Black Diamond Cosmo Review
A good light, but caught in a no-mans land between better lights and cheaper lights
Photo: Abriah Wofford
Price: $30 List | $21.00 at Backcountry
Compare prices at 3 resellers Pros: Lightweight, small size, excellent flood lighting
Cons: Below average spot beam, disappointing low-mode battery life
Manufacturer: Black Diamond
Compare prices at 3 resellers Pros: Lightweight, small size, excellent flood lighting
Cons: Below average spot beam, disappointing low-mode battery life
Manufacturer: Black Diamond
By Jediah Porter and RJ Spurrier ⋅ May 28, 2018
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Our Verdict
While this is a good headlamp, we implore you to spend another $10 and get something like the Black Diamond Spot which has much better beam brightness and quality combined with a very respectable battery life. The Cosmo is a middle of the road kind of light. It offers average performance and average battery life at an average price. If you are on a budget, look to the Petzl Tikkina which scored slightly better for a fraction of the price.
Compare to Similar Products
 This Product
Black Diamond Cosmo | |||||
|---|---|---|---|---|---|
| Awards |  |  | | ||
| Price | $21.00 at Backcountry Compare at 3 sellers | $89.00 at Amazon | $50 List | $28.00 at Backcountry | $28.74 at Amazon |
Overall Score  |
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| Star Rating | |||||
| Pros | Lightweight, small size, excellent flood lighting | Bright wide beam, good battery life, durable design, rechargeable | Excellent trail finding and close proximity beam, waterproof, above average battery life | Excellent spot light capability, wide evenly lit flood beam, above average in most ways | Excellent brightness and beam control, often available online at discount |
| Cons | Below average spot beam, disappointing low-mode battery life | Expensive, 18650 Li-ion battery is not included, heavier than average | More expensive, heavier than average, claimed battery life is very misleading | Below average battery life, claimed battery life is wildly misleading, single button hard to use, lame waterproofing | Average battery life, heavier and bulkier than most |
| Bottom Line | A solid product overall, but priced precariously with cheaper lights offering more for less | A stunningly bright light that offers impressive battery life. If you can afford it, it won't disappoint | You can't go wrong with the Storm, high performance, quality optics, and durable design | Offering excellent optics, a bright wide beam, and strong performance for the price, the Spot is one of our favorites | We used to love the Coast, but competing lights have stepped up, while the HL7 is unchanged |
| Rating Categories | Black Diamond Cosmo | Zebralight H600w Mk IV | Black Diamond Storm | Black Diamond Spot | Coast HL7 |
| Trail Finding (35%) | |||||
| Close Proximity (20%) | |||||
| Battery Life (15%) | |||||
| Weight (15%) | |||||
| Ease Of Use (15%) | |||||
| Specs | Black Diamond Cosmo | Zebralight H600w... | Black Diamond Storm | Black Diamond Spot | Coast HL7 |
| Measured Beam Distance | 66 m | 121 m | 91 m | 94 m | 112 m |
| Claimed Distance | 65 m | Not specified | 85 m | 80 m | 119 m |
| Measured High Mode Run-time (ANSI) | 3.9 hrs | 3.1 hrs | 5 hrs | 2.9 hrs | 3.1 hrs |
| Claimed High Mode Run-time | 45 hrs | 2.9 hrs | 40 hrs | 30 hrs | 1.5 hrs |
| Measured Low Mode Run-time | 39 hrs | 232 hrs | 42 hrs | 9.7 hrs | 25 hrs |
| Claimed Low Mode Run-time | 180 hrs | 203 hrs | 120 hrs | 175 hrs | 70 hrs |
| Measured Weight | 3 oz, 86 g | 4.5 oz, 127 g | 4 oz, 112 g | 3.1 oz, 89 g | 4.5 oz, 127 g |
| Battery Type | 3 AAA | 18650 rechargeable Li-ion | 4 AAA | 3 AAA | 3 AAA |
| Water Resistance | IPX8 waterproof beyond one meter | IPX8 waterproof to 2 meters, 30 minutes | IP67 waterproof to one meter and dustproof | Splash proof (dubious IPX8 claim) | water resistant |
| Manuf Claimed Lumens | 200 lumens | 1400 lumens | 350 lumens | 300 lumens | 285 lumens |
| Beam Type | flood/spot, dimmable | flood | flood/spot | flood/spot | flood/spot |
| Red Light | yes | no | yes, red/green/blue night-vision modes | yes | no |
| On Switch Lock | yes | yes (tailcap lockout) | yes | yes | no |
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Our Analysis and Test Results
The Cosmo is a solid headlamp with good performance overall, and excellent flood lighting for close proximity use. At $30 list, it falls into a tough price range where a little more money gets you a much higher performance headlamp, like the Spot, and products like the Tikkina offer better overall performance for 33% lower price.
Performance Comparison
Photo: Abriah Wofford
Trail Finding
A score of 4 for trail finding is disappointing for a $30 headlamp, and most similarly priced competitors offer significantly better performance.
Beam Distance Photos
Black Diamond Cosmo
Black Diamond Spot
In comparing the Cosmo (above left) and Black Diamond Spot (right), two products from the same manufacturer and priced just $10 apart, it is remarkable that they can vary so much. The Spot casts a much superior distance beam.
Close Proximity
The strongest performance from the Cosmo is when used around camp, or in the tent, for close proximity work. The flood beam is one of the very best of all headlamps we tested, wide, evenly lit, and dimmable from nice soft lighting for use in the tent, and brighter for use in the camp kitchen. It is worth noting that the Black Diamond Astro offers a flood beam that is nearly as good, at a price 33% lower.
Photo: Abriah Wofford
Battery Life
Battery life is where the Cosmo edges slightly ahead of the Spot.
Photo: Abriah Wofford
Weight
At 3.0 ounces or 86 grams, this is a compact but not ultralight headlamp. It is about the same weight as the Spot. For comparison, the featherweight champion Petzl e+LITE is less than a third the weight at 27 g.
Conclusion
This is a solid light but tough to justify buying. At $30 list it is wedged between competitors that either score much better for another $6-10 or offer the same or better performance for lower cost. The BD Spot, for example, performs significantly better for only $10 more. It has a nearly identical form factor and mass with a much better beam. On the low-end, the Petzl Tikkina offers better all-around performance at 33% lower cost.
— Jediah Porter and RJ Spurrier