Just watched the final episode of the current series of Dr Who. Excellent stuff, shot with a Sony F35 and it looks very good indeed. On BBC HD that was followed by Dr Who Confidential, a behind the scenes look at Dr Who. A large part of this followed a trip to the USA to promote the series. Lots of shots in Cabs and walking down NYC streets, some intercut with shots from the main series.It all looked very good, the quality of the NYC footage not looking out of place compared to the footage from the F35′s used on the Dr Who series. This got me wondering what the NYC material was shot on, afterall shooting two people sat in the back of a cab from the same rear seat requires a compact camera. A big clue came during the press events where flash photography revealed it to be a CMOS camera. My money was on XDCAM EX. So I continued to watch the show and outside a NYC cinema there is sequence shot with two cameras and the other camera can be seen in many of the shots. It is, as I suspected an XDCAM EX1. But there is no sign of a NanoFlash, just a plain vanilla EX1, recording 35Mb/s 4:2:0. So the BBC once again prove that their own rules are being broken on internal productions ie, minimum 1/2″ sensor, 4:2:2, 50Mb/s. There is also no way they could claim that the EX footage only made up 20% of the show as the NYC sequences make up the bulk of the programme.
I just don’t know what all the fuss is about. The EX footage in Dr Who confidential holds it’s own against the F35 footage. I can’t see any more artefacts in the EX material or objectionable concatenation effects. The behind the scenes footage looks good too. Sure the F35 has shallower DoF and has a very filmic look, but the EX footage looks very good too. The XDCAM EX codec is a very good codec that really performs better than it should considering it’s compact size.
This isn’t a review, I have not had a play with one yet. I just wanted to discuss the camera in more detail than I have previously. The PM-320 on the outside is almost identical to the PMW-350. The only clues as to the cameras identity are a blue rubber grip under the camera handle and a slightly blue XDCAM badge on the side of the camera. I’m pleased that Sony have done this rather than making the camera some horrid light grey as they did with the PDW-330. Inside the box instead of the 2/3″ sensors of the PMW-350 you get the same 1/2″ sensors that are fitted to the EX3. The camera uses the same 1/2″ hot shoe lens mount that’s fitted to other Sony 1/2″ cameras like the DSR-300 or PDW-355. This would make the PMW-320 an interesting upgrade option for original XDCAM HD camera owners. Unlike the PMW-350, standard definition is included as standard, so no need to buy an additional dongle. The 320 uses the same menu structure as the 350 (which I really like) and has the same Cinealta type scene files as opposed to the picture profiles of the smaller EX cameras. These scene files use Hypergammas as opposed to Cinegammas and have a greater range of adjustments. Picture quality should be pretty much the same as you get from an EX3 but the extra ND filter and possibly a better lens may give the 320 a tiny edge in some circumstances, but I think overall it will be pretty much impossible to tell the difference. One thing to note is that the lens on the EX3 has an image stabilizer, while the lens fitted to the PMW-350 does not. At NAB the 320′s were being shown with the same lens as the 350 so it seems likely IMHO that the production 320 packages will not have an optical image stabilizer.
The shoulder mount design does make it easier to hold the camera steady when handheld, so the lack of a stabilizer is not necessarily a big deal. For many the form factor is what will be attractive. The PMW-320 looks and feels like a “proper” camera. This is important, there are some Hollywood actors that won’t allow themselves to be filmed unless it’s by a full size camera (sad) and when your shooting a corporate video the client often expects to see a large camera. Sitting, price wise, closer to a PMW-350 than an EX3 the 320 might be a hard sell. You do get the shoulder mount form factor, 4 channels of audio, a radio mic slot and SD, but for most applications there will be no difference in image quality. If you can get away with the EX3′s (or even EX1′s) form factor, why spend all that extra money on the PMW-320? If your looking at spending that kind of money, I think you would be better off going all the way to the PMW-350. This then adds a better sensor block producing a really stunning, low noise image with remarkably little grain. It also gives you the industry standard B4, 2/3″ lens mount, opening up the ability to directly fit a massive range of lenses that can be hired from most broadcast rental companies. 2/3″ also has a noticeably shallower DoF giving you more creative control.
