Astrophotography often means taking your gear out in the cold and leaving it there, which can expose it to a number of problems. The first is foxes stealing your camera and having fun with it, but a more common and serious problem is condensation. Your camera and lens can be cooler than the surrounding air, causing water to condense on their surface. Get enough of it, and when your lens is tilted upwards, gravity will cause small drops of water to flow straight onto your camera body or the lens end of the lens to fog it up. Neither of these scenarios are good.
Cameras and water just don’t mix, despite advances in rubber gaskets and other seals to keep moisture out of sensitive areas. Fortunately, there are a few things you can do about it. Just as astronomers use heaters near telescopes to keep condensation off their expensive tubes, owners of the best cameras use it for astrophotography (opens in new tab) can protect their glass and camera body with it and prevent the formation of dew and condensation by gently heating the lens body.
Modern lens heaters are a simple and affordable solution that no avid astrophotographer can do without. They generally take the form of a padded strip that can be wrapped around a lens and then connected to an AC adapter or other power source via USB. Often offering multiple incremental temperature adjustments to suit most environments, and used correctly, lens heaters can mean the difference between a rewarding night of astrophotography or a wasted effort with results tainted by fog and dew.
You can try making a solution yourself using heated gel packs or similar products, but they don’t reach a consistent temperature or often last long enough, especially for late-night Star Trail sessions. So here are some of the best camera lens heating solutions we’ve seen.
Looking for more camera kit guides? We have guides on the best lenses for astrophotography and the best camera backpacks to keep all your gear safe.
The best lens heaters
A simple neoprene strap that slips around your lens, with a USB connector for taking power from a rechargeable power supply (or a phone charger if you have an extension cord that goes far enough), this lens heater will keep dew off your lens for as long as it takes endures its power source.
The 3.5 cm wide strap is suitable for lenses with a circumference of up to 41 cm and is attached with Velcro. The heater also features a temperature dial on its power cord that allows you to change the amount of heat generated through Low, Medium, and High modes. That means you can also use it to keep your water bottle from freezing in really cold weather.
This is a 72cm long band with 56cm heated area so it can be used on even the largest lenses and many telescopes. It draws its energy from a 1.6 to 1.8 A power tank and has three heat settings: low, medium and high.
Aluminum alloy heating elements allow for rapid and even heating, while three layers of insulation prevent contact between the heating elements and your gear and also help prevent heat loss into the night air.
A shorter, more affordable version is available, but we like the universal fit and future-proofing that the longer strap offers. Since the heater wraps around the lens or scope at its widest point, it’s always good to have a little extra length in the bag in case new and unexpected gear presents itself.
This Haida anti-fog belt is incredibly easy to install thanks to its simple Velcro design. It’s also made of graphene, which Haida says allows for rapid belt heating, allowing you to save your lens from fogging in no time.
Like most lens heaters, it has a USB connection, which is best plugged into some sort of external power bank, and has three “heat” settings for you to try. A small LED light indicates it’s on and working – this could affect your night vision while taking astrophotographs, so it’s best to find a way to shield it. It’s not the biggest lens heater on this list, but it should fit any camera lens 110mm in diameter or smaller.