An image pickup apparatus of the present invention can eliminate the trouble of starting up the image pickup apparatus once to change settings in order to turn off a start-up picture image and mute start-up sound or operation sound. The amine agent is present in stoichiometric excess and functions as both curing agent and chloride selective agent. 001 where \u03c61s represents optical power of the scanning optical system within a sub scanning section. The guide rail is provided with a horizontal main cam groove, a front cam groove for smoothly guiding the front cam piece into and out of the main cam groove and a rear cam groove for smoothly guiding the rear cam piece into and out of the main cam groove. An active counterbalance system automatically offsets the increasing weight of a grass basket on the reel cutting unit to maintain quality of cut. A deflection coil tilts the input beam relative to the object point, and measures the defocus data and aberration quantity at high speed while the beam is tilted from one image, and perform least squares fitting on these results to find the absolute value of the aberration coefficient prior to tilting the beam, and to adjust the aberration corrector.