Optical potential parameters have been discussed as an art more than physics. The effects of optical model parameters (OMPs) on differential cross section calculations and hence extraction of spectroscopic factor has been discussed. Optical model parameters have been expected especially for charged particles with light nuclei. The ambiguity of the optical potential parameters has been solved. Global optical potential parameters have been explained as not the best choice for extraction spectroscopic factor and hence calculate astrophysical S-factor. The measurements of experimental data have been discussed as the most important parameter that produces discrepancy in the astrophysical S-factor. The models used to extract spectroscopic factor is briefly discussed where examples are discussed. The importance of astrophysical s-factor has been explained under nuclear models. Few models have been chosen as just examples of discrepancy of astrophysical S-factor in spite of there are many models deal with such point of view. The discussion has neglected some effects of extraction astrophysical S-factor as coulomb barrier and electron screening.