Astrozap Focusing Cap - Built-In Bahtinov Focusing Mask for Celestron 4" or Meade ETX105 Maks

AstroZap Focusing Cap with Built-In Bahtinov Mask – For Celestron 4" Maks & Meade ETX105

Don’t let your compact telescope fool you—precise focus is just as critical on small optics as it is on the big rigs. Whether you're using a Celestron 4" Maksutov or a Meade ETX105, the AstroZap Focusing Cap with Built-In Bahtinov Mask brings professional-level focus accuracy to your grab-and-go setup.

This compact dual-purpose cap fits snugly over the corrector plate of your Mak or similar small-aperture telescope. Hidden behind a sliding shutter, the integrated Bahtinov focusing mask produces a crisp diffraction pattern when aimed at a bright star. As you fine-tune focus, the central spike shifts position—when it’s perfectly centered, you’re in sharp, repeatable focus. No trial and error. No wasted imaging frames.

When you’re done, simply close the shutter and the cap functions as a full dust shield, keeping your front element safe during transport and storage. It’s a fast, efficient, and compact upgrade that makes a big difference in your focusing workflow—especially valuable on smaller scopes with narrow focus tolerances.

Features:

• Designed for Celestron 4" Maksutov-Cassegrain and Meade ETX105

• Combines a Bahtinov focusing mask and protective dust cap in one unit

• Sliding shutter mechanism lets you switch modes in seconds

• Enables fast, precise focusing using the Bahtinov diffraction pattern

• Lightweight and compact—ideal for travel scopes and smaller OTAs

• Perfect for imaging or high-power lunar and planetary observing

Compatibility Note:

This cap is specifically sized for scopes with front cell diameters matching the Celestron 102mm Mak and Meade ETX105, and may also fit similar compact Maksutov-Cassegrain telescopes with ~4" apertures.

Observing Tip:

Small Maks and compact imaging scopes offer excellent contrast and portability—but they don’t give much room for focus error. This cap lets you focus faster and more confidently, which is especially helpful for planetary imaging, double star work, and public outreach where time matters.