Finally back in the UK!! This week I’m running a workshop on NXCAM and XDCAM EX at Prokit on Thursday the 29th of April. If you would like to attend this free workshop please register on the Sony Power of Images website or give Prokit a ring to reserve a space. Next week I will be running a further workshops at H. Prestons on the 5th of May and then another workshop at CameraKit in Leeds on the 11th of May.
Until a couple of years ago CMOS sensors were definitely the underdog, they tended to be very noisy due to electrical noise generated the on chip by the readout circuits and A/D converters. In addition they lacked sensitivity due to the electronics on the face of the chip leaving less room for the light sensitive parts. Today, on chip noise reduction has made it possible to produce CMOS sensors with very low noise and micro lenses and better design has mitigated most of the sensitivity problems. In terms of a static image there is very little difference between a CMOS sensor and a CCD sensor. Dynamic range is remarkably similar (both types of sensor use essentially the same light gathering methods), in some respects CMOS has the edge as they are less prone to overload issues. CCD’s are very expensive to manufacture as the way they are read out requires near lossless transfer of minute charges through a thousand or more (for HD) memory cells. The first pixel to be read passes down through over 1000 memory cells, if it was to loose 5% of it’s charge in each cell, the signal would be seriously reduced by the time it left the chip. The last pixel to be read out only passes through one memory cell, so it would be less degraded, this variation could ruin an image making it uneven. Although there is more electronics on a CMOS sensor, as each pixel is read directly a small amount of loss in the transfer is acceptable as each pixel would have a similar amount of loss. So the chips are easier to make as although the design is more complex, it is less demanding and most semiconductor plants can make CMOS sensors while CCD needs much more specialised production methods. Yes, CMOS sensors are more prone to motion artifacts as the sensor is scanned from top to bottom, one pixel at a time (A CCD is read in it’s entirety just about instantaneously). This means that as you pan, at the start of the pan the top of the sensor is being read and as the pan progresses the scan moves down the chip. This can make things appear to lean over and it’s known as skew. The severity of the skew is dependent on the readout speed of the chip. Stills cameras and mobile phone cameras suffer from terrible skew as they typically have very slow readout speeds, the sensors used in an EX have a much higher readout speed and in most real world situations skew is not an issue. However there may be some circumstances where skew can cause problems but my experience is that these are few and far between. The other issue is Flash Banding. Again this is caused by the CMOS scan system. As a flash gun or strobe light is of very short duration compared to the CMOS scan it can appear that only part of the frame is illuminated by the flash of light. You can reduce the impact of Flash Banding by shooting at the slowest possible shutter speed (for example shooting 25P or 24P with no shutter) but it is impossible to completely eliminate. When I shoot lightning and thunderstorms I often use a 2 frame shutter, shooting this way I get very few partial bolts of lightning, maybe 1 in 50. If you shoot interlace then you can use the Flash Band removal tool in Sony’s Clip Browser software to eliminate flash gun problems. CMOS sensors are becoming much more common in high end cameras. Arri’s new Alexa film replacement camera uses a CMOS sensor rated at 800asa with 13 stops of latitude. Red uses CMOS as does SI2K. Slumdog Millionaire (SI2K) was the first electronically shot film to get an Oscar for cinematography, so certainly CMOS has come a long way in recent years. CMOS is here to stay, it will almost certainly make bigger and bigger inroads at higher levels. Read speeds will increase and skew etc will become less of an issue. IMHO skew is not an issue to loose sleep over with the EX’s anyway. I shoot all sorts from hurricanes and tornadoes to fast jets and race cars. I have yet to come across a shot spoilt by skew, generally motion blur tends to mask any skew long before it gets noticeable. If you shoot press conferences or red carpet events where flash guns will be going off, then you may prefer a CCD camera as this is harder to deal with, but the EXs are such good value for the money and bring many other advantages such as lower power and less weight that you have to look at the bigger picture and ask what you expect from your budget.
