Category Archives: Venice

DaVinci resolve Frame Rendering Issue and XAVC

There is a bug in some versions of DaVinci Resolve 17 that can cause frames in some XAVC files to be rendered in the wrong order. This results in renders where the resulting video appears to stutter or the motion may jump backwards for a frame or two. This has now been fixed in version 17.3.2 so all user of XAVC and DaVinci Resolve are urged to upgrade to at least version 17.3.2.

https://www.blackmagicdesign.com/uk/support/family/davinci-resolve-and-fusion

SDI Failures and what YOU can do to stop it happening to you.

Sadly this is not an uncommon problem. Suddenly and seemingly for no apparent reason the SDI output on your camera stops working. And this isn’t a new problem either, SDI ports have been failing ever since they were first introduced. This issue affect all types of SDI ports. But it is more likely with higher speed SDI ports such as 6G or 12G as they operate at higher frequencies and as a result the components used are more easily damaged as it is harder to protect them without degrading the high frequency performance.

Probably the most common cause of an SDI port failure is the use of the now near ubiquitous D-Tap cable to power accessories connected to the camera. The D-Tap connector is sadly shockingly crudely designed. Not only is it possible to plug in many of the cheaper ones the wrong way around but with a standard D-Tap plug there is no mechanism to ensure that the negative or “ground” connection of the D-Tap cable makes or breaks before the live connection. There is a however a special but much more expensive D-Tap connector available that includes electronic protection against this very issue – see: https://lentequip.com/products/safetap

Imagine for a moment you are using a monitor that’s connected to your cameras SDI port. You are powering the monitor via the D-Tap on the cameras battery as you always do and everything is working just fine. Then the battery has to be changed. To change the battery you have to unplug the D-Tap cable and as you pull the D-Tap out, the ground connection disconnects fractionally before the live connection. During that moment there is still positive power going to the monitor but because the ground on the D-Tap is now disconnected the only ground route back to the battery becomes via the SDI cable through the camera. For a fraction of a second the SDI cable becomes the power cable and that power surge blows the SDI driver chip.

After you have completed the battery swap, you turn everything back on and at first all appears good, but now you can’t get the SDI output to work. There’s no smoke, no burning smells, no obvious damage as it all happened in a tiny fraction of a second. The only symptom is a dead SDI.

And it’s not only D-Tap cables that can cause problems. A lot of the cheap DC barrel connectors have a center positive terminal that can connect before the outer barrel makes a good connection. There are many connectors where the positive can make before the negative.

It can also happen when powering the camera and monitor (or other SDI connected devices like a video transmitter) via separate mains adapters. The power outputs of most of the small, modern, generally plastic bodied switch mode type power adapters and chargers are not connected to ground. They have a positive and negative terminal that “floats” above ground at some unknown voltage. Each power supplies negative rail may be at a completely different voltage compared to ground.  So again an SDI cable connected between two devices, powered by different power supplies will act as the ground between them and power may briefly flow down the SDI cable as the SDI cables ground brings both power supply negative rails to the same common voltage. Failures this way are less common, but do still occur. 

For these reasons you should always connect all your power supplies, power cables and especially D-Tap or other DC power cables first. Then while everything remains switched off connect the SDI cables. Only when everything is connected should you turn anything on. If unplugging or re-plugging a monitor (or anything else for that matter) turn everything off first. Do not connect or disconnect anything while any of the equipment is on.  Although to be honest the greatest risk is at the time you connect or disconnect any power cables such as when swapping a battery where you are using the D-Tap to power any accessories. So if changing batteries, switch EVERYTHING off first, then disconnect your SDI cables before disconnecting the D-Tap or other power cables next.

(NOTE: It’s been brought to my attention that Red recommend that after connecting the power, but before connecting any SDI cables you should turn on any monitors etc. If the monitor comes on OK, this is evidence that the power is correctly connected. There is certainly some merit to this. However this only indicates that there is some power to the monitor, it does not ensure that the ground connection is 100% OK or that the ground voltages at the camera and monitor are the same. By all means power the monitor up to check it has power, then I still recommend that you turn it off again before connecting the SDI).
 
