In Part Five we looked at the costs of putting together a Blackmagic Pocket Cinema Camera kit. In this final part we’ll look at the post production workflow for the Blackmagic Pocket Cinema Camera, for both CinemaDNG and Prores options.
This article builds on the following, so please read them first:
- The CinemaDNG Workflow
- Comparison of RAW Processors for the Blackmagic Pocket Cinema Camera
- The Blackmagic Cinema Camera CinemaDNG workflow with Adobe Premiere Pro
Recording modes on the Blackmagic Pocket Cinema Camera
The recording modes on the Blackmagic Pocket Cinema Camera are as follows (as per Firmware update 1.5):
|Compression||Compressed, lossless||Compressed, lossy|
|Color Specs||12-bit, Film mode only||10-bit 4:2:2, Video mode (Rec. 709) and Film mode|
|Data rate at (in MB/s)|
|24p & 23.976p||52.8||27.5|
|30p & 29.97p||66|
|Footage on 64GB Card (minutes)||18||37|
The file naming convention is as follows:
|Camera ID||Reel Number||Date||Time||Clip Number||Extension|
The parts of the filename are combined with an underscore, like this:
MyPocket_2_2014-02-03_1534_C000343.mov (or .dng)
In the case of CinemaDNG files, the image sequences are stored in folders (one per shot). Blackmagic Design warns not to trust the time and date on the camera. It is also a good idea to manually insert the Camera ID (Create a different one per project) for easier organization later.
The camera can also take in metadata from your production, but try typing out words using the joystick!
Ideally, you should keep the ISO (written as ASA) at 800. This will give you the maximum dynamic range from the sensor. However, when you’re shooting in bright conditions without an ND filter, it might become impossible to shoot at ISO 800.
The camera offers the following white balance presets:
You can’t choose values between them, which is a real shame.
Shutter angles available are (in degrees):
- 180 (normal, for 24p in countries where power frequency is 60 Hz)
- 172.8 (normal, for 24p in countries where power frequency is 50 Hz)
To understand shutter angles and how it translates into the shutter speeds you see on DSLRs, click here. Ideally, you’d want to start with either 172.8 or 180 as written above.
Do you need to shoot in CinemaDNG?
I don’t think so, unless you’re shooting in a highly demanding situation. If you have bad lighting, poor production design and sloppy camera work, no amount of dynamic range can save you. The difference between Prores HQ and CinemaDNG modes on the Pocket Camera are negligible.
If you’ve read Comparison of RAW Processors for the Blackmagic Pocket Cinema Camera, you’ll know I consider DaVinci Resolve to be the best option for the camera when shooting in CinemaDNG. The new Premiere Pro update hasn’t changed my opinion. RAW, even compressed RAW, is extremely cumbersome to work with, and the Prores files look like film anyway – and are great to grade with, too.
Bottom line, I recommend shooting in Prores HQ Film mode for best results. Create your own LUT (or start from scratch) in Resolve Lite or Speedgrade, and grade only after the edit is completed.
Avoid at all costs. If you value audio, record it separately, period.
However, to make your editing life easier, you could send a synced line-level signal from your audio recorder, pre-amp or mixer to the camera to Channels 1 and 2. The camera automatically records audio if it comes from an external source.
Select Chl 2 uses Ch 2 input if you want to create a backup at a lower volume. There are no levels to verify what you’re doing, so I only recommend recording audio for faster editing, and nothing else.
Monitoring and Exposure
Connecting an external monitor allows you to choose Rec. 709 (Video mode) to see what it might look like. If you’re shooting in Film mode for a creative grade, this workflow doesn’t make much sense. Monitoring Video mode (while shooting Prores HQ) in Video mode (Display) is the right way to go.
You can add overlays to the HDMI signal. The following overlays are available:
- All – Frame Guides + Recording Info
- Status – Recording Info only
- Guides – Frame Guides only
How do you expose the damn camera?
One of the biggest frustrations of the Pocket Camera is exposing it. Actually, this frustration is not caused by the camera, but by individuals who think it’s an iPhone, and want to use it as such.
One crutch everyone loves to fall back on is the Zebra function. The crappy ‘conventional wisdom’ goes something like this: If I set my Zebra at xx% and I don’t see stripes I should be okay, right?