As you may have seen from my earlier post I became the owner of the new Canon T2i (or 550D as it’s known in the UK) at the weekend. Clearly before using any camera in anger it’s important to see what it can and can’t do. I will say that I am not a Canon DSLR expert. I have been following the fuss and much admire some of the work done with these cameras by Phil Bloom, but frankly after playing with the Canon over the weekend I have to say I’m disappointed. Yes you can achieve shallow depth of field very easily and you do get a filmic look to the pictures, but look at the footage on a big monitor and it just looks soft. At first I wondered if this was the lens I was using, so I tried a couple of others including a nice Tamron 28mm prime. I tried different apertures, shutter speeds etc, but every clip I’ve taken looks soft. In isolation, on scenes with low detail this isn’t immediately apparent, but anything with lots of fine detail looks soft. Some of this is aliasing, look at the roof of the house in the T2i image, it appears to have diagonal roof tiles, this is a pretty typical aliasing artifact. I shot some closer shots of the buildings and the brickwork aliased like crazy.
Flowers, EX1 on left, T2i on the right.
Looking at the flowers picture you can see that the EX1 has picked up more of the subtle texture, or at least it has recorded more of the texture. I’m sure some of the Canon’s softness is due to compression artifacts. The other thing that I found is that it is tending to crush blacks a bit. I have played around with the picture styles and you can reduce this a bit, but there is very little detail in deep blacks, which would IMHO make grading tricky. The one good thing I did find was that it is very noise free at 200 and 400 asa, it’s also useable up to 800 asa or at a push 1600asa, so it would make a good camera for very low key scenes, provided you use a good fast lens. Looking at the Canon pictures there was something pleasing about the deep, almost crushed blacks. I think this helps contribute to the Canon DSLR “look” so I quickly threw together a new picture profile for the EX1/3 and PMW-350, but I’m afraid that the details of that will be the subject of another post, as I have work that I must do first! The EX images in the frame grabs were shot with this picture profile. As we all know the ergonomics of the video DSLR’s is pretty poor for video. It’s tricky to hold and you have to use an add on Loupe to make the LCD useable as a viewfinder. You can’t zoom mid shot and without peaking or zebras adjusting exposure and focus accurately is difficult. I was hoping to be able to use the 550D as a B camera for those situations where I need a small, discreet camera, but having seen the pictures, so far, for me it will be reserved for holidays and shooting where you not supposed to video and for shoots where supper shallow DoF is essential. I have to say I’m really disappointed, I wanted this camera to be so much better, I knew it would suffer from aliasing, but I wasn’t expecting the soft pictures, I guess some will say that the softness adds to the filmic look, but I’d much rather do that with some nice pro-mists or filtration in post production rather than starting out with soft pictures. Perhaps I’ve done something wrong? If I have please add a comment!
UPDATE: I was so convinced that I must be doing something wrong that I shot some more clips, this time with less harsh lighting. No, change however, the T2i is still soft and the new clips show just how big a problem aliasing is. You have to consider that the coloured moire patterns are recorded like that, no amount of grading will get rid of it. A small amount of diffusion on the camera should help, but then your going to have to work out how much to soften and diffuse each shot to make sure your not making the pictures even softer than they already are.
Sony XDCAM EX top and Canon T2i bottom.
The frame grabs are all 1:1 pixel for pixel, no trickery has been used! You can download some further examples by clicking here. Even if you were shooting stuff for the web this level of aliasing could cause big problems as it’s really obvious. For this shot I had the Canons sharpness setting turned all the way down. I have also turned down the contrast setting as this gives better dynamic range with less crushed blacks. My workflow is to import the H264 files from the camera and then convert them to ProResHQ. This helps a little with sharpness over working with the native H264, but for me this last test was the nail in the coffin for DSLR’s as footage like this would simply be unusable. If you watch the YouTube clip please make sure you watch it full screen or at least at the 480P setting. The small embedded size doesn’t show the aliasing as much as the bigger versions.
FURTHER UPDATE:
OK, so it’s defiantly not just me doing something wrong. When in focus the T2i/550D aliases (as do all the current Canon DSLR’s). This is a grab from Philip Blooms latest Canon short. For once this is a daylight piece and as I expected it exhibits a lot of aliasing. The grab is actually taken from the thumbnail on his exposure room page. I’m really pleased to see this as it shows that aliasing is a problem for the experts too. You start to appreciate why so many of the Canon shorts are shot at night, with millimeter deep DoF… it’s to stay clear of having stuff in focus that will alias. there are filters from Caprock that are supposed to help, but you need a different filter for each focal length and aperture that you use, they also soften the picture somewhat.