The reason Arri talk about shielded power cables is because most shielded power cables use connectors such as Lemo or Hirose where the body of the connector is grounded to the cable shield. This helps ensure that when plugging the power cable in it is the ground connection that is made first and the power connection after. Then when unplugging the power breaks first and ground after. When using properly constructed shielded power cables with Lemo or Hirose connectors it is much less likely that these issues will occur (but not impossible).

Is this an SD fault? No, not really. The fault lies in the choice of power cables that allow the power to make before the ground or the ground to break before the power breaks.  Or the fault is with power supplies that have poor or no ground connection. Additionally you can put it down to user error. I know I’m guilty of rushing to change a battery and pulling a D-Tap connector without first disconnecting the SDI on many occasions, but so far I’ve mostly gotten away with it (I have blown an SDI on one of my Convergent Design Odysseys).

If you are working with an assistant or as part of a larger crew do make sure that everyone on set knows not to plug or unplug power cables or SDI cables without checking that it’s OK to do so. How many of us have set up a camera, powered it up, got a picture in the viewfinder and then plugged an SDI cable between the camera and a monitor that doesn’t have a power connection yet or already on and plugged in to some other power supply? Don’t do it! Plug and unplug in the right order – ALL power cables and power supplies first, check power is going to the camera, check power is going to the monitor, then turn it all off first, finally plug in the SDI.

Sony Introduces Cinema Line and teases the PXW-FX6

FX6_side_44062_02-Mid Sony Introduces Cinema Line and teases the PXW-FX6
Sony are teasing the PXW-FX6.

So there is no IBC show this year and instead Sony are doing various online sessions with the latest news as well as guides to some of the most recent products and firmware. 

Today’s news is of new branding for Sony most recent digital cinema cameras, Vence and the PXW-FX9. These cameras are now members of what Sony are calling “Cinema Line” and in addition there are pictures of a smaller camera not surprisingly called the FX6 that looks like – well – what you would expect an FS5 replacement to look like. 

In the past Sony’s digital cinematography cameras were denoted by their “Cinealta” badges. But to some extent this became somewhat confused as all sorts of cameras like the Sony EX1 and Venice were classed as Cinealta. So what exactly is the new Cinema Line?

To quote from the Sony Press Release:

“At Sony, we celebrate and have the deepest respect for filmmakers, cinematographers, and storytellers. With Cinema Line, we’re tapping into our DNA from both the film industry and digital imaging prosumer market and combining it to develop new creative tools. This line of products will enable creators to push their creative boundaries further and capture the emotion in each and every frame.” says Claus Pfeifer, Head of Connected Content Acquisition, Media Solutions, Sony Professional Europe.

So, I’m not really sure! My guess is it’s a set of products, not just cameras  aimed at what we now tend to call Cinematography rather than broadcast television or industrial video applications. Of course there is a huge amount of cross-over between all these different genres these days, so I’m sure the Cinema Line products will be used all over the place.

My main hope from this is a more unified look from any cameras in the Cinema Line. My big hope is that the FX6 will have S-Cinetone and that when you shoot S-Log3 with the FX6 that it will look like the S-log3 from the FX9 or Venice. This will make grading and post production easier where you mix and match cameras.

What about the FX6?

I don’t have any more solid information than you right now. We can expect it to be Full Frame, to shoot 10 bit 4:2:2 4K using S-Log3 and to probably have a raw output. As the FS5 is based on the A7S hardware with an F5 sensor it wouldn’t surprise me if the FX6 was based on the A7SIII hardware with the FX9 sensor perhaps. So it might have 4K at 120fps. From the pictures it appears to only have 2 channels of audio and the cover for the card slots (there must be 2 as there is a slot select switch) doesn’t look big enough for two XQD or CF Express Type B, so I would guess that like the A7SIII it’s SD cards or perhaps CF Express Type A.  Another thing I notice in the pictures is a lack of an AF/MF focus switch and in particular no menu navigation controls, so I will guess the LCD is a touch screen and it will rely on this for a lot of function control and menu navigation. But this is just speculation, so don’t hold me to any of it!!!

Don’t Upgrade FCP-X or OSX!

UPDATE 29th Sept 2020.
The issues have now been resolved so it is now safe to update.


