# Best Dew Heaters to Keep Optics Clear (2026) Source: https://stargazernest.com/best/dew-heaters Updated: 2026-09-15 Publisher: Stargazer Nest. Our score is an editorial rating out of 10 (fit 35%, features 25%, build 20%, value 20%), not a customer rating. Method: https://stargazernest.com/how-we-research#our-score Dew forms when optics cool below the dew point, fogging lenses and corrector plates mid-session. A dew heater strap wraps around the tube near the front glass and applies gentle warmth to keep it just above that temperature. Match the strap length to the circumference of your objective, finder, or eyepiece, and pair it with a controller that lets you vary the heat so you use only what the night requires. Check the power source too, since most run from a 12 volt battery or portable power pack. Dew heaters suit refractor, SCT, and Maksutov owners, whose exposed front glass dews up fast, and anyone observing in humid or coastal conditions. A practical tip: run the heater on the lowest setting that keeps optics clear, rather than blasting full power. Excess heat creates tube currents that blur the image, and lower draw stretches your battery across a long night. ## Picks ### 1. SVBONY SV172 Lens Heater Warmer Dew 240mm 3 Gear Regulator Temperature USB Dew Heater Strip Our score: 8.4/10 (Fit for the job 9/10 · Features and specs 8/10 · Build and materials 7/10 · Value 9/10) SVBONY SV172 USB dew heater strip, 240mm long with a 3 gear temperature regulator for lenses and small telescopes. Pros: - 3 gear regulator lets you pick just enough heat to stop dew without wasting power - 240mm length wraps small camera lenses, finders and small refractor dew shields - USB power works with common power banks for portable setups Cons: - 240mm is too short for mid-size telescope tubes and large lenses - Power bank runtime limits all-night use in cold weather Details: https://stargazernest.com/product/B08DN6KCVX ### 2. SVBONY Dew Heater Strip 5V for Telescopes and Camera DSLR Lens Linear Temperature Control 25cm Our score: 8.4/10 (Fit for the job 9/10 · Features and specs 8/10 · Build and materials 7/10 · Value 9/10) SVBONY 5V dew heater strip, 25cm long with linear temperature control for telescopes and DSLR lenses. Pros: - Linear temperature control fine-tunes heat output to conditions - 5V power runs from standard USB power banks - 25cm length suits small telescopes and camera lenses Cons: - Short 25cm strip will not wrap larger optics - Low-voltage heat may struggle on very cold, humid nights Details: https://stargazernest.com/product/B07R299MQT ### 3. SVBONY SV192 Dew Heater Strip 560 mm Lens Heater Warmer for Telescope DSLR Camera Lens Our score: 7.9/10 (Fit for the job 9/10 · Features and specs 7/10 · Build and materials 7/10 · Value 8/10) SVBONY SV192 dew heater strip, 560 mm long, for keeping telescope and DSLR camera lenses clear of dew. Pros: - 560 mm length fits larger telescope tubes and big camera lenses - Prevents dew from ruining long astrophotography sessions - Simple wrap-around strip is easy to attach and remove Cons: - Check controller features, since some heater strips are on or off only - Larger strip draws more power from batteries or power banks Details: https://stargazernest.com/product/B08YJZ46VQ ### 4. Dew-Not Dew Heater Strip 9 inch DN03 Our score: 7.7/10 (Fit for the job 9/10 · Features and specs 6/10 · Build and materials 7/10 · Value 8/10) Dew-Not dew heater strip DN03, 9 inch, for keeping telescope objectives and corrector plates dew-free. Pros: - 9 inch size suits mid-size telescope dew shields and correctors - Proven Dew-Not design used by many amateur astronomers - Keeps optics clear for long observing and imaging sessions Cons: - Controller and power supply are not included - Must match your tube size, so measure before ordering Details: https://stargazernest.com/product/B003UNR43U ### 5. Celestron Smart DewHeater Controller 2X Our score: 7.5/10 (Fit for the job 7/10 · Features and specs 8/10 · Build and materials 8/10 · Value 7/10) Celestron Smart DewHeater Controller 2X, a controller that manages dew heater strips on telescopes and lenses. Pros: - Smart controller automatically adjusts heat based on conditions - 2X design powers two dew heaters at once - Celestron quality integrates well with their dew strip range Cons: - Controller only, so heater strips must be bought separately - Needs a suitable field power supply, which adds another battery to carry Details: https://stargazernest.com/product/B09Y2HDX13 ### 6. DewNot 3 inch Dew Heater Strip DN004 Our score: 7.3/10 (Fit for the job 8/10 · Features and specs 6/10 · Build and materials 7/10 · Value 8/10) DewNot 3 inch dew heater strip, DN004, sized for eyepieces, finders and small optics. Pros: - 3 inch size is ideal for eyepieces and finder objectives that fog first - Dedicated astronomy brand focused on dew prevention - Low power draw is efficient for small targets Cons: - Requires a separate controller and power source - Too small for main telescope objectives or wide dew shields Details: https://stargazernest.com/product/B003UNN8Z8 ### 7. DewNot 4 inch Dew Heater Strip DN005 Our score: 7.3/10 (Fit for the job 8/10 · Features and specs 6/10 · Build and materials 7/10 · Value 8/10) DewNot 4 inch dew heater strip, DN005, for small telescopes, finders and camera lenses. Pros: - 4 inch size fits small refractors, finders and camera lenses - Efficient heating prevents dew with minimal power - Durable strip from an astronomy-focused brand Cons: - Separate controller needed for adjustable heat - Limited to small optics, so bigger scopes need larger strips Details: https://stargazernest.com/product/B003UNSK74 As an Amazon Associate I earn from qualifying purchases.