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What is “Crispening” and how does it effect the picture?

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What is “Crispening” and how does it effect the picture?

Crispening is one of the adjustments you can make in many of Sony’s video cameras that adjusts the way the image is sharpened via the detail correction circuit. On an EX1 or EX3 it is in the Picture Profiles section. If use wisely Crispening can be used to help deal with camera noise by making it less visible, thus giving a cleaner image. Crispening works across the entire luma (brightness) range. It’s really difficult to explain how the level adjustment works, it is a threshold adjustment for the detail circuit, but I’ll have a go anyway.

First off lets consider how the detail circuit works. The camera uses delay circuits to compare how the brightness (luma) levels of adjacent pixels are changing, both from left to right and line by line. If the circuit sees a rapid change from light to dark or dark to light (or light to lighter, dark to darker etc) the circuit regards this as an edge and detail correction is applied by brightening or darkening the transition, exaggerating the edge. This is seen in extreme cases as a black or white halo around edges.

On the EX cameras crispening works by adjusting the threshold at which the light to dark transition between pixels triggers the application of detail correction. So when you set a negative number, say -99 even the slightest luma difference between pixels will have detail correction applied. Set it to +99 and it takes a much greater luma change to trigger the detail circuit.

What you need to understand is that if you set crispening such that the threshold before detail is applied is 100mV (for example) then between 0v (black) and 99mV little to no detail correction will be applied, keeping blacks clean by not applying detail correction to any noise with an amplitude less than 100mV. But if there are subtle textures in the image, going say from 500mV to 599mV (mid tones) then no detail correction will be applied here either, so the image will appear a little softer, only larger luma changes of more than 100mV will have detail correction applied. These small luma changes can be anywhere within the full luma range and it is not confined just to the darker parts of the image.

Raising the crispening level setting to a positive number raises the threshold at which detail is applied to the image, so a high number prevents detail correction from being added to small luma changes. A negative number means that detail correction will be applied to smaller luma changes, this increases the appearance of noise but also makes textures appear sharper.

One thing to consider is that the noise the camera produces is not only in the blacks. If the noise amplitude (level) is for example 5mV, then if you have a subject at 500mV (mid tones) it will still have random 5mV noise added to it. It just tends to be that noise is most visible in the blacks as 5mV of noise on a 5mV (very dark) signal is modulating (varying) the signal by 100% so it’s quite obvious, however 5mV on top of 500mV is only 1% so less obvious, but still there and still visible.

You should remember that the cleaner you can make the recorded image the less stress there is on the codec. This in turn means less mosquito noise and macro blocking giving an image that looks cleaner still and grades better. I struggle to see the difference between crispening at 0 and at +20 in most normally exposed shots, but if I look closely I do see less noise in shadow and low contrast areas. Low contrast areas tend to have little detail anyway, so being able to clean these up a little helps in post production.

Sony have a PDF about it here:?http://www.sony.co.uk/res/attachment…6605183226.pdf

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Just how big is the 3D market?

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As you walked around the BVE show in London last week you could not help but notice that just about every stand had some kind of reference to 3D production. The impression given was that 3D is here, it is going to be huge and everyone needs to be able to shoot in 3D. But is this really the case? Certainly there has been a big increase in the number of 3D movies produced in the last 18 months and Avatar is now the largest grossing movie ever made, much of the profits coming from 3D screenings. Sky TV in the UK are starting a 3D TV channel later in the year and Discovery, ESPN and others have announced their intentions to launch stereoscopic channels. To add to all this the TV manufacturers are also bringing large ranges of 3D TV’s to market.

But before you all rush out and spend large sums of money on expensive 3D camera rigs you need to look more closely at what’s going on and consider who will actually want to watch 3D. Now I am a fan of 3D, don’t get me wrong and I do believe that 3D is here to stay, but as I see it, until display technology finds a way to eliminate the need to wear special glasses 3D is going to be reserved for special events, movies and spectaculars. Lets face it who’s going to want to have to put on a pair of glasses after a hard days work, just to watch the news or a soap. This is supported by Sky’s recent 3D seminar where they stated that they are only looking at showing 4 hours of new 3D programming every week and the only things they are looking for are movies, major sporting events, special events and one off, mega specials – “planet earth” type big budget docs. The rest of the week will be repeats and re-runs. So, in the UK it’s likely that there will be a couple of OB trucks kitted out for 3D for sports and other events filing a couple of hours a week leaving just two hours which will be split between docs, specials and movies.