27th Aug 2020
If you are a mac user and especially of you use it to edit footage from a Sony camera I recommend that you do not upgrade the operating system to OSX 10.15.6, Pro Video Codecs to 2.1.2 or upgrade FCP-X to version 10.4.9 at this time.

At the moment there is clearly an issue with footage from the FX9 after these updates. It is not clear whether this is due to the new Pro Video Codecs package 2.1.2  that is comes as part of the update to OSX 10.15.6 or whether it is just related to the FCP-X 10.4.9 update. Some users are reporting that some FX9 MXF files can not be previewed in Finder after updating as well as not being visible in FCP-X.

While so far it I have only seen reports that footage from the FX9 is affected, but it wouldn’t surprise me if Venice material is also affected.

I would suggest waiting for a few weeks after the release of any update before updating and never do an update half way through an important project.

UPDATE: Sony know about the issue and are working with Apple to resolve it. It only seems to affect some FX9 footage and possibly some Venice footage. It appears as the culprit is the Pro Video Codecs update, but this is yet to be confirmed. I would still suggest waiting before upgrading  even if you are using a different camera.

Inside the Big Top. A short film from Glastonbury 2019. Shot on Venice.

As there is no Glastonbury Festival this year the organisers and production company have been releasing some videos from last year. This video was shot mostly with Venice using Cooke 1.8x anamorphics. The non Venice material is from an FS5. It’s a behind the scenes look at the activities and performances around the Glastonbury Big Top and the Theater and Circus fields. 

 

What’s So Magical About Full Frame – Or Is It all Just ANOTHER INTERNET MYTH?

FIRST THINGS FIRST:
The only way to change the perspective of a shot is to change the position of the camera relative to the subject or scene.  Just put a 1.5x wider lens on a s35camera and you have exactly the same angle of view as a Full Frame camera. It is an internet myth that Full Frame changes the perspective or the appearance of the image in a way that cannot be exactly replicated with other sensor or frame sizes. The only thing that changes perspective is how far you are from the subject. It’s one of those laws of physics and optics that can’t be broken. The only way to see more or less around an object is by changing your physical position.

The only thing changing the focal length or sensor size changes is magnification and you can change the magnification either by changing sensor size or focal length and the effect is exactly the same either way. So in terms of perspective, angle of view or field of view an 18mm s35 setup will produce an identical image to a 27mm FF setup. The only difference may be in DoF depending on the aperture where  f4 on FF will provide the same DoF as f2.8 on s35. If both lenses are f4 then the FF image will have a shallower DoF.

