Skip to content

Filter wheels

Astromania 2 in five-position filter wheel (FW2M5)

A manual filter wheel holding five 2 in filters in an aluminium body, with a 2 in adapter on the telescope side and T-2 and M48 threads on the camera side.

Astromania five-position 2 inch filter wheel

Astromania 2 in five-position filter wheel (FW2M5)

A manual filter wheel holding five 2 in filters in an aluminium body, with a 2 in adapter on the telescope side and T-2 and M48 threads on the camera side.

Slot count and filter size
Five, numbered 1 to 5 · 2 in (5.1 cm) standard filters · T-2 and M48, as the maker states them
Optical path length
The focuser must travel about 20 mm further inward than normal, as the maker states it
Manual or motorised operation
A filter wheel — the only one in this group · Supplied with a 2 in adapter for the focuser
Light sealing
Aluminium, described by the maker as suitable for heavy cameras
Power
Not published by the maker.
Software support
Not published by the maker.
Amazon reference
B0140UA9F6 (same reference on 6 Amazon marketplaces)
EAN
6970019290355
  • Publishes the 20 mm of inward focus it consumes, which is the figure that decides whether it works at all
  • Two accessory threads — T-2 and M48 — cover most imaging trains
  • Twenty millimetres of inward focus is more than some refractors have to give

Best for: A Newtonian or Dobsonian imaging train where back focus is short and filters change often

≈ $91 / £95 / €105
Check price on Amazon

Specifications

Slot count and filter size
Five, numbered 1 to 5 · 2 in (5.1 cm) standard filters · T-2 and M48, as the maker states them
Optical path length
The focuser must travel about 20 mm further inward than normal, as the maker states it
Manual or motorised operation
A filter wheel — the only one in this group · Supplied with a 2 in adapter for the focuser
Light sealing
Aluminium, described by the maker as suitable for heavy cameras
Power
Not published by the maker.
Software support
Not published by the maker.
Amazon reference
B0140UA9F6 (same reference on 6 Amazon marketplaces)
EAN
6970019290355

The only actual wheel here

Five numbered positions, each taking a standard 2 in filter, in an aluminium housing the maker describes as stiff enough for a heavy camera. Everything else filed under this heading on the shelf is an adapter or a drawer.

The figure that decides compatibility

About 20 mm of additional inward focus travel. A wheel occupies space in the light path, and the focuser has to compensate. Astromania publishes the number, which means a buyer can check their own focuser travel first — the single most common reason a filter wheel ends up unused.

The threads

T-2 and M48 on the accessory side, a 2 in adapter on the telescope side. That covers a camera with a T-ring, a camera with an M48 nose, and a focuser with a 2 in receptacle. Three of the four common cases, without a further purchase.

Short build, and who needs it

The maker makes a point of the short construction and names Newtonians and Dobsonians. Those instruments have little room behind the focuser, and a tall accessory simply will not reach focus on them.

Availability

German, French, Italian and Spanish Amazon stores ran from 105 € to 109 € 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 filter wheels

  • ASToptics M54 male to T2 female adapter

    ASToptics M54 male to T2 female adapter (57801)

    A thread adapter from M54 male to T2 female, whose entire listing consists of generic statements about quality.

    Slot count and filter size
    M54 male, from the title · T2 female, from the title · Not stated for either thread
    Optical path length
    The listing gives none
    Manual or motorised operation
    A thread adapter — no optics, and not a filter wheel
    Light sealing
    Not stated
    Power
    Not published by the maker.
    Software support
    Not published by the maker.
    Amazon reference
    B0BPXFY2VT (same reference on 5 Amazon marketplaces)
    EAN
    4049467578017
    • M54 to T2 is a conversion the larger imaging trains genuinely need
    • From a maker whose range is sold through astronomy specialists
    • Five bullets and not one measurement, material or figure among them

    Best for: An M54 imaging train that has to meet a T2 camera fitting

    ≈ £36 / €39
    Check price on Amazon
  • Briny River M42 to M48 anodised aluminium step-up ring

    Briny River M42 to M48 step-up ring (390-EG)

    A step-up ring converting the T-2 thread to M48, so that 2 in filters and M48 accessories can be fitted to T-2 components.

