The Blackmagic Production Camera 4K experience Part 2

In part 1 of this blog I documented the first experiences of using the Blackmagic Design Production Camera (BMPC) and how I chose the SanDisk Extreme II 240GB SSDs, a cheap battery solution and a low priced EVF monitor. So far this setup has cost £2310 for the camera, nothing for the battery system (OK about £16 if you bought it), £260 for 2 SSD cards and £400 for the Cineroid EVF-4CSS a total of £2986 (or €3577 or $4936). To this I have to add a tripod and of course suitable Canon lenses which can easily double the price.

But as a result I have a rig capable of shooting 4K pictures on a good codec (ProRes at the moment) with a global shutter (so no "jello") and I have a piece of software that would cost $995 if bought separately, more about this later. But the usability of the BMPC is always an issue and the form factor of the camera worried me because it is heavy and, I predict, easy to drop. I also needed something to attach the EVF and an external microphone. 

I had looked at a lot of cages but the cheap ones were, well cheap, and all of them were bulky and meant I couldn't fit all the kit in my brilliant Lowepro Stealth Reporter D550AW bag. My solution is from Redrock Micro with a top handle and the Ultraplate which added about £100 to the total. The Ultraplate offers just enough screw points to attach the handle, the EVF on a mini magic arm and a mic or recorder if needed.

So the whole rig looks like this.

Post Production

So I have shot the footage, got (most of) it in focus thanks to the EVF and now I need to edit it and Blackmagic Design have kindly included a copy of DaVinci Resolve 10 with a USB key in the BMPC box to help me. This is the first time I have tried to work with 4K footage and I have a pretty powerful PC to do so with i7 processor, 32 GB RAM, Nvidia GeForce GTX 570 and Quadro FX580 graphics cards. Unfortunately this is far to weak to properly edit 4K footage and as I don't have a 4K monitor I can either view the footage in HD or just see the top half of the footage spread over two 1920 monitors. 

It's not brilliant but it is possible to work this way and produce great results. I work mainly with Avid Media Composer which is less than useless for 4K or Adobe After Effects which is more than good but Resolve is like neither of these and if you are going to use it properly will take fair bit of learning  - persevere it is well worth it. This is not a tutorial in Resolve so I just want to highlight some of the Eureka moments I have had so far. 

Where you store your footage for editing is really important, run the included Blackmagic Disk Speed Test on all your drives and put the material on the fastest one - you can archive to a slower drive later. A raid drive such as the G-Raid is likely to be the best, better than the fast SSD (that was a surprise). 

Unless you have a monster $1000+ GPU like the GTX690 or NVIDIA Titan you will not be able to play 4K on your timeline, you will get a screen of shash and a GPU out of memory message. Go to project settings and select 1920x1080 as your timeline resolution. 

THIS IS IMPORTANT. When you have finished editing and grading and you go to the "delivery" window and select UHD as your output you have to go back into project settings and set the timeline to UHD, if you don't your final output will be HD expanded to fit the UHD raster. Resolve is actually very good at this and it took a lot of looking to see the difference. Below is a still from a scene in Trafalgar Square and two crops with the timeline set to different resolutions. The middle picture shows the image at 400% with the timeline set to UHD and the bottom picture with it set to HD. The bottom picture shows a lot less detail.

If you look at the comparison table of Resolve lite and the full version there doesn't seem to be a lot of difference, but go about a third of the way down and you will see this section:

After the sharpening tool (like the 5D the images generally benefit from a bit of sharpening) the noise reduction tools make a huge difference particularly in areas like sky or flesh tones, be gentle with it and you will be rewarded. The BMPC is not good at shooting in low light (and I am not a fan of ProRes for this) and sometimes scenes like the one below in St Pancras Station mean lifting the dark areas considerably which can bring in really bad speckle. The noise reduction tool in Resolve is amazing at reducing this.

The format you output will always depend on where you will put it, but I have established a workflow from producing 4K time lapses where I output QuickTime Cineform versions which are indistinguishable from uncompressed files but much smaller and then use Adobe Media Encoder to produce QuickTime PhotoJPEG versions for stock companies or broadcasters since that is such a user friendly format and one that Resolve cannot output directly. 


These two blogs have been a quick summary of what I have learnt "hands-on" with this amazing camera and what I feel is the minimum requirement to shoot good footage. Hopefully it will give a bit of guidance to those still in the queue for the 4K Production Camera.

4K codecs - the good, the big and the ugly. Part 2

The first part of this blog looked at the file sizes of a 1 second 4K video clip using various QuickTime codecs. This part looks at the image quality of the codecs that use an efficient lossy compression system. Some codecs can compress an image and uncompress it without any loss of information (lossless compression), but these produce extremely large file sizes and I have left them out of this test as they should, in theory, show no difference to the original.   

The codecs compared here are GoPro's Cineform, Avid's DNxHD, MJPEG A, MJPEG B, MPEG 4 and Photo JPEG. Here is the table of file sizes for the various versions I made:

File sizes of 4K 1 second clip

Here is the link to the 1 second clip at HD 1920x1080 size in the MPEG 4 codec at 90%.

I made 2 JPEG (100%) stills of the first frame of the clip. One is the full size 4K image and the other is a 640x360 pixel crop with the image zoomed up to 200%. The cropped image is the top of the tower with the crane by the side. All the images are shown below, but I also made a stack of the crops in Photoshop and sliced out the layers for a comparison. 

Quality of various codecs 90% quality. 200% zoom and cropped

I haven't included MJPEGB here because it is no different from MJPEGA, but both MJPEGs show a large variation in the original colour, lifting the gamma significantly. All the other codecs were consistent and matched the uncompressed version.


