by Michael Reichmann
The Background on 4K
Sony always wants to be first. They also play the long game, and are therefore willing to get into a new market segment first as well as push the envelope when it comes to technology and pricing. Sometimes they lose –remember Betamax?But mostly they win, and don’t forget than when its competitor, VHS, became the consumer standard Sony turned Beta into a pro format, and it was used by broadcasters for many years afterward in preference to most anything else.
Now we have the dawn of the 4K video revolution. 3D TV was the industry’s previous attempt to create a surge in consumer TV sales, but it flopped because there was little product to watch, broadcasters didn’t want to spare the bandwidth, and consumers found sitting at home in front of their TV with special glasses an isolating experience.
But 4K isnow, and in my opinion will be here to stay. When it comes to 4K TVs, even regular HD material seems sharper, and if you can watch 4K material it’s really quite a thrilling experience. Sony’s first 4K TVs last year were $25,000, but now, in late 2013, you can buy a Sony 55″ 4K TV for under $3,500, and sets from some of the Korean makes are even less expensive. In 2014 we can of course expect prices to drop even further. Indeed,Seikihas a 50″ set currently for under $1,000, so downward price pressure has already started in earnest and therefore price is not likely to be much of an impediment to uptake.
But, there are the pundits, who, citing math and optics, will tell you that unless you have a really huge screen in a very large room, and an optimal viewing distance, you won’t see the difference between 4K and HD. Nonsense. These are the same people who tell you that bumble bees can’t fly. Ask any bumble bee if this is true, and while you’re at it ask anyone who’s watched a 4K screen with 4K content. Case closed. Back to your slide rules guys.
But there is the issue of 4K content. Sony to the rescue again with their4K media server. Brillant. A 4K player, a huge drive for storage, and a content delivery service all rolled into one.
Unfortunately, and so dumb it almost boggles the mind, at this time the service is only available in the US . In my opinion, in Canada, Europe and elsewhere 4K TV set sales are doomed unless this or a similar service is made available. 3D TV failed in large measure for lack of content. Do Sony’s non-US subsidiaries imagine otherwise with 4K?Sony – brilliant in the US, not so much in the rest of the world. Fix this!
There is no broadcast 4K TV (yet), and no other physical 4K distribution media such as disks. Yes, YouTube has some 4K material, but few will buy a new TV just to watch highly compressed amateur content. 4K TV sales will rest on the back of 4K content availability. Any country where there is none available might as well reduce their 4K set sales forecast by 80%. It’s hard to imagine that Sony’s subsidiaries in other major countries won’t wake up and smell the coffee. But. big companies can make big mistakes. It happens all the time.
Then there are 4K cameras. For those people who are semi-professional or advanced amateur content producers there are currently quite a few 4K camera to be had from Sony, RED, Canon and others. But, prices till now have been at pro levels, and only if there is a potentially commercial production at the end of the production pipeline does a $15,000 – $50,000 camera make much sense.
Black Magic 4K Production Camera
Blackmagic has announced the least expensive 4K camera yet, theBlack Magic Production Camera 4K, at $4,000. But shipping has been delayed, and delayed, and delayed, and Black Magic is mum about when it will actually appear. The BM camera looks appealing, especially at the price, but it brings with it many compromises associated with its design. Like all non-integrated cameras it requires a set of lenses and an array of bulky accessories. Frankly it is best suited to a cinema production environment, where a camera gets rigged with matte boxes, filter sets, follow focus devices and external viewfinders and monitors. The promotional image from Blackmagic seen above shows what a fully rigged camera looks like. Unless this is how you expect to work, enough said.
Now the Sony FDR-AX1 takes the stage. Priced at $4,500 the AX1 is an affordable alternative for pros and creative amateur film makers who want a camcorder-style all-in-one solution. The specs can be read on theSony web site, but here are the main bullet points…
– N ative 3840 x 2160 4K resolution from an 8MP 1/2.3″ back-illuminated Exmor R CMOS sensor.
That the sensor is “native” sized means that there’s no line skipping, sampling, ressing down, or interpolation needed. Sensor and output pixels are 1:1
– Recording is possible at 60P, 50P, 30P, 25P, 24P in either 4K UHD or regular 1920 X 1080 HD
– 20X zoom lens with 31.5 – 630mm equivalent coverage; f/1.6 – f/3.4
– Uses the XAVC / S codec at up to 150 Mbps
– Regular HD can also be recorded at 50 Mbps, which is broadcast spec
– Uses XQD cards for 4K recording, with two slots and auto-switching, and also an SD card slot for regular HD recording
– Ships with a 32GB XQD card and also a full copy of Sony Vegas (Windows only). Curiously, no card reader is included.
