From our ongoing exploration of 10 Things You Should Know Before Shooting with RED Epic:
1. How to Properly Perform Black Shading Calibration
The bane of any camera assistant’s existence with the RED One has always been the long boot time — around 90 seconds of pure agony while the entire production waits for the camera to power up.
So when RED announced the Epic’s boot time had been whittled down to a mere 7 seconds, many celebrated the achievement.
But now, with Epic, there’s a different time wasting culprit — black shading calibration.
What is Black Shading Calibration?
You may have never heard of black shading calibration before unless you’ve already worked with Epic, own one, or work within a rental house. That’s because with the RED One, black shading calibration was mostly reserved for after a major change in the camera’s software such as a firmware update or factory reset.
Epic is different, though.
In the Epic manual itself, RED recommends doing a black shading calibration in certain instances like:
- When shooting long exposure (about more than 1/24 sec) or high-speed framerates
- When there is a “significant” temperature shift to the sensor from the prior calibration
- After major software changes (not mentioned by RED, but generally recommended)
Granted, this won’t be something you have to do every day, but it will crop up much more frequently than it ever did with the RED One — especially if you switch between studio environments and exteriors where the temperature change could be drastic.
At the very least, you should perform one during your first use of the camera (whether that’s prep or Day 1) since you won’t be sure what the calibration was like before you got your hands on it.
How Long Does the Calibration Take?
The RED Epic Operations Guide says black shading calibration takes “about 10 minutes,” but this information is outdated both in my research and my own experience.
While reading through forum posts and articles, I consistently found other AC’s or operators complaining about the process being ballooned to a 30-minute time-suck. My own black shading experiences have lasted around 20 minutes or so.
You can mitigate the amount of time spent calibrating, however, by saving different calmaps (calibration maps) in the camera for common shooting scenarios.
What’s the Process for Calibration?
The good news is that black shading calibration itself is fairly straightforward.
Like the slow boot times for the RED One, once you put the Epic black shading calibration in motion, it requires very little maintenance on your end. You just have to make sure the lens port stays firmly covered and the camera has enough power throughout.
I suggest you follow this process as described by REDuser.net member Phil Holland:
Proper Black Shading Technique
- Attach the Red Body Cap to your lens mount and secure the cap with the locking collar on the mount.
- Place your camera in a dark place or cover your camera with opaque fabric. Do not cover the vents.
- Power up the camera. A/C Power is preferred. Black shading currently takes over 20 minutes.
- Wait for the camera to come up to operating temperature. Usually takes 10 to 15 minutes.
- Set your shutter speed to suit the project that you are shooting.
- Begin your Black Shading Calibration.
After it completes you may want to verify things are okay. Leave the Red Body Cap on and crank the ISO up to 12800 and make sure your focus assist tools are turned off.
What you are looking for is an even black field. If for some reason it is not, likely light has some how leaked in.
To perform the actual calibration itself, navigate to SETTINGS > MAINTENANCE > CALIBRATION. You have two options at that point:
- Black Shading (Default)
Use this to calibrate at fixed factory settings of 24 FPS @ 1/48 sec shutter speed
- Black Shading (Current FPS/Exposure)
Use this when calibrating for Varispeed/longer exposure shooting scenarios.
Once selected, the screen seen at the top of this post appears — select “OK” and wait.
Even though it is a simple process, black shading calibration is an excruciating thing to do because of the amount of time it takes — especially if you’re working on a production with little time to spare.
Now let me turn it over to you…
If you have experience with Epic, how often do you calibrate the black shading? What tips do you have to make the process more successful? And do you have any horror stories about it?
Share your thoughts in the comments!
Update: Since this post was written, RED has released official instructions on how to calibrate black shading. The instructions are the same as those listed here, though RED provides additional details on the technical processes you may find interesting and informative. Read their post here.