TargetTalk

When I shoot (in prone position)with sun I hit higher that when I shoot with shade.
Does an explanation exist?
How can mitigate the effect of the change of light? Filters of colors, polarizer, etc.

It is generally admitted that the light attracts the impacts.
If you are shooting in shade and it begins to get the sunshine in the target the shot will go towards the position where is the sun.
I have not noticed that effect never and for that reason I suppose that it is due to the individuals characteristic of the anatomy of the eyes of each one.
Another thing is the effect of elevation due to the reverberation. The air in contact with the ground warmed up by the sun is less dense and tends to raise. The image of the target moves upwards and the shots go high. The problem is greater when there is breeze that drags this air laterally which modifies the impact upwards and laterally.
Regards from Madrid.[/b]

I have read many articles and still have questions about the subject, but as I see it there are more than one reasons for this phenomina.
1 When the air heats up, the warm air starts to rise (thermals) and acts in the same way as crosswind, but pushing the bullet upwards. Just like a glider plane uses the thermals to gain hight. Thermals can not be seen when the air is dry and hot, but when there is more moisture in the air they can be seen as mirage. - This info was discused in length on the forum of Bechrest Central.
www.benchrest.com
2 Very strong (sun)light falling from an angle on the edge of a surface – in our case the lower edge of the front insert – is reflected and distorted causing a patch of light on this position in our eyes. This makes the thickness of the ring look smaller on that point/making the opening look bigger, and we act accordingly, moving the frontsight upwards to compensate, centering the target in the seemingly bigger hole. This ads to the displacement of the thermals/mirage. (This is clearly visable using a handgun with post frontsight and a very bright lit target)

Sorry for a poor translation, but I hope it is clear enough.
Albert
(The Netherlands)

What I have noticed is that sun shining on the target from one side "washes out" the aiming black on that side. That illusion tricks the eye into centering on the black that you can see (which is offset to the side away from the sun) and your shots will inexplicably be off to the side away from the sun.

When I see a strong sun shining predominantly from one side, I simply add windage towards the sun and confirm with the sighting shots.

Thank you Juan Carlos and Albert
I also think that the effect of the light depends on each person's eye. I don't refer to the reverberation, neither to changes in the temperature of the air. I refer to changes of light for the constant movement of the clouds. I believe that nobody has the bull-eye 100% in the center of the aim (it is difficult to look simultaneously around the bull-eye), and most of the shooters maintain a consistent disalignment. But when it varies the light, the disalignment varies the impact point.
I have obtained good results pursuing the clouds putting and taking out the gray filter. In my country this is frequent and in a competition I had to change up to 10 times the filter.
Albert: excuse me also my poor translation. Anyway your message was very clear.

Good point there. I had not though about the influence of the moving clouds before. Will look into that.
As a short time member of the Dutch National smallbore team (1 season) about 8 years ago. I had the change to observe the best of the best in Pilzn (Chechie). It was a constantly changing sun/cloud situation that afternoon and guys like Hubert Bichler (Olympic 3rd place), and the Russions were traning 3P. I noticed them clicking with each shot for the changing conditions. They are experts in this game.
If you ever have a chance to shoot there, it has an earth backstop that forms sort of a half circle and trees on top. Wind is very nasty there!

Albert
(the Netherlands)