By reducing the outer diameter, increasing the overall length, and correcting chromatic aberration well, the invention realizes an objective optical system and examination apparatus that are suitable for in-vivo examination with a sufficiently increased length and widened observation range. A first subset of the plurality of data packets is usable to generate a video display of content having a first quality and all of the plurality of data packets are usable to generate a second video display of the content having a second quality. The plate element can be fixed to the plate seat by way of a bolt extending through a bore hole in the plate element. Each detector logic unit comprises half adder logic operable to perform a half adder operation to logically subtract one of the first and second exponents from the other of the first and second exponents to produce at least a sum data value of sum and carry data values representing the result of the half adder operation.