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Understanding Lumens, Beam Distance and IP Ratings

👨James Mitchell
December 28, 2025 8 min read

Torch specifications can seem like a foreign language: lumens, candela, beam distance, CRI, IP ratings, and more. Manufacturers throw these numbers around, but what do they actually mean for your real-world use? Understanding these specifications helps you cut through marketing hype and choose a torch that genuinely meets your needs.

This guide translates technical jargon into practical terms, helping you understand what matters and what's just impressive-sounding numbers.

Lumens: Total Light Output

Lumens measure the total amount of visible light a torch produces. More lumens means more light overall, but the number alone doesn't tell you how that light is distributed or how useful it will be for your purposes.

What Lumens Actually Mean

  • 1-20 lumens: Enough to read by, navigate a dark room, or find a keyhole
  • 20-100 lumens: Walking paths, general indoor tasks, close-range work
  • 100-300 lumens: Practical outdoor brightness for most tasks
  • 300-1000 lumens: Serious illumination for demanding situations
  • 1000+ lumens: High-performance territory, significant battery drain
đź’ˇImportant Context

Doubling lumens doesn't double perceived brightness. Our eyes perceive brightness logarithmically—you need roughly four times the lumens to see a doubling of brightness. A 1000-lumen torch won't look five times brighter than a 200-lumen torch.

Lumen Measurement Standards

The ANSI FL1 standard provides consistent testing methodology:

  • Measured at initial turn-on with fresh batteries
  • Accounts for warm-up time
  • Provides comparable figures across brands

Beware of brands not specifying ANSI FL1 testing—their numbers may be inflated or measured under ideal conditions that don't reflect real use.

Candela and Beam Intensity

While lumens measure total output, candela (cd) measures intensity in a specific direction—essentially, how concentrated the light is. A torch with high candela and modest lumens will throw a focused beam far; one with high lumens but lower candela provides broader, floodier illumination.

Understanding the Difference

  • High candela, lower lumens: Long-throw "search" lights, spotlights
  • Lower candela, higher lumens: Floody worklights, headlamps for close work
  • Balanced: General-purpose torches with useful throw and spill

Key Takeaway

  • Compare candela when you need to see distant objects
  • Compare lumens when you need broad illumination
  • Most practical torches balance both

Beam Distance

Beam distance, measured in metres, indicates how far the torch's beam travels before dropping to 0.25 lux—roughly equivalent to full moon illumination. This is the distance at which you can perceive objects but not necessarily see them clearly.

What the Numbers Mean

  • Under 50m: Close-range flood lights, reading lights
  • 50-150m: General-purpose torches, most headlamps
  • 150-300m: Capable outdoor torches, tactical lights
  • 300-500m: Dedicated throwers, search lights
  • 500m+: Specialised long-throw lights

Practical Considerations

Rated beam distance is measured under ideal conditions. Real-world factors reduce effective range:

  • Atmospheric conditions (fog, dust, humidity)
  • Ambient light pollution
  • Target reflectivity (dark objects need more light)
  • Your specific task requirements
đź’ˇPractical Rule

For comfortable vision of detail, divide the rated beam distance by 3-4. A torch rated at 300m will let you clearly see details at 75-100m under typical conditions.

IP Ratings: Water and Dust Resistance

IP (Ingress Protection) ratings indicate how well a torch is sealed against dust and water. The rating consists of two numbers: the first for solids (dust), the second for liquids (water).

Dust Protection (First Number)

  • 0: No protection
  • 1-4: Protection against objects of decreasing size
  • 5: Dust protected (limited ingress permitted)
  • 6: Dust tight (no ingress)
  • X: Not tested (e.g., IPX7 means water-tested only)

Water Protection (Second Number)

  • 0: No protection
  • 1-3: Protection against dripping water and spray
  • 4: Splash-resistant from any direction
  • 5: Protected against water jets
  • 6: Protected against powerful water jets
  • 7: Temporary immersion (up to 1m for 30 minutes)
  • 8: Continuous submersion beyond 1m (depth specified by manufacturer)

Recommended Ratings for Australian Use

  • IPX4: Minimum for any outdoor torch—handles rain
  • IPX6: Good for serious outdoor use, camping
  • IPX7: Recommended standard—survives drops in water
  • IPX8: Required for diving and extreme water exposure
⚠️Important Note

IP ratings are tested with fresh O-rings at room temperature. Worn O-rings, temperature changes, or impact damage can compromise water resistance. Maintain your torch's seals for continued protection.

Other Specifications Worth Understanding

Runtime

Runtime indicates how long the torch operates before output drops to 10% of initial brightness. Understanding the caveats is crucial:

  • High modes often step down due to heat management
  • Runtime on turbo mode may be minutes, not hours
  • Regulated drivers maintain brightness then drop suddenly
  • Unregulated drivers dim gradually throughout runtime

CRI: Colour Rendering Index

CRI measures how accurately colours appear under the light compared to natural sunlight (CRI 100). Higher CRI means more natural-looking colours.

  • Below 70: Poor colour rendering, "cool" blue-white light
  • 70-80: Acceptable for most uses
  • 80-90: Good colour rendering
  • 90+: Excellent, near-natural colours

High CRI matters for tasks requiring colour accuracy (photography, medical assessment, evaluating materials) but is less critical for basic navigation.

Colour Temperature

Measured in Kelvin (K), colour temperature describes the "warmth" of light:

  • 2700-3000K: Warm (yellowish), easier on eyes, less throw
  • 4000-5000K: Neutral, balanced appearance
  • 5000-6500K: Cool (bluish-white), appears brighter, better throw

Reading Specifications Critically

Marketing vs Reality

Be sceptical of:

  • Extremely high lumen claims from unknown brands
  • Specifications without ANSI FL1 certification
  • Runtime claims at maximum brightness (check the fine print)
  • "Military-grade" without specific certifications

What to Prioritise

Rather than chasing the highest numbers, consider:

  • Does it have the output you actually need?
  • Will the beam pattern suit your primary use?
  • Is the runtime adequate on useful brightness levels?
  • Is water resistance appropriate for your conditions?

Conclusion

Understanding torch specifications empowers you to make informed decisions rather than being swayed by impressive-sounding numbers. Lumens indicate total output, candela indicates intensity, beam distance indicates reach, and IP ratings indicate durability. But the numbers only matter in context—what works perfectly for one person's needs may be entirely wrong for another's.

Use specifications as a starting point, then consider real-world reviews and, if possible, hands-on testing. The best torch isn't necessarily the one with the highest specs—it's the one that best matches how you'll actually use it.

For help selecting a torch based on your needs, try our interactive torch finder or explore our product comparisons.

👨

James Mitchell

Founder & Lead Reviewer

With an electrical engineering background, James brings technical rigour to torch analysis. He specialises in demystifying specifications and explaining what numbers actually mean for everyday users.