Because the implementation of digital cinema is a relatively recent development, the role of a DIT is still being defined.
OVS feels that there are some basic expectations of your DIT that everyone considering shooting on the RED cameras should know.
1.) It should not be considered a replacement for a 1st or 2nd AC. The assistant camera positions handle camera operation, and the DIT should not interfere with their usual workflow if at all possible. The role of the DIT starts from the image processor back.
2.) There are two major roles that a DIT can play on-set:
A.) "Data Wrangler" - this is the process of preparing and receiving the media for the camera on the day of the shoot. This role does not require of the DIT any significant technical understanding, and the same role exists for cameras using P2 cards. Basically the wrangler should confirm that the information is copied to the right location on a production drive. A good wrangler will also compare camera reports with the number of clips on the magazine, and will verify that the file sizes of the two directories are the same. Also, it is very important not to erase the media untill the copy has been verified.
B.) "Imaging Tech" - a far more complicated role. To be a good DIT one needs an understanding of both film methods and workflows as well as their translation to the digital world. This role involves setting all the menus, imaging settings, and codec settings for the camera. One needs an understanding of timecodes, IRE, and post-production workflow. The DIT will work woth the DP and Director to achieve a desired look in the camera, as well as working with the ACs to set up menu functions for commonly used tasks or meters. Finally, some DITs can also be asked to perform some minor on-set color correction.