Oleg

Thank you Ken. This is useful information for me. I found some pictures of a flip mirror in 'Spectroscopy for Amateur Astronomers'. It looks not difficult for 3D printing. I found a report about dependence of wavelenght calibration accuracy on lamp orientation here https://stargazerslounge.com/topic/348122-relco-sc480-starter-lines-position-depends-on-bulb-orientation/?tab=comments#comment-3786014 As I understand it, the glow discharge of the lamp should be located exactly opposite the center of the slit. In your opinion, can a milky glass window after the glow lamp eliminate the orientation problem?

Hi everybody! I am amateur astronomer from Russia, I have been reading this forum for a long time and with pleasure. I recently decided to sign up. Paul, thank you so much for a wonderful Lowspec project. I assembled the Lowspec, spectrograms are excellent. Now I am thinking how to calibrate the spectrograph mounted on the scope. The discussed option of installing the bulb inside the spectrograph does not seem optimal to me due to the inability to accurately center the bulb. Using a flip mirror seems more reliable to me. Some people here probably use flip mirrors for wavelenght calibration. Are there any problems when using flip mirrors? Maybe someone will show some pictures how the flip mirror was made?