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Reviews > Lighting > Headlamps - LED > Princeton Tec Byte Headlamp > Test Report by Ralph Ditton

Princeton Tec Byte Headlamp
Test Series by Ralph Ditton
Initial Report : 14th November, 2010
Field Report :25th January, 2011
Long Term Report: 18th March,2011

                                                 Byte Headlamp
                                                                                                   byte headlamp
Personal Information
Name Ralph Ditton
Age 59
Gender Male
Height 1.76 m (5 ft 9 in)
Weight 74 kg (163 lb)
Email rdassettsAToptusnetDOTcomDOTau
Location Perth, Western Australia. Australia

Backpacking Background
My playgrounds are the Bibbulmun Track, the Coastal Plain Trail, Darling Scarp and Cape to Cape Track. I lead walks for my bushwalking club and they consist of day walks and overnighters. My pack weight for multi day trips including food and water, tends to hover around 18 kg (40 lb) but I am trying to get lighter. My trips range from overnighters to six days duration.

Product Information
Manufacturer Princeton Tec
Year of Manufacturer 2010 (Made in China)
Model Byte
Colour Black/Grey
Lamps 1 Maxbright LED
1, 3 mm Red Ultrabright LED
Beam Distance Maxbright - High - 30 m (98 ft)
                   Low - 15 m (49 ft)
Red Ultrabright - 6 m (20 ft)
Brightness Maxbright - 35 Lumens
Red Ultrabright - Not stated
Burn Time Range 80 to 146 hours
Listed weight 64 g (2.25 oz)
Measured weight 64 g (2.25 oz) incl. batteries
Water Resistant Yes
Batteries 2 AAA Alkaline or Lithium
2 AAA Rechargeable NiCad or NiMH
Warranty International - USA
5 year Warranty
MSRP US$19.99

Product Description
The lamp and components arrived in a card and blister pack. The headband and batteries were in separate blisters on the reverse of the card. (See photos)

                                                          front of card
                                                                                                           front of card

                                                          reverse of card
                                                                                                   reverse of card

The batteries that were supplied are two AAA Energizer Alkaline Model 03-2017 manufactured in the USA.
There is a mixture of English and French on both sides of the card, however the instruction sheet is in English, French and German.

What I received matched my expectations from the manufacturer's web site.

Battery Compartment
This is located at the rear with access on the right hand side when being worn.
To open, I pop the door latch over the catch by either using the buckle tool on the headband or my thumb. I prefer the buckle tool as my thumb goes through a bit of discomfort when putting pressure on the latch.

                                                        using buckle tool
                                                                                                      using buckle tool

When open, I slipped the batteries into their tubes in their right polarity. There is no + or - stamped on the inside of the door or body of the battery compartment. The only clue to the polarity is the tall spring on the door. That denotes that the negative end of the battery should be at the opening which means that the other battery has the positive end at the door opening to make a circuit.

The battery door closes with a loud click.

I had to attach the wraparound headband to the headlamp after I took it out of its packaging. It was just a matter of easing the headband through the side gates that are part of the asymmetrical single arm bracket.
The headband is adjustable by sliding the buckle tool forwards or backwards to suit my head for when I am and am not wearing a beanie at night.
The headband adjusts easily. It is just a matter of holding the buckle and pushing the headband up through the buckle and pulling through the other side.
I found the headband very comfortable against my forehead.

Lamp Design
The one Maxbright LED should develop heat but there is no obvious heatsink feature visible to prevent overheating. Perhaps it is internal. I was unable to open up the light to find out. No mention is made in any literature on this model.
The Maxbright LED is housed in a collimator assembly so that all of the light from the LED is reflected outwards in a focused wide beam. This allows for my eyes to take advantage of peripheral vision at close range.

The Red Ultrabright LED has no collimator because its range is very small and the beam very wide at a distance of 2 metres (6.5 ft). The light from this LED is really for close work where the beam is much more focused, say 20 cm (8 in).

There is a 3 Mode Switch on top of the headlamp and it is Grey in colour. It has 5 small raised round bumps which I would guess is to help locate the switch in the dark by feel.
Conversely, there are also 5 larger round bumps underneath the Maxbright housing and to the front. These are to assist with grip when adjusting the tilt of the headlamp.

The battery and lights body is attached at one end by an asymmetrical single arm bracket. This bracket had the headband passing through it.
Where they are joined, there is a ratcheting arrangement that allows the headlamp angle to be adjusted. I can hear the clicks as I rotate the headlamp up and down.
I can very easily rotate the lamp down about 80 degrees and up about 50 degrees.
A ratcheting sound can be heard as I rotate the headlamp.
My fear is that each time I adjust the angle I am wearing down the teeth through friction and in time the headlamp will not stay in place at the desired angle.