Now Sky 3D won’t be the only outlet for 3D in the UK. There will be some corporate productions with budgets big enough for 3D and there will be a market for a few on-demand specialist channels and 3D BluRay’s and DVD’s but the really big market will be the 3D games market. Even so for most production companies, 3D could be an expensive mistake. Investing in expensive 3D rigs, pairs of cameras, 3D production monitors and edit systems won’t be cheap. In addition there is a whole new set of skills to be learnt, shooting 3D is very different to 2D. Perhaps (sadly) the real future of 3D TV lies not with true 3D capture and filming but with clever boxes like the JVC IF-2D3D1 2D to 3D converter which can take existing 2D material and convert it in to pretty convincing 3D for the price of a single pro camcorder. It may even be that one day all home TV’s will contain a similar converter and you will be able to watch whatever you want in Pseudo 3D at the press of a button.

So back to the original question, how big is the 3D market? Well I think it’s actually pretty small, probably best left to a few specialist production companies or 3D consultants and  facilities companies. Certainly lots of 3D TV’s will get sold to affluent techno geeks and home cinema enthusiasts, but lets face it, HD was a hard sell and you don’t need glasses for that.

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NextoDI Demonstrate writing to BluRay from NVS2500

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At the recent BVE show in London, NextoDI were showing a demo of what will be available in the next firmware release, due around NAB time. The most significant feature is the ability to archive your material directly from the NVS2500 to BluRay!

You will be able to plug the NVS2500 into a USB BluRay burner and burn your files from the NextoDI straight on to BD-R discs!

So, no need for a computer or BluRay software, just the NextoDI and a BD burner. This makes the NVS2500 a truly pivotal device. You take your rushes in the feild, back them up on to the 2500, then plug in a BD writer and produce your archive discs. Remember that BD-R should have a shelf life of around 25 years. It doesn’t tie up a computer and there’s no reason why you couldn’t do this on location, the recommended LG drive even runs off 12v so you could do it in a car or running off another 12v battery.

As well as writing to BluRay the new firmware will also have the ability to recover some types of corrupt clips. To be honest, if you use SxS this should not be a problem, but it’s a useful tool to have. It will also reject bad sectors when writing to a hard drive thus reducing the risk of errors in the first place.

I know the NVS2500 is not the cheapest piece of kit on the planet, but it really, really, really is worth every penny. If you took mine away from me now it would be like cutting off an arm. It is one piece of the whole file based jigsaw that has really made my life so much simpler, faster, less stressful.

10/10 product, fantastic, excellent….

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NextoDI Demonstrate writing to BluRay from NVS2500

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At the recent BVE show in London, NextoDI were showing a demo of what will be available in the next firmware release, due around NAB time. The most significant feature is the ability to archive your material directly from the NVS2500 to BluRay!

You will be able to plug the NVS2500 into a USB BluRay burner and burn your files from the NextoDI straight on to BD-R discs!

So, no need for a computer or BluRay software, just the NextoDI and a BD burner. This makes the NVS2500 a truly pivotal device. You take your rushes in the feild, back them up on to the 2500, then plug in a BD writer and produce your archive discs. Remember that BD-R should have a shelf life of around 25 years. It doesn’t tie up a computer and there’s no reason why you couldn’t do this on location, the recommended LG drive even runs off 12v so you could do it in a car or running off another 12v battery.

As well as writing to BluRay the new firmware will also have the ability to recover some types of corrupt clips. To be honest, if you use SxS this should not be a problem, but it’s a useful tool to have. It will also reject bad sectors when writing to a hard drive thus reducing the risk of errors in the first place.

