Home Astrophotography Accessories by Optec Astro-Physics 2.7-inch Threaded Extension Rings, Adapters and Retaining Rings
Astro-Physics 2.7-inch Threaded Extension Rings, Adapters and Retaining Rings
Astro-Physics 2.7-inch Threaded Extension Rings, Adapters and Retaining Rings
Astro-Physics 2.7-inch Threaded Extension Rings, Adapters and Retaining Rings
Astro-Physics 2.7-inch Threaded Extension Rings, Adapters and Retaining Rings
Astro-Physics 2.7-inch Threaded Extension Rings, Adapters and Retaining Rings
Astro-Physics 2.7-inch Threaded Extension Rings, Adapters and Retaining Rings
Astro-Physics 2.7-inch Threaded Extension Rings, Adapters and Retaining Rings
Astro-Physics 2.7-inch Threaded Extension Rings, Adapters and Retaining Rings
Astro-Physics 2.7-inch Threaded Extension Rings, Adapters and Retaining Rings
Astro-Physics 2.7-inch Threaded Extension Rings, Adapters and Retaining Rings
Astro-Physics 2.7-inch Threaded Extension Rings, Adapters and Retaining Rings

    Optec

    Astro-Physics 2.7-inch Threaded Extension Rings, Adapters and Retaining Rings

    $ 165.00
    $ 165.00

    This item is out of stock but you can place an order now and we’ll ship when it becomes available.

    Description

    Telescope Adapters and Extensions for the AstroPhysics 2.7 thread

    Extensions, Adapters and Retaining Rings

    The ubiquitous AP2.7 inch thread has become an astronomy industry standard thanks to the tireless efforts of Roland and his team at Astro-Physics.   Optec has produced an extension set and a few new adapters in an effort to extend this industry standard. 

    Optec's AP 2.7-inch extension tubes feature female threads on one end with male threads on the opposite end with knurled bases to help attach and detach these tubes.  The extensions can be combined and stacked. We believe our four and five piece sets will provide all the needed extension for fixed focal length telescopes with 1/4" (6.35mm) increments using a minimum number of pieces.  

    All extensions and mounts are made from high strength 6061 aluminum alloy and black anodized.  Anti-reflection threading and internal baffles on the largest extension tube help minimize internal reflections.  All internal surfaces are painted and baked with a non-reflecting ultra-flat black paint. 

    Specifications

    • Spacer Lengths Available: 1/2", 3/4", 1", 1-1/2", and 3"
    • Clear Aperture: 2.52" (64mm)

    Extension Tube Sets

    Stock #19880
    AP2.7 Extension Tube Set, 4-piece set
    • Includes: 1/2", 3/4", 1", and 1-1/2"
    • Possible spacer combinations:
      0.5" through 3.25" with 1/4-inch increments plus 3.75" with all spacers combined.  (See Table below for combinations.)

     
    Stock #19881
    AP2.7 Extension Tube Set, 5-piece set
    • Includes:  1/2", 3/4", 1", 1-1/2", and 3"
    • Possible spacer combinations:  
      0.5" through 6.25" with 1/4-inch increments plus 6.75" with all spacers combined.  (See Table below for combinations.)

    Individual Extension Tubes and Retainers

    Stock #19882
    AP2.7 Extension - 1/2" Length
    • Overall Height: 0.88"  (22.4mm)
    • Clear Aperture: 2.52" (64mm)
    • Weight: 1.0 oz (30 g)
    • Back-focus Usage: 0.50" (12.7mm)

     
    Stock #19883
    AP2.7 Extension - 3/4" Length
    • Overall Height: 1.13" (28.7mm)
    • Clear Aperture: 2.52" (64mm)
    • Weight: 1.4 oz (40 g)
    • Back-focus Usage: 0.75" (19.1mm)

    Stock #19884
    AP2.7 Extension - 1" Length
    • Overall Height: 1.38" (35.0mm)
    • Clear Aperture: 2.52" (64mm)
    • Weight: 1.8 oz (55 g)
    • Back-focus Usage: 1.00" (25.4mm)

    Stock #19885
    AP2.7 Extension - 1-1/2" Length
    • Overall Height: 1.87"  (47.5mm)
    • Clear Aperture: 2.52" (64mm)
    • Weight: 2.4 oz (70 g)
    • Back-focus Usage: 1.50" (38.1mm)

    Stock #19886
    AP2.7 Extension - 3" Length
    • Overall Height: 3.38" (85.8mm)
    • Clear Aperture: 2.52" (64mm)
    • Weight: 8.2 oz (230 g)
    • Back-focus Usage: 3.00" (76.2mm)

    Stock #19887

    AP2.7 Male-to-Male Adapter

    • Includes #19888
    Stock #19888
    AP2.7 Retaining Ring
    • Overall Height: 0.10" (2.5mm)
    • Outside Diameter: 3.5" (88.9mm)
    • Clear Aperture: 2.69" (68 mm)
    • Weight: 0.6 oz (15 g)
    • Anodize:  Gold

    Target Extension

    Spacers Required

    AP2.7 Spacer Stock Numbers

    DSI 3.5x24 Stock Numbers

    0.50”

    ½”

    19882

    19891

    0.75”

    ¾”

    19883

    19892

    1.00”

    1”

    19884

    19893

    1.25”

    ½” + ¾”

    19882, 19883

    19891, 19892

    1.50”

    1-½”

    19885

    19894

    1.75”

    1” + ¾”

    19884, 19883

    19893, 19892

    2.00”

    1-½” + ½”

    19885, 19882

    19894, 19891

    2.25”

    1-½” + ¾”

    19885, 19883

    19894, 19892

    2.50”

    1-½” + 1”

    19885, 19884

    19894, 19893

    2.75”

    1-½” + ¾” + ½”

    19885, 19883, 19882

    19894, 19892, 19891

    3.00”

    3”

    19886

    19895

    3.25”

    1-½” + 1” + ¾”

    19885, 19884, 19883

    19894, 19893, 19892

    3.50”

    3” + ½”

    19886, 19882

    19895, 19891

    3.75”

    3” + ¾”

    19886, 19883

    19895, 19892

    4.00”

    3” + 1”

    19886, 19884

    19895, 19893

    4.25”

    3” + ¾” + ½”

    19886, 19883, 19882

    19895, 19892, 19891

    4.50”

    3” + 1-½”

    19886, 19885

    19895, 19894

    4.75”

    3” + 1” + ¾”

    19886, 19884, 19883

    19895, 19893, 19892

    5.00”

    3” + 1-½” + ½”

    19886, 19885, 19882

    19895, 19894, 19891

    5.25”

    3” + 1” + ¾” + ½”  

    19886, 19885, 19883, 19882

    19895, 19893, 19892, 19891

    5.50”

    3” + 1-½” + 1”

    19886, 19885, 19884

    19895, 19894, 19893

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