While the D4s may look very similar to the D4, Nikon has included a long list of improvements over its flagship predecessor. The EXPEED4 image processing engine allows the D4s to shoot more stills and video per battery charge, support 1080 video at 60p, and improves video quality at higher ISOs. The camera features a processing time that is 30% faster, in addition to a 200-shot buffer (JPEG) at full resolution at the maximum continuous mode. Wedding photographers will appreciate the addition of 12-bit uncompressed small RAW files, which are half the size (2464 x1640) of a standard RAW file.