This post deals with the influences of light and visibility conditions on biathlon shooting.
The light and visibility conditions are, on the one hand, cloudy and restricted visibility, e.g. due to fog or precipitation (rain and snowfall) or also high cloud cover, which create a diffuse light effect. On the other hand, extremely bright light incidence due to direct sunlight and the possible intensifying reflection in the snow.
With limited visibility/vision, the athlete tends to form the aiming error high front sight due to the changed target image, with the consequence of missed shots high. However, this cannot be detected by the athlete due to the lighting conditions, which also explains the frequent occurrence of this error. This can basically be counteracted by 2 measures.
Measure 1 is clearly to be preferred, as it is clearly the more stress-resistant measure and can also be used to control changing conditions without changes to the line of sight. However, the effects described are only relevant for prone shooting.
[1] Applies to a hit pattern of 12 mm for prone shooting, since the maximum displacement of the MHP may be 16.5 mm in order to still achieve a safe hit. Assuming an effect up to the miss due to the light conditions, the deviation of 16.5 mm must therefore be compensated for (16.5 mm / 3 mm = 6 clicks).
In the case of extremely bright light incidence in the direction of firing directly onto the targets, the exact opposite case of shifting the aiming image occurs. The athlete tends to form the aiming error low front sight, which leads to low shots. Again, the athlete cannot see this through the target image visible to him. The reaction possibilities are the same as in poor visibility conditions, but in the "other" direction.
Measure 1 should also be given clear preference here, as it is clearly the more stress-resistant measure and can also be used to control changing conditions without changes to the sighting line. Here, too, it must be noted that the effects will only be relevant for prone shooting.
The bright incidence of light creates another potential problem. If it is not only from behind, but also from the side, there is an additional shift of the hit pattern in the side, which can also lead to errors. Just as with wind effects, the shift takes place in the opposite direction to the direction of irradiation. This means that if, for example, the sun shines on the targets from the left, the hit pattern is shifted to the right. The cause is again to be found in the unconscious and imperceptible production of an aiming error, in this case "right jammed". At the same time, as the angle of irradiation increases, the aiming error low front sight decreases. Theoretically, the effect is greatest at an angle of incidence of 90°, i.e., from 3 or 9 o'clock. Assuming the same conditions as for the high and low shot error, the reaction must also be 6 clicks "at left/right". The reaction can be halved if the angle of irradiation is between 4 and 8 o'clock. If the athlete reacts with a correction in the side, the height correction is to be halved at the same time.
An increasingly common aspect in terms of lighting conditions are competitions under illumination. Here, the IBU competition rules provide for certain specifications in order to be able to hold fair competitions. These are, for example, minimum illuminance levels on the shooting range. The challenges that arise here are therefore not in the possible change of light and visibility conditions, but in the specific nature of the type of light and the prescribed luminosity. This can generally be compensated for by shooting under these conditions. Training under illumination makes it much easier to adapt to such conditions. The peculiarities of the light effect can also be attenuated with appropriate measures on the sighting equipment (e.g. filter disks, adjustment of the sight and front sight sizes).
Overall, the sighting device should be optimized accordingly for changing or difficult lighting conditions (also applies to illumination). Adjustable ring sights, diopter inserts and color filters are suitable for this purpose. It is important to bear in mind that every additional (technical) element to be controlled also carries the risk of misapplication. Therefore, these optimization tools must also be a permanent part of the training.
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