When you’re optic shopping you spend a lot of time considering cost, clarity, and eye relief. You want the best possible glass for the money, but have you stopped to consider how the optic in question will handle the weather? It’s easy to get used to seeing optics that are fogproof or waterproof, but you shouldn’t dismiss or ignore the importance of that and other weather-related features. We’re going to explain why it’s important to have a weather-resistant optic and what to look for to ensure yours can handle whatever you throw at it. Consider this your cold-weather optics primer.
Are all optics fogproof and waterproof?
The vast majority of optics are designed and marketed as being fogproof and waterproof. However, they’re not all made the same. Seals and standards vary and while “you get what you pay for” isn’t precisely accurate across the board, it is generally true. Optics made at a lower quality level are more prone to leaking seals and bumps and bangs, causing more serious issues than just a scratch here and there. It’s important to ensure the optic you select is manufactured according to exacting tolerances and in adherence to strict quality control, and that tends to mean spending a bit more.
Are optics freezing-weather resistant?
Many optics include the temperature range at which they’re capable of operating in the manual or on the manufacturer’s website. An example of a stellar extreme climate optics comes from Zeiss. Their testing and quality control process is fantastic. Among other things, Zeiss subjects optics to deep freezes as low as -40° C and also puts them through a temperature shock, meaning the temps change from -25° to 50° Celsius in a span of five minutes. This is accomplished by the use of what the company calls a climactic chamber, but it’s worth mentioning they — and other manufacturers — also test optics in the field.
So yes, certain optics are designed to be resistant to freezing weather. If you live in a region known for frigid conditions such as Alaska or even Wisconsin, it’s worth using optics that can take the cold. And if you’re a hunter who tends to travel, it’s also a good idea to have optics that can handle a wide range of temperatures.
How do you pick a cold-weather optic?
The simplest way to select a rifle optic for cold weather use is to do a combination of reading the manufacturer’s specifications and checking reviews from customers. Remember that someone else’s idea of extreme cold might not match yours, so if the temperatures aren’t specific, don’t make assumptions.
Aside from making sure the optic has been properly tested and manufactured to handle extreme temperatures, you can also select rifle optics or binoculars that offer greater eye relief (this is especially important with binoculars). This helps keep body heat away from the glass and reduces the risk of external fogging. There are also products on the market that can be applied to external glass to reduce fogging. If there’s internal fogging, you have a significant issue and the optic likely needs to go back to the manufacturer.
When addressing the issue of how most optics are now considered waterproof or fogproof, consider exactly what that means. A good example is that certain brands of optics retain their weather ratings even if the turret covers are removed while others need the lenses covered and turret covers in place to retain their ratings. It is a good idea to take the time to find out how an optic’s fogproof or waterproof ratings are or are not affected by seemingly minor changes.
Also, make sure the turrets, power rings, and any other rings and controls on the optic continue to function properly in freezing weather. Not only does the cold sometimes cause them to slip or stick but if it gets cold enough it can negatively affect the seals or grease used in the optics’ construction. Some answers you’ll only get by using the equipment, but most things you can figure out from the manual or from the experience of other users.
Here’s what Bushnell has to say about cold weather optics use and the risk of moisture-related issues:
This is where purging comes in. High-quality rifle scopes are usually filled with inert gas, such as nitrogen or argon, rather than air. Air carries dust and moisture, both of which can affect the image viewed through the scope. Pushing the air out of the scope body with nitrogen gas is intended to eliminate this problem.
The quality of the scope will become apparent in cold weather. A low-quality scope may allow ambient air, along with the dust and humidity carried by the ambient air, to enter the scope’s body. The result is fogging, frost, and dust on the inside of the lenses. The best cold weather scopes, on the other hand, are sealed against interior fog, frost, and dust.
Tips for Cold Weather Optic Use
If you’re going to use your rifle optic in cold weather, there are things you can do to improve the experience. For example, one of the things that’s harder on optics is a sudden weather change, so while you might want to keep your optic warm as long as possible it’s actually better in most cases to let it cool gradually instead of suddenly exposing it to freezing weather. That can mean storing the rifle and optic in question in a cooler place prior to a hunt instead of making efforts to keep them toasty warm until the last minute.
Something you might not have considered is the usefulness of optic covers. Those flip-up lens covers some optics come with are for more than protecting the glass from scrapes and scratches. If you’re hunting in the snow, keeping the ends of the lenses covered until it’s time to use the rifle can be extremely helpful. It also keeps potentially freezing rain and snow from accumulating on the glass, and both are problems when it’s truly cold out. Yes, moisture on the exterior lens of your optics can freeze and cause some major problems with your hunting success. You can certainly use different types of optics covers but the flip-up lens caps tend to be easiest to operate, especially when time and sound level matter.
Don’t stop considering the effects of cold on your optics just because the hunt has ended and you’re back in your truck. If you put your rifle scope or binos close to a heat source after they’ve gotten super cold outdoors, it’s possible to cause thermal stress that can result in a number of issues including cracked lenses. Gradual heating, like gradual cooling, is preferable.
A question that’s often asked is whether someone should focus on a pricey rifle or a higher-end optic as their priority. While having an awesome rifle is great, it is typically smart to focus on getting a better-quality optic before putting a lot of money into the rifle itself. Your rifle won’t get you far without good glass, and if you’re shooting in cold climates, it’s even more important.
