Image pickup apparatus of which display start timing and display quality are selectable, method of controlling the same

An image pickup apparatus comprising:

• an image pickup device which converts a received light into an electrical signal to output image data;
• a first memory which stores the image data output from the image pickup device;
• a first development circuit which develops the image data output to generate first display data;
• a second development circuit which develops the output image data transferred by a transfer circuit, to generate second display data which has larger amount of data than that of the first display data;
• a second memory which stores the output image data transferred by a transfer circuit or the second display data developed by the second development circuit;
• and
• wherein the transfer circuit includes a first communication I/F which is configured to transfer the image data stored in the first memory to the second memory, and a second communication I/F which is separately provided from the first communication I/F and is configured to transfer the first display data to a display device directly.