In the five years since John Newhook and I drafted this document describing the use of lasers in curling the technology has continued to improve and become more affordable, so it seemed like an update was in order.
With many curling clubs moving to LED lighting for their arenas, green light lasers have now become the norm, rather than the exception, and their cost has plummeted. The lasers that I use (see below) can now be purchased from Amazon for a mere $38.69 Canadian, a significant drop from five years ago. Even a rechargeable, green laser pointer for presentations can be had for only $16, a long way from the nearly $200 I spent on a red laser pointer when I was in graduate school at the University of Manitoba.
Of course, none of the lasers for sale anywhere are intended for curling, and the majority are intended for one of three use cases:
- for use with a firearm, usually a rifle or shotgun;
- a laser pointer for presentations;
- a toy for pets, typically cats.
My current laser setup consists of these 3 components: a Neewer 3-dial leveling tripod mount; a Streamlight flashlight mount for a cycling helmet, re-tapped to fit the 3/8 threads on the tripod mount; and a Strong Tools green laser sight with fittings for a rifle mount. All of these are available on Amazon; clicking on each image will take you to the appropriate page on amazon.ca.
The complete assembly is shown at left. The laser is a Class 3R 532nm green light laser that is easily bright enough for use in curling clubs, even from the far tee line. A disadvantage of this particular model, however, is that the battery life is rather short; green light lasers use a lot of energy, especially at cooler air temperatures. So for this laser I use lithium Energizer CR123 batteries, but the downside is that CR123 lithium batteries are fairly expensive (about $16 each retail, though you can find better deals if you buy in quantity).
However, another option now available is to use a laser pen light with a rechargeable battery. This green laser penlight from Yilemi, also available on Amazon, is relatively inexpensive at just under $25 and features a large BRC 18650 4200 mAh rechargeable lithium battery. The photograph at right shows the penlight with the red battery and its USB-A charger. The penlight is mounted in an easy-to-use aluminum penlight mount which is mounted on a Neewar tripod level base so as to adjust the height of the beam so that it shines in the middle of a stone’s striking band. An adapter is required to convert the 3/8 inch mount of the tripod base to the 1/4 inch tripod mount threaded hole on the penlight mount.
This past week I’ve had an opportunity to try this combination on the ice and it works really well; the laser is bright and the massive rechargeable battery easily lasts a full two-hour practice.
One thing to be careful of when purchasing a device intended for presentations is to make sure the laser pointer has a true on/off switch so that it can be left on unattended; most laser pointers intended for presentations or for use as a toy don’t have this feature.
Finally I mention two other items that may prove useful to coaches and athletes. The first, at right, is a folding Neewar 3/8 inch mount tripod head that can serve equally well as a tripod base. In fact, this base – alas currently unavailable on Amazon – has the advantage of having only one degree of freedom for adjustment (up or down) and so is easier to align than a 3-wheel tripod base.
The other item of interest is that blue light lasers are also available for sale now on Amazon, for a cost of just over $100. However, while these blue lasers could be of interest to coaches or athletes that are red-green colourblind, they are very powerful lasers (they will etch wood or light a match at a few metres distance) and the battery life is extremely short, with product specifications indicating a life of 2-3 minutes continuous use. It isn’t clear to me that these blue lasers are class 3R (the maximum power allowable without a special permit for their use in Canada). Moreover, with their very short battery life they are inappropriate for use on the ice in a curling context.
A second blue laser option is this Votatu M4L-B rechargeable blue laser, again designed for mounting on a firearm (see photograph at right). The integrated rechargeable battery is unique; however, the laser is not sufficiently bright enough to work well in a curling venue, where bright LED ambient light drowns out the laser from even short distances (top of the house, or 24 feet). The lower power output makes this model quite unsuitable for on-ice coaching.
I work with lasers and have some training in laser safety, and I thought it would be worth sharing a few thoughts.
– I would stay away from blue / violet lasers entirely. They are almost always more powerful than the rating suggests, as the most readily available diodes in that wavelength are well outside the rating for Class 3R. Additionally, the eye is not very sensitive to blueish light – meaning that to get decent visibility, you need a LOT of power. Keep in mind that the ice will cause specular reflections, too. With a blue laser I can see only one of two scenarios occuring: either the laser is too dim to be useful, or it is dangerous.
– For green lasers, I would be *extremely* skeptical of your Yilemi pointer actually being safe. 532 nm lasers are difficult to build at low power levels, and they also often put out a bunch of unsafe, invisible IR laser light (it’s a consequence of how they work internally). There’s countless forum posts and youtube videos showing Amazon / eBay / Aliexpress 532 nm lasers measuring at power levels far beyond what their label states.
– If you want this to be safe, I highly suggest selecting a laser from a large / well regarded manufacturer. A tool manufacturer like Bosch, or a reputable firearms brand would be places to look.
– If possible, look for 515 or 520 nm lasers instead of 532. Because of how these lasers are built, they tend to have much more stable outputs, don’t output any IR laser light, and are more readily available at safe power levels.
– Another option for *very* long battery life would be to buy a USB-powered laser module. Thorlabs makes the PL251 which you can trust to *actually* be under 5 mW. Plug that into a power bank and you’d get hours and hours of operation. It’s a bit spendy, but you don’t want to take chances with people’s eyesight.
– If that’s too expensive, another option is to buy a bare laser module from China. While it’s a crapshoot as to whether these are safe or not, I’ve personally bought a couple of modules from a brand called ‘ZhonNa’ on Aliexpress and have found that their 520 nm modules (1 and 5 mW versions) *seem* to be at, or close to their rated power. I haven’t had a chance to actually measure them so they could still be over, but they aren’t drastically overpowered like some lasers I’ve purchased. I don’t really suggest this route, but I’d be more confident in these modules than the pointer you’re currently using.
Thank you for your commentary. You’re quite right about blue lasers; as I said in the article, their power isn’t sufficient in a curling context at all, and I don’t recommend them. I was hoping that a low-power one would be enough to help colour-blind athletes, but one would require something much, much more powerful to work at any distance and the power required would be hazardous.
Thank you regarding your recommendations for green lasers. I did find one video from Denmark that performed some tests (https://www.youtube.com/watch?v=i9WS7Jo2TAY) and I’ll make it a point to do some testing myself with the two red and three green lasers that I have.