Laser Caching Tutorial

 Geocaching, Lasers  Comments Off on Laser Caching Tutorial
Jan 282014

We were welcomed back on GeoGearHeads for an unprecedented fourth time.   This makes Cache At Night the most frequent guest on their podcast.   We think that’s a sign that more people like nighttime geocaching.

Here is a video from the podcast.

Lasers and Geocaching

 Geocaching, Lasers  Comments Off on Lasers and Geocaching
Dec 092013

Over the years I’ve encountered a few geocaches that uses lasers.  They are always fun geocaches.  I will be a guest on the GeoGearheads podcast on January 23rd to discuss lasers and geocaching.   While preparing for that broadcast I discovered this little stat.

Laser One Degree

We have done the math and over 30m (~100ft) an aiming difference of just 1 degree from a fixed location means a difference of 1.5m (~4ft) at the target.   To put that in perspective a coin under one end of our most popular laser represents 1 degree change in angle.   We learned a lot about aiming issues when we built BFL 8: Hot Blooded (Predator).  Adding lasers to your cache can be quite tricky.

We’ve found that the Laser Loci is a great way to incorporate lasers into your cache.  It removes fixed point aiming as an issue.

Nov 262013
multi colour UV ink

It’s time to add some flair to your UV clues.    For the last couple of years if you wanted to use invisible ink that fluoresces under UV light you only had one choice.   Now you have three!  We have just added red and blue pens that are solvent based.  This means they are more durable then our existing water based UV Pen.  In addition to being more durable you now have more choices on how to use your UV clues.

multi colour UV ink

On certain papers or with the light at a specific angle it is sometimes possible to determine which numbers are written on the paper.   On some papers the UV ink gives a bit of a shine allowing the searcher to determine the hidden coordinates.    Now that we have red and blue inks you can use both colors to write on the paper but have the coordinates show up in one colour while the other works to obscure which numbers are written down.   We are sure you will think of other ways to take advantage of these new UV pens.

 Posted by at 13:56

Geocaching Safety

 Safety Lights  Comments Off on Geocaching Safety
Oct 312013
SnapLit, Ideal for runners.

Two things happen in our part of the world at this time of year:  The clocks move back an hour and hunting season is open.    That means it’s darker sooner (more time for night caching) and the woods become a little more active.   This doesn’t mean we have to stop caching but it does mean we could use a little reminder of what to do to be more visible.  

  1. Bright colors are a good first step and you might even want to think of wearing something hunter orange.   I keep an orange toque hand for just this reason.  There are several cachers in our area that way day-glo jackets with reflective strips.   You can always spot them in a group photo.   That kind of visibility helps at night. 
  2. Carry a flashlight and extra batteries.  While not traditionally thought of a as a safety item a flashlight will help you see your way at night and can also be used so that others see you.   If you are walking along a road at night keep your flashlight on.   My Link flashlight has a built in carabiner making it ideal for this kind of use. 
  3. Special purpose safety lights can be used when caching or when doing other outdoor activities.    The Snap Lit is a great choice for personal safety while the Krill Glow Light works for both personal safety and to mark your equipment.   The Krill light is a great addition for camping.  The advantage of a light over a reflector is that the light is an active awareness enhancer.   It makes it easier to be seen in someone’s peripheral vision. 
  4. Many people like to go caching with their dog so we have something just for them.  The illuminated collar greatly enhances the visibility of your geodog whether you are caching or not.   Night time walks are that much safer when Fido can easily be seen from a distance. 
  5. One of my favourite safety lights is the Zip Lit.  I’ve been using it on my GPSr for three years.   Originally intended to be used on a zipper pull I use mine on my GPSr.   It would work equally well on a Camera or backpack.   Small and lightweight it is a convenient way to give my electronics more visibility.   An alternative to a light for your electronics are retro-reflective stickers.   I put these on my flashlights that way if I drop it when it’s off I have a chance of finding it.   
 Posted by at 01:42

Illuminate for Safety

 Safety Lights  Comments Off on Illuminate for Safety
Feb 042013
SnapLit, Ideal for runners.

SnapLit, Ideal for runners.

We made it!  We are half way through winter.   The days are certainly getting longer but there is still plenty of darkness out there.   Whether you are caching, walking the dog or doing some other type of activity you should be visible to those around you.   The easiest thing you can do is where lighter clothes.   Black jackets over blue jeans with dark boots is that the best way to make yourself visible to motorists and those around you.   To help you be seen at night there are two types of products you can use:  passive and active.  If you think of a car the active protection are the headlights and tail lights.  The passive protection are the reflectors on all four sides and in some doors.

