Astrozap Focusing Cap w/ Built-In Bahtinov Focusing Mask for 12" Schmidt-Cassegrains and Similar Scopes

AstroZap Focusing Cap with Built-In Bahtinov Mask – 12" SCT and Similar OTAs

If you’re imaging through a 12" SCT or similar optical tube, you know how critical fine focus is—and how easy it is to miss without help. The AstroZap Focusing Cap with Built-In Bahtinov Mask takes the guesswork out of focusing by combining two essential tools into one: a protective dust cap and an integrated Bahtinov focusing mask, all in one sleek package.

This version is precision-fit for 12" Schmidt-Cassegrain telescopes and other scopes with similar front-cell diameters. Instead of juggling separate masks or trying to line up gear in the dark, just slide the internal shutter open to reveal the built-in Bahtinov pattern. Center the diffraction spikes using your camera’s live view or a focus aid, adjust until the middle spike is perfectly aligned—and you’re in razor-sharp focus, ready to capture fine lunar, planetary, or deep-sky detail.

When you're done focusing, slide the shutter closed, and the cap returns to its role as a full-time dust protector for your front corrector plate. No extra parts to lose, no hassle.

Features:

• Made for 12" Schmidt-Cassegrain telescopes and similar optical tubes

• Combines a standard protective cap with a built-in Bahtinov mask

• Sliding shutter design reveals or conceals the mask as needed

• Enables fast, accurate focus using diffraction spikes on bright stars

• Durable construction built to handle regular use in the field

• Ideal for both imaging and visual focusing with high-accuracy optics

Observing Tip:

Don’t let soft focus ruin a great night of imaging. With this built-in Bahtinov solution, you can lock in perfect focus even under mediocre seeing conditions. The diffraction spike pattern is easy to interpret and far more accurate than trying to guess by eye or rely solely on software-driven autofocus.