Spectrophotometric accuracy of spectra obtained from spectroscopic plates measured with a commercial flatbed scanner

TL;DR

This study demonstrates that commercial flatbed scanners can accurately measure spectroscopic photographic plates, achieving a difference of only 2.5% compared to CCD spectra, challenging previous assumptions about measurement limitations.

Contribution

The paper shows that commercial flatbed scanners are sufficient for spectrophotometric measurements, enabling easier digital archiving of spectroscopic plates.

Findings

Flatbed scanners achieve 2.5% difference from CCD spectra.

Microdensitometers are not necessary for accurate measurements.

Spectroscopic plate accuracy is approximately 2.5%.

Abstract

The intensity spectra recovered from the spectroscopic photographic plates were compared with the CCD spectra, and we found the difference between the two was 2.5%.The measurements were taken using a commercial flatbed scanner instead of a microdensitometer. The results indicate that the following two statements are inaccurate: (1) Correct measurement of spectroscopic plates requires a microdensitometer, and a commercial flatbed scanner is insufficient; (2) The spectrophotometric accuracy of spectroscopic plate is approximately 10% accurate. These results will encourage the creation and publication of a digital archive of spectroscopic plates. This paper presents the measurement of spectroscopic plates, the method of recovering intensity spectra from photographic density spectra, the results of comparison with CCD spectra, and discusses the causes of the high accuracy spectra obtained with a commercial flatbed scanner.