In daily astrophotography, users often experience unsatisfactory image results due to the focuser or camera sensor is not flat. As sensor sizes increase, the need for greater precision in adjustments increases. Users need to ensure the focal plane is perpendicular to the optical axis of the system. The Askar focal plane adjuster helps make precise adjustments to the tilt of the focuser or camera sensor, improving image quality. Currently, most common focal plane adjusters use a three-point push-pull mechanism. While adjusting the tilted angle, the relative distance between the two ends changes, which will affect the back focus, thus impacting the star quality at the edges of the image.The Askar focal plane adjuster uses a unique spherical adjustment design. This method adjusts the tilt angle without affecting the relative distance, ensuring more accurate and consistent adjustments.