Again though physics play a part here as if you want to get that shallower DoF from a FF camera then the lens FF lens will normally need to have the same aperture as the s35 lens. To do that the elements in the FF lens need to be bigger to gather twice as much light so that it can put the same amount of light as the s35 lens across the twice as large surface area of the FF sensor.  So generally you will pay more for a comparable FF like for like aperture lens as a s35 lens. Or you simply won’t be able to get an equivalent in FF because the optical design becomes too complex, too big, too heavy or too costly.
This in particular is a big issue for parfocal zooms. At FF and larger imager sizes they can be fast or have a big zoom range, but to do both is very, very hard and typically requires some very exotic glass. You won’t see anything like the affordable super 35mm Fujinon MK’s in full frame, certainly not at anywhere near the same price. This is why for decades 2/3″ sensors and 16mm film before that, ruled the roost for TV news as lenses with big zoom ranges and large fast apertures were relatively affordable.
Perhaps one of the commonest complaints I see today with larger sensors is “why can’t I find an affordable fast, parfocal zoom with more than a 4x zoom range”. Such lenses do exist, for s35 you have lenses like the $22K Canon CN7 17-120mm  T2.9, which is pretty big and pretty heavy. For Full Frame the nearest equivalent is the more expensive $40K Fujinon Premista 28-100 t2.9. which is a really big lens weighing in at almost 4kg. But look at the numbers: Both will give a very similar AoV on their respective sensors at the wide end but the much cheaper Canon has a greatly extended zoom range and will get a tighter shot than the Premista at the long end. Yes, the DoF will be shallower with the Premista, but you are paying almost double, it is a significantly heavier lens and it has a much reduced zoom ratio. So you may need both the $40K Premista 28-100 and the $40K Premista 80-250 to cover everything the Canon does (and a bit more). So as you can see, getting that extra shallow DoF may be very costly. And it’s not so much about the sensor, but more about the lens.
The History of large formats:
It is worth considering that back in the 50’s and 60’s we had VistaVision, a horizontal 35mm format the equivalent of 35mm FF, plus 65mm and a number of other larger than s35 formats. All in an effort to get better image quality.
VistaVision (The closet equivalent to 35mm Full Frame).
VistaVision didn’t last long, about 7 or 8 years because better quality film stocks meant that similar image quality could be obtained from regular s35mm film and shooting VistaVision was difficult due to the very shallow DoF and focus challenges, plus it was twice the cost of regular 35mm film. It did make a brief comeback in the 70’s for shooting special effects sequences where very high resolutions were needed. VistaVision was superseded by Cinemascope which uses 2x Anamorphic lenses and conventional vertical super 35mm film and Cinemascope was subsequently largely replaced by 35mm Panavision (the two being virtually the same thing and often used interchangeably).
65mm formats.
 At around the same time there were various 65mm (with 70mm projection) formats including Super Panavision, Ultra Panavision and Todd-AO These too struggled and very few films were made using 65mm film after the end of the 60’s. There was a brief resurgence in the 80’s and again recently there have been a few films, but production difficulties and cost has meant they tend to be niche productions.
Historically there have been many attempts to establish mainstream  larger than s35 formats. But by and large audiences couldn’t tell the difference and even if they did they wouldn’t pay extra for them. Obviously today the cost implication is tiny compared to the extra cost of 65mm film or VistaVision. But the bottom line remains that normally the audience won’t actually be able to see any difference, because in reality there isn’t one, other than perhaps a marginal resolution increase. But it is harder to shoot FF than s35. Comparable lenses are more expensive, lens choices more limited, focus is more challenging at longer focal lengths or large apertures. If you get carried away with too large an aperture you get miniaturisation and cardboarding effects if you are not careful (these can occur with s35 too).
Can The Audience Tell – Does The Audience Care?
Cinema audiences have not been complaining that the DoF isn’t shallow enough, or that the resolution isn’t high enough (Arri’s success has proved that resolution is a minor image quality factor). But they are noticing focus issues, especially in 4K theaters.
 So while FF and the other larger format are here to stay. Full Frame is not the be-all and end-all. Many, many people believe that FF has some kind of magic that makes the images different to smaller formats because they “read it on the internet so it must be true”.  I think sometimes some things read on the internet create a placebo effect where when you read it enough times you will actually become convinced that the images are different, even when in fact they are not. Once they realise that actually it isn’t different, I’m quite sure many will return to s35 because that does seem to be the sweet spot where DoF and focus is manageable and IQ is plenty good enough. Only time will tell, but history suggest s35 isn’t going anywhere any time soon.

Today’s modern cameras give us the choice to shoot either FF or s35. Either can result in an identical image, it’s only a matter of aperture and focal length. So pick the one that you feel most comfortable with for you production. FF is nice, but it isn’t magic.

Really it’s all about the lens.

The really important thing is your lens choice. I believe that what most people put down as “the full frame effect” is nothing to do with the sensor size but the qualities of the lenses they are using. Full frame stills cameras have been around for a long time and as a result there is a huge range of very high quality glass to choose from (as well as cheaper budget lenses). In the photography world APS-C which is similar to super 35mm movie film has always been considered a lower cost or budget option and many of the lenses designed for APS-C have been built down to a price rather than up in quality. This makes a difference to the way the images may look. So often Full Frame lenses may offer better quality or a more pleasing look, just because the glass is better.

I recently shot a project using Sony’s Venice camera over 2 different shoots. For the shoot we used Full Frame and the Sigma Cine Primes. The images we got looked amazing. But then the second shoot where we needed at times to use higher frame rates we shot using super 35 with a mix of the Fujinon MK zooms and Sony G-Master lenses. Again the images looked amazing and the client and the end audience really can’t tell the footage from the first shoot with the footage from the second shoot.

Downsampling from 6K.

One very real benefit shooting 6K full frame does bring, with both the FX9 and Sony Venice (or any other 6K FF camera) is that when you shoot at 6K and downsample to 4K you will have a higher resolution image with better colour and in most cases lower noise than if you started at 4K. This is because the bayer sensors that all the current large sensor camera use don’t resolve 4K when shooting at 4K. To get 4K you need to start with 6K.

