All posts by alisterchapman

Vegas, Slot Canyons and Venice.

I’m writing this from a hotel room in Page, Arizona. Half way through a shoot covering everything from the city lights of Las Vegas to the Slot Canyons of Arizona. I’m using a Sony Venice to shoot most of the material, but I also have an FS5 recording to ProRes Raw on a gimbal for some shots.

20180416_181614-1024x576 Vegas, Slot Canyons and Venice.
Shooting in Arizona with a Sony Venice.

It’s been an interesting shoot with many challenges. Some of the locations have been a long way from our vehicles, so we have had to lug the kit cross country by hand.

day1-3 Vegas, Slot Canyons and Venice.
Lugging the camera kit to the Slot Canyon. Thankful that the Miller CX18 tripod is nice and light.

Almost everything is being shot at 60fps with some 120fps from the FS5. We also had a Phantom Flex for a couple of days for some 1000fps footage. For some of the really big panoramic scenes we have used the 4:3 6K mode on the Venice (at 24fps).

JS_1983 Vegas, Slot Canyons and Venice.
FS5 on a gimbal shooting ProRes Raw via an Atomos Inferno.

Our main lenses are a set of full frame T1.5 Sigma primes. These are absolutely amazing lenses and when paired with the Venice camera, it’s hard to produce a poor image. Our Venice has a beta of the dual ISO firmware which has been an absolute godsend as the bottoms of the deep slot canyons are very dark, even in the middle of the day. So being able to shoot at 2500 ISO has been a huge help.

20180418_110634-1024x576 Vegas, Slot Canyons and Venice.
Sigma Full Frame PL lenses. Beautiful!!

I will write up this project in more detail once the shoot is over. I can’t share any footage yet, but once my client releases the film I will be able to let everyone see it. However I have been allowed to post some frame grabs which you will find below.

 

Venice3_1.5.1-1024x576 Vegas, Slot Canyons and Venice.
Freemont Street Las Vegas, shot with Venice and 35mm Sigma.
canyon-grab5_1.10.1-1024x576 Vegas, Slot Canyons and Venice.
Secret Canyon Slot Canyon.Sony Venice 4:3 full frame, Sigma 35mm.
vegas-5_1.3.2-1024x576 Vegas, Slot Canyons and Venice.
Las Vegas by night. Sony Venice, Sigma 25mm
canyon-grab2_1.6.1-1024x576 Vegas, Slot Canyons and Venice.
Secret Canyon, Arizona. Sony Venice Sigma 50mm
canyon-grab4_1.8.1-1024x576 Vegas, Slot Canyons and Venice.
Secret Canyon, Arizona. Sony Venice, sigma 35mm.
Navajo2-1024x537 Vegas, Slot Canyons and Venice.
Navajo dancer, Page, Arizona. Sony Venice.
Navajo3-1024x537 Vegas, Slot Canyons and Venice.
Navajo hoop dancer at Horseshoe bend, Grand Canyon. Sony Venice, Sigma 20mm
Horsehoe1-1024x679 Vegas, Slot Canyons and Venice.
Horseshoe bend, Grand Canyon. Sony Venice, Full Frame, Sigma 20mm
riding-1024x536 Vegas, Slot Canyons and Venice.
Riding into the sunset. Sony Venice, Sigma 135mm
campfire3-1024x537 Vegas, Slot Canyons and Venice.
Campfire cookout. Page, Arizona, Sony Venice, Sigma 85mm
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PXW-FS5 II Secret Sauce and Venice Colour Science.

At NAB 2018 a very hot topic is the launch of the FS5 II. The FS5 II is an update on the existing FS5 that includes the FS Raw output option and the HFR option as standard. So out of the box this means that this camera will be a great match to an Atomos Inferno to take advantage of the new Apple ProRes Raw codec.

