Demystifying Digital Camera Specifications
“Demystifying Digital Camera Specifications,” a seven-part series focusing on the complex science of image resolution and digital cinema cameras is now available on the Panavision website.
The in-depth symposium is presented by two icons of digital cinema technology: John Galt, Panavision Senior Vice President, Advanced Digital Imaging; and Larry Thorpe, National Marketing Manager, Canon Broadcast & Communication Division.
A master class for motion picture professionals and students, the series is also in the minds of its creators a precursor to a broader, crucial industry-wide discussion: the need for a scientifically valid, objective method of assessing the quality of digital and film images.
Recorded in high-definition video, the symposium was held April 3 before an audience of invited guests in the Panavision Theater, located in the company’s world headquarters in Woodland Hills, Calif.
Throughout the series, Galt and Thorpe challenge the simplistic and inaccurate assumption that digital camera resolution is “all about the camera output pixels.” Instead, they help serious motion picture creators to understand the difference between optical sampling from camera imagers (where resolution is totally determined) and the camera digital sampling.
They explore in depth what is meant by Modulation Transfer Function (MTF) and the compounding effect of lens MTF, camera MTF, and the MTF of subsequent production system elements.
Their discussion emphasizes that the relationship between the lens-camera MTF profile and associated residual aliasing – in both the horizontal and vertical domains – constitutes the only rational metric on imaging resolution. These two criteria apply to all 2/3-inch three-imager and to 35mm single-imager digital cameras. Nyquist theory, optical prefiltering and imager sampling lattice are explained in the context of camera design criteria that seek a pragmatic compromise between high MTF and minimum aliasing.
While camera manufacturers generally do not publish camera-specific information regarding lens-camera MTF and aliasing, various test charts are available to enable an objective assessment of both criteria. With these charts, fully demonstrated in the series, content developers can directly compare the performance between any two digital cameras regardless of image format size, number of imagers, or their optical sampling lattice.
Using the MTF metric, Galt and Thorpe conclude, digital movie makers now have better tools to help them gauge precisely what effect each step has on the production of the final image.
In addition to appearing on the Panavision website, the “Demystifying Digital Camera Specifications” series is being made available through various professional, trade and media Internet sites. For film schools, students and instructors, it is being showcased through the University Film and Video Association, in the news section. The UFVA is an international organization of almost 800 professionals and institutions involved in the production and study of film, video, and other media arts.
Transcripts of the seminars, with embedded slides, will soon be available to accompany the video presentation to facilitate class use or individual study.
“With programs like ‘Demystifying Digital Camera Specifications,’” said Bob Beitcher, President and CEO, “Panavision is trying both to educate our customers as well as raise the level of industry discussion about emerging technologies to focus on the science of what we do. I think that most everyone stands to benefit from a good look-and-listen at this stimulating presentation from two true experts.”
Source: ProVideo Coalition