Aliasing in Philip Blooms latest Canon short
If you want my opinion, then it has to be that the Canon’s are close, but still a mile away. The aliasing issue is a biggie. Sort it out and the skew, jello and overheating can be worked around, but if you have to worry about simply having a piece of wood in focus and whether it’s going to exhibit rainbows of colour or whether cobble stones will twitter and change colour (At 00.35 and this is from Canon) then it will limit what you can do. There is quite a lot of aliasing in Phil’s new daytime clip, basically anytime anything is steady, has texture and is in focus, it aliases. I’ve been shot down in flames on other forums for saying that this is a problem, but if even the experts can’t deal with it then what hope does everyone else have? I would love to have the option of shooting with the shallow DoF that the Canon’s offer, but not at the expense of having to avoid any kind of texture. Perhaps Red and Scarlet will be better, perhaps Canon will sort it out, or perhaps not, as the cameras are clearly selling like hot cakes, even with the issues. If they do fix it then the camera will almost certainly be for video only.
Sony have just released the firmware required to use the new 32Gb SxS-1 cards, the Memory Stick and SD Card adapters. This firmware also adds the ability to have much longer clip titles (46 Characters!) on the PMW-350 and EX1R. You can do the update yourself, you don’t have to send the camera back to Sony (hooray) to do the update. CLICK HERE to go to the firmware on the Sony UK site. Initial reports indicate that the update improves the performance of 3rd party SD card adapters and is straight forward to install. There are also indications that original EX3′s boot up a bit faster. At the moment the EX1 update appears to be missing from the download page, but I have been assured this will be rectified in the next 24 hours.
Well I have just returned from Iceland where I held a couple of 3D stereoscopic master classes and a workshop on video for the internet. They went well and we all had fun despite almost a foot of snow fall the morning of the classes. On the last day of my trip I decided to try and get some more Northern Lights footage. As I am often asked how I do this I put together the clip below which explains what settings I use for the Aurora and also gives a brief description of S&Q on an XDCAM EX. Basically what I do is use the EX Slow Shutter at 32 or 64 frames to increase the sensitivity of the camera. For a dim Northern Lights display I use 64 frames but for a bright display I drop down to 32 frames. The slow shutter acts like a long exposure on a stills camera. I then combine this with interval record shooting at 1 frame every second. I did also have a Canon DSLR with me and tried to shoot the Aurora with that. I found I needed a 10 second exposure at 800 asa to get a similar result to that achieved with the EX. The 10 second exposure means that it would take longer to get a decent length video sequence and most of the motion of the Aurora would be lost. Some of the exposure difference was I admit to the slower F4 lens on the Canon compared to the Sony EX’s F1.8, so perhaps with a faster lens you could bring the exposure down to around 5 seconds and this is something I hope to try when I go Aurora chasing next winter.
If you watch the video make sure you stay to the end to check out my attempt to record a piece to camera in 60 mph blowing snow! Don’t know why I even thought it would work. What I will say is that my new Vinten 5AS did a great job of keeping the camera steady in some pretty extreme conditions.
I decided to write a more detailed post to continue the discussions on scene file settings for the PMW-350. This is a work in progress. Some of this may also be of interest to other camera users as I hope to give a basic description of what all the various settings do.
First off let me say that there is no “right way” or “wrong way” to set up a scene file. What works for one person may not be to anothers taste, or suit different applications. For me, my requirements are a neutral look, not over corrected or too vivid, but retaining a pleasing contrast range. I hope, as this thread develops to explain a little bit about each of the settings and what they actually do in the hope that it will make it easy for you to adjust the scene files to suit your own needs. I hope others will jump in with their suggestions too!
So first of all I have been looking at the sharpness of the image. The principle settings that affect this are the Detail and Aperture settings.
