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Reviews > Lighting > Flashlights - LED > Princeton Tec Genesis Light > Test Report by Gail Staisil

Princeton Tec Genesis Light
Test Series by: Gail Staisil, Marquette, Michigan
Page Contents:

Initial Report:
Princeton Tec Genesis Light
October 30, 2008

Tester Information

Gail Staisil
Age: 56
Gender: Female
Height: 5' 9" (1.75 m)
Weight: 140 lb (64 kg)
Location: Marquette, Michigan USA
Email: woodswoman 2001 AT yahoo DOT com

For the last 18 years, backpacking has become a passion. I am a four-season backpacker and an off-trail navigator. Although I do take yearly trips to the American West or Southwest, the majority of my trips are in Michigan and Canada. My pack weight varies considerably but my base weight is below 18 lb (8 kg). I am primarily a tarp camper who averages more than 50 nights a year backpacking in a huge variety of weather conditions including relentless rain, wet snow and sub-zero temps.

Product Information

Princeton Tec
Model Genesis
Black  (Also available in Green/Silver)
Tested Dimensions
5.25 in/13.34 cm (length), 1.125 in/2.86 cm (diameter)
Light Output
47 Lumens
3W Maxbright LED
Manufacturer  Weight 5.5 oz /156 g (with batteries)
Tested Weight 
5.1 oz /145 g (with batteries)
2 - CR 123 Lithium Batteries (included)
Model Year 2008 


Initial Impressions and Product Description

Princeton Tec Genesis Light
The Princeton Tec Genesis arrived in perfect condition. The handheld light had a belt clip attached to the unit upon arrival. It appears much like it did on the website but since there wasn't any measurements on the website I didn't really have a grasp of how big it actually is. It's much larger than I expected measuring about 5.25 in/13.34 cm in length and approximately 1.125 in (2.86 cm) in diameter. Of course this is much smaller than a typical flashlight. The center section of the Genesis features a rubberized area to allow me to easily grasp the light.

Accessories and Details

The Genesis Light came with several accessories. They not only included the necessary 2 batteries (Lithium CR-123) but also a holster (0.6 oz/17 g) and three interchangeable tail ring accessories. The latter included a roll control ring (0.1 oz/2.83 g), lanyard ring (0.1 oz/2.83 g) and a belt clip (0.2 oz/5.67 g).

The roll control ring does exactly as it is named, it prevents the light from rolling away. It has a
slight octagon shape to the external ring. Any one of the tail ring accessories can be used at a time or none of them. In order to use any of the choices, the bottom end piece of the light must be unscrewed and then the tail ring of choice can be slipped on. Each of the choices has a bit of a notch that fits snugly against a cutout on the surface of the light.

A carrying holster also was included with the Genesis. The long rectangular holster appears to be made out of heavy-duty webbing with stretch fabric sides. There is a belt loop (over 2 in/ 5 cm long) on the back side of the holster case. The overall length of the holster is over 6 in (15 cm) and is about 1.5 in wide (4 cm). It weighs 0.6 oz (17 g).

The Genesis Light also arrived with three extra lens filters (total weight of 0.1 oz/2.83 g). The green and red lens filters are for Princeton Tec Genesis Light with accessoriesnight vision and the blue lens is reportedly for spotting blood. That sounds a bit scary but the intended use is for search and rescue. The lens can be changed by unscrewing the top end of the light and replacing the filter. There is also a waterproof seal in that opening.

An instruction sheet  (printed in English, French and German) with operating and maintenance information was also included. There are a few diagrams on the instruction sheet for different procedures such as installing the battery, changing the accessories, operation procedure and an LED diagram. Although I didn't need most of it for comprehension, it is a handy visual aid for those inclined. However I was interested in the Regulated LED diagram as it helped me understand what that name meant (more later).

The website did have a fine comparison chart that showed the differences in ten areas between the 25 different hand held lights that they produce. I found this handy to see where the Genesis fell in the realm of all the lights. It compared such things as weight, light output, battery type and usage.

I found the information to be highly useful but I would suggest the manufacturer add in the size dimensions of the light. This can be very helpful for a buyer as they might want to pack it or carry it in a certain spot where there might be a size limitation. I did notice that the manufacturer had a special page for their new Amp series of lights and they had size comparisons of the models for them.

The Genesis is rated to be used for outdoor and industrial purposes. It has a Level 2 Rating for waterproofness to 1 m (3.28 ft) for up to 30 minutes. While I don't plan to purposely drop it in water I'm glad that I don't have to worry about getting it wet.