– Uses standard Sony video batteries and lens accessories
– Available early November, 2013
In fairness, the Sony AX1 is not the first “affordable” 4K camera. I should mention theJVC HM10which beat it to market by some months. Unfortunately JVC decided to go with aRube Goldbergesquesystem of using four SD cards to separately record each of four HD sized quadrants of the image and then use software to stitch them together on a PC. This appears not to have gained much marketplace traction, and now that the AX1 is out seems unlikely to become more than an historical curiousity.
We’re about to enter a period of transition to a new type of memory card for both stills and video use, called XQD. The first camera to use them was the Nikon D4, and now the AX1 and others are ramping up the requirement.
These cards are capable of very high data rates, higher than SD or Compact Flash cards. I wouldn’t be surprised to see CF cards fade away over the next few years, with XQD cards appearing in high-end still and video cameras, and SD cards being the mainstream media for amateur and less demanding applications.
A 64GB CQD card from Sony is currently $289from B&H. High, but not outrageous. AUSB 3 readeris less than $40. Sony and Lexar are the main suppliers at the moment, but don’t expect this to be another Memorystick. This one is going to have legs.
In Hand and In The Field
Thanks to Sony Canada I had an opportunity to spend several days in early October working with an AX1. Not enough time to really discover all of its capabilities, and because it was a pre-production camera I was not able to really explore any failings. Until a full production camera is available in late in October it isn’t reasonable to draw any firm conclusions about image quality or any possiblegotchas.
But, with those caveats aside I have no reservation in saying that this isthemost exciting video camera that I’ve yet seen. It raises the bar in terms of image quality, at least when it comes to resolution, by a significant increment – even when displayed in HD format.
Let’s start with handling. If you’re familiar with current Sony Prosumer camcorders it’s a case ofdéja vu. There are small differences between the AX1 and preceding models, but controls are where you are used to them being located, menu structure is similar, and overall the fact that you’re using a high performance 4K camera really isn’t apparent while you’re shooting – (other than the use of XQD cards) . It’s only once you load files into your NLE that this changes. More on this soon.
Needless to say, this is not a Cinema Camera like the Blackmagic. It has a relatively small sensor, and a non-interchangeable zoom lens. This is both the bad news and the good news. Though it weighs in at about 6 lbs it is eminently hand-holdable, and has image stabilization that works effectively even out to the equivalent of 600mm. No shoulder mounts, rail systems, follow focus, matte boxes and camera assistants needed.
Of course the trade-off is that you don’t have the shallow DOF of a Super 35mm sensor. But for documentary, nature, wildlife and similar types of shooting this is not only unneeded, but often counterproductive. Not everyone wants the cinema conceit of very shallow depth of field.
The following short (1 minute) film was shot at Toronto’s Dundas Square, a main downtown hub. I could only shot for about 20 minutes. The footage was shot at 60P, but I downconverted to 24P with Pavtube (see below), because neither Premiere Pro nor FCP-X could smoothly handle 4K 60P files on my MacBook Pro Retina. In future I’ll be shooting exclusively in 24P (except for slo-mo).
After editing in FCP-X, I exported to 1920X1080P for upload to Vimeo. This brief video is not intended to show any particular strength or weakness of the AX1’s capabilities, but was the only coherent sequence that I was able to shoot during my short time with the loaner camera. I have lots of technical test footage, but nothing worth putting online.
I have a full production quality AX1 coming in late October, and plan on producing something a bit more interesting, and with higher production values, not soon after. Watch for it here.
Sensitivity and Noise
My initial impression is that this is not a particularly good camera for low-light shooting. A few initial tests show that higher gain settings can be somewhat noisy, but until I have a full production camera and have a chance to shoot in varied conditions, I am reluctant to comment further.Neat Videodoes a great job though when you must shoot with high gain.