Just like the FS5 the FS5 II can shoot using a range of different gamma curves including Rec-709, HLG, S-Log2  and S-Log3. So  for those more involved projects where image control is paramount you can shoot in log (or raw)  then take the footage into your favourite grading software and create whatever look you wish. You can tweak and tune your skin tones, play with the highlight roll off and create that Hollywood blockbuster look – with both the FS5 and the FS5 II. There is no change to this other than the addition of FS-Raw as standard on the FS5 II.

The big change, is to the cameras default colour science.

FS5II-1-1024x564 PXW-FS5 II Secret Sauce and Venice Colour Science.
New color science from the Sony PXW-FS5 II

Ever since I started shooting on Sony cameras, which was a very long time ago, they have always looked a certain way. If you point a Sony camera at a Rec-709 test chart you will find that the colours are actually quite accurate, the color patches on the chart lining up with the target boxes on a vector scope. All Sony cameras look this way so that if you use several different cameras on the same project they should at least look very similar, even if one of those cameras is a few years old.  But this look and standard was establish many years ago when camera and TV technology was nowhere near as advanced as it is today.

in addition, sometimes accurate isn’t pretty. Television display technology has come a long way in recent years. Digital broadcasting combined with good quality LCD and OLED displays now mean that we are able to see a wider range of colours and a larger dynamic range. Viewers expectations are changing, we all want prettier images.

When Sony launched the high end Venice digital cinema camera a bold step was taken, which was to break away from the standard Sony look and instead develop a new, modern, “pretty” look. A lot of research was done with both cinematographers and viewers trying to figure out what makes a pretty picture. Over several months I’ve watched Pablo, Sony’s colourist at the Digital Motion Picture Center at Pinewood studios develop new LUT’s with this new look for the Venice camera. It hasn’t been easy, but it looks really nice and is quite a departure from that standard Sony look.

The FS5 II includes many aspects of this new look. It isn’t just a change to the colours it is also a change to the default gamma curve that introduces a silky smooth highlight roll off that extends the dynamic range well beyond that normally possible with a conventional Rec-709 gamma curve. A lot of time was spent looking at how this new gamma behaves when shooting people and faces. In particular those troublesome highlights that you get on a nose or cheek that’s catching the light. You know – those pesky highlights that just don’t normally look nice on a video camera.

So as well as rolling off the brightness of these highlights in a smooth way, the color also subtly washes out to prevent the highlight color bloom that can be a video give away. This isn’t easy to do. Any colorist will tell you that getting bright skin tone highlights to look nice is tough. You bring down the brightness and it looks wrong because you loose too much contrast. De-saturate too much and it looks wrong as it just becomes a white blob. Finding the right balance of extended dynamic range with good contrast, plus a pleasing roll-off without a complete white-out is difficult enough to do in a grading suite where you can tweak and tune the settings for each shot. Coming up with a profile that will work over a vast range of shooting scenarios with no adjustment is even tougher. But it looks to me as though the engineers at Sony have really done a very nice job in the FS5 II.

Going forwards from here I would expect to see, or at least like to see, most of Sony’s future cameras have this new colour science. But this is a big step for Sony to break away from decades of one look and every camera looking more or less the same.  But do remember this change is primarily to the default, “standard” gamma look. It does not effect the FS5 II’s log or raw recordings. There is also going to have to be a set of LUT’s to go with this new color science so that those shooting with with a mix of the baked in look and S-log or raw can make all the footage match. In addition users of other S-Log cameras will want to be able to make their cameras match. I see no reason why this won’t be possible via a LUT or set of LUT’s, within the limitations of each cameras sensor technology.

There has been a lot of people that seem unhappy with the FS5 II. I think many people want a Sony Venice for the price of an FS5. Let’s be realistic, that isn’t going to happen. 10 bit recording in UHD would be nice, but that would need higher bit rates to avoid motion artefacts which would then need faster and more expensive media. If you want higher image quality in UHD or 4K DCI do consider an Atomos recorder and the new ProRes Raw codec. The files are barely any bigger than ProRes HQ, but offer 12 bit quality.

