At the Wednesday, September 26, 2012 meeting...
4K DIGITAL CINEMATOGRAPHY
With Juan Martinez, Senior Product Manager, Sony, Electronics
By Marty Feldman
Our season opener was devoted to 4K Digital Cinematography. Juan Martinez, Senior Product Manager, Sony Electronics was the featured presenter. Sony's Sales Support Engineer Tom Cubby, and New England Regional Sales Engineer Steve Dirksmeier were also on hand for the occasion.
Sony brought their F65 digital cinema camera, new NEX-FS700, as well as their 4K theater projector. This is the projector Sony has had so much success with in the motion picture theater market. It is truly a powerhouse, producing stunning images from all digital sources.
The Sony F65 Digital Camera.
Sony's Juan Martinez, a veteran video imaging engineer whose experience covers both the analog and digital arenas, covered several key aspects of 4K (and larger) imager design, including differences between traditional three-chip imagers and the newer single-chip mosaic filter designs employed both by both DSLR's and large-chip digital motion picture cameras.
One of the advantages of the latter technique is the elimination of the prism used to split the image into three separate images, one for each of the three additive primaries, red, green and blue. The prism demands a flange back distance that necessitates the use of lenses uniquely designed for this technique. The small imager size also makes it difficult to achieve shallow depth-of-field, a desirable trait in motion picture acquisition. The use of a large single imager permits a flange-back distance that is compatible with an entire universe of existing lenses from both the still camera and motion picture worlds and the larger image size makes these lenses more optically compatible in focal length.
Martinez provided an excellent and easily understandable explanation of modulation transfer function (MTF), how resolution that necessarily must begin with the lens is preserved and carried all the way through the recording process. He also compared the traditional Bayer pattern typically employed in single chip digital still and motion picture cameras to the advanced pattern Sony is now using to provide more effective picture area for any given sized imager.
The impressive high speed recording capability (over-cranking) of the NEX-FS700 (up to 240 fps in full HD resolution (960 fps in somewhat reduced resolution) was explained and displayed, exhibiting a truly smooth and natural slow-motion when played back at standard film or video frame rates.
A 4K music video shot with the Sony F65 featuring Taylor Swift was shown. The technical aspects of this production were addressed immediately following. It was pointed out that the F65 is capable of 14 stops of exposure latitude, the most currently available in any 4K motion picture digital cinema camera. Martinez described the benefits afforded by oversampling at 8K with the Sony F65's Super 35 Exmor chip. There was some discussion of post production workflow and the benefits of working with the F65's raw output.
During a lively Q&A that followed the main program, Martinez talked about the differences in cine gamma settings between their NEX-FS100 and NEX-FS700 digital motion picture cameras. One useful tip he pointed out for extending the latitude of the F700, is to use the Cine Gamma #4 setting, then raise the black level. This produces an 'S-log' like result. It looks pretty milky on a standard monitor, of course, but in the post production color grading process, it offers a huge range of tonal possibilities.
We especially want to acknowledge Rule Boston Camera's generosity for offering us the use of their exceptional facilities and to SMPTE-NE Manager Robin Shahid for so ably coordinating this meeting.
Our Wednesday, October 17th meeting on Advanced Video Codecs and DSLR Cinematography will also be held at Rule.
Martin P. Feldman, Chair, SMPTE New England.
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