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In this second part of his in-depth look at shooting video with the Nikon D3s, Simon Stafford describes how to achieve a classic cinematic look in its D-Movie mode, and discusses options for audio recording and preparing D3s D-Movie file for post-production.

Welcome to part two of this extended article about shooting video with the Nikon D3s; you can find part one here.

Achieving a “cinematic look” with the D3s

 Several aspects of the way the D3s records video are different to those of a conventional video camera and it is important to appreciate this, because it is what sets the two devices apart in terms of the “look” they produce in the image they record. 

Shooting moving pictures requires different techniques compared with shooting stills pictures. In stills photography it is common practice to set the ISO sensitivity according to the prevailing light conditions and leave it fixed at that value, before controlling the exposure through adjustment of the shutter speed and lens aperture. Shooting motion picture film, or video it is the shutter speed that is usually set and locked, with the aperture value then being selected to achieve the required depth-of-field, while exposure is controlled by adjusting the ISO sensitivity, often in combination with the use of neutral density filtration of the lens. 

The design decision for the D3s to record moving images at a 24 frames-per-second (fps) was not arbitrary; 24 fps is the standard frame rate of cameras used by cinematic photographers when shooting motion picture films. By comparison typical television broadcast video is recorded at 30 fps; for some applications, such as recording sports and other high-speed action, a frame rate of 60 fps is used by a process known as “over cranking” before it is slowed down to 30 fps in post production. Therefore to emulate the appearance of a cinematic film there should be a direct correlation between the frame rate of the D3s and the shutter speed selected in its D-Movie mode. 

The shutter mechanism in a motion picture camera uses a rotating disc to alternately expose the film to light and then block the light, as the film is transported through the film gate; this type of shutter is often known as a “180-degree shutter”, because it is open during a 180-degrees of the disc rotation and then closed for the other 180-degrees of its rotation. At a frame rate of 1 fps the shutter would be open for a half-second, so extrapolating from this to a frame rate of 24 fps the shutter is open for 1/48-second. The closest available shutter speed on the D3s is 1/50-second, so this is the shutter speed that should be set to match its frame rate in D-Movie mode to simulate the motion blur perceived with a cinematic film camera shooting at 24 fps. 

Another key difference between the D3s and video camera is the size of the sensor (chip). At 24 x 36 mm Nikon FX-format sensor of the D3s is significantly larger than the sensor used in a typical consumer video camera and even those of many professional video camera models. As the size of a sensor in a camera increases, so the depth-of-field for any given lens aperture value decreases. On a typical video consumer camera, or point and shoot digital camera with video capability, the relatively much smaller size of the sensor means that virtually everything is in focus, because even at large lens aperture values the depth of field is so extensive. By comparison the D3s can achieve a far more limited (shallower) depth of field at equivalent lens aperture values, which allows the user to isolate a subject by differential focus far more effectively, thereby directing the viewer’s attention to a precise point in the scene.    

The following is my suggested method on how to set up the D3s to achieve a “classic” cinematic motion picture effect, while maintaining full control over the camera to achieve a consistent exposure level, exploit the depth-of-field characteristics of the FX-format sensor in combination with the lens aperture, and produce smooth focus transitions, while recording in its D-Movie mode: 

• Before activating Live View, select [Tripod] mode via the Shooting menu, also adjust settings for sharpening and contrast as required (I recommend exercising restraint with both for the reasons stated in part 1, in the Picture Controls & White Balance in D-Movie Mode section) via the Picture Control system and select manual exposure mode.

• Set the camera to manual focus mode. If you use an AF Nikkor lens, set any focus mode switch on it to M (manual). For most shooting in D-Movie mode I prefer to use manual focus Nikkor lenses, as the action of their brass metal helicoid focusing mechanism is far smoother and has a much longer throw compared with modern AF Nikkor lenses, giving you far more control over focusing for smooth transitions; make sure the relevant non-CPU data is entered via the [Non-CPU lens data] item in the Setup menu.

• Activate Live View by pressing the LV button.

• Press the OK button to open exposure preview mode; the analogue exposure scale will appear down the right side of the monitor screen. Press the info button repeatedly to scroll the information display screens to display a composite (luminance), real-time histogram. The D3s always uses Matrix metering in Live View / D-Movie mode. 

• Frame the subject and adjust focus manually. My personally preference is to have the center button of the multi selector assigned to magnify the Live View image, which requires Custom Setting f1 to be set to, Multi selector center button > Live View > Zoom on/off, as this is can be useful for critical assessment of focus.