Given that the price of the FS5 II is going to be pretty much the same or maybe even a little lower than the regular FS5 (before you even add any options), I am not sure why so many people are complaining. The FS5-II takes a great little camera, makes it even better and costs even less.

 

Revised and improved HLG camera LUT for FS7, F5 and F55.

I have created a new and improved HLG camera LUT for the PXW-FS7, PMW-F5 and PMW-F55 cameras. This 3D LUT can be used to shoot HLG directly by baking the LUT in to the recordings in camera. This allows you to create “instant HDR” footage that just like the HLG footage from an FS5 or Z90 does not need to be graded or modified to provide an HDR image on an equipped HDR TV. Skin tones should be exposed at around 55-60% and white at around 70-75%.

Click here to download the LUT AC-HLGSL3-V2.cube

ProRes Raw and Atomos Inferno and Sumo – BIG deal for the FS5 and FS7!!

proresraw-logo ProRes Raw and Atomos Inferno and Sumo - BIG deal for the FS5 and FS7!!Over the last few days there have been various rumours and posts coming from Apple about how they intend to get back to providing decent support for professional users of their computers. Apple have openly admitted that the Trash Can Mac Pro has thermal problems and as a result has become a dead end design, which is why there haven’t been any big updates to the flagship workstation from Apple. Apple have hinted that new workstations are on the way, although it would seem that we won’t see these until next year perhaps.
Another announcement came out today, a new version of FCP-X is to be released which includes support for a new ProRes codec called ProRes Raw. This is BIG!

PRORES RAW.

Raw recordings can be made from certain cameras that have bayer sensors such as the Sony FS5 and FS7. Recording the raw data from the sensor maximises your post production flexibility and normally offers the best possible image quality from the camera. Currently if you record 4K raw with these cameras using an Atomos Shogun or similar the bit rate will be close to 3Gb/s at 24p. These are huge files and the cDNG format used to record them is difficult and clunky to work with.  As a result most users take the raw output from the camera and transform it to S-Log2 or S-Log3 and record it as 10 bit ProRes on the external recorder. This is a bit of a shame as going from 12 bit linear raw to 10 bit S-log means you are not getting the full benefit of the raw output.

Enter ProRes Raw:  ProRes Raw will allow users to record the cameras raw output at a much reduced bit rate with no significant of quality. There are two versions, ProRes Raw and ProRes Raw HQ. The HQ bit rate is around 1Gb/s at 24fps. This is not significantly bigger than the ProRes HQ (880Mb/s) that most users are using now to record the raw, yet the full benefit of 12 bit linear will be retained. A 1TB SSD will hold around an hour of ProRes Raw, compare that to uncompressed raw where you only get around 20 mins and you can see that this is a big step forwards for users of the FS5 in particular.

ProRes Raw (the non HQ version) is even smaller! The files are smaller than typical ProRes HQ files. This is possible because recording raw is inherently more efficient than recording component video.

It is claimed by Apple that ProRes Raw will play back in real time on MacBook Pro’s and iMacs without any additional rendering or external graphics cards, so it obviously isn’t terribly processor intensive. This is excellent news! Within FCP-X the playback resolution can be decreased to bring improved playback performance in less powerful systems or mutistream playback.

It looks like you will be able to record from a 4K DCI  from an FS5 or FS7 at up to 60fps continuously. This breaks through the previous limits for the Shogun of 30fps. The FS7 will be able to record 2K raw at up to 240fps and the FS5 will be able to record 4K raw at 100 and 120fps for 4 seconds. Other raw cameras are also supported by the Atomos recorders at differing frame sizes and frame rates.

At the moment the only recorders listed as supporting ProRes Raw are the Atomos Shogun Inferno and the Sumo19 and it looks like it will be a free update. In addition the DJI Inspire 2 drone and Zenmuse X7 Super 35mm camera will also support ProRes Raw.

