Nikon D5100 Digital Camera Review$799.00
The D5100 can shoot full HD 1080/30p, with options for both 25p and 24p, using the H.264 compression in a .MOV container. Depending on the quality mode selected, it will record at either 18 or 10 Mbps at full HD, though it can record as 424/25p at as little as 2 Mbps. Regardless of which resolution is selected, the maximum clip time is 4GB or 20 minutes. Find out how the performed in our video image quality test./r:link_to_content
The D5100 doesn’t provide a terrible amount of controls for video recording in live view. Aperture must be set prior to activating live view, while shutter speed and ISO are adjusted automatically. The camera does allow for exposure compensation in video recording, but only at a range of +/- 3 EV and only in the program, manual, priority, and night vision modes. Also: aperture can be adjusted while recording if using a Nikkor perspective control lens.
In every shooting mode except manual, aperture-priority, shutter-priority, program auto, and night vision, the camera automatically adjusts exposure and ISO speed for the user. The D5100 will also use matrix metering, regardless of what metering mode is selected prior to entering video recording. Autofocus is also available while recording video, as outlined below.
The Nikon D5100, being a DSLR, relies on its lenses to provide zoom range, which are turned manually using the independent zoom ring on the lens to cut down the angle of view and bring subjects closer.
The D5100 features full-time autofocus during video recording. It works, but the because it is a contrast detection focus system, it has to actually overshoot the correct focus point so that focus can be achieved. Generally, the system is slow, especially when shooting with a shallow depth of field, with the motor working in fits and starts until it achieves focus. The aperture can be stopped down to help make focus more forgiving, but must be done prior to entering live view to record.
When you enter live view and begin recording video on the D5100, aperture control is locked in. There is no direct control over shutter speed, regardless of what mode or setting the camera was at when recording began. There is some measure of control over shutter speed via exposure compensation, but it is limited to +/- 3EV and only available in certain modes.
There is no direct ISO control during video recording. There is an exposure compensation option available when recording in manual, aperture-priority, shutter-priority, program, and night vision, but with a maximum range of +/- 3EV and no direct control over ISO (though night vision employs an ISO of 102,000 for a black-and-white grainy image).
The D5100 has a built-in monaural microphone, with a 3.5mm stereo microphone input located on the side of the camera. The D5100 has the option to set three levels of microphone sensitivity, or to turn the audio off entirely.