An image pickup system includes a light source unit configured to perform illumination； an image pickup unit configured to output an image pickup signal； a pre-processing unit configured to generate a first image signal, a second image signal, and a third image signal, each corresponding to one field, and sequentially output the image signals； and a synchronization processing unit configured to selectively assign the image signals sequentially outputted to a first color channel, a second color channel, and a third color channel. The synchronization processing unit switches first assignment processing for assigning the first image signal to the first color channel and further assigning the second image signal to the second and third color channels and second assignment processing for assigning the first image signal to the first color channel and further assigning the third image signal to the second and third color channels.