Whether you will be able to use ProRes Raw in other applications such as Resolve or Premiere is unclear at this time. I hope that you can (or at least will be able to in the near future).

SEE: Apple Press Release.

SEE: Apple ProRes Raw White Paper

SEE: ATOMOS ProRes Raw INFO PAGE.

 

 

Beware the LC709 LUT double exposure offset.

The use o f the LC709 Type A LUT in Sony’s Cinealta cameras such as the PXW-FS7 or PMW-F55 is very common. This LUT is popular because it was designed to mimic the Arri cameras when in their Rec-709 mode. But before rushing out to use this LUT and any of the other LC709 series of LUT’s there are some things to consider.

The Arri cameras are rarely used in Rec-709 mode for anything other than quick turn around TV. You certainly wouldn’t normally record this for any feature or drama productions. It isn’t the “Arri Look” The Arri look normally comes as a result of shooting using Arri’s LogC and then grading that to get the look you want. The reason it exists is to provide a viewable image on set. It has more contrast than LogC and uses Rec 709 color primaries so the colors look right, but it isn’t Rec-709. It squeezes almost all of the cameras capture range into a something that can be viewed on a 709 monitor so it looks quite flat.

Because a very large dynamic range is being squeezed into a range suitable to be viewed on a regular, standard dynamic range monitor the white level is much reduced compared to regular Rec-709. In fact, white (such as a white piece of paper) should be exposed at around 70%. Skin tones should be exposed at around 55-60%.

If you are shooting S-Log on a Sony camera and using this LUT to monitor, if you were to expose using conventional levels, white at 85-90% skin tones at 65-70%, then you will be offsetting your exposure by around +1.5 stops. On it’s own this isn’t typically going to be a problem. In fact I often come across people that tell me that they always shoot at the cameras native EI using this LUT and get great, low noise pictures. When I dig a little deeper I often find that they are exposing white at 85% via the LC709 LUT. So in reality they are actually shooting with an exposure the equivalent of +1 to +1.5 stops over the base level.

Where you can really run into problems is when you have already added an exposure offset. Perhaps you are shooting on an FS7 where the native ISO is 2000 ISO and using an EI of 800. This is a little over a +1 stop exposure offset. Then if you use one of the LC709 LUT’s and expose the LUT so white is at 90% and skin tones at 70% you are adding another +1.5 stops to the exposure, so your total exposure offset is approaching 3 stops. This large an offset is rarely necessary and can be tricky to deal with in post. It’s also going to impact your highlight range.

So just be aware that different LUT’s require different white and grey levels and make sure you are exposing the LUT at it’s correct level so that you are not adding an additional offset to your desired exposure.

Guide to Hypegammas and Cinegammas Updated

I have just revisited a post I did some years ago about the correct way to expose Hypergammas and Cinegammas. I’ve revised some of it and updated some other bits. Hopefully the revisions make it  a little easier to understand why the brightness levels should be a little different and I’ve provided some suggested settings for zebra levels. You will find the revised guide here: Guide To Hypergamma and Cinegamma Exposure.

DaVinci Resolve, ACES and the “Sony Raw” input transform.

A quick heads up for users of Resolve with Sony Raw and X-OCN. Don’t make the same mistake I have been making. For some time I have been unhappy with the way the Sony raw looked in DaVinci Resolve and ACES prior to grading. Apparently there used to be a small problem with the raw input transform that could lead to a red/pink hue getting added to the footage. This problem was fixed some time ago. You should now not use the the “Sony Raw” input transform, if you do, it will tint your Raw or X-OCN files slightly pink/red. Instead you should select “no transform”. With no transform selected my images look so much nicer and match Sony’s own Raw Viewer so much better. Thanks to Nick Shaw of Antler Post for helping me out on this and all on the CML list.

How to get the best White Balance (Push Auto WB).

