Last Modified: December 3, 2014
RED Epic/Scarlet Connections
Most often, when a camera manufacturer writes that their output is 23.98p, they actually mean that it outputs 23.98PsF. The Red Epic, however, actually outputs a 1080/23.98p (not PsF) output.
As of Build 6466, Previzion’s 1080/23.98p video format setting takes this signal directly and outputs it without any video conversion. In other words, Previzion takes in a “p” signal and outputs a “p” signal.
Previzion also supports 1080/25.0p and 1080/29.97p inputs. This discards the need for any video converter boxes in virtually all RED Epic/Scarlet applications.
EPIC at 25fps and 24fps
It is important to note that, unlike the RED ONE camera, RED EPICs have an extra setting for its HDSDI output that needs to be changed whenever going from 24fps to 25fps and vice versa.
An indication that your timebase is off will be to see “timecode repeating” flashing in random intervals in Previzion or by hooking up a professional reference monitor to the HDSDI output from the RED directly. There are two settings in EPIC cameras to watch out for:
- Timebase – the internal recording of RED EPIC/SCARLET cameras is set under SETTINGS > PROJECT > TIMEBASE > 25fps or desired frame rate
- HDSDI Output – the frequency of the HDSDI output from EPICs can be set independently from the internal recording. The mismatch is what can cause monitors and Previzion to act up. Make sure that whatever frame rate your project is set to the HDSDI output matches it. Under SETTINGS > AUDIO/VIDEO > MONITOR CNTL > HD-SDI> FREQUENCY (BRAIN HDSDI) > 25Hz or corresponding frequency. Verified with RED EPIC X firmware version 3.3.14.
The designation “Brain HD SDI” refers to the left-most mini-SDI port that is next to the HDMI output in the rear of the EPIC. This is the output that should be going to Previzion.
As long and the HDSDI output frequency matches your project’s frame rate, Previzion is able to read ANC Timecode (build 6903) as well as embed tracking metadata properly.
Older Builds of Previzion (< build 6466) – For older versions of Previzion, a converter must be used to convert the 1080/23.98p signal to 1080/23.98 PsF. The following 2 converters are known to do this: Cobalt Digital 8021,Decimator MD-DUCC.
Genlock and Sync
It is recommended to use an external 1080/23.98p or 1080/25.0p sync generator to directly sync the Red Epic and the Airtrack, instead of deriving sync from the Epic HDSDI output. This is because the HDSDI output can drift, requiring adjusting the tracking delay to keep the foreground and background in sync.
Epic/Scarlet Sensor Size (Mysterium-X)
As of June 2012 firmwares, Red Epics have a “5K HD” mode, along side “5K 16:9” and the “5K” (Full Frame) mode. Make sure there is no look-around area being sent out the HD-SDI output. See the notes below for more information.
Here is the calculated sensor widths for all of the Red Epic settings (based on a 5.4 µm, or 0.0054 mm, pixel pitch):
|5120 x 2700||5K FF (Full-Frame)||27.648 mm|
|4800 x 2700||5K HD||25.920 mm|
|5120 x 2560||5K 2:1||27.648 mm|
|5120 x 2160||5K WS (2.37:1)||27.648 mm|
|3600 x 2700||5K ANA||19.44 mm|
|4096 x 2160||4K||22.1184 mm|
|3840 x 2160||4K HD||20.736 mm|
|4096 x 2048||4K 2:1||22.1184 mm|
|4096 x 1706||4K WS (2.4:1)||22.1184 mm|
|3072 x 1620||3K||16.5888 mm|
|2880 x 1620||3K HD||15.552 mm|
|3072 x 1536||3K 2:1||16.5888 mm|
|3072 x 1280||3K WS (2.4:1)||16.5888 mm|
|2048 x 1080||2K||11.0592 mm|
|1920 x 1080||2K HD||10.368 mm|
|2048 x 1024||2K 2:1||11.0592 mm|
|2048 x 854||2K WS (2.4:1)||11.0592 mm|
|1280 x 720||1K HD||6.912 mm|
|1280 x 480||1K WS (2.4:1)||6.912 mm|
** Based on 955-0003_v.3, Rev-A1
Epic Focus Magnification
If using the Epic focus magnification to get correct focus while calibrating lenses, be certain to turn it off before starting a lens calibration sequence! Otherwise, you will get incorrect results (a 32mm prime will read as a 85mm focal length.)
RED Epic/Scarlet “HD-SDI Output” with Look-Around
In addition to the above, it is important to check the “HD-SDI Output” before running lens calibrations and comps in Previzion. As of October 2012, RED Epics have a firmware update that allows for Lookaround that affects Previzion during lens calibration and tracking.
The default setting for “HD-SDI Output” in the new RED cameras is “PROGRAM” output, which provides a clean video feed. However, this setting can also be set to “MONITOR” output, which provides a slight look around view as well as burn-in Timecode and Title Safe/ Action Safe Frame guides.
Epic Black Bars in Video Signal
Since the Epic sensor is a 1.88:1 sensor, and the live HDSDI output is 1.78:1, there are black bars on the top and bottom of the image. These will create a slightly strange artifact when they intersect with garbage mattes, but will not affect the 5k recorded data.