Operating the Genesis Light

The first thing I did was to insert the two batteries correctly into the light. The bottom end of the light twists off counterclockwise so that I could place the batteries. It is very noticeable that there's a waterproof rubber seal located on the twist-off area to keep the batteries safe. There is a rubber-type button switch located on the end of the light. The button works by simply depressing it with my thumb. It can be used by depressing it momentarily for intermittent use but it can also be used continuously be depressing the button until a click is heard. I only had to depress the button again to turn it off. The button seems easy to use in the warmth of my house so I will investigate further how it works in the cold outdoors.

What is a Regulated LED?

Although I was familiar with the term LED, I wasn't sure what a "Regulated LED" was. According to the manufacturer the Genesis "uses a sophisticated current-regulating circuit that maintains initial brightness as long as the batteries have sufficient voltage". Essentially this just means that the light does not dim over a given time period. Since I have trouble with the latter with my old headlamp this should be interesting to observe. When the light is in the continuous "on" position the regulated burn time is reported to be 1.70 hours with a total burn time of 20 hours for the life of the batteries. 


The optic system included in the Genesis has been developed by the manufacturer. Reportedly the lens technology gathers all of the available photons from the LED and projects them forward to create a beam that goes a long distance. According to the manufacturer, the Genesis can provide up to 47 Lumens of light output.

A Lumen is a unit derived by the International System of Units (SI) for measuring light output. Although the science behind this can get rather complex, in simple terms it just means that a high Lumen Rating is related to the overall efficiency of a light source for illumination. In this case some types of LED's produce more light than others. The 3 W Maxbright LED is a high quality light that is both an extremely bright and powerful white light. Since it was late evening when I tried the Genesis Light I had fun seeing how far the light penetrated. I could see very clearly from one end of my house to the other. It certainly will be fun to use in the outdoors.

Heatsink Technology

A special technology prevents the light from overheating. It uses ultralight heatsinks to protect the LED's from getting too hot. It allows the light to burn at extreme brightness for long periods of time.


The Genesis has two watertight seals at each end of the light (one for the battery area and the other for the lamp area). These seals are supposed to be kept free from dirt and harsh chemicals. Seals should be inspected periodically and a silicone lubricant can be used if the seals appear dry. The manufacturer also recommends to remove batteries during a long period of storage.

So far, the Princeton Tec Genesis seems to be a very powerful light. I'm looking forward to taking it on my late fall and winter backpacking trips. Due to the season there is not an abundance of daylight so the Genesis will get used a lot during the morning and evening hours at camp. It will replace my headlamp for the duration of the test and I look forward to evaluating its usefulness in that capacity.

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Field Report:
Princeton Tec Genesis Light
January 17, 2009

Locations and Conditions

During the field test period, I have used the Princeton Tec Genesis Light during two extended trips. The
backpacking trips totaled seven days of activity. In addition, the light has been used around my home at various times. Locations ranged from and included conifer and deciduous forest communities with many rock outcroppings to lakeshores and hiking trails. Elevation ranged from 600 ft (183 m) to approximately 1200 ft (366 m).

Early November Backpacking Trip:

Location: Hiawatha National Forest - Upper Peninsula of Michigan
Type of Trip: Bushwhack, thick forest and swamps
Distance: 13 mi (21 km)
Length of Trip:
4 days
Backpack Weight: 30 lb (13.6 kg)
Sky and Air Conditions: Cloudy, rain, light snow
0.92 in (2.34 cm)
Temperature Range: 27 F (-3 C) to 55 F (13 C)

Early December Backpacking/Sledge Trip:

Location: Pigeon River Country State Forest - Lower Peninsula of Michigan
Type of Trip: Bushwhack, old two-tracks
Distance: Approx 10 mi (16 km)
Length of Trip:
3 days
Sledge Weight: 45 lb (20 kg)
Sky and Air Conditions: Cloudy, light snow and partly sunny 
0.43 in (1.09 cm)
Temperature Range: 10 F (-13 C) to 22 F (-6 C)

Performance in the Field

Handy from the start

I had literally just finished uploading my Initial Report for the Princeton Tec Genesis Light to the BGT site when I heard a big boom and the lights went out. The winds had been wild all evening leading to the crash. I think a transformer blew. Anyway, the Princeton Tec Genesis Light was sitting about 3 ft (1 m) away from me at the time. What luck! Since I knew where it was I quickly grabbed it and depressed the switch button to turn it on. I then scurried around the house finding a lantern and candles for use in other areas of the house.