Getting a good white balance is critical to getting a great image, especially if you are not going to be color correcting or grading your footage. When shooting traditionally ie – not with log or raw – A common way to set the cameras white balance is to use the one push auto white balance combined with a white target. You point the camera at the white target, then press the WB button (normally found at the front of the camera just under the lens).
The white target needs to occupy a good portion of the shot but it doesn’t have to completely fill the shot. It can be a pretty small area, 30% is normally enough. The key is to make sure that the white or middle grey target is obvious enough and at the right brightness that the camera uses the right part of the image for the white balance. For example, you could have a white card filling 50% of the screen, but there might be a large white car filling the rest of the shot. The camera could be confused by the car if the brightness of the car is closer to the brightness the camera wants than the white/grey card.
The way it normally works is that the camera looks for a uniformly bright part of the image with very little saturation (color) somewhere between 45 and 90IRE. The camera will then assume this area to be the white balance target. The camera then adjusts the gain of the red and blue channels so that the saturation in that part of the image becomes zero and as a result there is no color over the white or grey target.
 
If you fill the frame with your white/grey card then there can be no confusion. But that isn’t always possible or practical as the card needs to be in the scene and under the light you are balancing for rather than just directly in front of the lens. The larger your white or grey card is the more likely it is that you will get a successful and accurate white balance – provided it’s correctly exposed and in the right place.
 
The white target needs to be in reasonable focus as if it is out of focus this will create a blurred edge with color from any background objects blending into the blur. This could upset the white balance as the camera uses an average value for the whole of white area, so any color bleed at the edges due to defocussing may result in a small color offset.
 
You can use a white card or grey card (white paper at a push, but most paper is bleached slightly blue to make it look whiter to our eyes and this will offset the white balance). The best white balance is normally achieved by using a good quality photography grey card. As the grey card will be lower down in the brightness range, if there is any color, it will be more saturated. So when the camera offsets the R and B gain to eliminate the color it will be more accurate.
 
The shiny white plastic cards often sold as white balance cards are often not good choices for white balance. They are too bright and shiny. Any reflections off a glossy white card will seriously degrade the cameras ability to perform an accurate white balance as the highlights will be in the cameras knee or roll-off and as a result have much reduced saturation and also reduced R and B gain, making it harder for the camera to get a good white balance. In addition the plastics used tend to yellow with age, so if you do use a plastic white balance card make sure it isn’t past it’s best.
Don’t try to white balance off clouds or white cars, they tend to introduce offsets into the white balance.
 
Don’t read too much into the Kelvin reading the camera might give. These values are only a guide, different lenses and many other factors will introduce inaccuracies. It is not at all unusual to have two identical cameras give two different Kelvin values even though both are perfectly white balance matched. If you are not sure that your white balance is correct, repeat the process. If you keep getting the same kelvin number it’s likely you are doing it correctly.

Sony Venice – A close look at the dynamic range and noise.

With Sony Venice X-OCN files to download!

I have been working with Sony’s colour science guru Pablo at the Digital Motion Picture Center at Pinewood, looking at the outer limits of what Sony’s Venice camera can do. A large part of the reason for this is that Pablo is developing some really nice LUT’s for use on dailies or even as a grade starting point (Pablo tells me the LUT’s are finished but he is waiting for approvals and feedback from Japan).

As part of this process we have shot test footage with the Venice camera for ourselves and also looked long and hard at test shots done by other cinematographers. Last week we were able to preview a beta version of the cameras dual ISO modes. This beta firmware allowed us to shoot tests at both 500 ISO and 2500 ISO and the results of both are equally impressive.

I can’t share any of the test footage shot at 2500 ISO at this stage. The firmware is still in it’s early stages and the final version may well perform a little differently (probably better). But I can share some of the footage shot at 500 ISO.

Please remember what we were exploring was the extreme ends of the exposure range. So our little test set was set up with some challenges for the camera rather than trying to make a pretty picture.

