Celestron 93625 T-Adapter for Schmidt-Cassegrain Telescopes

Prime focus astrophotography with a Schmidt-Cassegrain telescope often fails at the connection point: the camera won't mate securely to the telescope's rear cell, causing vignetting, tilt, and lost light. The Celestron 93625 T-Adapter eliminates that weak link. It threads directly onto the 2-inch, 24 TPI SCT thread of your telescope's visual back and provides a standard T-thread (M42 x 0.75 mm) on the camera side. Add a T-ring for your specific camera mount, and you have a rigid, light-tight, perfectly aligned imaging train. No more guesswork, no more wobble — just crisp, full-frame astrophotos.

Who is it for

This adapter is built for astrophotographers using Celestron or compatible Schmidt-Cassegrain telescopes (C5, C6, C8, C9.25, C11, C14, EdgeHD, and similar) who want to attach a DSLR or mirrorless camera at prime focus. It is equally suited to beginners moving beyond afocal smartphone shots and to experienced imagers who demand repeatable, solid connections. If you already own a T-ring for your camera brand, this adapter completes the optical chain in seconds.

Main features

• Direct SCT thread: 2" x 24 TPI screws onto the telescope's rear cell or visual back — no additional adapters needed.
• Standard T-thread (M42 x 0.75 mm): accepts any camera-specific T-ring for DSLR or mirrorless bodies.
• Precision-machined anodized aluminum: lightweight, durable, and resistant to corrosion.
• 38 mm optical path length: maintains correct back focus for most SCTs without extra spacers.
• Wide 42 mm clear aperture: prevents vignetting on full-frame sensors.
• Matte black internal finish: reduces stray reflections and improves contrast.

Specifications

• Adapter type: T-Adapter
• Telescope compatibility: Schmidt-Cassegrain (SCT) telescopes
• Telescope connection thread: SCT thread (2" x 24 TPI)
• Camera connection thread: T-thread (M42 x 0.75 mm)
• Optical path length: 38 mm (1.5 inches)
• Internal diameter (camera side): 42 mm
• External diameter (telescope side): 51 mm
• Material: Anodized aluminum
• Colour: Black
• Required accessory: T-ring (specific to camera brand/mount)

Tips

Always attach the T-ring to your camera body first, then thread the adapter onto the T-ring. Finally, thread the entire assembly onto the telescope's visual back. For best results, use a Bahtinov mask to achieve precise focus. If your telescope has a 1.25" visual back, you will need an SCT-to-1.25" adapter (not included). Store the adapter in a dust-free case when not in use to protect the threads.