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Optec

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


  • 11500

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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