Astrozap Focusing Cap for 6" SCT

AstroZap AZ-423 Focusing Cap for 6" SCT

Achieving razor-sharp focus is one of the most critical steps in astrophotography—and also one of the most frustrating. The AstroZap AZ-423 focusing cap is a clever dual-purpose solution designed specifically for 6" Schmidt-Cassegrain telescopes. It combines a precision Bahtinov mask with a durable aluminum front cover, making it easy to nail focus and protect your optics in a single accessory.

The AZ-423 works by producing a distinctive diffraction spike pattern when aimed at a bright star. As you adjust focus, the central spike moves between two angled spikes. When the central spike is centered, you’re in perfect focus. This method is faster, more accurate, and more repeatable than guessing by eye, especially with the unforgiving demands of high-resolution imaging.

Unlike traditional Bahtinov masks that attach with rubber bands or clip-on tabs, this version is permanently mounted inside a custom-machined cap. It installs just like your regular dust cover—quick, secure, and easy to handle even with gloves on in cold weather. And because it's made of lightweight aluminum instead of plastic, there's no risk of warping over time or in temperature swings. The entire cap is finished in a textured black powder coat that looks as sharp as the images it helps you produce.

The AZ-423 is designed to fit snugly over the front cell of standard 6" SCTs, including Celestron and Meade models. Whether you’re using a DSLR, a cooled astro camera, or just trying to wring every last bit of sharpness from your visual sessions, this cap is an essential tool. Sharp stars are just one alignment away.

Key Features:

• Integrated Bahtinov mask built into a durable front cap

• Designed with  6" Schmidt-Cassegrain telescopes in mind

• Machined from lightweight aluminum—strong, stable, and warp-resistant

• Textured black powder-coated finish resists wear and looks great in the field

• Precision laser-cut mask provides fast, repeatable focusing

• Installs like a standard dust cover—no clips, cords, or clamps

• Ideal for imaging or critical visual work

• 180mm-190mm