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Dew control

ASToptics HazeAway USB heater strip 30 cm (49556)

A 30 cm dew heater strip that wraps around the tube and runs from common 12 V power sources, for long observing and imaging sessions.

ASToptics HazeAway 30 cm dew heater strip on a telescope tube

ASToptics HazeAway USB heater strip 30 cm (49556)

A 30 cm dew heater strip that wraps around the tube and runs from common 12 V power sources, for long observing and imaging sessions.

Tube fit
Not published by the maker.
Outside diameter
Not published by the maker.
Shield length
30 cm; the maker states other lengths exist for other apertures
Construction
Electrically heated dew strip — it warms the tube rather than shielding it
Heater width
Described as even
Power draw
Compatible with common 12 V sources, per the maker · The listing gives none
Controller support
Not published by the maker.
Cable
USB, from the product name
Connector
Not published by the maker.
Amazon reference
B0BPXKKMVC (same reference on 6 Amazon marketplaces)
EAN
4049467495567
  • A heater works where a shield fails: on a night when dew forms regardless
  • Several lengths exist, so the strip can match the tube circumference
  • No power draw figure, which is what decides battery life

Best for: Imaging sessions where a shield alone does not keep the corrector clear

≈ £91 / €103
Check price on Amazon

Specifications

Tube fit
Not published by the maker.
Outside diameter
Not published by the maker.
Shield length
30 cm; the maker states other lengths exist for other apertures
Construction
Electrically heated dew strip — it warms the tube rather than shielding it
Heater width
Described as even
Power draw
Compatible with common 12 V sources, per the maker · The listing gives none
Controller support
Not published by the maker.
Cable
USB, from the product name
Connector
Not published by the maker.
Amazon reference
B0BPXKKMVC (same reference on 6 Amazon marketplaces)
EAN
4049467495567

Heating rather than shielding

A dew shield restricts the objective’s view of the sky and delays dew. A heater strip keeps the glass a little above the dew point so dew never forms. On the worst nights — still, damp, clear — only the second works.

The length question

Thirty centimetres here, with other lengths named for other apertures. The strip has to go round the tube at the front, so the right length is a matter of circumference rather than aperture. A strip too short leaves a cold gap; one too long overlaps and wastes power.

The power figure that is missing

Nothing is published about how much it draws. That is what decides whether a power bank lasts the night, and it is the one number an imaging session needs.

The controller question

Run at full power, a heater warms the glass more than necessary and sets up turbulence in the light path. A controller keeps it just above the dew point. None is mentioned here, and it is the usual accompanying purchase.

Availability

German, French, Italian and Spanish Amazon stores ran from 103 € to 106 € on the day of the survey.

American and British Amazon stores list it in local currency, which the euro range above sets aside.

Figures as Keepa reported them on the day this page was last updated. Stock and pricing shift without warning.

Prices quoted in this text were read on 17 September 2026. The live price is at the top of the page.

What this fits

More dew control

  • Explore Scientific dew cap fitted to a Telrad finder

    Explore Scientific Dew cap for the Telrad finder (620225)

    A dew cap for the Telrad projection finder, preventing the projection window fogging and covering it when the finder is not in use.

    Tube fit
    The Telrad projection finder, named by the maker
    Outside diameter
    Not published by the maker.
    Shield length
    Not published by the maker.
    Construction
    Dew cap for a projection finder · Impact-resistant plastic
    Heater width
    Not published by the maker.
    Power draw
    Not published by the maker.
    Controller support
    Not published by the maker.
    Cable
    Not published by the maker.
    Connector
    Not published by the maker.
    Amazon reference
    B07VG8B9CD (same reference on 5 Amazon marketplaces)
    EAN
    4007922063492
    • Addresses the single commonest failure of a projection finder on a damp night
    • Doubles as a cover, so it earns its place in the case twice
    • Made for one named finder only

    Best for: A Telrad owner whose finder fogs before the telescope does

    ≈ €29
    Check price on Amazon
  • Omegon flexible dew shield for 8 inch telescopes

    Omegon Flexible dew shield 8 in (225–245 mm)

    A flexible plastic dew shield with a velvet inner finish for tubes of 225 to 245 mm outside diameter, closed with hook-and-loop.