Handling XAVC S Files
In 2012 when Sony introduced its pro level PMW-F55 and Sony PMW-F5 4K cameras it created a new format called XAVC. This is capable of handling 4K video at the extremely high data rates required. XAVC is an Intra Frame method of recording. Every frame of video is an individual image. Compressed, like a JPG for example, but still a stand alone frame.
For the new AX1 a variation on XAVC has been developed called XAVC / S. This format differs from XAVC in that it uses Long GOP compression. In this method the first frame of a group, called an i Frame, is the complete image, while the next ones in the series are so-called P and B Frames which contain information on spatial and motion differences between frames in the group. In other words, there is one master frame in a group and then a series of frames that don’t contain all of the image data but rather only information on what’s changed within the frame.
Sounds a bit strange, but it’s a very well established technology. Indeed AVCHD, which is used to encode Blu-Ray discs and also used in virtually every camcorder on the market, is also a similar Long GOP format, so Sony isn’t blazing any completely new trails here.
There are a few issues when it comes to viewing, loading and editing XAVC and XAVC / S files in your non-linear editing software. Sony provides a copy of Sony Vegas with the AX1, which I presume nicely handles the camera’s files. I don’t own a Windows machine, so I can’t say. Mac users are out of luck in terms of a solution from Sony, since Vegas is a Windows only program.
I found that Premiere Pro CC, (available on Mac and Windows) handles these files reasonably well without transcoding. Just load them – they play. While 24P files will play without rendering, 60P files will play but are stuttery until they are rendered. (This, on a MacBook Pro Retina, 2.6 Ghz i7, with 16GB of RAM and a 1T SSD drive.).
At this time Final Cut X does not support XAVC / S files directly. The solution is a $35 program called Pavtube HD Video Converter which can be used to convert the files to ProRes. Be aware though that the camera’s files, which are in an MP4 wrapper, will increase in size by a factor of about 3X when converted in 24P to ProRes, and up to 9X for 60P. This may be reason enough for some to switch from Final Cut X to Premiere Pro if the AX1 is going to become part of your production kit. The camera’s output files are large to begin with. In ProRes they are, well, 3X to 9X larger. You might as well buy shares in Seagate. Of course if you are happy with Vegas then this may be a non-issue, but it’s for Windows users only.
One hint – if you do convert to ProRes you can eventually delete your original camera files to save space, or better yet save them off to another drive as your field backups. The ProRes files lose nothing over the camera originals. They’re just bigger because they’re no longer Long GOP.
I tried DaVinci Resolve 10 Pro, but while it would handle the files to some extent, there was stuttering and black flashes. For this reason, for anyone not using Sony Vegas (which I have no experience with), I would suggest Premiere Pro CC, or if you prefer, and don’t mind the large files generated, Final Cut X along with Pavtube does the job. This is my personal preference because I find FCP-X to be a faster and easier NLE to work with than Premiere.
24P vs 60P
By shooting 24P you’ll have a more filmic cadence to your shooting. You can vary the shutter speed on the AX1 if you wish, so if you’re shooting sports, for example, you can up the shutter speed from a ‘normal’ 1/48 sec to say, 1/125 sec for less blur on fast motion. It’s more of a video look, but then life is full of compromises. I would also suggest shooting 24P at 1/125 sec if you expect to extract still images from your 8 Megapixel files. 1/48 sec has too much blur most of the time for stills.
You can also reserve shooting 60P for when you want high quality slow motion, by dropping the 60P footage onto a 24P timeline and Conforming.
4K for HD – Reason Enough?
What does 4K for HD mean? Well, if you’re a still photographer you’ll understand what downressing does when you take a medium format digital file and res it down from say 800PPI to 360PPI for printing. You end up with superior image quality to what you would see if your original file had only been able to print natively at that same 360PPI.
In video it’s the same. 4K has four times the spatial resolution of 1920X1080 HD. If you then take a 4K camera file and res it down for HD display you end up with a much higher res appearing display image, and also better colour depth. A 4:2:0 image, which the AX1 produces, becomes close to 4:2:2 because of the increased colour sampling that down-resing creates. This means that when strong grading is needed, and HD resolution is the final distribution format, shooting in 4K is definitely an advantage in several respects. The much better looking image is reason enough, to my mind, for shooting with a 4K camera, even of HD is your distribution format.
