Astrozap Focusing Cap w/ Built-In Bahtinov Focusing Mask for 11" Schmidt-Cassegrains and Similar Scopes

AstroZap Focusing Cap with Built-In Bahtinov Mask – 11" SCT and Similar OTAs

When you're working with a high-powered telescope like an 11" Schmidt-Cassegrain, even the smallest focus error can rob your images of detail. The AstroZap Focusing Cap with Built-In Bahtinov Mask helps you achieve pinpoint focus quickly and reliably—without adding extra steps or accessories to your setup.

This smart, dual-purpose design functions as both a dust cap and a precision Bahtinov mask, purpose-built to fit 11" SCTs and similar front-cell diameters. When it’s time to focus, just slide open the internal shutter to expose the Bahtinov mask embedded in the cap. A bright star will instantly produce a trio of diffraction spikes on your camera or live view screen. Adjust your focuser until the center spike aligns perfectly between the outer two—and you’re dialed in.

When focus is locked, simply slide the shutter closed and your corrector is once again protected from dust and debris. It’s a seamless solution for imagers and serious observers who want faster setup, fewer moving parts, and more reliable results.

Features:

• Custom fit for 11" Schmidt-Cassegrain telescopes and similar OTAs

• Built-in Bahtinov mask makes critical focusing fast and repeatable

• Sliding shutter reveals or conceals the mask—no removal needed

• Durable plastic construction with a precision-cut diffraction pattern

• Dual-function design acts as both focusing tool and dust cap

• Ideal for astrophotography and high-resolution visual observing

Observing Tip:

This is the kind of tool you’ll wonder how you ever lived without. Whether you’re setting up a deep-sky imaging run or focusing for a high-magnification planetary session, this built-in Bahtinov design saves time and increases accuracy. Best of all, you’ll never forget it at home—it’s already on your scope.