What is Dual Base ISO and why is it important?

Almost all modern day video and electronic stills cameras have the ability to change the brightness of the images they record. The most common way to achieve this is through the addition of gain or through the amplification of the signal that comes from the sensor. 

On older video cameras this amplification was expressed as dB (decibels) of gain. A brightness change of 6dB is the same as one stop of exposure or a doubling of the ISO rating. But you must understand that adding gain to raise the ISO rating of a camera is very different to actually changing the sensitivity of a camera.

The problem with increasing the amplification or adding gain to the sensor output is that when you raise the gain you increase the level of the entire signal that comes from the sensor. So, as well as increasing the levels of the desirable parts of the image, making it brighter, the extra gain also increases the amplitude of the noise, making that brighter too.

Imagine you are listening to an FM radio. The signal starts to get a bit scratchy, so in order to hear the music better you turn up the volume (increasing the gain). The music will get louder, but so too will the scratchy noise, so you may still struggle to hear the music. Changing the ISO rating of an electronic camera by adding gain is little different. When you raise the gain the picture does get brighter but the increase in noise means that the darkest things that can be seen by the camera remain hidden in the noise which has also increased in amplitude.

Another issue with adding gain to make the image brighter is that you will also normally reduce the dynamic range that you can record.

Screenshot-2019-11-27-at-18.21.19-1024x576 What is Dual Base ISO and why is it important?

This is because amplification makes the entire signal bigger. So bright highlights that may be recordable within the recording range of the camera at 0dB or the native ISO may be exceed the upper range of the recording format when even only a small amount of gain is added, limiting the high end.

Screenshot-2019-11-27-at-18.22.59-1024x576 What is Dual Base ISO and why is it important?
Adding gain amplifies the brighter parts of the image so they can now exceed the cameras recording range.

 

At the same time the increased noise floor masks any additional shadow information so there is little if any increase in the shadow range.

Reducing the gain doesn’t really help either as now the brightest parts of the image from the sensor are not amplified sufficiently to reach the cameras full output. Very often the recordings from a camera with -3dB or -6dB  of gain will never reach 100%.

Screenshot-2019-11-27-at-18.23.08-1024x576 What is Dual Base ISO and why is it important?
Negative gain may also reduce the cameras dynamic range.



A camera with dual base ISO’s works differently.

Instead of adding gain to increase the sensitivity of the camera a camera with a dual base ISO sensor will operate the sensor in two different sensitivity modes. This will allow you to shoot at the low sensitivity mode when you have plenty of light, avoiding the need to add lots of ND filters when you want to obtain a shallow depth of field. Then when you are short of light you can switch the camera to it’s high sensitivity mode.

When done correctly, a dual ISO camera will have the same dynamic range and colour performance in both the high and low ISO modes and only a very small difference in noise between the two.

How dual sensitivity with no loss of dynamic range is achieved is often kept very secret by the camera and sensor manufacturers. Getting good, reliable and solid information is hard. Various patents describe different methods. Based on my own research this is a simplified description of how I believe Sony achieve two completely different sensitivity ranges on both the Venice and FX9 cameras.

The image below represents a single microscopic pixel from a CMOS video sensor. There will be millions of these on a modern sensor. Light from the camera lens passes first through a micro lens and colour filter at the top of the pixel structure. From there the light hits a part of the pixel called a photodiode. The photodiode converts the photons of light into electrons of electricity. 

Screenshot-2019-11-27-at-17.40.52-1024x605 What is Dual Base ISO and why is it important?
Layout of a sensor pixel including the image well.

In order to measure the pixel output we have to store the electrons for the duration of the shutter period. The part of the pixel used to store the electrons is called the “image well” (in an electrical circuit diagram the image well would be represented as a capacitor and is often simply the capacitance of the the photodiode itself).

Screenshot-2019-11-27-at-17.41.00-1024x605 What is Dual Base ISO and why is it important?
The pixels image well starts to fill up and the signal output level increases.

Then as more and more light hits the pixel, the photodiode produces more electrons. These pass into the image well and the signal increases. Once we reach the end of the shutter opening period the signal in the image well is read out, empty representing black and full representing very bright.