To operate the headlamp is very easy.
All that I have to do is press on the Mode Switch. The Red Ultrabright LED switches on first. The next two presses on the Mode Switch switches the light to the Maxbright LED commencing at the Low then moving onto the High settings.

To switch off the headlamp I have to cycle through the modes until it switches off. There is no facility for holding down the Mode Switch for a few seconds to turn off the headlamp.

Some Early Observations
I carried out some brightness measurements using my Light Metre. The units are expressed as "Lux".
By way of explanation the lux illuminance is equivalent to the following:
0.01 Lux Quarter moon
0.27 Lux Full moon on a clear night
1 Lux Full moon overhead at tropical latitudes
50 Lux Family living room
100 Lux Very dark overcast day
320-500 Lux Office lighting

My experience of illumination using the new batteries that were provided with the headlamp.
I will refer to the light simply as, Red, Low and High as they represent the Red Ultrabright LED and the Maxbright's two settings of Low and High.
Distance Colour Lux
1 metre (3.2 ft) Red
metre (1.6 ft) Red
metre (10 in) Red
20 cm (8 in) Red 7.5
10 cm (4 in) Red 22.1

I did not worry about measuring the Maxbright at the very short distances as the light is exceptionally good for the distances measured.

The photo below shows the red light shining on a sporting trophy at a distance of metre (1.6 ft).

                                               red light on trophy
                                                                                               red light on trophy

On initial impressions, I am very pleased with this headlamp. It is light, only requires two AAA batteries and the headband is comfortable to wear.
I am not bothered by having to scroll through all of the settings to turn the light off although
having a facility to hold down the switch to turn off the headlamp would be nice.
The only nagging fear is that over time the teeth/notches will wear through angle adjustment making the headlamp sloppy and not stay in place.

This unit is aesthetically pleasing to me. Most impressed.

Field Report
I went to my usual testing ground at Prickly Bark, north of Perth on the Coastal Plain Trail.
This campsite sits at an elevation of 83m (272 ft) amongst Banksia trees on top of a large sand dune that has shrubs, grass and wildflowers.

In all I spent three overnighters there.

Temperatures ranged from 14 C - 33 C (57 F - 91 F), 19 C - 37 C (66 F - 99 F), 22 C - 31 C (73 F - 88 F) over the three nights and six days. I.E. We went on the Saturday and back on the Sunday.

Prior to taking the headlamp out on its first excursion, I had been using it a bit at home when scratching around in the attic looking for Christmas wrapping stuff for the wife. I estimate that in all I used the batteries for about a total of 30 minutes.

Whilst at camp I put the headlamp through its paces.
This involved using the red light to see how useful it was, then the low and high settings for the Maxbright LED.
I did this very early in the night before and during the cooking of dinner.

The red light is of no value in cooking a meal as the distance between the lamp and the stove was too great. It was a good 60 cm (2 ft) away.
I could see it but I needed more light for safety reasons.
The red light was ok up to 25 cm (10 in). I could read the map to get by.
The instruction sheet states that the red light throws a beam up to 4 metres (13 ft).
Quite frankly, objects at that distance were very hard to make out.
The best usable distance of the red light where I could make out objects was 1.5 m (5 ft). After that it was guess work as to what I was looking at in the bush.
Not my favourite setting and I am not in a war zone where light can give you away.

Apart from not destroying my night vision, I could find no compelling reason to use the red light around camp.

I used the low and high settings to cook the meal and go for a walk along the track after dinner to walk it off. Both worked well in that I could see a reasonable distance with great clarity. I did not measure the distance, however I estimate that on high, the maximum distance that was of use to me where I could see everything in my way, was about 7 metres (23 ft).
Low beam was about, in my estimation, 4 metres (13 ft).

                                             cooking dinner
                                                                                   cooking dinner

                    without the flash
                                                                            cooking dinner without the flash

My walking partner and I eventually settled down about 9 pm and played Yahtzee till midnight.
For this I had the headlamp on the high setting and it performed very well.
At the end of the session I then went to scroll through the settings for another test and it died without any warning. Pressing on the light switch did nothing. All that I had was a very faint light in the LED. No beam was being emitted. I could see a little square of light.

To rectify the situation, I opened up the battery compartment, withdrew the batteries and this killed what little light that was remaining.
I replaced the batteries with similar alkaline ones and the headlamp worked just fine.
I used it for a few minutes getting ready for bed.

