H.K.Das,
	Abhay Kohok,  and S.N.Tandon 
Inter University
Center for Astronomy and Astrophysics (IUCAA), Post Bag 4, Ganeshkhind,
Pune - 411 007, India  
Abstract. Based on the transfer pupil technique we develop a method to measure the lower order aberration coeffcients for optical telescopes; the method makes use of a Hartmann mask in a spectrograph for sampling the wavefront at different locations.