Reflectors and reflective products do a good job of making you more visible for vehicles come at you.   They are not as effect when the vehicle is approaching you from an angle.  That’s because most reflectors are retro reflective and will only shine back at the light source when it is close to straight on.   This reduces the the amount of time that a driver can see you.   In order to increase the time you need to use something that is more active, you need some the emits it’s own light.

We carry a wide selection of active safety gear that can make your night caching experience safer.    We have products that clip on, products that snap on and even some that attach to the equipment loop on your gear.  We even have an illuminated collar that will help make your dog visible on the trails and on the streets.   Many of our active safety lights include passive reflective markings as well.

Be safe, be seen.

 Posted by at 18:45
Dec 012011

When caching at night the color in most things tends to go away. The blue light of the Moon doesn’t reveal a lot of color. There are two parts of the light spectrum that make for interesting cache experiences. Those are infra-red light and ultra violet light (it’s actually near ultra violet but we’ll let the science slip for a moment).

8 Segment Numbers in ultra violet light

8 Segment Numbers in UV Light

A little over a year ago Groundspeak added the UV attribute that can be assigned to geocaches. Since that time we’ve seen UV enabled caches grow. In a typical UV scenario a hint or coordinates are written in an ink that is UV reactive. The UV clue is sometimes written on the back side of a clue that is written such that it’s visible in white light. A cacher that is unaware of the UV attribute might be tricked by this approach.

In order to protect the UV inks from the elements we recommend placing them in non-UV blocking laminate. We carry non-reactive paper and self-sealing laminate pouches for this very reason. There is another way to provide clues using UV light and that is with UV reactive monofilament line.

8 Segment Numbers in White LIght

8 Segment Numbers in White LIght

We recommend creating eight segment digits like you see on a digital clock where some segments are not UV reactive and others are. Under white like the two lines are very hard to differentiate. Turn on a UV light and the correct coordinates pop out. In the pictures for this article the UV line is protected inside a sealable container. This is mostly for protection from the Sun’s rays. UV reactive features will degrade over time when exposed to sunlight. The UV line does not need to be protected from the elements, water won’t hurt it. You’ll also want to make sure that the cacher can’t see the backside of the coordinate segments. If they can see the backside they can see which segments use which kind of line and deduce the coordinates from that information.
The only special equipment you need to find a night cache with UV clues is a UV flashlight. There are a variety of UV lights available from small button lights to larger 3-in-1 lights. If UV caches are growing in your area then you’ll want to add one of these lights to your pack.

Coordinates Visible with IR Light

Coordinates Visible with IR Light

Coordinates Not Visible with White Light

Coordinates Not Visible with White Light

Caches that use infra-red (IR) light are harder to create and require special equipment to find them. An IR cache needs two components, an infra-red light source and an infra-red capable camera. Any remote control where you have to point it at the TV uses an infra-red LED. You can either take apart an old remote control or you can buy IR LEDs for about 50 cents each. We opted to buy them for our Lunar Lander BFL Boot Camp cache.

Now that we had an IR light source we needed to figure out what to do about a camera. I learned a while ago that webcams will pick up IR light but those aren’t too convenient to take into the field. I suppose if you had a little netbook that might work. I discovered that my BlackBerry makes for a decent enough IR camera for what we had planned. The facetime camera on an iPhone might work if you are patient. Many cameras have a built in IR filter. You can test your camera by viewing the front of a remote control through your camera as you push the buttons. If you see a light then your

Coordinates Visible with Infra-Red Light (close up)

Coordinates Visible with IR Light (close up)

camera will work to view IR light. You can also use cameras that have a “night vision” mode. As you can tell it’s not easy finding a way to view infra-red light. If you choose to build and IR cache it will be important to provide sufficient details in the description relative to your difficulty rating to allow people to find the cache. If you set your difficulty rating at 5 then you might not need to provide too many clues on how to solve the cache.

The trick to making and IR cache is finding plastic that is opaque to white light but easily transmits IR light.   Black or smoked plastics work best.  I used multiple layers of a red plastic.  It is very hard to pass white light through multiple layers but the IR easily passes.

We’ve just described a few ways that we have used ultra violet and infra-red to create caches. Hopefully these will be your starting point when you build your own creative night cache.

Remember to Grab a Light (white, UV or otherwise) and Cache at Night.

