Important Quirks and Features of the Sony FX3 for Cinematography

The Sony FX3 (Amazon, B&H) is a surprising addition to the Sony cinema camera lineup. Why on earth would Sony make a near-Sony a7S III clone?

Let us see what’s the deal here. Let’s go over some important quirks and features of the Sony FX3 for cinematography and video.

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The lightest cinema camera?

The Sony FX3 (Amazon, B&H) weighs around 715g (body + cards and battery).

Though it’s lower than the Red Komodo or the Sony FX6, but Sony made crucial sacrifices when it comes to features to achieve this weight. The biggest are the lack of inbuilt variable ND filters, SDI ports and internal RAW recording.

It’s important to understand the FX3 has been marketed heavily towards videographers instead of cinematographers.

4K up to 120p. What do you really get?

The most important points:

• You get 4K UHD (3840×2160) up to 120 fps.
• Best file format is XAVC S-I 4K (up to 60p) and XAVC-HS (up to 120p).
• You get 10-bit 4:2:2 internally in all modes.
• Dynamic range is claimed to be 15+ stops in S-Log3 (S-Gamut3, and S-Gamut3.Cine).
• 16-bit RAW output is available in both 4K DCI (4264 x 2408) and UHD up to 60p, via HDMI.
• There is a 10% crop in 120p and with RAW over HDMI.
• You get continuous auto focus all the way to 120p.
• You can record audio in 120p, if you don’t pick S&Q.
• Proxy files can be written in 8-bit 4:2:0 XAVC-L 1080p at 16Mbps.
• You can transfer video directly to a computer via USB-C 5Gbps (USB 3.2).

What is the crop factor in 4K?

There is no crop factor up to 60p.

There is a 10% crop factor at 100p/120p and with RAW via HDMI. E.g., a 50mm lens will give you a 35mm equivalent of about 55mm. It’s not a big difference, but it’s important to highlight, especially if you’re trying to match the FX3 to other full frame cine cameras.

What are the data rates for 4K?

Here are the data rates for 10-bit 4:2:2 for the Sony FX3 (Amazon, B&H):

Frame rates at 4K	Codec	Data rate
23.976p to 59.94p*	XAVC S-I	200 to 600 Mbps
23.976p to 119.88p	XAVC HS	60 to 200 Mbps

If you want to grade your videos, you might want to stick to XAVC S-I, because it gives you the least compression in 10-bit 4:2:2. 600 Mbps is 75 MB/s.

The ‘S’ is a seriously bad move. Cinema cameras should ideally have the XAVC-I codec. The S codec was specifically designed for low budget cameras. It is not befitting a ‘cine camera’.

I understand Sony had to protect the FX6, but they should have just called this camera the a7S III.

Just to put some perspective, this equates to:

• About 85 minutes on a 160 GB card at 200 Mbps (for 59.95p).
• About 25 minutes on a 160 GB card at 600 Mbps (for 59.95p).

What about 1080p or HD?

The maximum frame rate for HD is 240 fps. No crop at all.

Proxy files are written in 1080p.

What is the dynamic range of the Sony FX3?

According to Sony, the dynamic range is about 15+ stops in S-Log3. It’ll probably be the same as the Sony a7S III, which I found lacking:

Sony a7S III Review for Professional Cinematography

Here is the sample footage that Sony released that has been shot with the FX3:

It looks good, but nothing different about it compared to the a7S III.

What is the recording time limit for 4K ?

There is no internal recording time limit mentioned by Sony’s official website. Till 60p. Sony doesn’t claim uninterrupted 120 fps shooting.

Does it overheat like the Sony a7S III?

No. There is an active fan that allows you long record times.

For uninterrupted 4K 60p recording, the FX3 features an innovative heat dissipation structure, including a unique Sony (sigma) shaped graphite-alloy heatsink. A complete internal redesign optimized airflow and placement of heatsinks. When required, a silent cooling fan provides ventilation for continuous recording at full resolution, with intake and exhaust air structurally isolated to maintain strong dust and moisture resistance.

Sony

We’ll need to see how loud (or quiet) the fan is in full operation. This is a significant improvement over the a7S III.

However, please note: Sony doesn’t say anything about 120p. Does it still overheat? What’s the catch here?

What media card do you need?

The Sony FX3 (Amazon, B&H) has dual CFexpress Card Type A slots.