I quickly found the Genesis to have an amazing amount of light. Since I was leaving in the morning for a trip and hadn't packed yet, I used the light to gather all my belongings, do last minute chores around the house that didn't require electricity and even read the newspaper. I actually put on a light fleece hat and inserted the light between my hair and the hat so that I wouldn't have to hold the light. Yeah, I know I could of got a headlamp out of my gear stash but since I was testing a light I figured I should use it for every opportunity, trail or not. The power outage only lasted a few hours as the electric company was right on top of it.

Backpacking Usage

For my backpacking trips I carefully considered what attachment (s) I was going to use with the light. The choices were the lanyard ring, the clip, the holster with belt loop or the anti-roll ring. Since I normally use a headlamp I decided that the lanyard option might give me the best flexibility. I took a length of light weight cordage and tied it through the lanyard ring to make a loop big enough to go over my head. That way I could let the light dangle from around my neck or slip the cordage through a loop on the ceiling of the tent.

I also brought a narrow non-slip headband that I could not only use for my hair but I could also lodge the handheld light underneath it between my hair and headband so that I could use the light for reading and other tasks that otherwise occupied my hands. Although this worked well enough the light is a bit heavy and would slightly move once in awhile so that I would have to readjust it.

During the first trip the light was used consistently for a lighting source for three nights of backpacking during foul, cold, rainy and snowy weather. Darkness fell around 5:30 PM and the light was used until 7:30 or 8 PM each night. It especially came handy for finding my bear hang in impossibly thick forest as I was camped off trail. I also used it for jaunts in the night to find my way around the tree branches that made every attempt to poke me in the eyes. During this trip I used the light approximately 6.5 hrs.

Cold Wet Weather

During my second backpacking/sledge trip the landscape was completely covered by deep snow. Even though it got dark early the half moon provided an additional source of lighting. With that said, I still used the light extensively for cooking chores at camp and to read my book as I retired for the night. I hung the light from one of the loops on the tent I was testing but the light was too focused in one area to do detail work so I decided to slide the light between my two hats that I was wearing. This worked OK for the chores but for reading I slid the light under an elasticized headband to concentrate the light. Each night the light was used from about 5:30 PM to about 8 or 8:30 PM. Estimated burn time was approximately 6 hrs for the two nights.

The light still seams to beam as bright as when I got it however I have no way of measuring that for certain. I just know that when I read my book that I can actually see! The light has been exposed cold temperatures with the low for the trip usage being 10 F (-13 C). The light on/off switch seems easy enough to use at the low temperatures as well as the high.

Besides usage during the backpacking trips and use during the power outage, I have also found the light handy for other tasks at home. I have checked my fuse box for amp numbers, looked underneath car seats for lost items and checked out the dark attic in my parents home. I have continued to use the light with the lanyard for security purposes. When the light is not in use I do keep the light in the holster that came with it but more for protective purposes. At this time of year wearing the holster on a belt is nonproductive as I usually have on several layers of clothes and it would be hard to get to at camp.

I have not used the colored lens in the field but have checked them out outside of my home. However, I have carried the extra lenses with me stored in the small outside pocket of my digital camera case where I store the extra card and battery for my camera. Because the light doesn't come with a storage place for these tiny lenses this works well for me as I know exactly where they are. They would be too easy to lose otherwise. I hope to play with them more in the long term period.

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Long Term Report:
Princeton Tec Genesis Light
February 24, 2009

Locations and Conditions

During the long term period, I have used the Princeton Tec Genesis Light during two extended trips of four days each. The first trip involved pulling a sledge every day to a different backcountry site and the second trip involved pulling a sledge of gear to and from a backcountry rustic cabin (that served as basecamp).
Locations ranged from and included conifer and deciduous forest communities with many rock outcroppings to lakeshores and hiking trails. Elevation ranged from 600 ft (183 m) to approximately 1200 ft (366 m).

