American Cinematographer - February 2010 - 65

This is a simple illustration demonstrating the various scanning sizes the Red One uses in its different resolution settings. Note that as the resolution goes down, so does the physical size of the sensor used. 35mm-sized sensor to looking at an area half that size, comparable to Super 16mm. This characteristic comes to the fore when capturing material at higher frame rates. Suppose you want to capture a shot at 24 fps and then, with the same composition, do a take in slow-motion at 72 fps. Currently, with Build 20 of Red One firmware, you must switch the camera to 2K resolution in order to shoot 72 fps. And because the camera is now scanning half the sensor size it was scanning in the 4K take, you must change lenses on the camera to compensate. This becomes increasingly problematic if the shot in question is a wide shot. If you originally rolled with a 14mm Ultra Prime on the camera, you need a 7mm prime lens to achieve the same field-ofview when you switch to 2K 72 fps. Certainly, extreme-wide-angle 35mmformat lenses exist, but they often exhibit certain distortion characteristics and are usually slower than their standard-focal-length counterparts. The need to switch the lenses at all is nuisance enough, but if you want to accomplish wide slow-motion shots, you must therefore carry a separate set of wide 16mm-format lenses to cover the 2K Super 16mm scan size. Red Digital Cinema has corrected much of this problem in its next camera system, the Epic S35, which will offer up to 100 fps in 5K resolution and 125 fps in 4K resolution. Additionally, the Epic line will feature several different “brain” modules with different sensor options, including Super 35-sized Mysterium-X chips, full-frame 35mm still photo, 645 format, and even 617 format-sized Monstro sensors. These cameras will also feature improvements in the Redcode compression-setting options. This brings me to one of the most important considerations for those considering the Red platform: compression. One of the miracles of the Red One is also one of its Achilles’ heels. Taking what should be a massive file of RAW 4K image data and recording it to a small CF card would seem to require some form of internal computational alchemy that Red isn’t keen to publicize. (It is based on the JPEG 2000 compression algorithm). However, in general terms, if you break a 12-bit 4K Bayer-pattern movingimage file down to its mathematical components, it would add up to something like the theoretical data boxed below. Currently, Red’s highest Theoretical uncompressed 4K image data: 4K 16x9 image (4096 x 2304 pixels) = 9,368,064 pixels per frame 12 bits per pixel = 12 x 9,368,064 = 112,416,768 bits per Bayer-pattern frame 112,416,768 bits /8 = 14,052,096 Bytes 14,052,096 Bytes /1024 = 13,722 KB 13,772.75 KB /1024 = 13.401 MB per frame 13.401 MB x 24fps = 321.627 MB per second or 2573 Mb/s www.theasc.com February 2010

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American Cinematographer - February 2010

Table of Contents for the Digital Edition of American Cinematographer - February 2010