I know the NVS2500 is not the cheapest piece of kit on the planet, but it really, really, really is worth every penny. If you took mine away from me now it would be like cutting off an arm. It is one piece of the whole file based jigsaw that has really made my life so much simpler, faster, less stressful.

10/10 product, fantastic, excellent….

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Multi-Camera Shoot-out Update

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UPDATE: You can download some frame grabs from the shoot-out by clicking here.

I just spent the day shooting the same scene with 6 different file based cameras. I am working with Visual Imapact to produce a series of DVD’s containing sample clips in their native format and file structure from a range of cameras. On the set today I had the following cameras: Sony PDW-700, Sony PMW-350, Sony EX3, Panasonic HPX3700, Panasonic HPX301 and a Panasonic HVX200. We also recorded the output from the PMW-350 on a NanoFlash and this footage will also be available within the DVD set. The idea is to provide people with a way to directly compare the image quality and workflow of all these cameras, in effect, side-by side.

In order to keep things fair each camera was set to it’s factory defaults. Now I know that with careful tweaking all the camera are capable of better pictures, but it was decided the fairest test was to present them in their default settings.

The scene used in the shoot comprised of a colorful Lego train on a small circle of track, some crumpled foil to give bright specular highlights, a chamois leather for natural texture along with a couple of rose blooms. A metal bodied torch and paint brush finished off the still life. In the background there is a sharpness chart and a color chart. All this was then placed on a chroma key green fabric covered table with a chroma key blue back drop.

The scene was shot at 3 different frame sizes in 1080P25, 1080i50 and where available 720P50 and SD. The scene was shot at 0db gain and also at +6db gain. It was exposed using a 50% grey card measured with a Hamlet Microflex scope to ensure matching exposures. A slate was used at the beginning of each shot to identify the camera, the frame rate, aperture and recording mode. The Panasonic P2 cameras were used in both AVC-I modes and DVCPROHD modes. All the 2/3? cameras used the same Canon HJ14x4.3 lens but I did in addition use the kit lens on the PMW-350 for comparison as well as an SD lens on the PDW-700. The HPX301 and EX3 used their standard lenses.

I’ll be spending the next couple of days checking the footage and compiling the DVD’s, but hope to have the full set of disks available for purchase very soon.

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Multi Camera Shoot-Out at Visual Impact.

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Cameras waiting to be tested

I’m doing a multi camera shoot out at Visual Impact tomorrow in order to put together a DVD of native clips from many of the currently available HD cameras. So far we have  the following cameras lined up for the test:

PDW-700, PMW-350, EX3, HPX-301 and HPX3700. Hopefully we will be able to include some JVC’s cameras in a future session. The idea is to compile a DVD of raw footage from all of these cameras under identical lighting situations to enable potential buyers to see for themselves the differences (or not) between the cameras and workflows. It is not going to be a “which is best” review or comparison as all the cameras have strengths and weaknesses. I’ll post details of how to get a copy of the DVD in due course.

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Canon To Launch 4:2:2 50Mb/s MXF HD Camcorder!

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Canon has been keeping quiet for some time now and there has been lots of speculation about their next video camera, including many that had hoped for a 35mm sized sensor. Well this morning Canon posted a press release on their website. The main and most exciting point is that the camera under development will be full 1920×1080 and it will be 50Mb/s 4:2:2 Mpeg 2 MXF. Now this looks on paper to be an extremely similar format to XDCAM HD422. It would certainly make edit suite integration a lot simpler if the MXF files are the same as the Sony XDAM MXF’s.

Mockups of a camera seen in recent months have shown a handycam style, fixed lens camera with two slots for some type of memory card, which could possibly be express card slots. The mockup lens looks like it might be an EX1 style lens with manual and auto focus and might be big enough to accommodate 1/2? sensors. Is this the camera that the press release refers to, or is there another camera in the pipelines? There is a lot of stuff not mentioned in the press release, like recording media. It says “file based”, this could be solid state or it could be something else, maybe optical disc. Might this be a full size XDCAM HD camcorder from Canon? The release gives no sensor or form factor information which I find a little odd. Having shown mockups of an EX1 sized camera why not a more detailed press release with info on the lens, sensors, recording media etc? (apparently there will be another press release on the 8th of Feb).

