Cinematography

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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 has to be 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 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 and have to deal with a significantly heavier lens with a 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 (7 or 8 years) as better quality film stocks meant that similar 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 struggle to see any difference, because in reality there isn’t one other than 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”. 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.


What’s So Magical About Full Frame – Or Is It all Just ANOTHER INTERNET MYTH? was first posted on December 26, 2019 at 5:38 pm.
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Guess The Lens! A little bit of fun and an interesting test.

Last week I was at O-Video in Bucharest preparing for a workshop the following day. They are a full service dealer. We had an FX9 for the workshop and they had some very nice lenses. So with their help I decided to do a very quick comparison of the lenses we had. I was actually very surprised by the results. At the end of the day I definitely had a favourite lens. But I’m not going to tell you which one yet.

The 5 lenses we tested were: Rokinon Xeen, Cooke Panchro 50mm, Leitz (lecia) Thalia, Zeiss Supreme Radiance and the Sony 28-135mm zoom that can be purchased as part of a kit with the FX9.

I included a strong backlight in the shot to see how the different lenses dealt with flare from off-axis lights. 2 of the lenses produced very pronounced flare, so for those lenses you will see two frame grabs. One with the flare and one with the back light flagged off.

I used S-Cinetone on the FX9 and set the aperture to f2.8 for all of the lenses except the Sony 28-135mm. For that lens I added 6dB of gain to normalise the exposure, you should be able to figure out which of the examples is the Sony zoom.

One of the lenses was an odd focal length compared to all the others. Some of you might be able to work out which one that is, but again I’m not going to tell you just yet.

Anyway, enjoy playing guess the lens. This isn’t intended to be an in depth test. But it’s interesting to compare lenses when you have access to them.  I’ll reveal which lens is which in a couple of weeks in the comments. You can click on each image to enlarge it.

Big thanks to everyone at O-Video Bucharest for making this happen.

Lens1-flare Guess The Lens! A little bit of fun and an interesting test.
Lens 1 with flare from backlight.
lens1-no-flare Guess The Lens! A little bit of fun and an interesting test.
Lens 1 with backlight flagged to reduce the flare.
lens2 Guess The Lens! A little bit of fun and an interesting test.
Lens 2
lens-3 Guess The Lens! A little bit of fun and an interesting test.
Lens 3
lens-4-no-flare Guess The Lens! A little bit of fun and an interesting test.
Lens 4
lens-5-flare Guess The Lens! A little bit of fun and an interesting test.
Lens 5 with flare from backlight
lens-5-No-flare Guess The Lens! A little bit of fun and an interesting test.
Lens 5 with backlight masked to kill the flare.

Guess The Lens! A little bit of fun and an interesting test. was first posted on December 16, 2019 at 5:55 pm.
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The “E” in “E-Mount” stands for Eighteen.

A completely useless bit of trivia for you is that the “E” in E-mount stands for eighteen. 18mm is the E-mount flange back distance. That’s the distance between the sensor and the face of the lens mount. The fact the e-mount is only 18mm while most other DSLR systems have a flange back distance of around 40mm means thare are 20mm or more in hand that can be used for adapters to go between the camera body and 3rd party lenses with different mounts.

Here’s a little table of some common flange back distances:

MOUNT FLANGE BACK SPARE/Difference
e-mount 18mm
Sony FZ (F3/F5/F55) 19mm 1mm
Canon EF 44mm 26mm
Nikon F Mount 46.5mm 28.5mm
PL 52mm 34mm
Arri LPL 44mm 26mm
Sony A, Minolta 44.5mm 26.5mm
M42 45.46mm 27.46mm

The “E” in “E-Mount” stands for Eighteen. was first posted on November 27, 2019 at 4:00 pm.
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Can You Shoot Anamorphic with the PXW-FX9?

The simple answer as to whether you can shoot anamorphic on the FX9 or not, is no, you can’t. The FX9 certainly to start with, will not have an anamorphic mode and it’s unknown whether it ever will. I certainly wouldn’t count on it ever getting one (but who knows, perhaps if we keep asking for it we will get it).

But just because a camera doesn’t have a dedicated anamorphic mode it doesn’t mean you can’t shoot anamorphic. The main thing you won’t have is de-squeeze. So the image will be distorted and stretched in the viewfinder. But most external monitors now have anamorphic de-squeeze so this is not a huge deal and easy enough to work around.

1.3x or 2x Anamorphic?

