Black Diamond Gemini Headlamp

Reviewer Biography

Name:  Danny Sedivec

Age:  22

Gender:  Male

Height:  6’ 0” (1.83 m)

Weight: 165 lbs (75 kg)

Email Address:  dsedivec@saonet.ucla.edu

City, State, Country:  San Diego, California, USA

Date: August 18, 2004

Backpacking Background:  I started backpacking about five years ago taking mainly three to seven day trips.  I hike mainly in the southwestern US with the majority of my experience in the California Sierras, as well as a few trips in Arizona and Nevada.  I am a very adventurous hiker, frequently pushing myself with long, challenging trips, both on and off trail.  Although I push myself during the day, I like to be comfortable in camp but I still try to keep my pack as light as possible.  The climate that I hike in is predominately dry, however, on summer trips in the Sierras I often encounter afternoon thunderstorms.

Product Information

Manufacturer:  Black Diamond

Year of Manufacture:  2002 

URL:  http://www.bdel.com

Listed Weight with Battery:  6.9 oz (195 g)

Weight as Delivered with Battery:  7.4 oz (210 g)

Batteries Required:  3 AA

Burn time for LED:  500 hrs

Illumination Distance with LED:  49 ft (15 m)

Burn time for Bright Xenon:  3.5 hrs

Illumination Distance with Bright Xenon:  328 ft (100 m)

Burn time for Super Bright Xenon:  2.5 hrs

Illumination Distance with Super Bright Xenon:  459 ft (140 m)

The Gemini came in a hard plastic packaging.  It included the headlamp, headstrap, battery pack, 1 LED bulb and 1 Bright Xenon bulb.  Also included was a Super Bright Xenon bulb which is conveniently located inside the battery pack.

            The Gemini runs on 3 AA batteries, which are housed in the battery case located on the unit’s head strap.  The head strap consists of not only a strap going around the circumference of the user’s head (circular strap), but also a strap that runs from the light housing directly over the top of their head (top strap) to the battery pack which sits on the back of their head.  All straps are made from a soft elastic material and are adjustable to achieve a custom fit.  The light housing is attached to a small plastic plate that is 2.5 in (64 mm) wide by 1.75 in (44 mm) high.  The circular strap runs through two slits on either side of the plate, while the top strap is attached via the same type of slit on the top of the plate.  All straps are removable from the plate.  There is also a 0.125 in (3 mm) circle of foam attached to the back of the plate to give the user’s head some padding. 

            The light housing is attached to the plastic plate by a flat head screw that threads into a fixed nut.  This allows the light itself to swivel up and down, and the screw can easily be adjusted with a coin or fingernail to tighten or loosen the light’s ability to swivel.  The light housing is made of durable plastic, and the lens can be unscrewed to access the bulbs for replacement.  The light itself is connected to the battery pack by a 13 in (330 mm) plastic coated wire.  The wire can be hooked into two plastic clips that are attached to the circular strap.  The clips can be adjusted along the circular strap and can also be completely removed.  The batteries are housed in a durable plastic case with a rubber backing that is removable to allow access to the batteries.  The circular strap passes through two slits on either side of the battery pack, while the top strap attaches to the top of the battery pack.  All straps are removable from the battery pack.  The light is given an IPX 7 waterproof rating which says that it will function for 30 min when submerged in 3.28 ft (1 m) of distilled water.  The light is operated by pushing a small button on the bottom of the light housing.  Push it once to get the LED mode.  Push it again and the light turns off.  One more push turns on the Xenon bulb, and a final push turns it off again thus completing the cycle.

            I have used the Gemini as my sole headlamp for the past two years.  It has seen many a trip, and has been exposed to temperatures ranging from 0 degrees F (-17.8 C) to 100 degrees F (37.8 C).  The Gemini is much more comfortable than headlamps that have only one strap that runs around the circumference of the head.  Because the Gemini also has a top strap, there is no need to have the circular strap as tight to keep the headlamp securely on the head.  I’ve found this to reduce the incidence of headlamp induced headaches, especially at altitude.  Black Diamond claims that the illumination distance of the Bright Xenon bulb is 328 ft (100 m).  I agree that it would be able to illuminate something 328 ft (100 m) away with fresh batteries, but I have found that the useful distance of the bulb for hiking is about 50 ft (15.2 m).  On one trip, I was caught descending a third class scree slope with my partner at night.  Unfortunately we only had my one headlamp between the two of us.  This forced me to walk ahead while he waited, and then turn around to shine for him so that he could make his way to me. In this instance, we found that 50 ft (15.2 m) was about the maximum distance that we could safely travel in this manner.  I have also found the burn time of the Bright xenon bulb to be about 5 hrs, which is 1.5 hrs more than suggested by the manufacturer. 

            The Bright xenon bulb illuminates the night well enough to be comfortable hiking at night, even on technical trails and off trail.  I have found the LED bulb to be very useful for everything around the camp including cooking, setting up tents, answering the call of nature, and reading.  I have also found that the LED bulb creates enough light to comfortably hike at night on non-technical trails.  My favorite aspect of the Gemini is the fact that when the batteries run down to the point where the xenon bulb is no longer useful, the LED will still give light for many more hours.  I’ve never actually used the batteries until the LED went dead, but I have used the LED for up to 10 hrs past the point where the Xenon bulb was no longer useful.  This gives me the security of knowing that I will at least have some form of useable light for my whole trip, even if the Xenon bulb loses power, allowing me to leave the spare batteries at home.  One downside to the Gemini is that the wire between the battery pack and the light itself is not long enough to allow me to comfortably remove the pack and put it in my pocket or down my shirt when it gets cold.  I have found that battery life diminishes by about 25% in temperatures below 32 degrees F (0 C).  Having an easy way to keep the battery pack warm would help in prolonging the life of the batteries even in cold climates.

             I have used the Gemini in damp, misty conditions and it has worked normally.  However I have never submerged it in water or used it while it was raining, so I can neither confirm nor deny the manufactures claim as to how waterproof it is.  Something that I have found bothersome about this headlamp is the push button and the way in which it is operated.  It’s not a big hassle, but it can get frustrating to have to push multiple times to get the desired setting.  For instance, say I’m cooking with the LED but decide to turn off my headlamp while waiting for the water to boil.  Once it is boiling, I want to return to LED to finish cooking.  To do this I will have to push the button 3 times to get the headlamp back to the LED bulb.  If the manufacturer used, for example, a sliding switch with the middle setting as off, and the setting on the right as LED and the setting on the left as Xenon, this would alleviate the problem.  Over the two years that I have owned the light, I would guess that I have probably used the Bright Xenon bulb for 50 hrs and the LED bulb for 200 hrs.  After all this time, neither bulb has needed replacement.

            In closing, I have found the Gemini headlamp to be a great piece of equipment.  The fact that it has both an LED and Xenon bulb allows me to save batteries around camp and comfortably hike at night even on difficult trails.  Although I feel that it could use some improvement in how it switches between LED and Xenon, I feel the Gemini is a fully functional, comfortable headlamp.