Technological Differences
by Michael Scott
*The Modern HD Video Camera has been largely built as a rival to film stock. A result of this is that they have, by and large, attempted to replicate much of film’s qualities. However, there are some key differences.
*Depth of Field- HiDef Video has infinitely greater depth of field than film cameras. This means that video can have a far greater area set in focus. The current trend dictates that focus be quite fixed in one area, and so the main challenge for DV camera manufacturers is curbing the Depth of Field issues.
*Resolution- HiDef Video has a far greater resolution than Standard Definition. When shooting progressive scan, the resolution can be as large as 1280 × 720 pixels (per inch). When using the interlacing method, we can achieve 1920 x 1080. If you compare this to the standard in film (academy aperture), which rates at 4096×2980. This means that a film image has more than double the detail.
*Exposure Latitude- This refers to a kind of threshold of exposure (the min and max value of light) a camera can capture. In the case of film, 35mm stock can usually expose (to a visible level) through 13 different stops. HiDef on the other hand has a current latitude range of only 8 stops, though they are working on a new technology that will work through 10. HiDef is often used to shoot at night because of the gain function, which brightens the whole shot, and tones down contrast ranges.
*Frames- HD captures at 25 frames per second. Film captures at 24 frames per second. This doesn’t make a huge difference.
*Motion Blur- A Digital Video capture has little motion blur. This is being eliminated by 24progressive technology, which is again simulating film. When a subject moves, the human eye is conditioned to that subject being blurry.
*Projection - Once a negative has been developed, it can be printed to a positive to be shown an analog projector. When shooting on HiDef, filmmakers need to either transfer a digital format on to film or project on a digital projector.
sources;
N/A. “Video to Film”, Film versus Video. 2005: www.vtpcorp.com/htm/vidfilm.htm, May 2006
N/A. “New Insights in an Ongoing Debate”, Film vs. Video- Advantages and Disadvantages. 2006: http://www.cybercollege.com/filmtap.htm, June 2006.
N/A, “Cinematography”, Digital Filmmaking Secrets. 2005: http://filmschoolonline.com/web_DFS/cinematography.htm,
June 2006
N/A. “Friday- June- 09- 2006”, Cinematography Mailing List. 2005: http://www.cinematography.net/Pages%20GB/hd-latitude.htm, June 2006