Moving Within the Frame
Assuming for the moment that your display or release format is 1920X1080 HD, either for online, TV broadcast or just personal use on your own non-4K TV, there is an additional advantage to shooting in 4K. You have four times the image size to work with than you eventually need. This means that you can crop down to as much as a 1/4 of the image, from anywhere within the frame, and use that area for final display. You can also position within the motion frame and do Ken Burns style tracking moves. This can be an alternative to zooming in camera, or adding some motion to an otherwise static image. A simulated dolly shot is trivial to do.
The above video shows such a crop. It was done using the Crop tool in FCP-X. The first version of the clip is full 4K while the second is cropped down to HD size. There is some loss of comparitive resolution, and because the original was hand-held some Stabilization was added in Final Cut. Yes, there is a noticeable difference, but it’s not great, and in many situations this technique will be able to save the day when proper framing wasn’t possible, or even to enable cropping two separate shots – a wide and a close up, for example, from the same clip.
This next clip shows using the Ken Burns effect in FCP-X to simulate a zoom. Just select the starting frame size and ending frame size, and as long as the smaller of the two isn’t less than 1920X1080 you have the ability to add zoom-like motion to an otherwise static shot. Actually, the effect is more like a dolly than a zoom, because there is no change in focal length.
Shooting Still Images with the AX1
Canon 1D MKII – 2004
No, the AX1 can’t actually shoot stills. But on the other hand, yes it can. Each video frame shot, whether at 24 frames per second, 30, 50, or 60 frames per second is an 8 Megapixel still image. So in essence you have a very high speed still camera that produces a sequence of 8 Megapixel images.
Now don’t scoff at 8MP. It wasn’t that many years ago that pro level cameras like the Canon 1D MKII had 8MP sensors, and we all thought that we’d died and gone to heaven. We also were making exhibition prints, shooting magazine covers and the rest with our measly 8MP.
If you think that you’ll be turning video frames into stills, my suggestion is that you shoot with a minimum speed of 1/125sec. This should be your shutter speed for 60P in any event. For 24P it would normally be 1/48 sec, but little will be wrong with the “look” of most motion if you bump it to 1/125, even at 24FPS. The AX1 has a convenient dial on the side of the camera that allows changing the shutter speed at any time.
The reason for wanting at least 1/125 sec is to prevent blur in the frame. Blur may be fine in video, but not so much in stills. Of course this also helps with any unintended hand shake, but since the camera is image stabilized this shouldn’t be too much of a problem in any event.
Still frame from AX1
Please note that I not suggesting that you ditch your DSLR or any other still camera. Nothing of the kind. But, if you find yourself shooting with a 4K video camera such as the AX1, and there is an opportunity for what might also make a great still image, you have in hand a “motor drive” camera that can shoot between 24 and 60 8 Megapixel images per second, with no buffer to run into. Pretty cool actually.
Getting it Out
If you read the section above about how XAVC / S is a Long GOP format, and therefore each frame is not necessarily an I frame, worry not. Your NLE’s transcoding job is to convert all the intermediate frames into complete frames, and that’s what happens when you convert to ProRes or some other editing format. When you export a still frame from your NLE it does the same thing, so regardless of which frame you happen to want to export the software will convert it into a proper looking integrated frame.
So – how is the quality? Pretty damn good, actually. I’d rather shoot with my Nikon D800e (36MP), or even Olympus E-M1(16MP), but 8MP is still pretty good, and I’ve made quite good 9X16″ prints from AX1 frames. Interestingly, the frames are 9X16″ at 240PPI, which is by coincidence the same as the 16/9 aspect ratio. This then becomes a good way to remember how big a print can be comfortably made – call it 11X14″ for tradition’s sake. Of course quite good larger prints are possible with ressing up, and this is discussed in detail in ourseveral video tutorials on Lightroom and printing.
Exporting a still image from your NLE is pretty easy. In FCP-X, if you haven’t already done so once before, you’ll need to go to theSharecontrol, go toAdd Destination, and then dragSave Current Frameto your list of export options. From then on simply position the Play head over the frame you want to export, either in the Timeline or the Event Viewer, and hit Share. Choosing TIF as the format used is to be preferred for subsequent editing in Lightroom or Photoshop.
I intended to produce a video tutorial before the end of 2013 on this topic, and also on the previous topic above –Moving Within The Frame.
Is 3840×2160 Really 4K?
