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  • Post last modified:October 29, 2023

Is your red dot sight not bright enough?

This guide shows you how to manage red dot brightness over the wide variety of lighting conditions from bright daylight to night.

Pro Tip: Pick the setting that works satisfactorily across all conditions


When to dial it up?

  • If the dot is obviously too dim to see, please up the brightness a little bit
  • Bright sunny day
  • Shooting in direct sunlight (Sunrise & sunset)
  • Bright indoor lighting
fnx45 with holosun 507c pov

Most red dot sights on the market today offer 1 - 10+ brightness settings that work under bright desert sunlight and indoor lighting.

When to dial it down?

  • Red dot too bright for night use
  • Shooting mid - long range in low light or pitch black darkness 
  • Reticle starburst & bloom block the targets
  • Too much dot starburst and glare cover the FOV
  • Large MOA dot sights with too much brightness

Be sure to dial the red dot brightness down for indoor use on your range / home defense firearm after an outdoor range trip.

Night (Minimum Ambient Light)

red dot brightness dialed up too high

If the brightness is set too high - The red dot emitter starburst covers the whole field of view, and the emitter diode is also reflected onto the glass.


Not completely dark yet, but the same reticle brightness set for the midday noon time is not as user friendly right before sunset.

Features Holosun HM3X and Leupold LCO (1 MOA)

red dot brightness too high

The reticle brightness has been dialed up high for the day, and now it obscures the target when the sun goes down.

red dot reticle brightness dusk

The reticle brightness has been dialed down, and the shooter can ID the target better.

holosun hm3x with leupold lco pov

For a clean sight picture under low light (based on preference), try a single dot to keep the sight picture less cluttered. 1 MOA or 2 MOA is recommended

Low light with use of weapon light

Must ID targets and what's behind before sending rounds down range

The weapon light's hot spot will wash out the dot at close range if it's too bright.

The Cloud Defensive REIN can 100% lit up that area ~520 ft away, but...

  • Reticle may obscure the target if it's too bright
  • Barely able to see clearly
  • Even worse experience for shooters with poor eye sight 
holosun 510c reticles

Also recommend using a 1 or 2 MOA dot in this case at night, so the dot doesn't cover up the entire target (depend on target sizes & distance)

In the popular "Aimpoint Micro VS EOTech" or "When to using a ring reticle over a single dot" debates, this will be a valid reason to: 

  • Pick the Aimpoint Micro instead of EOTech for some users
  • Use a smaller dot in similar situations
  • Cycle back to the single dot when using the Holosun 510C or 507C at night
eotech exps3 in the dark

Pro Tip: Set the brightness to normal daytime setting for low light use

Night Vision Mode

Night Vision Aiming Device

Night vision shooting with nods is a completely different ball game.

The best resources for night vision shooting currently we enjoy learning from are TREX ARMS and TNVC.

Be sure to check out their night vision content regarding this topic.

Common FAQ

When To Use Auto Brightness Adjustment Feature?

Trijicon SRO, Holosun's solar fail-safe feature, Sig optics, and many others have started offering the auto-brightness features on their optics so the shooter can transition under the sun to indoors to match ambient lighting conditions without messing with the control.

When To Use

  • For outdoor class training where the sky condition changes throughout the day
  • For conceal carry users in a wide range of lighting conditions (indoor, outdoor, power outrage...etc)

NOT The Best Time To Use, But Still Works

  • Optic can sense light source from the top and sides, but not so perfect when the weapon light beam is pointed forward

Please check out the Holosun optics or our red dot sight guide for more information.

Does Red Dot Brightness Change Point Of Impact?

For a zeroed red dot sight, cranking up the red dot brightness won't change the point of impact, however the emitter glare taking up the whole screen of the optic will obscure the shooter's ability to see the target clearly, which can lead to inaccurate shots.

For more information, please check out our red dot sight beginner guide. The guide goes A - Z on everything you need to know about using a reflex sight on your firearms.