We have deep, deep shadows on the right behind the couch and we also have strong highlights coming off the guitar, the film can on the shelves and from the practical lamp in the background. The reds of the cushion on the couch look very different with most Rec-709 cameras as the colors are outside the Rec-709 gamut.

Another aspect of the test was to check the exposure rating. For this I used my Sekonic lightmeter to measure both the incident light and the light reflected by the Kodak grey card. My light meter gave me T4 at 1/48th for 500 ISO and this turned out to be pretty much spot on with what the scopes told us. So straight away we were able to establish that the 500 ISO exposure rating appears to be correct. We also found that when we stopped down by 2.3 stops we got the correct exposure at 2500 ISO, so that too appears to be correctly rated.

Once the base exposure was established we shot at 2 stops over and 2 stops under, so from T2 down to T8 using a Sony 35mm PL prime. We used the XOCN-ST codec as we felt this will be the most widely used codec.  When looking at the files do remember that the 16 bit XOCN-ST files are smaller than 10 bit ProResHQ. So these are files that are very easy to manage. There is the option to go up in quality to Sony’s linear raw codec or down to X-OCN LT. XOCN-ST sits in the middle and offers a nice balance between file size and image quality, it being very hard to find any visual difference between this and the larger raw files.

The files I’m providing here are single X-OCN frames. They have not been adjusted in any way, they are just as shot (including being perhaps a touch out of focus). You can view them using the latest version of Sony’s raw viewer software or the latest version of DaVinci Resolve. For the best quality preview, at this time I recommend using Sony’s Raw Viewer to view the clips.

Click here to download these Venice Samples

If you find these files useful please consider buying me a coffee or beer.


Type



pixel Sony Venice - A close look at the dynamic range and noise.

So what do the files look like? First I recommend you download and play with them for yourself. Anything I do has to have a LUT,  grade or other process applied so that the linear data can be viewed on a normal computer screen. So it’s better to take a look at the original files and see what you can do with them rather than just accepting my word. The images here were create in DaVinci Resolve using ACES. ACES adds a film type highlight roll-off and uses film type levels, so the images look a touch dark as there were a lot of low light level areas in the test shots.

Venice at T4 The base exposure for the test.

Venice-base-T4_1.1.1-1024x540 Sony Venice - A close look at the dynamic range and noise.
Venice at T4 (From ACES). This was the “base” exposure for this test. Click on the image to enlarge.

Venice at T8 – 2 Stops under exposed (As exposed).

Venice-T8-uncor_1.4.1-1024x540 Sony Venice - A close look at the dynamic range and noise.
Venice at T8 (2 stops under). Click on the image to enlarge.

Venice at T8 – 2 Stops under exposed (Brightness corrected to match base exposure).

Venice-T8-norm_1.4.2-1024x540 Sony Venice - A close look at the dynamic range and noise.
Venice at T8 (2 stops under). Brightness match to base exposure via metadata shift. Click on the image to enlarge.

Venice at T5.6 – 1 stop under exposed (brightness corrected to match base exposure).

Venice-T5.6-norm_1.5.1-1024x540 Sony Venice - A close look at the dynamic range and noise.
Venice at T5.6 (1 stops under). Brightness match to base exposure via metadata shift. Click on the image to enlarge.

Venice at T4 The base exposure for the test.

Venice-base-T4_1.1.1-1024x540 Sony Venice - A close look at the dynamic range and noise.
Venice at T4 (From ACES). This was the “base” exposure for this test. Click on the image to enlarge.

Venice at T2.8 – 1 stop over exposed (brightness adjusted to match base exposure).

Venice-t2.8-norm_1.2.1-1-1024x540 Sony Venice - A close look at the dynamic range and noise.
Venice at T2.8 (1 stops over). Brightness match to base exposure via metadata shift. Click on the image to enlarge.

