Fenix vs Black Diamond headlamps

These two brands rarely appear on the same shortlist, which is odd, because they are aimed at the same buyer from opposite directions. Fenix publishes battery capacity, weight, ingress ratings and beam distance. Black Diamond publishes output. Everything below follows from that.

It would be easy to stop there and declare it, and that would be lazy. Black Diamond fields two features Fenix does not answer at all, and for a buyer who needs them the spec sheet is beside the point.

How we picked

Three matched pairs by role and price, plus Fenix's endurance outlier, which Black Diamond fields no equivalent to in our set. Every figure is the maker's own, linked with the date we read it. Black Diamond's own site would not serve us a spec page from this build, so its figures come from the brand's own retail listing and are labeled as such. We have handled none of these lamps — our methodology sets out what we do instead.

What each brand tells you

Fenix publishes a capacity figure for all four lamps and an ingress rating for three. Black Diamond publishes neither, for any lamp. That is not a close call, and it is the reason this site ranks Fenix second and Black Diamond eighth in the headlamp brand ranking.

What Black Diamond has that Fenix does not

• Red, green and blue night vision on the Storm 500-R. Green preserves dark adaptation the way red does while rendering contours and blood trails differently, which is why hunters ask for it specifically. No Fenix lamp we cover offers green at all.
• Brightness memory on the Spot 400-R. The lamp returns to the level you switched off at, so the dim setting is one press away rather than a cycle through full white. In a shared tent that is the difference between a lamp people tolerate and one they resent.
• Dual-fuel on the Cosmo 350. Three AAA cells or Black Diamond's rechargeable pack in the same body, at the cheapest price here.

Fenix answers with standard removable cells rather than proprietary packs: the HM65R-T takes an 18650 or two CR123A primaries, the HM50R a 16340, the HL18R-T three AAA. You can carry a charged spare and swap it in the dark, and CR123A cells store for roughly a decade. Whether that beats a green LED depends entirely on what you do at night.

The three matched pairs

Flagship: Fenix HM65R-T vs Black Diamond Storm 500-R

The Fenix publishes 1,600 lumens, 170 m, 12.2 Wh, 140 g and IP68 — the only immersion rating in this comparison. The Storm publishes 500 lumens and a three-color night-vision set. Three times the output and a verified waterproofing claim against a feature no Fenix matches.

Skip the HM65R-T if you sit still at night and want your dark adaptation protected — the Storm's green mode is a real advantage the figures do not capture. Skip the Storm if the lamp will be submerged, or if you want to know what it does before you buy. There is a full review of the HM65R-T if it is the one you are deciding on.

Mid-range: Fenix HL18R-T vs Black Diamond Spot 400-R

800 lumens, 6.8 Wh, 103 g and IP66 against 400 lumens with brightness memory. Twice the output and a published weather rating against better ergonomics in the dark. The HL18R-T also takes three AAA cells when its pack is flat, which the Spot's integrated battery cannot match.

Skip the HL18R-T if you want a published beam distance — Fenix does not state one for it, which on an 800-lumen lamp is the figure you would most want. Skip the Spot if a runtime you can plan around matters.

Budget: Fenix HM50R vs Black Diamond Cosmo 350

The Fenix publishes 700 lumens at 78 g, the lightest lamp in this comparison, and detaches to work as a pocket light. The Cosmo publishes 350 lumens, runs on AAA cells or a rechargeable pack, and costs less. Worth knowing on the Fenix: it states that a CR123A primary works but caps output at 130 lumens, which is exactly the caveat most makers leave out.

Skip the HM50R if you need a fallback that keeps full output — 130 lumens on a primary is a big step down. Skip the Cosmo if you want any figure beyond lumens. See headlamps under $50 for the wider budget field.

The lamp with no Black Diamond answer

The Fenix HM75R carries an 18650 and a 21700 at once for a computed 30.2 watt-hours, the largest energy store on this site, and publishes 223 m, 234 hours on floodlight and 365 on red. It also works as a power bank. At 321 g complete it is a work lamp rather than a hiking one, and Fenix states it is completely waterproof without giving an IP code — a claim we can repeat but not place on a scale. There is a full review.

The cell formats, and what each brand commits you to

Underneath the disclosure gap there is a structural difference that outlasts any single model: Fenix builds around standard, removable cells with a primary-battery fallback, and Black Diamond builds around integrated packs with an AAA option at the bottom of the range.

Read the fallback column, because it is the one that decides a trip. Three of the four Fenix lamps take a battery you can buy in a gas station, and CR123A primaries store for roughly a decade. Two of the three Black Diamond lamps have a sealed cell and no alternative: flat is flat until you find a socket.

The Cosmo 350 is the exception and the interesting one. It runs on three AAA cells out of the box and accepts Black Diamond's own rechargeable pack, which is the same hybrid arrangement Petzl uses — and the arrangement we would recommend to most buyers in most categories.

There is a real argument on the other side, and it is not a weak one. A sealed lamp has no battery door to break, no contacts to corrode and no way for a user to fit the wrong cell. Black Diamond is not being careless here; it is optimizing for a hiker who charges at home and a product that survives being packed wet. It is simply the opposite bet from Fenix's.

The cost of the Fenix approach is knowledge. Standard cells mean you need to know that a 16340 is not a CR123A even though they fit the same tube, that protected and unprotected cells differ, and that the HM50R's output drops to 130 lumens on a primary. Black Diamond asks none of that of you. See 18650 versus 21700 for the formats.

What neither brand publishes

It is worth being even-handed about the gaps, because Fenix wins the disclosure comparison without winning it outright.

• Neither publishes a peak candela figure for any lamp in this comparison. Fenix publishes beam distance, which converts, so the gap is recoverable on its side and not on Black Diamond's.
• Neither publishes a per-mode runtime table. Fenix publishes a single maximum — 300 hours on the HM65R-T, 160 on the HL18R-T, 42 on the HM50R — which describes the lowest mode and tells you nothing about the mode on the box. Petzl publishes the full table and both brands here look worse for it.
• Neither publishes a beam profile or tint figure. Whether a lamp floods or spots, and whether its white is warm or blue, are things you find out by owning it.
• Neither publishes a charge cycle count, which is the specification that decides how long an integrated-cell lamp actually lasts — and it matters far more to Black Diamond's range than to Fenix's.

Which brand should you buy

• You want to know what you are getting — Fenix, on every lamp.
• You need green or blue night vision — Black Diamond Storm 500-R. Nothing from Fenix answers it. See hunting headlamps.
• The lamp gets submerged — Fenix HM65R-T, the only published IP68 here.
• You want to carry a spare cell — Fenix. Standard 18650, 16340, AAA and CR123A fallbacks.
• You want the cheapest lamp that still has a red mode — Black Diamond Cosmo 350.
• You need all-shift runtime — Fenix HM75R at 30.2 Wh. See headlamps for work.

What we would not tell you

We would not tell you Black Diamond makes worse lamps. It has a deserved reputation among climbers and its lamps are in more gear closets than almost anything else. What we can say is that if a Fenix lamp underperforms its published figures you have a documented claim to hold it to, and with Black Diamond you have a lumen number.

We would also not fill in the four empty columns on the Black Diamond rows. Estimating a runtime or assuming an IP rating would make the table tidier and would be exactly the thing this site exists not to do.