I estimate that I had a total burn time of 4.5 hours out of the batteries. They were the ones supplied by the manufacturer.

My next occasion camping had a similar result. I did play around with the various settings but again settled for the high setting to play Yahtzee.
Total burn time, just over 4 hours.

The instruction sheet states that I should get 80 hours on high or 96 hours on low.
Mine obviously fell well short of those claims.

However, at home I did achieve 85 .75 hours burn time on the high setting. This was achieved by putting fresh alkaline batteries in and leaving the headlamp switched on.
At the end of 85.75 hours, I went to scroll through the settings and got the same result. No response to the switch, just a little square light.

This is all very well but I do not know of any bushwalker who leaves their headlamp burning day and night. They may exist, but I have never met them.

I repeated this with a shortened version. This time I did it for 14.5 hours. Tried to scroll through the settings at the end of the 14.5 hours. No go. Same result as the other times. Just died.

                                                     non responsive LED
                                                                                            non responsive LED
I tried to capture the little square of light but it came out round in the photo.
The other interesting thing that occurred when I was lining up the light was a red light would flash and alternate between the top and bottom of the white light. I could see it in the LCD monitor but I could not capture it in a photo.

The table below is for High Beam which was left on for 85.75 hours.
I took measurements at three distances, 220 mm (8.5 in), 400 mm (15.5 in) and 1 metre (3.2 ft).

220 mm (8.5 in)
400 mm (15.5 in)
1 metre
(3.2 ft)
7.15 am
1528 lux
455 lux
69.8 lux

11 am
1113 lux
455 lux
70.9 lux

1 pm
 631 lux
428 lux
75 lux

8.30 pm
64.8 lux
16.6 lux
2.1 lux

11.30 pm
34.6 lux
10.3 lux
1.7 lux
7.25 am
6.1 lux
1.7 lux
0.2 lux

2.10 pm
3.3 lux
1.7 lux
0.2 lux

9 pm
2.2 lux
0.9 lux
0.1 lux

Where the readings are a little bit higher than the previous reading for the metre distance, I suspect that as the beam became weaker and narrower it concentrated more light at the further distance.
I did try and have the room as dark as possible.

The table shows the first and last days only.

For my last camp, I replaced the batteries with rechargeables. They are NiMH type 800mAh 1.2 V.
They were fully charged and I scrolled through all of the settings again testing the light and finally settled down again to playing Yahtzee until 10.30 pm.
When I finally went to bed I had used the headlamp for 4 hours continually.

The headlamp worked fine early next morning when I had to go out for a call of nature.
It is still working fine at the moment at home.
I tested the batteries, whilst writing this report, on my very basic battery tester and they show a charge on the extreme left of "Good" and just kissing the yellow strip of "Low".

The alkaline MN2400, 1.5 V, LR03 batteries when tested after the light failed registered well into the "Replace" indicator.

It is interesting to note that the instruction sheet mentions that they (Princeton Tec) calculate total burn time as the time it takes for the light source to produce a minimum of 0.25 lux at 2 metres (6 ft 7 in). 0.25 lux is about the equivalent of a full moon on a clear night.
When I tried to read my light meter at 1 metre (3.2 ft) when it was 0.2 lux I had the greatest difficulty in trying to read the numerals. I had to resort to a little torch to read the display to ensure that I had it correct.

For the batteries just to die without any warning there must be some microprocessor at work.

I checked with Dr. Roger Caffin BSc (hons) Physics, MSc Physics, PhD Systems & Automation, as to what is at play.

His advice to me is as follows, "To drive the Maxbright LED there needs to be some sort of Switched Mode Power Supply to increase the voltage.
The reason is, most SMPS units do not actually incorporate a transformer.
Instead they use an inductor or even a bunch of capacitors."

During use, the batteries drain power and it must get to the stage where there is not enough juice in the batteries to switch on the SMPS when I want to change the setting, hence the failure.
The light switch does not respond to any pushing. I could not even turn the light off. The only way to do so was to take the batteries out.
Fortunately I had a spare set of batteries.

Judging by the performance to date, I'll need a spare set of batteries for every overnight use as I usually have my headlamp on during summer for a minimum of 4 hours, from 7 pm to 11 pm.
This just adds to the weight of carrying multiple spare batteries when I do my occasional 5 day bush bash. I'll need an extra 8 batteries as spares.