Canon make some very good video cameras, I had an XL-H1 and it was a great HDV camcorder. I have no doubt that this new camera will be very good and competitively priced. IF it is the EX1 sized camera and it has 1/2? sensors then this would tick all of the BBC’s boxes for HD. If it’s CCD (which seems likely) it won’t have skew or flash banding. This is a very significant announcement and could push Canon to the front of the Pro Handycam pack. Here is the full press release from the Canon web site.

New Canon MPEG-2 Codec chosen for file-based professional video camcorder promises compatibility with industry-standard editing & processing software

United Kingdom / Republic of Ireland February 2nd 2010 – Canon Inc. today announces the adoption of an MPEG-2 Full HD (4:2:2) file-based recording codec for a new professional video camcorder currently under development. The Canon MPEG-2 codec will enable high-quality imaging and audio performance with up to 50 Mbps data recording and twice the colour data of HDV HDV is a standard for the recording and playback of high definition (1,440 x 1,080 pixels) video and audio on DV-format cassette tapes profile formats. File-based recording helps video operations realise greater efficiencies during post-production processing, making it an ideal format for many industry applications such as news gathering, documentary filmmaking and event videography.

MPEG-2 Full HD compression and 4:2:2 colour sampling?The adoption of MPEG-2 Full HD (MPEG-2 4:2:2 HP@HL compliant) compression enables the recording of 1,920 x 1,080-pixel full high-definition video. Additionally, compared with the 4:2:0 profile format used in HDV and other standards, 4:2:2 colour sampling offers twice the volume of colour data, providing double the level of colour resolution.

Maximum 50 Mbps data recording?With approximately twice the total data volume of HDV, the codec supports higher resolution and increased colour data to enable the recording of high-quality video.

Industry-standard MXF file format (see note (II))?MXF (Material eXchange Format) is a widely supported open source file format for the recording of video, audio and metadata, developed to suit the latest editing systems used by broadcasters.

Canon partners with major editing and processing software?With the adoption of the MPEG-2 Full HD (4:2:2) file-based recording codec, Canon is working in cooperation with Adobe Systems Incorporated, Apple Inc., Avid Technology, Inc. and Grass Valley to ensure compatibility with major editing and processing software programs widely used within the video imaging industry. Additionally, at future industry events Canon intends to demonstrate the overall video-production workflow, from initial video capture to clip-trimming and final editing. Video clips stored in a file-based recording system and industry-standard software applications will be used.

(II) A format for professional digital video and audio media defined by the Society of Motion Picture and Television Engineers (SMPTE)

Notes to editor

Advantages of File-Based Recording

File-based recording enables video and audio data to be managed and stored by file, much in the same way as computer data. It supports efficiency throughout the production process, from initial video capture to final editing through the entire workflow. Additionally, file-based recording provides users with the flexibility to utilise different editing environments and workflow solutions without the restrictions associated with some other video recording formats, helping to reduce investment costs.

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PMW-350 or PDW-700, sample clips.

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OK, not very scientific I know, but for those that want to see how close the pictures from theses two cameras are I have shot a quick clip with each and put them in a 54mb zip file for download. The PMW-350 clip is a 35Mb/s MP4 and the PDW-700 clip is a 50Mb/s XDCAM MXF.

The cameras were both set up with similar paint settings using Hypergamma 4. The detail is backed off a bit from the factory settings on both and I used the same lens on both cameras which was the Fujinon 16×8 lens that comes with the PMW-350. The clips have not been adjusted in any way other than trimed in length, this is how they look out of the camera.

Both are remarkably similar. I can see that the 350 is more highly saturated and that you can just about make out the difference between 4:2:0 and 4:2:2. The interesting area is how the 350 handles the overexposed sky behind the trees, or rather the way the trees don’t appear to blur into the overexposure as with the PDW-700.

Cinematographer and film maker Alister Chapman's Personal Website