Venice at T2.0 – 2 stops over exposed (brightness adjusted to match base exposure).

Venice-T2-norm_1.3.2-1024x540 Sony Venice - A close look at the dynamic range and noise.
Venice at T2 (2 stops over). Brightness match to base exposure via metadata shift. Click on the image to enlarge.

Venice at T2.0 – 2 stops over exposed (as shot).

Venice-T2-uncor_1.3.1-1024x540 Sony Venice - A close look at the dynamic range and noise.
Venice at T2.0, 2 stops over, as shot. Click on the image to enlarge.

NOTES AND OBSERVATIONS:

I shouldn’t rush these tests! I should have set the focus at T2, not at T4. Focus is on the chart, not the dummy head. It would have been better if the eyes and chart were at the same distance.

It’s amazing how similar all the shots across this 5 stop range look. Just by adjusting the metadata ISO rating in Resolve I was able to get a near perfect match. There is more noise in the under exposed images and less in the over exposed images, that’s expected. But even the 2 under images are still pretty nice.

NOISE:

What noise there is, is very fine in structure. Noise is pretty even across each of the R, G and B channels so there won’t be a big noise change if skewing the white balance towards blue as can happen with some other cameras where the blur channel is noisier than red or green. Even at T8 and 2 stops under the noise is not unacceptable. A touch of post production NR would clean this up nicely. So shooting at 500 ISO base and rating the camera at 2000 EI would be useable if needed, or perhaps to deliberately add some grain. However instead of shooting at 500 ISO / 2000 EI you might be better off using the upper 2500 base ISO instead for low light shoots because that will give a nice sensitivity increase with no change to the dynamic range and only a touch (and it really is just a touch) more noise.

If shooting something super bright or with lot and lots of very important highlights  I would not be concerned about rating the camera at 1000EI.  For most projects I would probably rate the camera at 500EI. If the scene is generally dark I may choose 400EI just to be a touch cleaner. With such a clean image and so much dynamic range you really can pick and choose how you wish to rate the camera.

Venice has more dynamic range than an F55 and maybe a bit more than the F65. Most of the extra dynamic range is in the shadows. There is an amazing amount of picture information that can be pulled out of the darker parts of the images. The very low noise floor is a big help here. In the example below I have taken the base exposure sample and brought the metadata ISO up to 2000 ISO. Then I have used a luma curve to pull up the shadows still further. If you look at the shelves on the left, even in the deep shadow areas it’s possible to see the grain effect on the dark wood panels. In addition you can see both the white and black text on the back of the grey book on the bottom shelf. Yes, there is some noise but my meter put these areas at -6 stops, so being able to pull out so much detail from these areas is really impressive.

Venice-deep-shadows_1.1.2-1024x540 Sony Venice - A close look at the dynamic range and noise.
An amazing amount of information still exists in even the darkest shadow areas. This image adjusted up significantly from base exposure (at least +4 stops).

In the highlights the way the camera reaches it’s upper limit is very pleasing, it does seem to have a tiny roll off just before it clips and this looks really nice. If you look at the light bulbs in this test, at the base exposure, if you bring the highlights down in post you can see that not all of the bulb is completely over exposed they are only over exposed where the element is. Also the highlights reflecting off the guitar and film can on the shelf look very “real” and don’t have that hard clipped look that specular highlights on other cameras can sometimes have.

Another thing that is very nice is the colour tracking. As you go up and down in exposure there are no obvious colour shifts. It’s one of the things that really helps make it so easy to make all 5 exposures look the same.

The start up time of the Venice camera is very impressive at around 6 to 8 seconds. It’s up and running very quickly. The one stop steps in the ND filter system are fantastic. The camera is very simple to use and the menu seems logically laid out. It’s surprisingly small, it’s not much bigger than a PMW-F55, just a little taller and a little longer. Battery consumption is lower than most of the competition, the camera appears to consume around 50w which is half the power consumption of a lot of the competition. It can be run of either 12v or 24v. So all in all it can be rigged as a very compact camera with a standard V-Lock battery on the back.