Screenshot-2019-11-27-at-17.41.09-1024x605 What is Dual Base ISO and why is it important?

Consider what would happen if the image well, instead of being a single charge storage area was actually two charge storage areas and there is a way to select whether we use the combined image well storage areas or just one part of the image well.

Screenshot-2019-11-27-at-18.10.02-1024x575 What is Dual Base ISO and why is it important?
Dual ISO pixel where the size of the image well can be altered.

When both areas are connected to the pixel the combined capacity is large. So it will take more electrons to fill it up, so more light is needed to produce the increased amount of electrons. This is the low sensitivity mode. 

If part of the charge storage area is disconnected and all of the photodiodes output is directed into the remaining, now smaller storage area then it will fill up faster, producing a bigger signal more quickly. This is the high sensitivity mode.

What about noise?

In the low sensitivity mode with the bigger storage area any unwanted noise generated by the photodiode will be more diluted by the greater volume of electrons, so noise will be low. When the size of the storage area or image well is reduced the noise from the photodiode will be less diluted so the noise will be a little bit higher. But overall the noise will be much less that that which would be seen if a large amount of extra gain was added.

Note for the more technical amongst you: Strictly speaking the image well starts full. Electrons have a negative charge so as more electrons are added the signal in the image well is reduced until maximum brightness output is achieved when the image well is empty!!

As well as what I have illustrated above there may be other things going on such as changes to the amplifiers that boost the pixels output before it is passed to the converters that convert the pixel output from an analog signal to a digital one. But hopefully this will help explain why dual base ISO is very different to the conventional gain changes used to give electronic cameras a wide range of different ISO rating.

On the Sony Venice and the PXW-FX9 there is only a very small difference between the noise levels when you switch from the low base ISO to the high one. This means that you can pick and choose between either base sensitivity level depending on the type of scene you are shooting without having to worry about the image becoming unusable due to noise.

NOTE: This article is my own work and was prepared without any input from Sony. I believe that the dual ISO process illustrated above is at the core of how Sony achieve two different base sensitivities on the Venice and FX9 cameras. However I can not categorically guarantee this to be correct.

If you have an AXS-AR1, you need to update the firmware.

A firmware bug has been identified with the Sony AXS-AR1 AXS and SXS card reader that can result in the corruption of the data on a card when performing concurrent data reads. To ensure this does not happen you should update the firmware of your AXS-AR1 immediately. 

For more information please see the post linked below on the the official Sony Cine website where you will find instructions on how to perform the update and where to download the necessary update files.

https://sonycine.com/articles/sony-axs-ar1-firmware-update—do-this-now/

Venice to get even higher frame rates in V5 firmware.

VENICE-copy Venice to get even higher frame rates in V5 firmware.

Last night I attended the official opening of Sony’s new Digital Media Production center in LA. This is a very nice facility where Sony can show end users how to get the most from full end to end digital production, from camera to display. And a most impressive display it is as the facility has a huge permanent 26ft HDR C-Led equipped cinema.

One of the key announcements made at the event was details of what will be the 5th major firmware update for the Venice cameras. Due January 2020 version 5 will extend the cameras high frame rate capabilities as well as adding or improving on a number of existing options:

·       HFR Capabilities – Up to 90fps at 6K 2.39:1 and 72fps at 6K 17:9.

·       Apple ProRes 4444 – Record HD videos in the high picture quality on SxS PRO+ cards, without Sony’s AXS-R7 recorder. This is especially effective for HD VFX workflow.

·       180 Degree Rotation Monitor Out– Flip and flop images via viewfinder and SDI.

·       High Resolution Magnification via HD Monitor Out – Existing advanced viewfinder technology for clearer magnification is now extended to HD Monitor Out.

·       Improved User Marker Settings – Menu updates for easier selection of frame lines on viewfinder.

90fps in 6K means that a full 3x slow down will be possible for 6K 24fps projects. In addition to the above Sony now have a new IDT for Venice for ACES. so now VENICE has officially joined The F65, F55 and F55 in earning the ACES logo, meeting the specifications laid out in the ACES Product Partner Logo Program. I will post more details of this and how to get hold of the IDT over the weekend.