The original purpose of this test was to see if the Avid DNxHD codec was suitable for 4K use but when I saw how poor the quality was I looked at all the other codecs to see what was wrong. You can see from the sliced picture how blurred the image of the crane has become, but the MPEG4 version is as sharp as the Photo JPEG image below. I was surprised when I looked at the file size how much DNxHD was compressing the image because I hadn't seen such degradation when editing high definition material and the file size is larger than MPEG4. I rendered out this clip in 1920x1080 with the codecs again set to 90% quality. The DNxHD clip was 44 MB in size and the MPEG4 was only 14 MB in size.

To be precise the HD version of the DNxHD codec was 44,808 KB in size which is exactly the size of the 4K version, which gave the solution. The DNxHD codec is only designed for the 1920x1080 video space and when the image dimension goes beyond that the pixels are duplicated (or more) to fill in the gaps, hence why it is blurred and the file size doesn't increase.

I think this is a mistake and Avid should limit the dimension the codec can produce, like H.264 does. Or it should ignore file size and produce a similar quality of image that the other codecs show here. I assume Avid will come up with a native 4K codec very soon which can be used in the next generation of cameras such as the Blackmagic Design Cinema Camera and their edit tools.

Meanwhile the best solution for moving 4K videos around the web appears to be MPEG 4 because it scales well, reproduces the original colour and is the smallest of all the options. However I hope that the GoPro Cineform codec becomes more widely used (and free) as it is robust and platform agnostic. And of course we wait for the launch of H.265 which is likely to be the choice of the broadcast world.

For videographers producing 4K clips the only solution is to use a lossless codec 

Here are the JPEG images of all the test clips. Please download them to compare.

Cineform 90%

Cineform 90% crop with 200% zoom

Avid DNxHD 90%

Avid DNxHD 90% crop with 200% zoom

MPEG A 90%

MPEG A 90% crop with 200% zoom

MPEG 4 90%

MPEG 4 90% crop with 200% zoom

Photo JPEG 90%

Photo JPEG 90% crop with 200% zoom

4K codecs - the good, the big and the ugly. Part 1

There can be little doubt that there is going to be a huge increase in the demand for 4K footage over the next few years and much of that early demand will have to satisfied by stock material. Currently broadcasters can turn to an enormous library of SD and HD material compiled over decades of shooting, but that won't cut the mustard when intercut with newly acquired 4K footage.

Which is good news for those of us who are planning on making our own library of high quality 4K stock shots. One question I would love to answer is which flavour of 4K will be the choice of stock libraries and I really hope that the big boys can come to some sort of agreement here, because uploading four different versions of a 4K clip is not a quick process.

Now H.265 has been announced and I think this will become the bookies favourite even though its younger cousin H.264 is not currently stock libraries first choice for progressive footage. But efficient as H.265 is, it's unlikely to be a good format to edit with for reasons I won't go into here. This means any stock footage will have to be transcoded to another format or codec before editing.

So I ran some tests on existing codecs using a 4K clip from a time lapse within Adobe After Effects to see if any of them would be good enough to host on the web and edit with natively. Here is a still from the sequence. 

The One Tower, St Georges Wharf, Vauxhall, London

The crane on the tall building behind Vauxhall Bridge was unfortunately hit by a helicopter in January 2013 in case it looks familiar - you can see a 1080p version of the time lapse here. I chose this clip because of the complexity of the image with lots of vertical and horizontal lines and a lot of detail in the sky and water.

Here are the codec candidates:

Avid DNxHD - works on Mac and PC and the codec is free.
BlackMagic codec - great quality but probably too big and not widely used.
Cineform - again works on Mac and PC but you need the Premium version of Cineform Studio to create files and this is $299.
Photo JPEG - An old codec, with good compatibility. Currently the choice of many stock companies but not the most efficient of compression choices.
TIFF - Using LZW compression should give a perfect image but with file sizes to match. Also tried a QT using TIFF.
Animation - Not used so much any more but moving between editing and graphics tools is used to be the king. Huge differences in file size depending on the compression ratio.
MPEG A & B - Had their day I think and largely used only for interlaced  
ProRes - A really great codec but will not play well (if at all) on PCs, which really is a ridiculous situation. If it did this would be numero uno. I'm working on a PC so couldn't produce any test results. Pah!

I created a 4K (4096x2304) 1 second clip in each format at two or three compression settings (75%, 90% & 100% where possible) to look at file size and quality. Here are the results:

File sizes of  1 second 4K clip in various codecs 

The TIFF sequence adds up to 288 MB for the 25 frames. 

Unsurprisingly the uncompressed or lossless compression codecs are significantly larger than the lossy compressed versions. The embedded TIFF QTs were significantly larger than the sequence of stills using the LZW lossless compression and the TIFF sequence would still be a good way to exchange between editing and graphic systems.

The lossy compression codecs start with Cineform (100% quality) at 126 MB for a 1 second clip. Bearing in mind that the maximum  length of a clip on iStock is 30 seconds and you could end up with a files of 3.78 GB! At 75% quality it would be a mere 1.8 GB

The tests showed that DNxHD 444 10 bit was almost the same size at 100%, 90% and 75%. Somewhat surprisingly it made little difference on MJPEG codecs whether 75% or 90% compression was chosen. But Cineform at 100% jumped up to 126 MB - almost double the 90% file size, which shows remarkably efficient compression if the quality stands up.

Photo JPEG and MPEG4 also showed a big difference between 75% and 90% and a 30 second clip at the higher compression (75% quality) would be just over 1 GB in size.

In Part 2 of this blog I look at the picture quality of the smaller files to see whether they have a future as a 4K stock format.