The sad part is, there’s no answer to that question. If someone really wants to understand how Zebras work, they need to understand how a Rec. 709 signal is generated and defined. The right questions to ask are:
- Why does it have 75% and 90% and 100% and so on? What do these numbers really stand for?
- When should I use a Zebra?
- When I see stripes (which means you’ve clipped the limit you’ve set), how many channels are clipped – all channels, only one channel, or two channels?
Don’t want to know the answer to these questions? Then you’ll never know how to use a Zebra, and my suggestion to you is: Stop using it.
Okay, let’s back up a bit and look at the available options for exposing the Blackmagic Pocket Camera:
- 100% Zebra in Film mode- this will Expose To The Right (ETTR) and will give you the best signal-to-noise performance you can get (at 800 ASA).
- 75% Zebra in Prores HQ Video mode – this is a tradition that places Caucasian skin at 70-75% for television. What exactly is caucasian skin? There is no standard definition. What about other skin colors? There is no sane answer.
- 90-95% Zebra in Prores HQ Vide mode – which is the ‘traditional’ limit for clipping in Rec. 709. However, there is no exact value which is why Blackmagic Design doesn’t tell you what to choose. Take the hint.
The Blackmagic Pocket Cinema camera judges exposure (using the IRIS button) based on the Dynamic Range setting. The two types of exposures are:
- Video Mode – Middle grey, at about 8%-10% at 12-13 stops. Since this is calibrated internally, it will match middle grey exposure ratings from light meters (not precisely, of course).
- Film Mode – ETTR only.
Because the middle grey value isn’t 18%, I do not recommend using an 18% grey card (or any grey card for that matter). It just adds to the confusion.
Now, let’s see how to best expose your Pocket Camera:
|Prores Film||Light Meter||100%|
|CinemaDNG Film||Light Meter||100%|
As you can see, I suggest you leave the Zebra at 100%, or better yet, not use it at all. You’re better off using a light meter to place your mid-tones where you want it to be, and let the shadows and highlights fall accordingly, as per the Zone system. You do know there is no single correct exposure for a scene, right? Show the same scene to different DPs, and they’ll choose different exposures. Exposure, like everything else, is a subjective thing.
And the time-tested way to nail the exposure as you see fit, is by using a light meter. If you can’t afford one, or don’t want to carry one, use the camera IRIS feature instead. I don’t recommend the last option, but at least you’ll be exposing around a common standard which will help you match your shots in post. Even if you’re shooting in Film mode, you can quickly swap over to Video mode, meter, set your exposure and come back to film mode. Does it work correctly? No.
Learn to use a meter, and treat Film mode like Film (Now you know why it’s called ‘Film mode’, and not ‘Log mode’).
One last word about ETTR: It’s easy to assume that ETTR is the right way to go for video. In the stills world, photographers only have to play with one image at a time. However, video is composed of shots, sometimes taken days apart, that need to match. The problem with ETTR is:
- It works great on large sensor cameras with greater pixel pitch. On smaller sensors, like the 2 MP Blackmagic Pocket Camera, the results are not always clear.
- The noise levels will not match from shot to shot. If you try ETTR on two scenes with wildly varying dynamic ranges, the noise levels in the shadow areas can be as chalk and cheese. The Blackmagic Pocket Camera does tend to get noisy in the shadows.
All in all, if you’re working on a project that is shot across varying light and color levels, avoid ETTR.
There’s a ton of moire on the Blackmagic Pocket Camera, because it doesn’t have an optical low-pass filter (OLPF). In one way, it’s a good thing, because you get greater resolution. On the other hand, you also get moire.
Here’s where shooting Prores really helps. If you shoot Prores, the color information is sub-sampled to 4:2:2, and this blurs the color information – which reduces moire! Check out this video, at about 0.45:
The other alternative is using DaVinci Resolve to separate Luma and Chroma and slightly blur just the Chroma channels. It won’t help though, if your aliasing is all across the board.
There you have it. To recap, shoot Prores HQ Film mode, exposed using a Light Meter, just like with film.
For post production workflows, refer to the links I’ve given at the top of this article. To recap post production, use any NLE of choice to edit Prores HQ, and grade with After Effects, Speedgrade or Resolve. If you’re shooting CinemaDNG RAW, stick to Resolve.
Doesn’t get any simpler, or harder, than that.