Quick Start Guide for Solar Guiding
Before we dive into the quick start guide, it's crucial to emphasize the importance of safety when observing or photographing the Sun. Always use proper solar filters to protect your eyes and equipment. Recommended filters include single or double layers of Thousand Oaks Optical SolarLite Solar Filter Film, Baader Solar Film, or any other reputable brand. Alternatively, use a solar 1.25" filter mounted in front of the guiding camera. Never attempt to observe or photograph the Sun without proper filtration.
Mount: Use a German Equatorial Mount (GE mount) capable of guiding in both RA and DEC axes.
Alignment: Perform mount leveling and at least rough polar alignment using a compass, adjusting the mount's altitude to match your current GPS location.
Hardware Profile: Ensure the correct focal length and camera pixel size are set to match your hardware profile in PHD2.
Software Setup: Connect your camera and mount drivers in PHD2. Start looping exposures to find the Sun in the PHD2 field of view.
Point Your Scope: Aim your telescope at the Sun, making sure it's safely filtered. To enhance pointing accuracy, especially important for post-meridian flip, star-sync your telescope with the Sun or your chosen planetary body while it's centered in the main scope's field of view. This synchronization helps in minimizing errors and adjustment times after the meridian flip.
Planetary Tracking: In PHD2, navigate to and enable the Planetary Tracking tool.
Tracking Rate: Verify your mount is tracking at the Solar rate.
Adjust Camera Settings: Modify exposure and gain to achieve a clear, non-overexposed view. Focus until sunspots are visible. For alternative focusing methods, temporarily switch to software like SharpCap, then revert to PHD2 once focused.
Camera Gain: Note that PHD2's camera gain range is normalized (0-100), differing from the physical gain values specified by manufacturers.
Time Lapse (ms): If using short exposures, adjust Time Lapse (ms) so the total cycle (exposure + time lapse) approximates 2-5 seconds, aligning with standard astrophotography guiding frequency.
Adjust Min/Max Radii: Set the Min Radius slightly smaller (5-10 pixels less) and the Max Radius slightly larger (5-10 pixels more) than the actual Sun's radius.
Edge Detection Threshold: Increase to the maximum stable value where the green circle closely matches the Sun's edges. Optionally, enable "Display Internal Edges/Features" to refine this adjustment. When the signal strength is high, it's beneficial to use higher Edge Detection Threshold values. Conversely, in conditions of reduced signal strength, such as under cloud cover or approaching totality, lower Edge Detection Threshold values may be more effective.
Focus: Utilize the Star Profile Window for fine-tuning. Toggle (by clicking on the label) between 'RADIUS' and 'SHARPNESS' displays to maximize SHARPNESS by adjusting the focusing knob of your guide scope.
PHD2 Calibration: With a stable detection (indicated by a steady green circle around the Sun), proceed to calibrate PHD2. Access advanced settings via the 'Brain' icon, adjust as needed, and initiate calibration with a Shift-click on the "Begin Guiding" button.
PHD2 calibration is essential before guiding because it allows the software to accurately map how your telescope mount responds to guiding commands. During calibration, PHD2 determines the necessary adjustments for both right ascension and declination, accounting for factors like gear ratios and mount mechanics. This ensures precise tracking, minimizes drift and errors, and enhances the overall quality of your astrophotography by keeping celestial objects steady during long periods of time.
Start Autoguiding: Following successful calibration, you're ready to begin autoguiding on the Sun.
