Rifle Shooting Visual Task Analysis

Question 1

Adaptation effects - light/dark/glare - for rifle shooting?

Answer 1

• Shooting as a sport is always done under good lighting conditions, indoors or out
• Adaptation effects only come into play in form of light adaptation
• High levels of illumination outside would make shooting a v difficult hobby for an albino (to find target)

Question 2

Time taken to respond to particular stimulus for rifle shooting?

Answer 2

• Shooting normally performed from a static position
• So, effects of a space scotoma are not important

Question 3

Flicker (strobe effect) for rifle shooting?

Answer 3

• Not a problem for rifle shooter  usually because of good & uniform illuminations

Question 4

Position in VF for rifle shooting?

Answer 4

• Targets are always centred on fovea to attain maximum possible acuity
• Because of fixed nature of target, good scanning is not required
  o For clay pigeon shooting or real bird – reaction time has to be quick as target is moving

Question 5

Viewing distance (accommodation) for rifle shooting?

Answer 5

• Viewing distance is always at infinity to target
• Gun sight may be 50m away
• Accommodation not particular problem
• Presbyopic marksmen normally prefer full distance correction, & suffer from small amount of blue at distance of gun sight
• Some marksmen use pinholes or variable apertures on a corrective lens in order to ↑ depth of field, bringing both gun sight & target into clear simultaneous focus

Question 6

Viewing distance (convergence) for rifle shooting?

Answer 6

• As task is monocular, convergence is not a problem
• Physical diplopia may occur when sighting a target
• Many marksmen use an occluder over their non-sighting eye to suppress this
  o Occluder is normally light coloured

Question 7

Visual subtense of task detail (size/acuity) for rifle shooting?

Answer 7

• Visual subtense of target can be v small, sometimes beyond marksman’s ability to see
• Vernier acuity in form of sighting to centre for larger circles in target, is often used to improve resolution
• Telescopic aids for scoring or telescopic sights on gun are often used

Question 8

Motion of task for rifle shooting?

Answer 8

• Task is static whilst practicing so dynamic effects are not considered
  o Hunting as a sport has moving targets – clay pigeon shooting too

Question 9

Contrast of task detail in rifle shooting?

Answer 9

• Contrast of task detail is usually as high as possible because of small angular subtense of target

Question 10

Colour of task in rifle shooting?

Answer 10

• Unimportant in rifle shooting

Question 11

Clarity of task detail in rifle shooting?

Answer 11

• Hazy conditions can prevent clarity of task detail
• Some marksmen use yellow filters as a contrast enhancing device
• Scientific effectiveness of filters yet to be proved – usefulness varies person to person
  o Px should try various filters to see if they help

Question 12

Stereopsis Requirements for rifle shooting?

Answer 12

• Task normally viewed monocularly, so stereopsis not required

Question 13

VF Requirements for rifle shooting?

Answer 13

• Small – should be larger for safety purposes
• Marksmen must be able to confirm area they are shooting into is free of any people wandering about

Question 14

Hazards for rifle shooting?

Answer 14

• Hot gasses & particles from explosive used to propel bullet, & from gun recoil
• Marksmen should always wear safety lenses whilst shooting to reduce the risk from this mechanical injury
• They should also always wear ear covering

Question 15

Training requirements in rifle shooting?

Answer 15

• Nature of visual task is v demanding
• Practice & training for use of visual equipment, gun sights & for shooting will rapidly enhance visual performance