These slots are also compatible with SDXC cards supporting UHS-I and UHS-II speed classes.

If you need sustained 4K at the highest frame rates, CFExpress cards are recommended by Sony. You can use any UHS-II card, preferably V90, to record in UHD XAVC-I up to 60fps. While the camera won’t stop you from using a V90 or even a V30, it will pop up a “not recommended media” warning and halt the recording.

Sony doesn’t include a card in the camera package, and CFexpress Type A cards are still rare (and expensive).

Note: Other camera brands have preferred to use the faster Type B CFexpress card. Unfortunately, Type B is not supported.

What is the ISO range for 4K?

The ISO range for video is up to 102,400 in S-Log3. Sony mentions that this range is expandable up to 409,600. The a7S-line are legends in the low light category. This camera is a low light beast.

Even though many claim the a7S III has dual native ISO, it doesn’t have that with hardware. And neither does the Sony FX3. You might get a cleaner image due to noise. reduction, but that’s something you can do in post production anyway. Keep in mind, as you raise the ISO, you will lose dynamic range. That’s just how sensors work.

I guess it should be easy to shoot with this camera to ISO 25,600 without penalty.

What type of stabilization is in the Sony FX3?

The Sony FX3 (Amazon, B&H) has 5-axis In Built Image Stabilization (IBIS). They claim that this can provide 5.5 stops of image stabilization.

For video, they have an Active Mode of recording, similar to the a7S III, which provides yaw, pitch and roll stability. Active mode is only available till 60p in 4K and it comes with a slight image crop:

Much like the FX9 and the FX6, the FX3 also has a gyroscope in it. So you can use the gyro data to stabilize the footage even more accurately in the post using Sony’s own Catalyst Software.

What video exposure tools are available in camera?

The big difference is you get the S-Cinetone profile. S-Log3 and S-Log2 still provide the best dynamic range, so I wouldn’t call this a significant improvement over the a7S III.

S-Log2 and S-Log3 gamma curves are available, with S-Log3 giving better gradations from shadows to the mid-grey range (18% grey), enabling a dynamic range of up to 15+ stops. For camera matching with other S-Log3 capable Cinema Line cameras, three color gamut settings (S-Gamut, S-Gamut3, and S-Gamut3.Cine) are available, offering creative flexibility and efficiency during post production

Sony

It comes with Zebras and Focus Peaking, but no false color or waveform. This is a disappointing omission in a “cine” camera.

Zoom Ring control

The Sony FX3 (Amazon, B&H) has a zoom ring control lever on top of the grip provided with the camera. This will enable you to operate powered zoom lenses through the lever.

The zoom lever placed at the top of the grip allows operation of power zoom lenses. Additionally, our innovative Clear Image Zoom provides for practical angle of view options even with minimal equipment. Zoom speeds can also be adjusted to suit everything from quick documentary re-framing to purposeful cinematic zooms

Sony

The Clear Image Zoom is a digital zoom. This is useful, if you are handholding the camera like a stills camera. If you’re on a tripod or shoulder mount or gimbal, good luck. I think this is one thing Sony didn’t completely think through. The position is half baked.

You know what would have been cool? An attachment that could be connected by cable so it could be positioned anywhere.

What about the LCD?

You get a 3.0-type, approximately 1.44 million-dot (720p) LCD touchscreen. It is almost completely free to swivel out. Its maximum rotational degree is 270 degrees.

The problem is it blocks some functionality, because the HDMI and audio ports are on the same side. The least Sony could have done is to shift them to the other side, like a true “cine camera”.

What is the best format for external video recording?

The best video format that can be exported is 16-bit 4K RAW via HDMI Type A. The maximum frame rate is 59.94p.

Currently, the Atomos Ninja V (Amazon, B&H) supports 16-bit RAW recording to 12-bit Apple Prores RAW.

What format should I choose for the best video quality on the Sony FX3?

I suggest S-Log3, XAVC S-I in 10-bit 4:2:2. This would give you the best dynamic range and the most flexible video for post production.

What about timecode?

The Sony FX3 (Amazon, B&H) has omitted timecode input and output for multi camera sync. One can argue that this camera was heavily marketed and designed for solo shooters but this was another wasted opportunity.

Can you record simultaneously to both CFexpress cards?