    Slot count and filter size
    M42 × 0.75 male — the T-2 thread · M48 × 0.75 female — the 2 in filter thread
    Optical path length
    The listing gives none
    Manual or motorised operation
    A thread adapter — no optics, and not a filter wheel
    Light sealing
    Aluminium alloy, anodised
    Power
    Not published by the maker.
    Software support
    Not published by the maker.
    Amazon reference
    DE B0FM49SGJH · US B0FM48JF46 · GB B0FM48JF46 · FR B0FM48JF46 · IT B0FM48JF46 · ES B0FM48JF46
    EAN
    4895264934644
    • Both threads are named precisely with pitch, which is what an adapter listing must do
    • Anodised aluminium resists the corrosion that ruins a thread left damp
    • No length figure, and every adapter consumes back focus

    Best for: Putting an M48 filter or accessory onto a T-2 threaded component

    ≈ €9
    Check price on Amazon
  • ECSiNG M48 to M42 double-male adapter ring

    ECSiNG M48 male to M42 male adapter

    A male-to-male ring joining M48 × 0.75 to M42 × 0.75 with the shortest possible mechanical length, blackened inside against reflections.

    Slot count and filter size
    M48 × 0.75 and M42 × 0.75, both male
    Optical path length
    Described as the minimum mechanically possible; no figure is given
    Manual or motorised operation
    A thread adapter — no optics, and not a filter wheel
    Light sealing
    Aluminium, anodised black with a matt internal wall
    Power
    Not published by the maker.
    Software support
    Not published by the maker.
    Amazon reference
    B0C7BYJ588 (same reference on 5 Amazon marketplaces)
    EAN
    4895243557307
    • The matt internal finish addresses internal reflections, which few adapter listings mention
    • Both threads are named with their pitch
    • A double-male ring only helps where both sides are female — which is not every junction

    Best for: Joining two female-threaded components of different sizes in an imaging train

    ≈ €10
    Check price on Amazon

The rest of this rack

  • EBTOOLS 2 inch to T2 telescope camera adapter

    EBTOOLS 2 in to T2 adapter

    A 2 in nosepiece adapter carrying a T2 male thread for the camera and an M48 internal thread for a filter, with a fully matted bore.

    Reduction factor
    Not published by the maker.
    Required back focus
    Not published by the maker.
    Image circle
    Not published by the maker.
    Corrector function
    Not published by the maker.
    Thread standards
    2 in nosepiece for a 2 in focuser · M42 × 0.75 male — the T2 thread · M48 × 0.75 internal, at the front
    Vignetting
    “Full frame with 2 inch, no dark corners”, as the maker states it
    Housing
    Fully matted internal thread; black hard-anodised outside
    Amazon reference
    B07MCH2CVN (same reference on 5 Amazon marketplaces)
    EAN
    0719527383403
    • Carries an M48 filter thread at the front, so a 2 in filter fits in the same part
    • Fully matted bore, which matters immediately in front of a sensor
    • The no-dark-corners claim is made without naming a sensor size

    Best for: Putting a T2-threaded camera into a 2 in focuser with a filter in the path

    ≈ £15 / €15
    Check price on Amazon
  • ECSiNG M48 to M42 adapter ring in black anodised aluminium

    ECSiNG M48 to M42 double-male adapter

    An anodised aluminium ring with M48 × 0.75 and M42 × 0.75 male threads, blackened inside, containing no optical element at all.

    Reduction factor
    Not published by the maker.
    Required back focus
    Not published by the maker.
    Image circle
    Not published by the maker.
    Corrector function
    Not published by the maker.
    Thread standards
    M48 × 0.75 and M42 × 0.75, both male
    Vignetting
    Not published by the maker.
    Housing
    Aluminium, black anodised, matt internal wall
    Amazon reference
    B0C773T289 (same reference on 5 Amazon marketplaces)
    EAN
    4895243556683
    • Both threads named with their pitch
    • A matt bore, which reduces the reflections a shiny adapter introduces
    • It reduces nothing: the category is wrong and this page says so

    Best for: Joining a female M48 component to a female T2 one

    ≈ £10 / €12
    Check price on Amazon
  • Oumij1 0.5x focal reducer with M28.5 thread

    Oumij1 0.5x reducer, M28.5 × 0.6

    A 0.5x reducer for 1.25 in eyepiece noses in an aluminium housing, with the same stated exclusions as its twin listing.

    Reduction factor
    0.5x, per the maker
    Required back focus
    Not published by the maker.
    Image circle
    Not published by the maker.
    Corrector function
    Focal reducer with optics
    Thread standards
    M28.5 × 0.6 — the standard 1.25 in filter thread · Screws onto the nose of a 1.25 in eyepiece
    Vignetting
    Not published by the maker.
    Housing
    Aluminium alloy
    Amazon reference
    B093ZSLSDJ (same reference on 4 Amazon marketplaces)
    EAN
    9182438203992
    • The thread is named correctly, which several neighbours on this shelf fail to do
    • The exclusions are published rather than discovered
    • Shares its entire description with another listing

    Best for: A second reducer, or a first one where price decides

    ≈ €21
    Check price on Amazon

All filter wheels