    Tube fit
    225 to 245 mm, from the title
    Outside diameter
    Not published by the maker.
    Shield length
    Neither is published
    Construction
    Flexible wrap-around dew shield · Flexible plastic with a black textile velvet finish inside · Hook-and-loop
    Heater width
    Not published by the maker.
    Power draw
    Not published by the maker.
    Controller support
    Not published by the maker.
    Cable
    Not published by the maker.
    Connector
    Not published by the maker.
    Amazon reference
    B00X5KH8SE (same reference on 6 Amazon marketplaces)
    EAN
    4049467457848
    • Covers the 8 in class, which is where dew is most expensive to fix
    • Velvet finish inside against both dew and reflections
    • Neither the height nor the length is published

    Best for: An 8 in Schmidt-Cassegrain or a 200 mm reflector on an autumn evening

    ≈ £88 / €96
    Check price on Amazon
  • Astromania flexible dew shield wrapped on a telescope tube

    Astromania Flexible dew shield 148–167 mm (FDS580)

    A flexible black ABS dew shield with a velvet lining and a foam contact strip, for tube outside diameters of 148 to 167 mm.

    Tube fit
    148 to 167 mm, as the maker publishes them
    Outside diameter
    Not published by the maker.
    Shield length
    200 mm, as the maker publishes it · 580 mm, as the maker publishes it
    Construction
    Flexible wrap-around dew shield · Black ABS, lined with a black velvet-like fabric · Non-slip foam rubber against the tube · Hook-and-loop, adjustable within the range
    Heater width
    Not published by the maker.
    Power draw
    Not published by the maker.
    Controller support
    Not published by the maker.
    Cable
    Not published by the maker.
    Connector
    Not published by the maker.
    Amazon reference
    B01LZPCQBV (same reference on 6 Amazon marketplaces)
    EAN
    6970019295695
    • Four published dimensions where most dew shields give one vague size
    • A velvet lining does two jobs: it absorbs moisture and it kills stray light
    • The diameter to measure is the tube outside, not the aperture — an easy mistake

    Best for: A 150 mm reflector or a Schmidt-Cassegrain whose front diameter has been measured

    ≈ $36 / £44
    Check price on Amazon

The rest of this rack

  • SG Store 90 mm finder dovetail base in black aluminium

    SG Store 90 mm finder guide base

    A 90 mm black anodised aluminium dovetail base for finders and guide scopes, published with all five of its mounting holes.

    Profile
    Not named as Vixen or otherwise
    Length
    90 mm, from the product name
    Hole spacing
    Two M8 and one 1/4 in, as the maker publishes them · Two of 7 mm
    Slots
    Not published by the maker.
    Material
    Black anodised aluminium alloy
    Thickness
    Not published by the maker.
    Safety stops
    Not published by the maker.
    Accessory holes
    Not published by the maker.
    Amazon reference
    B0FD3CPRWL (same reference on 6 Amazon marketplaces)
    EAN
    4895253946818
    • Every mounting hole is specified by thread and diameter
    • Both M8 and 1/4 in threads, which covers photographic and astronomical fittings
    • The dovetail profile is not named

    Best for: Adding a finder or a small guide scope to a tube that has the holes for it

    ≈ €14
    Check price on Amazon
  • Sky-Watcher Star Adventurer ball head adapter in green

    Sky-Watcher Star Adventurer ball head adapter (S20550)

    A green ball head adapter for the Star Adventurer, listed with two different post lengths both labelled 3/8 inch.

    Profile
    Not published by the maker.
    Length
    Not published by the maker.
    Hole spacing
    Not published by the maker.
    Slots
    Not published by the maker.
    Material
    Neither is published
    Thickness
    The listing gives “0.95 cm (3/8 in)” in one bullet and “1.9 cm (3/8 in)” in another; both are reproduced
    Safety stops
    Not published by the maker.
    Accessory holes
    Attaches a ball head to the Star Adventurer
    Amazon reference
    B00YWPCNJU (same reference on 6 Amazon marketplaces)
    EAN
    0050234205504
    • The part that makes a photographic ball head usable on a tracker
    • Made by the manufacturer of the mount
    • Two different post lengths are given for the same fitting

    Best for: Putting a photographic ball head on a Star Adventurer

    ≈ $18 / £22
    Check price on Amazon
  • Wisyurt 48 mm dovetail plate for a finder base

    Wisyurt 48 mm dovetail plate

    A short 48 mm metal dovetail plate for extending a telescope finder base to carry a smartphone mount or another accessory.

    Profile
    Not named
    Length
    48 mm (1.89 in), from the product name · Two bullets
    Hole spacing
    Not specified
    Slots
    Not published by the maker.
    Material
    Metal, not further specified
    Thickness
    Not published by the maker.
    Safety stops
    Not published by the maker.
    Accessory holes
    Extends the finder base to carry another accessory
    Amazon reference
    B0G6LHJQP6 (same reference on 5 Amazon marketplaces)
    EAN
    4894962836304
    • Very small and light, so it adds little to the top of a tube
    • Extends an existing base rather than requiring a new one
    • Neither the profile nor the hole pattern is specified

    Best for: Adding a second small accessory where a finder shoe already exists

    ≈ €9
    Check price on Amazon

All dew control