so, I wrote to the Cornwall Astronomy Society
and someone kindly replied: “My guess would be an internal reflection of the sun back onto your lens from the sensor…”
They also cleverly removed the blue dot and yet I have grown to like it…

so, I wrote to the Cornwall Astronomy Society
and someone kindly replied: “My guess would be an internal reflection of the sun back onto your lens from the sensor…”
They also cleverly removed the blue dot and yet I have grown to like it…