Perhaps I’m splitting hairs here a little bit – and I still think the FX6 is an amazing camera. But the more I look at it’s different scan modes and recording mode the more I’ve realised that it’s only actually “Full Frame” in few certain settings.
When the FX6 is set to UHD and operating from 1 to 60 fps then it’s full frame and the whole width of the sensor is used. Put a Full Frame lens on the camera and you get the same FoV as an FX9 or any other camera with a similar sized sensor.
But if you want to shoot 4K DCI then something strange happens. Switch the FX6 to 4K DCI and the sensor is cropped/windowed by 5% and instead of the field of view becoming 5% wider as happens on most cameras, it instead becomes 5% narrower. In 4K DCI the FX6 is very slightly less than Full Frame.
To shoot at more than 60fps the camera has to be in UHD. 60 fps and below it’s full frame but when you go above 60fps the image is cropped even more, this time by 10% so the FoV gets 10% narrower.
If you want to record UHD Raw at any frame rate the image is also cropped by 10% so UHD with raw out at 30fps results in a 10% narrower FoV than when you are not outputting raw. When you enable raw at 4K DCI raw it’s a 5% crop.
So while none of these crops are huge it is worth noting that the FX6 is actually a little less than full frame more often than not!
Just to put all this into some perspective the FX9’s Full Frame Crop 5K mode involves a 17% crop. The FX6 outputting UHD raw or recording UHD at more than 60fps is a 10% crop. That’s not a vast difference. In these modes the FX6 is closer to the FX9 5K mode than to Full Frame.
Why is this? Well the FX6’s sensor is 4.2K pixels across. In the “normal” UHD frame rates (up to 60fps) the full 4.2K is read and downscaled on the fly to 3840 x 2160 UHD. When you shoot 4K DCI there is no downscale and instead the sensor is read out at 4K and the extra 0.2K of pixels at the edges of the frame are not used – 0.2K being 5% of 4.2K and thus you have a 5% crop and the FoV becomes 5% narrower in DCI 4K than in UHD.
When you shoot above 60 fps then the sensor is read directly at 3840 pixels rather than 4.2K to make the readout simpler and faster. So now we are reading 0.4K fewer pixels from the sides of the sensor which is 10% of the total pixels and we get a 10% narrower FoV above 60fps as a result.
As I said at the start, perhaps I’m splitting hairs. I certainly don’t think this detracts from the FX6 in any significant way. But if it’s a camera you are thinking of getting, you should be aware of this.
Tag Archives: full frame
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.
Sony Venice. Full Frame Digital Cinema Camera.
So here it finally is. Sony’s latest digital cinema camera and finally it has a name rather than a number and it’s called Venice.
I was lucky enough to be involved with Venice during the filming of the UK promo film, so I have had a little bit of a chance to play with one, seen it in action in the hands of an experienced DP (Ed Wild B.S.C.) and I have copies of the footage from it (I did the BTS film). So I have a pretty good idea of what we are dealing with…… and it’s good, it’s very, very good.
For a long time I have been saying that what we need is better pixels, not more pixels and that’s precisely what Sony have delivered in Venice. The newly developed sensor is a full frame sensor, 36mm x 24mm with 6K’s worth of horizontal pixels. This means that if you use the camera as a super 35mm camera you have 4K (and for the demo films the pre production cameras used only worked at 4K, the equivalent of 35mm 4 perf. 6K will come a little later). Venice will be able to do a huge range of resolutions and aspect ratios including Anamorphic.
Why only 6K? Well it’s down to pixel size. Bigger pixels can capture more light and they can also store more electrons before they overload. This means you get a bigger dynamic range than would typically be possible with smaller pixels. The extra light capturing capability can be used in one of 2 ways, to increase sensitivity or to decrease noise. It appears that the engineers behind Venice went for the latter, lower noise.
A lot of research was done for this camera. Engineers from Japan met with many ASC and BSC cinematographers. They talked to post houses and colourists to find out what was really needed. I know that Claudio Miranda A.S.C. played an important part in the development process, he also shot the US demo film. The end result is a pretty sensitive camera (500 ISO) with very low noise and over 15 stops of dynamic range. Yes – that’s right over 15 stops without resorting to double exposures or any other tricks!!
While the sensor isn’t a global shutter sensor it does have an extremely fast readout rate. This extra fast readout means that jello and other rolling shutter artefacts are minimised to the point where it behaves much more like a global shutter sensor. Generally speaking, the extra memory circuits needed to get a global shutter either add noise, reduce sensitivity or reduce dynamic range. So it’s not a huge surprise to see the fast read out approach. There was quite a bit of filming done with a rather lovely Lamborghini Uraco, both hand held inside the car and mounted on the front of the car. Looking at the rushes there is no sign of any noticeable rolling shutter artefacts, even the trees flashing past in the background are still nice and vertical.
A lot of the car shooting took place at dusk and an interesting thing that came out of the UK demo reel shoot was how well it performed in low light. The 500 ISO rating is deceptive, because the camera produces so little noise you can rate the camera at a higher ISO and still get good results. Most current cinema cameras don’t produce the best results unless you rate them lower than their base ISO’s. Venice is different, the base ISO is very low noise and very high dynamic range. There appears to be little need to rate it lower for even less noise, although you could if you wish. I asked Ed Wild about this and he was really pleased with Venice’s ISO rating commenting that he often had to rate cameras from other manufacturers lower than the base ISO while he felt Venice at 500 ISO worked really well and that he would even consider rating it higher if needed.