Detail enhances rapid transitions from light to dark within the pictures by exaggerating the transition with the addition of a black or white edge. So it only really works on object outlines and larger details (low frequency). The circuitry that determines where these edges are uses an electronic delay to compare adjacent pixels to see whether they are brighter or darker compared to each other. Because of this any rapid movement within the frame stops the circuitry from working. If you have picture with a lot of detail correction and you do a pan for example the image will appear to go soft as soon as the camera moves as the detail circuitry can no longer determine where the edges within the image are and thus applies less detail correction. A good way to visually gauge how much detail a camera is applying to a clip is to look for this. With a good high resolution camera, set up well, it should not be all that obvious, but a low resolution camera that uses lots of detail correction to compensate will exhibit lots of softening on pans.
As well as adjusting the amount of detail correction (Detail Level), you can also adjust the ratio of horizontal and vertical correction, the maximum brightness or darkness of the applied edges (white and black limit). The thickness of the edges (frequency), the minimum contrast change that the correction will be applied to (crispening) and you can tell the camera not to apply detail correction to dark areas (level depend).
The other setting that effects picture sharpness is Aperture. Aperture correction is a high frequency boost circuit, it simply, in effect, enhances transitions from dark to light or light to dark in fine detail and textures such as fabrics, skin, hair, grass etc. It’s operation is not as obvious as “Detail” correction, but if overdone it can make textures sparkle with flashes of white or black, all very un-natural.
An important note about image detail is that if you have too much of it for the given image resolution then you get problems such as aliasing and moire which manifest themselves as rainbows of colour or buzzing, jittering areas in the picture. If you want to know more about this look up Nyquist theory. This is one of the reasons why downconverting HD to SD and getting a good picture can be harder than you might think as you are often starting out with too much detail (but that’s another topic on it’s own).
So… on to the PMW-350. Out of the box it’s really sharp. The camera has full 1920×1080 sensors, so even with all detail correction turned off the image is still pretty sharp. However most viewers are used to seeing picture with some detail correction, so if you turn it all off, to many it looks soft. If you were going for a really filmic look, detail off and aperture off would have to be a serious option. For my customers though a little bit of subtle “zing” seems to be what they like.
I found that these settings worked well for general all-round use.
Detail Level -14
H/V Ratio +20 (helps balance horizontal and vertical resolution)
Frequency +35 (makes the edges thinner, if your doing a lot of SD you may want to go the other way to -50 so that the edges can still be seen in SD)
White Limit +35 (limits brightness of white edges)
Black Limit +30 (limits darkness of black edges)
Aperture -20
If you are doing a lot of grading and work with low key scenes (large dark areas) you can use the level depend and crispening settings to help prevent “detail” being added to any picture noise. This makes any noise less apparent.
A starting point for this would be:
Crispening +35
Level depend +20
For normal light levels these are not needed with the 350 IMHO. If you are shooting with more than +6db gain then raising the level depend to +60 will help with noise.
I have been playing with a Sony PXU-MS240 SxS backup device. It’s quite different to my NextoDi NVS2500 even though it essentially does the same job. I will be reviewing it in some detail very soon, but here are my first thoughts.
The key feature is that unit has a removable 240Gb hard drive module. Extra drives are readily available and the removable drives can be used as stand-alone USB hard drives without the main unit. Each hard drive cartridge comes in a sturdy box that is much like a Betacam cassette box. There is space on the drives for labels and the box has an insert sleeve that can be used to write on, just like a tape. Clearly this has been done so that as you fill up drives you can pop them on a shelf for longer term storage as you would with a tape. The beauty of the MS240 is that you never need to off load footage, you just add cartridges as you fill them up.
The main unit is 12 volt powered or can run off a standard EX battery. There is a slot at the front for a SxS card and a big Copy button on the top panel along with the power button and menu controls. There is also a small and very clear LCD display that tells you what the unit is doing. In the setup menu you can choose whether to simply copy the SxS cards contents or to do a copy with full verification in one pass.
Another way to verify your clips is to plug it in to an EX camera. The MS240 is supplied with a USB to Express card adapter. You plug the adapter into an EX’s SxS slot and the USB end into the MS240 and then you can use the EX to playback any clips on the MS240 in full HD. This is something the Nexto cannot do. It also means that you could use the MS240 to store finished edits for playback via an EX over HDSDi.
The build quality is good and the range of connectivity is also good with eSATA and USB on the main unit and USB on the cartridges. A 16Gb card can be copied to the drive in around 5 mins.
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