In continuance from my June 15 post, here is the next step in calibrating the Arcturus spectra taken June 8: The original June 8 drift spectrograph of Arcturus http://gallery.utahastronomy.com/main.php?g2_itemId=11543 The partial spectrographs through filters registered to the x-axis pixels and associated with Angstrom wavelengths http://gallery.utahastronomy.com/main.php?g2_itemId=11593 Reference spectra from class K0III star http://gallery.utahastronomy.com/main.php?g2_itemId=11595 Wavelength x-axis calibrated spectra from raw image http://gallery.utahastronomy.com/main.php?g2_itemId=11597 Calibrating for the camera response on the y-axis http://gallery.utahastronomy.com/main.php?g2_itemId=11599 The completed camera response curve http://gallery.utahastronomy.com/main.php?g2_itemId=11601 Final spectra calibrated on x-axis (wavelength) and y-axis (camera response) with standard K0III spectra plot for comparision http://gallery.utahastronomy.com/main.php?g2_itemId=11603 Next step, which I may not do, is to identify the elements that correspond to the spectral absorption lines seen in the original raw image. Enjoy - Kurt