Having a low base ISO means there is less need to use large amounts of ND on outdoor shoots. But talking of ND filters one of the great features of Venice is an 8 stage, behind the lens glass ND filter system. This allows you to choose just the right amount of ND for the light levels you have with no loss of quality. During the pre-shoot test and prep day at Pinewood each stage of the ND was carefully tested for colour shifts and accuracy, no problems were found.
The lens mount on a Venice camera can be changed. It’s not a quick release mount as on the F55 or F5 cameras. It’s normally a PL mount. But the PL mount can be removed and the camera changed to a Sony E-Mount. 6 bolts remove the PL mount and a locking E mount similar to the one on the FS7 II is on the cameras body. This opens up the possibility of using a huge range of lenses, practically anything in fact as it’s easy to adapt from E-Mount to other mounts such as Canon EF for example. For the UK demo reel XTAL Anamorphics from MovieTec were used. Ultra Primes were used for the US promo film.
VENICE A Truly Modular Camera.
Not only can the lens mount be changed but the entire front part of the camera can be changed by removing just 4 screws. Venice is built as a modular camera and the front part of the camera that contains the sensor and ND filters is a removable module (no need for lab conditions or clean rooms to remove the module). This means that in the future Sony could release new sensor options for Venice. Maybe a higher resolution sensor, a monochrome sensor or a high speed sensor. Removing the front sensor module from the camera allows easy access to the cameras internal near silent fan so that it can be cleaned or replaced should that become necessary. All of the cameras electronics are in sealed compartments for dust and moisture protection and rubber seals are installed around any openings such as the SxS card access door. In addition if you do use the AXS-R7 recorder to record Raw/X-OCN this too is weather sealed.
Venice records to SxS cards and with the AXS-R7 attached to AXS cards. You can record XAVC, ProRes HD, ProRes Proxy, as well as Raw/X-OCN. The XAVC recording option allows you to record direct to compact but high quality ready to go files or to record lower resolution proxy files. X-OCN gives a 16 bit linear workflow with raw type performance but without massive files. There is very little difference between X-OCN and Sony 16 bit linear raw and different versions of X-OCN work at different bit rates so you can pick and choose the right balance of image quality against file size for each project.
For Venice Sony have developed new colour science that is designed to emulate film. Looking at the rushes from the camera it really looked nice without any grading. The images contain lots of lush colours. You could see amazing subtle tonal information in the leaves and trees in the shots. Skin tone highlights roll of in a particularly pleasing way.
One of the biggest criticisms of the PMW-F55 and F5 cameras when they were launched was that they were too complex to drive. The F55 menu system is very large containing many, many pages of settings and adjustments. This is a cinema camera without a lot of the fancy modes that cameras like the F5 or F55 have so the menus are simpler straight away. A lot of time was spent trialling different menu structures to determine the easiest and friendliest structure. At the press event during the hands on session most people found it quite easy to navigate around the menus. But really the way the side panel and the quick menu is set up means you won’t need to dive into the main menu very often.
The camera body is a bit bigger than an F55/F5 and a lot smaller and lighter than an F65. On the right side of the camera there is the main LCD display, which is very similar to the one on the F55/F5 with 6 hot keys around it and a rotary menu dial. This is actually quite similar to the F55’s new Quick Menu system and easy to master. All the key functions and setup options are just a couple of button presses away. This is the main display and where most of the cameras settings can be changed. It’s on the right side so the AC or DIT can get at it and see it easily. Pressing the user button turns 5 of the 6 buttons around the LCD into user assignable buttons (the 6th button is used to set the assignable functions).
On the left side of the camera there is a small information display that shows the frame rate, shutter speed, ND, ISO and white balance.
The white balance of the camera can be dialled in manually unlike the F55 you are no longer tied to 3 presets. You can now dial in the white balance you want down to 1 kelvin increments. Once you have set your white balance you can include your new custom setting in the preset list for quick recall at any time.
The camera can run off either 12V or 24V and it has an internal 24V inverter so that when using a 12V power source such as a V-Mount battery you still get 24V out of the industry standard 24V lemo connectors.
Venice is a modular camera system with various upgrade options. The base camera comes as a 4K super 35mm camera. the 6K option, anamorphic options (6K full frame and 4K 35mm) and other options will be available as option licences. These licences can be purchased as weekly, monthly or permanent options depending on your needs.
What about the picture? I spent a couple of days looking at footage from this camera both in my own grading suite and at Sony’s Pinewood facility during the production of the BTS film. I also saw it projected at the press day and it looks good. One problem today is that there are so many very good and very capable cameras that it’s tough to really pinpoint things that make one stand out as better than another. What I have found to be very pleasing from Venice is the skin tones. Sony have introduced new colour science and colour management for Venice and I think it looks really good. Even before grading, just looking at the clips on a monitor with S-Log3 gamma the pictures have a wonderful rich look. It’s worth noting that the cameras used for both the US and EU launch films were hand made pre-production units and the engineers are still learning how to fully exploit the new sensors in these cameras. So we can only expect them to get better between now and when they become available to buy.
Will I be getting one? Probably not. This is a wonderful camera and I would love to own one, but Venice will be more expensive than the F55 and probably not the best investment for me at least. However I fully intend to get my grubby fingers on one as soon as possible to learn all of it’s in’s and out’s as I hope to use a Venice for some short films I have planned. This is a serious Alexa or Red alternative It has image quality to rival or better almost any other digital cinema camera, but that does come at a price, although it’s no more expensive than any other comparable camera.
The estimated price for the base camera is expected to be around €37,000. Full frame and anamorphic options will be payable options, with the full-frame option costing a approx €4,000 and the anamorphic costing a approx €6,000. it should be available from around February 2018.