• Skip to main content
  • Skip to primary sidebar
The Loadout Room

The Loadout Room

Professional Gear Reviews

Hardcore Gear and Adventure

Menu
  • Shooting
        • Pistol
        • Pistol Accessories
        • Rifle
        • Rifle Accessories
        • Shotgun
        • Machine Guns
        • Air Guns
        • Ammunition
        • Optics and Sights
        • Weapon Lights
        • Tips & How-To
        • Concealed Carry
        • Holsters
        • Suppressors
        • Precision Rifle Shooting
        • Firearms Training
        • skorpFull-Auto Fun — Shooting the full-Auto vz. 61 Škorpion
        • p320-full-leftSIG Sauer M17/M18/P320 Pistol Just Can’t Seem to Escape Safety Controversies
        • TISAS_10100520_1__98179Tisas 1911A1 U.S. Army Review: Best Budget .45 ACP WW2 1911 Clone?
        • Photoroom_20250531_143432Pyramyd AIR’s Springfield Hellcat Pro CO2 BB Pistol Is the Ultimate Dry-Fire Trainer
    • Close
  • Gear Reviews
      • Mission Gear
      • Camping Gear
      • Survival Gear
      • Medical Gear
      • Adventure & Travel
      • Knives & Tools
      • Overland
      • Disaster Preparedness
      • Footwear
      • Womens Gear & Clothing
        • Hunting in TexasThese 5 ATV Dealers Will Get You Ready For Hunting Season in Texas
        • ac65a540-2ef3-4598-8d11-afdf53f46e94.__CR0,0,970,600_PT0_SX970_V1___Streamlight ProTac Rail Mount HL-X: A Thoroughly Bright Review
        • Bluetti 2 handsfree power backpackBluetti Handsfree 2 Review: The Ultimate Power Backpack for Off-Grid Adventurers
        • The Gallagator 10 day pack on the shoreline next to a hiking trail.Day Pack – Mystery Ranch Gallagator 10 – The Best Yet?
    • Close
  • Men’s Lifestyle
      • Fitness
      • EDC
      • Eyewear
      • Watches
      • Electronics & Technology
      • Downtime
      • Mens Clothing & Accessories
      • Manly Skills
      • Style & Grooming
      • Gentleman Drinks
      • Crate Club
        • Tom and Blake Sell TeaHow Sasquatch Tea Is Revitalizing a Stagnant Tea Market With Veterans and Outdoorsmen in Mind
        • redcat-blackwidow-articleheaderWar of Words: In the Ultra-Competitive Defense Tech Industry, Storytelling is a Secret Weapon
        • Photoroom_20250525_074933Juggernaut Tactical Frame Review: The Best Upgrade for Your 365
        • craft holstersCraft Holsters Makarov Tuckable IWB Holster Report
    • Close
  • News
  • Video Demo
  • Buying Guides
  • Shop
  • Advertise

Long Range Shooting: External Ballistics – Light Effects

In both Bullet Trajectory Part 1 and Part 2, I mentioned how light can act as a variable that affects point of impact. Light doesn’t directly affect bullet trajectory, but it changes the way you see the target through the telescopic sight. Essentially, you perceive the target in a different way, e.g., larger or smaller, and/or in a different place, depending on the sun’s position and light intensity. This leads to aiming errors. Every precision shooter faces these errors, but not all may have realized the underlying cause.

Although the cause of phenomenon is a subject of debate (just troll through a forum on the subject; you’ll find it), some attribute it to the light phenomena of refraction and diffraction. Unfortunately, there’s not a codified compensation method or a “rule of thumb” to deal with light. In many a text, you’ll find only a short paragraph regarding light effects on long range shooting, stating that the only way to manage it is to keep a logbook with annotation of the light conditions for every shot you take and use it to develop your own methods.