Things I like
  • Aesthetically pleasing
  • Lightweight
  • Takes up very little room in the backpack
  • High beam setting is useful around camp
Things I dislike
  • Extremely short battery life of 4 -5 hours
  • Not enamoured with the red light
  • No warning when the battery is going to die

Long Term Report

During this phase of the testing I was at Wellington Dam Reserve for two nights on the banks of the Collie River. The river flows at an elevation of 80 metres (263 ft) where I was camping.
during the day reached a maximum of 36 C (97 F) and of an evening 22 C (73 F). Humidity was also in the 60's%.
All in all, very hot, humid and dry as a chip.

The area that we walked in was so dry that moss turned to powder when trod upon when climbing over logs.
There was a constant dust haze in the air during the day and night due to the dryness.
I did not conduct any light metre test in this stage of testing, just wore it and observed the unit.
I started off with fresh alkaline batteries for my first night on the banks of the Collie River.
It started to get dark around 6.45 pm, so I then used the headlamp to do chores around camp such as cooking my evening meal on a gas camping stove, eating my meal then washing up.

My camping mate and I then had a nice relax sinking a few stubbies and having a quiet read of our respective bushwalking magazines under our respective headlamps.

After an hour and a half of reading I went for a bit of a stroll to see how the light performed under dusty conditions.
In the first mode, the red light was useless to walk with and I did have difficulty in reading my watch with the light, so I switched to the next mode, Low Beam.
I was able to walk on track but the bushes a few metres (feet) off to the side were not very clear. I knew what they were as far as botanical type as I had seen them during the day but I was struggling to identify them at night. The dust in the air did not help either. Everything appeared brown.
I then switched to High Beam. This beam threw a very wide beam with a distinct circle of light in the middle. However, I still could not see more than 10 metres where objects were clearly defined.
This became apparent very shortly.
A very loud moving crashing sound scared the living daylights out of me and it was only about 14 metres (46 ft) away. When my heart left my mouth I quickly turned to the source of the noise but could not see it. However, after listening for a few seconds, I identified the noise as belonging to a kangaroo crashing through the scrub. I must have frightened it by my presence.
Now a kangaroo is grey and the light did not pick it out at all. All that I did see was the red of its eyes when it propped to have a look at me and I estimate it was about 5 metres (16 ft) in stunted vegetation from me.
The high beam did not show up the body of the roo.

The light was still strong as the fresh batteries had been running for roughly 2 hours and yes, there was dust in the air but not thick to choke me such as if a vehicle went past me and threw up dust.

That incident frightened me. If I can't see a kangaroo moving at night and when they suddenly stop, then prop, on its hind legs and tail, (an adult kangaroo is about a fully grown person's height), then clearly, this light is not meant for night walking.

The following night I used the headlamp for similar activities around the camp.
I even went for another walk of about a kilometre (0.6 mi). I could see the track I was walking on and the high beam cast a large circle of light which showed up the trees and vegetation so I could see where I was going.
The fine detail of objects in the beam only showed up distinctly to a distance of about 5 metres (16 ft) in the dusty conditions. The dust from the drought conditions just hung in the air.
I could see the dust particles in the light beam.
Oh, and I did not have any repeat of an animal scaring the living daylights out of me.
Mind you, I heard lizards moving amongst the leaf litter next to me on the track (well, I hope that was what they were) but I was unable to see them in the light beam.

Total burn time for the second night was similar to the previous night. I did not cycle through the various settings after selecting High Beam. I just left the torch on High Beam.

I did not experience the headlamp dying on me when I tried to cycle through the various settings as I initially experienced.

When I reached home I checked on the batteries with my Battery Tester. The batteries tested "Low". The needle was in the yellow segment, so they were on the way out after only 5 hours of use over two nights.
This headlamp needs further development if it is to live up to its manufacturer's claim of a long battery life in real usage where it goes through the various setting cycles.
Achieving between 4 to 5 hours of total burn time, be it over one or two nights is not good enough. This takes us back to the old bulb style before the LED light.
I think what the manufacturer is trying to do:
a) Achieve a lightweight headlamp running on two AAA batteries.
b) Produce a powerful, small unit.

The manufacturer needs to revisit the Switched Mode Power Supply so that a longer battery life is achieved in the field with users constantly switching between modes and even turning it on and off a number of times.
It is all well and good to claim 80 hours battery life if the unit is just left on and on the High setting, but no one that I know leaves their headlamp on during the day.

This report concludes my test on the Byte Headlamp. Thanks to Princeton Tec for the opportunity to test it.

Read more reviews of Princeton Tec gear
Read more gear reviews by Ralph Ditton

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