Looking forward to shooting more with Venice in the very near future.

 

Banding in your footage. What Causes It, is it even there?

Once again it’s time to put pen to paper or fingers to keyboard as this is a subject that just keeps coming up again and again.

People really seem to have a lot of problems with banding in footage and I don’t really fully understand why as it’s something I only ever really encounter if I’m pushing a piece of material really, really hard in post production. General the vast majority of the content I shoot does not exhibit problematic banding, even the footage I shoot with 8 bit cameras.

First things first – Don’t blame it on the bits. Even an 8 bit recording  (from a good quality camera) shouldn’t exhibit noticeable banding. An 8 bit recording can contain up to 13 million tonal values. It’s extremely rare for us to shoot luma only, but even if you do it will still have 235 shades and these steps in standard dynamic range are too small for most people to discern so you shouldn’t ever be able to see them. I think that when most people see banding they are not seeing teeny, tiny almost invisible steps what most people see is something much more noticeable – so where is it coming from?

It’s worth considering at this stage that most TV’s, monitors and computer screens are only 8 bit, sometimes less! So if you are looking at one camera and it’s banding free and then you look at another and you see banding, in both cases you are probably looking at an 8 bit image, so it can’t just be the capture bit depth that causing the problem as you cant see 10 bit steps on an 8 bit monitor.

So what could it be?

A very common cause of banding is compression. DCT based codecs such as Jpeg, MJPEG, H264 etc break the image up into small blocks of pixels called macro blocks. Then all the pixels in each block is processed in a similar manner and as a result sometimes there may be a small step between each block or between groups of blocks across a gradient. This can show up as banding. Often we see this with 8 bit codecs because typically 8 bit codecs use older technology or are more highly compressed. It’s not because there are not enough code values. Decreasing the compression ratio will normally eliminate the stepping.

Scaling between bit depths or frame sizes is another very common cause of banding. It’s absolutely vital that you ensure that your monitoring system is up to scratch. It’s very common to see banding in video footage on a computer screen as the video data levels are different to computer data levels and in addition there may also be some small gamma differences so the image has to be scaled on the fly. In addition computer desktops runs at one bit range, the HDMI output another, so all kinds of conversions are taking place that can lead to all kinds of problems when you go from a video clip, to computer levels, to HDMI levels. See this article to fully understand how important it is to get your monitoring pipeline properly sorted. http://www.xdcam-user.com/2017/06/why-you-need-to-sort-out-your-post-production-monitoring/

Look Up Tables (LUT’s) can also introduce banding. LUT’s were never really intended to be used as a quick fix grade, the intention was to use them as an on-set reference or guide, not the final output. The 3D LUT’s that we typically use for grading break the full video range into bands and each band will apply a slightly different correction to the footage than the band above or below. These bands can show up as steps in the LUT’s output, especially with the most common 17x17x17 3D LUT’s. This problem gets even worse if you apply a LUT and then grade on top – a really bad practice.

Noise reduction – In camera or postproduction noise reduction will also often introduce banding. Very often pixel averaging is used to reduce noise. If you have a bunch of pixels that are jittering up and down taking an average value for all those pixels will reduce the noise, but then you can end up with steps across a gradient as you jump from one average value to the next. If you shoot log it’s really important that you turn off any noise reduction (if you can) when you are shooting because when you grade the footage these steps will get exaggerated. Raising the ISO (gain) in a camera also makes this much worse as the cameras built in NR will be working harder, increasing the averaging to compensate the increased noise.

Coming back to 8 bit codecs again – Of course a similar quality 10 bit codec will normally give you more picture information than an 8 bit one. But we have been using 8 bits for decades, largely without any problems. So if you can shoot 10 bit you might get a better end result. But also consider all the other factors I’ve mentioned above.