Background: Scintillator is an important component of synchrotron X-ray imaging detectors

which converts the incident X-rays into visible light to be imaged by visible light imaging detectors. The thickness of scintillators has a great impact on the spatial resolution and contrast of the images. When the thickness of the scintillator is matched with detector lens (NA)

image quality of experimental results will be improved obviously. But in fact

users doing X-ray imaging experiments at Shanghai Synchrotron Radiation Facility (SSRF) don’t take into account this factor and it is difficult to obtain the best results with high image quality. Purpose: Matching thickness of scintillators with NA of objective can help us get good experimental results with high-quality images. Methods: We obtain the optimal thickness of scintillator for every objective lens by the way of mathematical computations of resolution theoretical curves and analysis of image contrast of experimental results. Results: Both of the results are nearly in accordance with each other. Conclusion: Users of SSRF will get better results of X-ray imaging experiment than before when they chose the optimal thickness of scintillator matched with the objective lens. Abstract