• Adjust the shutter speed to 1/50-second. Now set the aperture for the required depth of field. Finally, adjust the ISO sensitivity to achieve a proper exposure using the exposure preview scale and histogram display on the monitor screen as a guide; if necessary use neutral density filtration to reduce light transmission through the lens (a variable neutral density filter can be very useful for this purpose). When recording a scene that contains a lot of tones that are significantly lighter, or darker than an average middle tone, compensate the exposure level, as required. 

• Alternatively, use a middle tone reference, such as an 18% grey card. Ensure it is placed in the same light as the light falling of the subject before pointing the camera at the reference and adjusting the ISO sensitivity, and neutral density lens filtration if applied, to achieve a proper exposure. This approach ensures that the camera will record average tones accurately, while lighter and darker tones will also be rendered accurately, provided they are within the dynamic range of the sensor (check the luminance histogram for any clipping of shadow and highlight tones). 

• Once the exposure settings have been made, press the info button again, to scroll the information display screens to display the small, white 16:9 frame guides. When recording video at 720p (1280 x 720) resolution, the D3s uses a 16:9 aspect ratio, which is different to the 3:2 aspect ratio used for stills pictures and lower resolution video recording. In Live View these frame guide markings appear on the each side of the screen close to the corners; however, during D-Movie recording the narrow strip above and below them will be greyed out to indicate these areas of the Live View frame will be cropped. Compose your first frame using the frame guides as a reference. 

• Check focus and adjust it manually if required 

• Press the Pv (preview) button to start recording; I recommend using the Pv button, as ergonomically it is easy to use. Alternatively, it is possible to use the multi selector center button; however, this requires Custom Setting f1 to be set to, Multi selector center button > Live View > REC), which prevents it being used to magnify the Live View image as described above.

• To stop recording press the Pv button again.

 Considerations for shooting moving pictures

Shooting moving images is quite different to shooting stills pictures and shooting in D-Movie mode is different again from shooting with a video camera. Your approach to planning, preparing, and shooting needs to considered accordingly:

• Plan your movie. It’s going to tell a story, so give it a beginning, middle and end; consider writing out a storyboard to detail each clip you will want to shoot (this will help at the editing stage as well)

• Prepare the camera as described above. Think about how you can use depth-of-field to direct the viewer’s attention by emphasizing a subject, or section of a scene. Use manual focus control to adjust the focus point during recording.

• Use a solid, heavy tripod for maximum stability and mount the camera on a fluid, or friction type tripod head for smooth pan and tilt movements. Viewing the monitor screen outdoors is difficult in the best conditions and virtually impossible in bright sunlight, so consider using a hood style loupe, such as the Hoodman HoodLoupe 3.0

• If the camera lens has the Nikon Vibration Reduction (VR) system, switch it off; when recording in D-Movie mode, even when the camera is mounted on a tripod head that has been left loose to facilitate pan, or tilt movement the VR action can cause the image of a stationary subject to appear to drift slightly, because the movement of the VR lens group.

• Shoot short clips, typically 15 to 45-seconds duration; short clips makes editing them to produce the finished movie much easier. The more clips you shoot the more editing options you will have.

• Think about audio. If you want to record sounds associated with the subject and its surroundings consider use of an external microphone, or a separate recording device. Avoid using any auto gain setting to control recording level automatically (see additional notes below). 

• Remember the D-Movie mode is just an extension of the Live View function, so while active the sensor is exposed continuously to light passing through the lens; therefore, it is absolute essential that the camera is never pointed directly at the sun, or any other very strong light source, as doing so risks damage being caused to the sensor and/or other associated electrical circuitry.

Audio Recording

The D3s can only record from one source at a time, either its internal microphone, or preferably a dedicated external stereo microphone. 

A far higher audio recording will be achieved by using an external stereo microphone, such as those manufactured by Rode www.rodemic.com; Audio Technica www.audio-technica.com; and Sennheiser www.sennheiser.com. Popular choices for the D3s include the, Rode Stereo Video microphone, the Audio Technica Pro 24CM, and the Sennheiser MKE 400 shotgun microphone but these are far from the only models available, so I recommend you spend a little time to research a microphone that meets your specific requirements.

As soon an external microphone is connected to the camera via the 3.5mm jack terminal the internal microphone is disabled. Once an external microphone is connected there are two sets of controls to consider: the external stereo microphone is likely to have at least a pre-attenuation (PAD) switch and high pass filter, while on the camera the microphone sensitivity must be set via the [Movie settings] item in the Shooting menu. 