There are some on the net who debate whether Quad UHD, 3840 X 2160 pixels, is really 4K. Come on guys, get over it. It’s like the difference between 1920X1080 HD and 2K. Yes, it’s slightly smaller, but so what? This is the stuff of web nerd debates, not the real-world. Ultra High Def TVis3840X2160. 4K Digital Cinema is 4096 × 2160. The difference is between 8,294,400 pixels at a 1.78:1 (16:9) aspect ratio, and 8,847,360 pixels at a 1.90:1 aspect ratio. Enough said.
I’ve been trying to think of an analogy for how the Sony AX1 relates to the video world in terms of the still photography world. Maybe the best way of putting it is that it’s akin to the Nikon D800. Prior to the D800 there was medium format. It gave higher image quality than was possible from 35mm and smaller formats, but was ultra-expensive. The D800, while maybe not up there with 50 – 80 Megapixel cameras, was noticably superior to just about anything in the 35mm world, and thus deserved recognition for bringing MF quality to a more affordable price point. That’s how I see the AX1 as it relates to the HD video world.
It’s Not Just About 4K Distribution
As we’ve seen, the AX1 joins previous more expensive 4K and 5K cameras in offering a higher resolution production and release format. At LuLa we started shooting our documentaries and training videos in HD as soon as that format because available. This means that now, much of our back catalog is in HD. Others who adopted HD later still have a great deal of SD content, which really does look dated now.
We see the move to 4K, or UHD as it’s also called, as future proofing. We may not distribute in this format for some time, but when the marketplace is ready so will be our products.
When you add to this the advantages in production – multi frame editing from one shot, movement within a frame, higher resolution in HD release, and of course the ability to pull 8 Megapixel stills from footage, the case for the new generation of 4K cameras becomes quite compelling. The Sony AX1 is simply the first of what will undoubtedly be a new generation of resonably priced 4K cameras.
What About the PXW-Z100?
At the same time as the AX1 was announced Sony also announced a look-alike higher-end model 4K camcorder called thePXW-Z100. It’s priced at about $2,000 more than the AX1 and has a number of enhancements, including a higher spec codec, SDI output, faster data rates, and 4:2:2 10 bit colour instead of the 4:2:0 8 bit of the AX1.
But, before you say, “Well, $2,000 more isn’t that much for a higher spec camera,” read the full specifications in detail. This camera is an absolute beast in terms of data rate. At 4K 60P from the Z100 a 64 Gigabyte card will hold just 10 minutes of footage! Yup. 6.4GB per minute. If a high spec computer chokes on the 150Mbps of the AX1, imagine what will happen with 600Mbps files from the Z100. Now imagine what the size of transcoded ProRes HQ files will be like, or what you’ll need by way of a computer to handle them.
By way of comparison, the AX1 will record 25 minutes on a 64GB card at 60P. I therefore extrapolate from this that it would be a minimum of 2.5X more difficult for a computer to handle the files than those from the AX1. (I know that these things aren’t linear, but it’s the best I can come up with.) Since handling 60P files stresses my computer to the max with AX1 files, I have to assume that this would be the case with 24P files from the Z100. With 60P files it would likely grind to an inglorious halt.
The solution might be to generate proxy files and then link via XML to full res files for rendering, but this is outside the bounds of what I consider fun. Also, since the Z100 files are 10 bit 4:2:2 I would naturally want to transcode to ProRes HQ or ProRes 4:4:4 to take maximum advantage, which would up the ante even more. I see this whole process as akin to trying to work with RED files without an accelerator card. Maybe worse, and not really do-able without a mega computer system and other tech resources.
It seems to me therefore that unless one is using one of the soon-to-be-announced new Mac Pros (and who knowsat this time what their performance will really be), have literally Terabytes of storage to spare, and have to do heavy grading and Green Screen work, the Z100 will in all likelihood be major overkill. If you have to have the biggest and the baddest, or really do have high-end technical requirements, then of course go for it. But while most people will find the AX1 more than adequate, and near the limit of what a typical high performance computer can handle, the Z100 may in fact be too much of a good thing. The AX1 seems to me to be closer to the sweet spot that typical users need, and is therefore the next main video camera that I’ll be getting for my own use. I have productions planned in both Mexico and Antarctica this winter, and the AX1 will now be my camera of choice for these.
The Sony FDR-AX1 begins availability around November 1, 2013 in Canada and the U.S. I expect to publish a detailed review of the camera before the end of the year.