Cloud Break Optics

12.5mm OPTEC-4300 Extension (19829)

12.5mm OPTEC-4300 Extension (19829) - Main image
$60 $100 In stock

Category: Astrophotography Accessories

Description

The OPTEC-4300 12.5mm Extension Ring provides approximately 1/2-inch of extension for any OPTEC-4300 telescope adapter. Ideal for telescopes where the Gemini Focusing Rotator may need to pushed out and away from the OTA to provide clearance for cooling fans or when a little extension is required to reach optimal focus.

Specifications

Inside Diameter: 3.9" (99mm)
Outside Diameter: 4.95" (126mm)

Overall Height:

0.81" (20.6mm)
Clear Aperture: 3.9" (99mm)
Weight: 5.0 oz (145 g)
Back-Focus Usage: 0.492" (12.5mm)

The OPTEC-4300 12.5mm Extension Ring provides approximately 1/2-inch of extension for any OPTEC-4300 telescope adapter.  

Compatibility

  • Any OPTEC-4300 telescope adapter.
  • Gemini Focusing Rotator.
  • TCF-Lynx3 3-inch Focuser.
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Standard Shipping · United States: $0.00

Express Shipping · United States: $3.99

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United States · Return window (days after delivery): 30. Return method: By mail. Return postage: Seller pays.

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Customer Reviews (4.8 / 5 · 5 reviews)

Eva P. ★★★★★

Had a slight backfocus issue with my imaging train, and this 12.5mm ring dialed it in perfectly. The 1/2-inch extension fits snugly into my OPTEC-4300 adapter threads without any play. Finicky spacing problems solved in one simple add-on.

Eli Y. ★★★★★

Putting this between my reducer and camera gave me exactly the back focus I needed for flat stars. The threads are smooth and it feels solidly machined.

Hannah ★★★★★

That 12.5mm ring snapped into my imaging train perfectly and gave me the exact spacing I needed. The fit on my OPTEC-4300 adapter is snug and secure—no wobble at all.