of mirage almost strictly in terms of optical displacement, mostly decoupled from lateral wind effect.

This article gets a little further into the weeds on the angles and whatnot...

http://southtexasshooting.org/multimedia/text/mirage.html

 

[seymour fish]

Is this most noticeable at longer distances? Is it the angle of the sun, mirage, heat in the optic, or combination off all three? Never heard of it before.

T, it happens big-time at 50 yes with 22 lr

 

[Tim Singleton]

What was the old Palma shooters saying
"Lights up sights up"

 

[Big Mc]

A mile is a huge shot for surveying. I think I used to use my K&E at 300 or so.

A mile with modern survey gear is childs play.. Tommy Mc.. RPLS Ret. TEXAS.