Photoshop by default handles a wide variety of file formats. But still there are some formats that require specific plug-ins. Case-in-point, Nikon-Raw formats.

Download the Photoshop plugin to render RAW formats: Click Here

Raw formats are the “digital” negatives for pictures. They retain all raw information that a digital-camera captures. Most off-the-shelf digital cameras convert to the most widely supported image file-format JPEG. But in reality, the picture taken is in RAW format, and then converted into JPEG for viewing purposes.

Having trouble opening and playing files in Quicktime? Quicktime doesn’t, by default, support that many codec

There are some very good alternative media players available:
VLC media player
MPlayer

These players support a vast-number of codecs. VLC also has amazing support for dumping streaming video, loading video over LAN and several other high-end networked video operations.