We report the results of our investigation on the viewing angle characteristics of achromatic waveplates. In our investigation, both Pancharatnam achromatic waveplate and Beckers achromatic waveplate are examined theoretically. We find that only Beckers configuration is capable of functioning as the achromatic waveplate over wide viewing angles and over the visible spectrum. Two types of extremely wide-viewing-angle achromatic crossed polarizers compensated by Beckers waveplates are obtained. The leakage of light is less than 10 -4 over a 50° viewing cone for the visible spectrum. The results are presented and discussed.