I’ve done that and compared my results with other shooters. What I’ve learned up to this point, confirmed by other shooters, is that light affects point of aim both on vertical and horizontal planes in this way:

On the vertical plane, light intensity can lead to aiming error. When shooting with low intensity of light, compared to the light intensity while zeroing the rifle, the shot goes high. On the contrary, when shooting with greater intensity of light, compared to the light during rifle zeroing, the shot flies low. I generally use an adjustment of 0.1MIL just at 100m, and 0.2 or 0.3 MIL over 600m. Translating those distances to yards and inches, that is about ½ inch at 100yds and about 7in at 600yds.

On the horizontal plane, changes in light direction can lead to aiming error. Basically, there is a sort of illusion effect associated with from which direction the light is travelling. If the light comes from the shooter’s right, the shot lands left, and vice versa. I’ve not been able to quantify the exact amount of horizontal error because I always shoot in windy conditions. It’s virtually impossible to tell wind defection errors from light angle errors. I usually adjust about one click, or 0.1MIL, to the opposite direction of the light.

Another optical phenomenon, related to light, that can lead to aiming errors is mirage. Mirage is the distortion of a distant image caused by the waves of hot air rising from the ground heated by the sun (hot air always moves upwards). This effect is also called heat haze or highway mirage. In fact, you can observe this phenomenon with the naked eye during a summer drive down the highway. In the distance, the road appears flooded, and the background beyond blurs. You may also notice that the road seems to veer uphill, even though you’re driving down a perfectly horizontal stretch. This is because the rising air waves tend to deflect the light, and thus the image of distant objects, in the same direction.

The same thing happens to the image of the target when you are shooting through a mirage. On hot days, you will have to deal with this effect. Not only will it blur the image you see through the scope, which forces you to lower the magnification, it alters the target image, moving it upward, throwing off your aim. Another issue with the mirage effect is that, airwaves don’t always rise straight upward. Sometimes, they’re also “bent” by the wind. In that case, the image of the target will not only migrate upward, but also in the direction the wind is blowing.

The amount of error due to mirage depends on how strong the mirage is, and on the wind speed. It is generally between ¼ inch and 1 ½in at 100m, and 2 ½in and 15in at 1000yds.

This effect of wind on mirage is also valuable tool to estimate the direction and the intensity of the wind. In a future post, I’ll talk about how we can use this to our advantage. But, for my next article in this series, I’ll focus on the aiming errors that arise from shooting with a canted rifle.

Share This

More From The Loadout Room

Comments

Primary Sidebar

Most Read

  • Mossberg 930: the affordable 12 gauge auto-loader
    Mossberg 930: the affordable 12 gauge auto-loader
  • The Biggest Little Roundgun: The 3-Inch Kimber K6s
    The Biggest Little Roundgun: The 3-Inch Kimber K6s
  • Springfield Range Officer 1911: Full Review
    Springfield Range Officer 1911: Full Review
  • Mossberg Shockwave Versus Remington Tac 14
    Mossberg Shockwave Versus Remington Tac 14
  • West Coast Armor IIIA Plates Review: Lightweight, American-Made Protection
    West Coast Armor IIIA Plates Review: Lightweight, American-Made Protection

Find Us on Facebook

Recent Comments

  • Winston Smiths on Mossberg 930: the affordable 12 gauge auto-loader
  • Jared Mize on The Fairbairn-Sykes Fighting Knife: A Commando Blade That Changed Special Forces Forever
  • GomeznSA on MAC-10: The Wild History of America’s Most Iconic (and Overrated) Submachine Gun

Latest From SOFREP

News

Evening Brief: Kenya Protests Turn Deadly, Former Russian Transportation Minister Found Dead, Secretary of State Rubio Heads to Malaysia

Op-Ed

America Must Not Repeat the Mistakes of Bush’s Afghan War

Expert Analysis

Situational Awareness: A Navy SEAL Explains

Military History

Medal of Honor Monday: Alwyn Cashe-A Hero Forged in Fire

Military Content Group

© Copyright 2025 Military Content Group · All Rights Reserved.

  • Privacy Policy
  • Terms of Use
  • Advertisers