With a 16:9 or 17:9 camera you can use 1.3x anamorphic lenses to get a 2:39 final image. So the FX9, like most 16:9 cameras will be suitable for use with 1.3x anamorphic lenses out of the box.

But for the full anamorphic effect you really want to shoot with 2x  anamorphic lenses. A 2x anamorphic lens will give your footage a much more interesting look than a 1.3x anamorphic. But if you want to produce the classic 2:39 aspect ratio normally associated with anamorphic lenses you need a 4:3 sensor rather than a 16:9 one.

What about Full Frame 16:9?

But -that’s super 35mm 4:3 or s35mm open gate. The FX9 has a 6K full frame sensor and a full frame sensor is bigger, most importantly it’s taller than s35mm and tall enough for use with a 2x s35 anamorphic lens! The FX9 sensor is approx 34mm wide and 19mm tall in FF6K mode.

In comparison the Arri  35mm 4:3 open gate sensor is area is 28mm x 18mm and we know this works very well with 2x Anamorphic lenses. The important bit here is the height – 18mm with the Arri open gate and 18.8mm for the FX9 in Full Frame Scan Mode.

Crunching the numbers.

If you do the maths – Start with the FX9 in FF mode and use a s35mm 2x anamorphic lens. 

Because the image is 6K subsampled to 4K the resulting recording will have 4K resolution.

But you will need to crop the sides of the final recording by roughly 30% to remove the left/right vignette caused by using an anamorphic lens designed for s35 on a full frame sensor (the exact amount of crop will depend on the lens). This then results in a 2.8K ish resolution image depending on how much you need to crop.

4K Bayer doesn’t won’t give 4K resolution.

That doesn’t seem very good until you consider that a 4K 4:3 bayer sensor will only yield about 2.8K resolution anyway.

And Arri’s s35mm cameras are open gate 3.2K bayer sensors so will result in an even lower resolution image, perhaps around 2.2K? Do remember that the original Arri ALEV sensor was designed when 2K was the norm for the cinema and HD TV was still new. The Arri super 35 cameras were for a long time the gold standard for Anamorphic. But now cameras like Sony’s Venice that can shoot the equivalent of 6K open gate or 6K 4:3 and 6:5 are now taking over.

What about Netflix?

While Netflix normally insist on a minimum of a sensor with 4K pixels horizontally for capture, they are permitting sensors with lower horizontal pixel counts to be used for anamorphic capture because the increased sensor height needed for 2x anamorphic means that there are more pixels vertically. The total pixel count when using a camera such as the Arri LF with a super 35mm 2x anamorphic lens is 3148 x 2636 pixels. Thats a total of  8 megapixels which is similar to the 8 megapixel total pixel count of a 4K 16:9 sensor. The argument is that the total captured picture information is similar for both, so both should (and are) allowed.

So could the FX9 get Netflix approval for 2x Anamorphic?

The FX9’s sensor has is 3168 pixel tall when shooting FF 16:9  as it’s pixel pitch is finer than the Arri LF sensor.  When working with a 2x anamorphic super 35mm lens the image circle from the lens will cover around 4K x 3K of pixels, a total of 12 megapixels on the sensor when it’s operating in the 6K Full Frame scan mode. But then the FX9 will internally down scale this to that vignetted 4K recording that needs to be cropped.

6K down to 4K means that the 4K covered by the lens becomes roughly 2.7K. But then the 3.1K from the Arri when debayered will more than likely be even less than this, perhaps only 2.1K

But whether Netflix will accept the in camera down conversion is a very big question. The maths indicates that  the resolution of the final output of the FX9 would be greater than that of the LF, even taking the necessary crop into account. But this would need to be tested in practice. If the math is right, I see no reason why the FX9 won’t be able to meet Netflix’s minimum requirements for 2x anamorphic production. If this is a workflow you wish to pursue I would recommend taking the 10 bit 4:2:2 HDMI out to a ProRes recorder and record using the best codec you can until the FX9 gains the ability to output raw. Meeting the Netflix standard is speculation on my part, perhaps it never will get accepted for anamorphic, but to answer the original question –

 – Can you shoot anamorphic with the FX9 – Absolutely, yes you can and the end result should be pretty good. But you’ll have to put up with a distorted image with the supplied viewfinder (for now at least).


Can You Shoot Anamorphic with the PXW-FX9? was first posted on October 3, 2019 at 10:57 am.
©2018 “XDCAM-USER.COM“. Use of this feed is for personal non-commercial use only. If you are not reading this article in your feed reader, then the site is guilty of copyright infringement. Please contact me at contact@xdcam-user.com