Battery Cost Calculator

 Flashlights  Comments Off on Battery Cost Calculator
Sep 212011

Rogue 2 Flashlights

Have you ever wondered how much you can expect to spend on batteries in a year? We did too so we built a handy little calculator to help you estimate what it will cost you. The calculator assumes single use batteries. You can change the values to fit your flashlight. The calculator is pre-populated with the values for the two flashlights described below.

  • Rogue 2 with two Alkaline AA batteries and 100 Lumen output
  • Fenix TK 35 with one lithium CR123 battery and 109 Lumen output

How the formula works:
(annual hours of night caching / runtime of fresh batteries) X cost of batteries.

How much night caching do you do in a month?
Values for a flashlight using AA batteries
Cost for single AA 0.83
Values for a flashlight using AA battery
Annual operating cost for AA $ 20
Annual operating cost for CR123 $ 99

Jun 282011
Link Flashlight Comparison

Link Flashlight Comparison

In a recent poll we conducted 94% of the respondents said they have cached at night. With numbers that high it’s no wonder that a flashlight is an essential part of your geocaching kit. How do you decide what kind of flashlight to carry? I do a lot of night caching so I carry four different lights for different purposes.

When I started caching I used a handheld Energizer LED light. This light served me well in the beginning. It wasn’t long before having to maintain two sets of batteries, AAA for my flashlight and AA for my GPSr became an aggravation. I started looking for a quality flashlight that used AA batteries. This was not as easy as it seems.

There are a number of high end flashlights that cost over $100 dollars. These lights typically use a lithium CR123 which cost something around $9 each. Rechargeable versions cost about twice as much. Not only are the batteries expensive they are not universally available.

I was introduced to the Icon line of quality flashlights. My favourite of these lights is the Link flashlight. The Link uses a single AA battery and puts out 50 lumens of light on high and 6 lumens on low. At the lowest setting one AA battery will last an astounding 70 hours! I only put my lights into high power mode when I’m searching for a cache.

When caching I carry three Icon flashlights:

I also carry a UV flashlight for those times when the cache requires it.

As mentioned previously my first criterion when upgrading my flashlights was standardizing on the type of battery to use.   Every handheld GPSr I’ve ever seen uses AA batteries.  That means I’m already carrying AA batteries so that’s what I standardized on.

Once I settled on my battery I started looking for flashlights that had good lumen output.  A 100 lumen flashlight is bright enough for me to light up any area I’m searching for a cache.  If you are doing a night cache that uses FireTacks it is possible for your light to be too bright.   FireTacks are most visible when they are at the end of your flashlight’s range.  If your flashlight illuminates the area around the FireTack too much you will lose contrast making it harder for you to spot the FireTack.   The lower lumen output combined with the distance from your eye make headlamps best choice when hunting down FireTacks.

The Rogue and the Link both have aluminum housings and are waterproof to 1m.  These are important considerations if you are going to be out in the field caching.  The real world has a way of being hard on flashlights.

Link Attached to Backpack

Link Attached to Backpack

A feature I find very helpful is the carabiner like clip on the Link.  I know the light is always handy because I clip it to the outside of my backpack.  I find the light helpful during the day to look inside trees or logs.  You can clip the link just about anywhere.  On a recent camping trip I hung it from a loop at the top of my tent and had ample light when getting myself situated at night.

If you are just starting to geocache you may not yet fully appreciate the difference in various flashlights.  There will come a time after a few night time caching runs that you realize you need a better light than you find in your local hardware store.  When that time comes you’ll want to find a flashlight that means these criteria:

  • Standard battery size
  • Ample lumen output (at least 50 lumen)
  • Rugged design
  • Waterproof

You will likely be happy with your flashlight if it meets the criteria listed above.

No matter what flashlight you buy it won’t do you any good if you run out of power.  Make sure you take extra batteries into the field.  The Powerpax Battery Caddy is a great way to keep your batteries organized.

Rember to, Grab a Light and Cache at Night!

Night Caching Poll Results

 Flashlights  Comments Off on Night Caching Poll Results
Apr 072011

We wanted to know if other caches enjoy night caching as we do so we conducted a poll on Facebook. It would appear that we are not alone in our night caching escapades!

Our poll was conducted on Facebook and had 148 responses. It doesn’t surprise us that a total of 94% of the respondents said they cache at night.

It’s apparent that most cachers will at some point be caching at night. Do you have the right equipment in your caching bag? We recommend carrying a Headlamp in your pack.

Night Caching Poll Results