Sony FX3 (Amazon, B&H) is capable of recording simultaneously on both the cards. This includes:

1. Auto Switch recording or Relay Recording: Auto Switch recording allows you to carry on your recording from one card to the other, i.e. if while recording one of your memory card is filled up auto switch recording will start writing on to the second memory card instantaneously.
2. Copy recording: This mode of recording allows you to basically create a backup of your recording parallel to your first recording.
3. Proxy recording: allows you to record 10-bit 4:2:2 to one card and a proxy 8-bit 4:2:0 format in the other card as backup.

How good is the autofocus for video?

It’s going to be fabulous, if it’s the same as the a7S III. Real eye tracking is precise and consistent.

The touch AF is precise and is a joy to work with. Another commendable feature of the Sony FX3 (Amazon, B&H) is the AF assist. Even when you are in Manual Focus mode, you can tap on the subject on your touchscreen and the camera will rack focus to the subject.

The good news is AF is available in most 4K modes, including 120p.

What are the audio specs?

The audio is recorded as Linear PCM in 24-bit mode. The cold shoe can transmit power directly to a Sony mic or XLR. The 2 full sized XLR inputs (XLR/TRS combo) are on the top handle grip of the Sony FX3. Thankfully, the top handle and audio unit comes with the camera so it won’t be an added expense. It can be removed.

The FX3 offers up to 4-channel audio recording by combining sources from the dual XLR inputs, the 2-channel multi-interface shoe input, and the stereo mic built into the camera’s top handle.

It also has a 3.5mm Stereo mini headphone jack.

Content Browser Mobile Compatibility

The Sony FX3 can be somewhat remotely controlled from your phone using the Content Browser mobile app. The FX3’s Wi-Fi function will allow you to monitor the camera remotely and have full control of the zoom, iris and the focus.

Mounting Options

Sony has made somewhat of a cage on the body of the Sony FX3 (Amazon, B&H). Five 1/4-20 mounting screw holes are on the body and three more of the same mounts are included in the XLR grip that comes with camera.

The problem is, these holes are in the weirdest places. With a regular cage, you get more mounting points to suit your style. I really think these mounting holes were made for YouTubers. Again, unbecoming of a cine-line camera. What’s so “cine” about it?

And more unbecoming is the omission of a second thread at the bottom for a more robust tripod mount.

Tally Lights

The Sony FX3 has three tally lights on its body which light up when recording. It is handy for small crews, live streaming, multi-camera setups and journalism.

Any word on battery life for video for the Sony FX3?

You get 95 mins (1 hour 45 minutes) of actual recording with a NP-FZ100  battery and 135 mins (2 hour 15 minutes) of continuous with a NP-FZ100  battery.

The FX3 draws about 7.3 Watts. I believe with three batteries you should be able to get through even the most demanding days.

You can also power it with a USB type C power bank/charger.

Is the Sony FX3 weather sealed?

Not really. Sony claims to have improved weather resistance:

In response to feedback from working professionals, sealing has been applied to all body seams and around the battery and media compartments, terminal covers and chassis joints. All routes for dust and moisture entry have been examined to ensure reliable operation in challenging environments..

Sony

However, in the fine print, we have this:

Not guaranteed to be 100% dust and moisture-proof.

Sony

To be honest, I will be surprised if this camera cannot handle most outdoor conditions.

What’s missing?

• Variable ND Filters
• SDI output
• Timecode and Genlock
• RAW internally
• EVF
• Good Exposure tools i.e. Waveform, False Color etc.
• LUTs
• Proper mounting points
• Locking E-mount
• Second Tripod thread
• Poor positioning of HDMI and audio ports
• Consumer-grade “S” codec

What’s better?

We’ll have a more detailed comparison with the a7S III soon, but for now, the only major practical benefit of the Sony FX3 over the a7S III is the fan and lack of overheating.

You “supposedly” save on the cost of a cage (not really, because the mounting threads are in the wrong places) and audio unit, but you lose an EVF in return.

The Sony FX3 (Amazon, B&H) is what the Sony a7S III should have been. And now that it’s here, I see no reason for anyone to buy the a7S III.

I’ve owned the a7S, a7R III and a7S II, and I’m glad I didn’t buy the a7S III. Those who bought it will already be regretting their purchase. Because…overheating.

In the coming weeks I’ll be comparing it to the Sony a7S III and FX6, to see what the real value proposition is.

Bottom line. Great camera, sucker punch to loyal a7S III customers.