The controls on the external microphone should be set first according to the recording conditions. The PAD switch allows you to attenuate the recording level of the microphone, typically by -10dB, or -20dB to prevent overloading the input level of the microphone and causing sound distortion when recording close to a very loud sound source. For most general recording situations you can leave the PAD switch set to its 0dB position. The high pass filter is used to eliminate recording of low frequency sound typically < 80Hz, for example, background traffic noise, or flowing water, which would otherwise distort or mask higher frequencies. 

The microphone sensitivity should be set on the camera according to the prevailing conditions; the available options are located under the [Movie settings] item in the Shooting menu. It is best to avoid the Auto setting, because auto gain will often produce variable recording levels that make achieving consistent sound impossible, especially if the sound(s) to be recorded may change in volume very rapidly. For example, if you attempt to record a person talking against some low-level background noise, as soon as the person stops talking the auto gain will boost the background noise and then suppress it as soon as the person begins speaking again. As with most aspects of recording video you should really exercise as much manual control over the camera as possible. Therefore use of the three other options is recommend as follows: 

•  In a noisy environment set microphone sensitivity to [Low]

• In a normal environment, for example conversation between two people with no strong background noise microphone sensitivity can be set to [Medium]

• In very quiet environments it can be set to [High]. 

Many photographers using D-SLR cameras with a video capability prefer to use a separate audio recording device and then bring the video and audio recordings together in a video editing application. This methodology certain has some advantages since the camera is not encumbered with the additional weight and bulk of a microphone and there is no risk that the microphone will pick up noise generated by the camera, camera operation or the user. Popular digital stereo recording devices include models such as the Olympus LS-10 and LS-11, and the Zoom H4n.

Working with D3s D-Movie files

Using its 720p HD (1280 x 720 pixels) resolution the D3s records at the rate of 1.7MB per second (approximately 100MB/minute), so each Gigabyte (GB) of storage on a memory card will store about 10-minutes (although the maximum clip length at this resolution is 5-minutes).

The D3s records moving images in an Open DML JPEG video format, which is known more informally as Motion JPEG (or M-JPEG). In the motion JPEG format each video frame in the recorded sequence is compressed, as a separate JPEG image. These JPEG images are then stored together with any audio recording in what is known as an Audio Video Interleave (.AVI) container file; AVI is the standard container file used by Microsoft Windows applications but it is also supported by applications such as QuickTime and therefore D3s video is viewable on computers running an Apple Macintosh operating system. Editing .AVI files in appropriate applications supported by the Windows operating system should not be an issue; however, using the highly popular Apple Macintosh Final Cut Express, or Final Cut Pro to edit video clips from the D3s requires that the video files be converted into a different format as the in-camera encoding is currently not supported in either application.

Importing a D3s video file directly into Final Cut Express without converting it into a supported format will require the file to be rendered to play the sequence back in real-time, which will increase the editing time and take up a larger amount of hard-drive disk space. Transcoding, the process of converting the camera-encoded files into a recognised format for editing, can be performed through MPEG Streamclip software (www.squared5.com), which will then allow the file recorded by the D3s to be edited in a format native to Final Cut Express. The recommended ‘Export settings’ in MPEG Streamclip are as follows:

• Compression - Apple Intermediate 
• Codec Quality - 100%
• Frame rate - 25 Frame 
• Blending - Selected 
• Deinterlace Video - Selected

When working with Final Cut Pro it is recommend that transcoding is performed by using Compressor 3.5, which is software included within Final Cut Pro 7, as it supports the Apple ProRes (LT) codec, as well as offering a batch processing option for multiple video clips. Nikon has created a Droplet (an automated Compressor setting) for use with Compressor 3.5 that can be downloaded from any Nikon technical support web site, which transcodes D3s video files into the Apple ProRes 422 (LT) codec, a format Final Cut Pro recognises natively, and one that maintains good quality with a low bit rate. Other Apple ProRes codecs, such as ProRes 422 (HQ) High Quality, or ProRes 4444 can also be used, although the size of the converted file is significantly larger than that produced by the ProRes 422 (LT) codec. Regardless of which ProRes codec is used they are only an intermediate step intended for editing of video material but not its final delivery, which will require exporting the finished file(s) into another format such as H.264, Blu-ray, or DVD. 

Video capture by D-SLR cameras has come a long way since the introduction of Nikon D90 and is a technology that is sure to expand as multi-media capture and presentation of images continues to grow in popularity at both an enthusiast and professional level. With new cameras, such as the Nikon D7000 on the way offering even greater video capabilities, shooting moving pictures is set to become even more exciting and creative.