Most professional photographers have grown accustomed to the flexibility that shooting with a raw format provides. When coupled with the great control of the Adobe Camera Raw plug-in, they have great control over highlights and shadows as well as the ability to recover exposure problems.
Unfortunately, your DSLR won’t shoot raw when it’s set to video mode. This means its like the old days (note we didn't say good old days) when you had to shoot JPEG. You’ll need to dig back into your past experience (be it film or JPEG) and retrieve the knowledge needed to help you make important decisions during acquisition.
When shooting outdoors, the use of a LCD viewfinder is highly recommended. These devices make it much easier to see a display as well as judge the quality of exposure. By removing all light pollution, you can make accurate decisions.
Just because you’re working with a movie file doesn’t mean all future options are limited. During postproduction, you can further enhance your footage. The first pass is color correction, which addresses issues with color and tone. Optionally, a color-grading pass can also be done to further improve the images with stylized adjustments that affect the mood and tone of the footage and thus develop the story.
For more on the fusion of photography and video, check out From Still to Motion.