The new Sensor Tilt Xterminator (STX) is now included with:
- Ultra-Cat Series
For the standard tilt adjusting, please refer to Sensor Tilt Adjustment (Standard)
Overview
The Sensor Tilt Xterminator (STX) features 4 push-out knobs and 4 auto tension screws, arranged diagonally. This seesaw-style design allows for easy and accurate tilt correction with minimal effort.
Identify the Tilt Direction
First, let's examine a sensor with no tilt.
After achieving focus, if the camera sensor is positioned too far from the optical plane, star shapes will appear elongated in the tangential direction—stretching around the center of the frame.
Conversely, if the sensor is too close, the stars will stretch in the sagittal (radial) direction—pointing toward or away from the center.
▼ Sensor Too Far Away
▼ Sensor Too Close
Next, analyze the star field images taken with your current setup.
Identify the region where the stars are in best focus and appear round, as well as the area where star distortion is most severe. This comparison allows you to roughly map the direction and position of the sensor tilt axis. Based on the distortion pattern, you can then infer whether the sensor is positioned too close to or too far from the focal plane in that specific region.
Example A
Stars in the lower right are round, while those in the upper left show strong sagittal (radial) elongation—indicating the sensor is too close in that area.
Example B
Stars at the top are sharp and round, while those in the lower left show strong tangential elongation—indicating the sensor is too far in that area.
Tilt Adjustment
- Locate the pair of diagonally opposing screws corresponding to the affected corners.
- Use 2mm hex key to release (turn clockwise) the knob near the corner where the sensor is too far.
- Push out (turn counterclockwise) the opposite knob accordingly.
- Do not touch the Auto Tension Screws. It may disrupt balance or cause loosening.
- Make small adjustments — turn each knobs only about 1/8 turn at a time.
Any 2mm rod or hex key can be used to twist the knob mechanism.
- After each adjustment, perform a test exposure to check the star shape and alignment. Fine-tune as needed until the stars are round and sharp across the entire frame.
Tips & Notice
- Typical adjustment sessions take 2–4 test exposures to reach optimal flatness. However, fine-tuning may vary depending on your camera, filter, and backfocus setup.
- Tilt does not need to be adjusted frequently. Once set, it should remain stable unless major components (e.g., camera, tilt plate, or spacing) are changed.
- For best results, perform tilt adjustments in a stable environment (minimal temperature change, fully cooled optics and sensor).
- Avoid overtightening, which may deform the sensor platform or affect collimation.