OCAL 4.0 Electronic Collimator

A Camera-Based System with 0.08 mm Theoretical Accuracy

The OCAL 4.0 works by displaying a live video feed of your telescope's optical components on your computer or tablet screen. This removes the errors that differences between people's eyes cause with traditional collimation tools, and you see the secondary and primary mirrors line up in real time. The system's core principle is to align the centers of all optical elements, achieving a theoretical precision of 0.08 mm for a perfectly concentric optical train.

While the final result depends on your telescope's mechanical tolerances, this method provides a direct, data-driven view of your alignment. The software overlays colored circles and crosshairs, turning the abstract task of collimation into a simple process of centering circles and aligning lines on a screen.

M42 Thread with 1.25" and M48 Adapters

The OCAL 4.0 is designed to be installed at the same focal plane as your imaging camera sensor for the most accurate results. It features a female M42 thread for direct mounting to focusers or coma correctors with a matching male thread. To ensure compatibility with a wide range of equipment, OCAL includes two essential adapters.

• M42-to-1.25" Adapter: Allows you to insert the collimator into any standard 1.25" focuser or visual back, treating it like a typical eyepiece.
• M42-to-M48 Adapter Ring: For equipment with an M48 thread.

4:3 Display Ratio Software for Windows, macOS, and Android

OCAL provides dedicated software for Windows (7 and newer), macOS (via the Mac App Store), and Android devices, connecting via a standard USB-A to USB-C cable. An OTG adapter is included for connecting to phones and tablets. The 4.0 model uses an improved CMOS sensor with a 4:3 aspect ratio, which more efficiently displays the circular mirrors and internal structures of the telescope compared to widescreen 16:9 formats.

Each OCAL 4.0 has a unique factory center calibration code tied to its serial number, which you enter into the software once. Save it in the software. An offset of 4 to 8 pixels is normal and can be corrected with the Center Offset function. The software's live view shows alignment shifts instantly as you make adjustments to your telescope's collimation screws.

The 4-Step Newtonian Collimation Method

For Newtonian reflectors, the OCAL software enables a straightforward, repeatable 4-step collimation process. Collimation can be done in daylight by pointing the scope at the sky or at night using a flat, even light source such as a computer screen or a brightly lit wall.

1. Secondary Mirror Positioning: Size the red circle to the primary and the green circle to the secondary's edge, rotate the secondary roughly toward you, correct its elevation with screw A, then align its left and right edges with the green circle using screws B and C.
2. Separate Secondary and Primary Positioning: Rotate the secondary slightly so the red circle sits evenly on the primary left and right, then use screw A to close the vertical gap.
3. Secondary Mirror Height: By observing the green circle's fit against the edge of the secondary mirror, you adjust the central screw to raise or lower the mirror until it is perfectly framed.
4. Primary Mirror Adjustment: Finally, you adjust the primary mirror's collimation screws until the crosshair aligns with the spider vanes, the blue circle is concentric with the collimator's reflection, and the primary center mark falls inside the black circle on the 4.0.

OCAL 4.0 vs. OCAL 3.0 MAX: Key Upgrades

The 4.0 is an upgrade over the 3.0 MAX in image quality and stability. The 3.0 MAX retains a slight advantage with a larger lens aperture, but the 4.0 introduces several key improvements for practical use.

• Image Quality and Clarity: The OCAL 4.0 uses a higher-pixel CMOS sensor, which shows clearer primary mirror markers and richer reflection details.
• Optimized Display: It moves to a 4:3 screen ratio, providing a more efficient view of the telescope's circular optical components compared to the 16:9 ratio on previous models.
• Improved Stability: With a smaller and lighter body, the 4.0 is not afraid of slight bumps and shakes in daily use and keeps its calibration accuracy.