In this tutorial, we will focus on the focusing workflow in StellaVita, starting from the electric focuser parameter settings, then completing coarse focus and auto focus, so that even beginners can obtain a smooth and accurate focus curve, laying the foundation for sharp and high-quality astrophotography images.

Set Electric Focuser Parameters in StellaVita

Before starting focusing, you need to configure the electronic focuser settings.

Tap Settings → Focuser. Set the following parameters according to your equipment and experience:

• Target position
• Maximum steps
• Reverse direction (if needed)
• Buzzer on/off
• Autofocus step size
• Backlash compensation step size

Notes:

1. When using the focuser for the first time, please set the zero position and maximum steps. It is recommended to set the fully retracted position as zero.

2. When reconnecting later, StellaVita will use the last known position as the current position.

3. When setting backlash compensation, the value should be slightly larger than the actual mechanical backlash.

4. If the focuser stops due to resistance, enabling the buzzer alert can remind the user to stop improper operation and prevent damage.

Coarse Focusing

Step 1: Enter Focus Mode

Open the function wheel and tap Focus. You can choose Single Mode or Video Mode.
Video mode provides faster real-time feedback.
Single frame mode is easier for observing star shapes, but takes longer to load.
Both modes can be used together depending on your preference.

Step 2: Star Preview

Using Video Mode as an example. Set proper gain and exposure time. The recommended exposure is 0.1s – 2s.

Step 3: Find the Focus Position

Observe the stars in the center preview area. Use coarse adjustment first:

• Press Up/Down buttons to move the focuser
• Watch the star shape while adjusting
• The star should shrink from a blurred spot into a small round point

After getting close to focus, switch to fine adjustment.

Besides the buttons, you can also:

• Use the slider in the floating panel
• Enter the target position directly
  

Step 4: Star Auto Focus

When the stars look clear, tap AF to start Auto Focus. Wait until the focus curve fitting is completed. When the message “Autofocus Success” appears, the focusing process is finished.

 

How StellaVita Autofocus Works

StellaVita evaluates star sharpness in captured images and determines the best focus position automatically. During autofocus:

• The focuser moves to multiple positions
• An image is captured at each position
• Star sharpness is analyzed
• A focus curve is generated
• The peak of the curve determines the best focus point

You do not need to understand the complex algorithm. Simply ensure the stars are visible, press AF, and wait for the system to complete the calculation.

Common Issues and Solutions

If you encounter problems such as no stars detected, capture failure, or autofocus failure, check the following:

• Enable mount tracking during focusing
• If stars are dim, increase exposure time, but avoid overexposure.
• If autofocus fails, try
  • changing the sky area
  • checking exposure settings
  • checking focuser parameters
  • checking backlash and max steps
• In environments with large temperature changes, refocusing during the session is recommended.
• Using a temperature probe with the focuser can improve focus stability.
• If images cannot be captured, check the main camera connection and power.
• If the focuser does not move, check:
  • motor rotation
  • coupling installation
  • cable connection

Focusing may seem complicated at first, but after a few operations, it becomes very intuitive. With StellaVita, the entire focusing workflow can be completed on a mobile device, without a computer, making astrophotography more efficient and beginner-friendly. We hope you enjoy a smooth focusing experience with StellaVita and easily achieve sharp, clean, and perfectly focused stars. Stay tuned for the next guide in the StellaVita series.