Early February Backpacking/Sledge Trip:

Location: Pictured Rocks National Lakeshore - Upper Peninsula of Michigan
Type of Trip: Ungroomed trail and bushwhack
Distance: 18 mi (29 km)
Length of Trip:
4 days
Sledge Weight: 45 lb (20 kg)
Sky and Air Conditions: Cloudy, light snow and partly sunny 
0.12 in (0.30 cm)
Temperature Range: 23 F (-5 C) to 41 F (5 C)

Mid-February Sledge/Rustic Cabin Trip:

Location: Hiawatha National Forest - Upper Peninsula of Michigan
Type of Trip: Deep snow-covered old two-tracks and hiking trails
Distance: 11 mi (18 km)
Length of Trip:
4 days
Sledge Weight: 45 lb (20 kg)
Sky and Air Conditions: Cloudy, heavy snow flurries and partly sunny 
0.34 in (0.86 cm)
Temperature Range: -1 (-18 C) to 20 F (-7 C)

Performance in the Field

Winter Sledge Trip

During the first evening of my early February trip I pulled the Genesis out of the holster inside a stuff sack where I had stored it. I was ready to start early evening tasks. The first task was setting up my stove to melt snow. As it was early evening there was still some fading natural light so with the addition of the Genesis I was able to light my stove and search for the food that I wanted to eat that evening. Soon darkness fell and I noticed that I couldn't see very far beyond the stove that was located about 3 ft (1 m) outside of my tent. Hmmmm...I opened my book that I had nearby and noticed that the words weren't very illuminated either. I guess it was time for a battery change.

I lit a candle so that I could see what I was doing and removed the end of the light where the batteries are inserted. As I took the light apart a ring fell out broken in two pieces. It was the rubber seal that was supposed to keep that department dry. Since I had only taken the light apart a few times to try the different accessories I was shocked that it was already broken.

I changed the batteries and put the broken rubber seal aside (all parts are guaranteed for life so I will contact the manufacturer for a replacement seal). Even though the seaI broke the battery compartment will most likely not leak unless dropped into water for a length of time. The absence of the ring doesn't seem to hurt the overall performance of the light.

I couldn't believe the difference in the light output after the battery change. I could see clear over the river bank and far upstream on the river.

What really surprised me more than anything else is that I thought a regulated light would just stop working and go from great light to no light. I didn't think it would fade out much like a regular light does but that's similar to what happened. It seems like one minute I had great light and then it was reduced suddenly. I was also surprised that the batteries didn't last longer than they did. At ten dollars for two lithium batteries for the battery change this could be an expensive light for winter evenings at camp. Before the battery change I had used the light for about 14 hours total. With the new batteries the usage during this trip amounted to about 7 hours over three nights.

Snowshoe-in Cabin Sledge Trip
Princeton Tec Genesis under headband of tester
The next trip I used the light on was to a backcountry rustic log cabin. I pulled a sledge of gear to the cabin for a distance of 3 mi (5 km) roundtrip and set up housekeeping for four days with daily snowshoe hikes. My only light sources were a small battery-powered lantern, candles, a bit of light from the wood stove fire and the Princeton Tec Genesis. Since the aforementioned sources don't emit much light for tasks but generally just ambiance, the Genesis was used for detailed tasks and for reading purposes.

The light was also used for those trips to the outhouse during the very dark evenings. I also went out to investigate the lake and surroundings after dark one night with the red lens for night vision.

Most of the Genesis usage during this trip was inside of the cabin that was at least 40 F (4 C) during most hours and up to 60 F (16 C) when I made a fire in the wood stove during some of the day time hours. I'm only mentioning the temperatures because the light was not subject to frigid cold during this trip for the most part.

I was surprised that the light source dimmed considerably after a few hours of use at the cabin (probably about 4 hours). That was only about 11 hours of light with the new set of batteries. I was disappointed that they didn't last longer and in the future I will probably regulate more carefully the amount of time that I need to use it.

I have continued to use the light mostly combined with an elasticized headband over my hat. This has worked out exceptionally well when reading and cooking. I will probably continue to use it this way for detailed chores but use the lanyard for most other purposes. Overall, the Genesis Light is a very powerful white light.

The only real nitpicks that remain for me are its size and weight as compared to what I normally carry and the cost of the batteries per hour of light. However its attributes weigh much more on the positive overall as I've become spoiled by the power of the light as compared to lesser light sources that I have used. I will definitely continue to use it for backpacking but probably mostly in the winter months when a powerful light source is optimal.

  • Bright "white" light 
  • Powerful light beam 
  • Easy to use

  • Light is a bit heavy for backpacking purposes
  • Batteries are expensive for the length of time they last
  • Rubber seal broke on the battery compartment

Tester Remarks 

Thanks to Princeton Tec and BackpackGearTest for this interesting opportunity to test the Genesis Light. This report concludes the test series.

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