Hi Paul! We are so sorry that your Sight Finder didn't work out on your Astroscan model. We have updated our product listing to reflect this issue, and we appreciate you leaving your feedback. Please contact our team of customer support experts to assist you with this issue. You can reach them at 1-800-818-4955 or support@scientificsonline.com Monday-Thursday 8 a.m.-8 p.m., Friday 8 a.m. - 7 p.m., or Saturday & Sunday from 9:30 a.m. - 5:30 p.m. EST. Thank you!