Review of Core Highlights and Design of DJI Ronin 4D Movie Camera

Review of Core Highlights and Design of DJI Ronin 4D Movie Camera

What’s the combination of a main body, a gimbal camera, a DL mount and lens?
Why does DJI develop this type of movie camera?
How about its performance? Is it practical? Is it suitable for me?

These questions may roll over you when you see DJI Ronin 4D… More than 20 days ago, we received the DJI Ronin 4D (6K version) prototype in advance. Using it, we shot a short film of motorcycle riding, and had conducted some tests for it. You may find answers from the following content. Let’s start.

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Generally speaking, DJI Ronin 4D boosts its cinematic imaging and its innovative LiDAR focusing greatly helps users’ focusing practices and is suitable for more lens; the addition of Z-axis decreases vertical shaking which traditional stabilizers struggle to deal with, thus improving the independent shooting ability of the camera operator; the O3 Pro/ O3 Pro OcuSync has versatile functions and modular accessories, which can benefit coordinated shooting very well.

Since DJI Ronin 4D belongs to a brand-new movie camera system, it includes too many parts that need to be understood. So, we list its product outline here. For more information, please refer to it.

Text Outline:
firstly, we will illustrate four highlights of DJI Ronin 4D including cinematic imaging, LiDAR focusing, 4-axis stabilization and Wireless transmission; secondly, we will introduce its shape, functional buttons, interfaces and other designs in detail.

We will then tweet two other articles titled Detailed Analysis of the Functions and imaging performance of DJI Ronin 4D Movie Camera and DJI Ronin 4D Movie Camera Versus DJI RS2 and DJI EOS R5 on Stability and Autofocus. Hopefully, the three tweets will help you to solve most of questions about DJI Ronin 4D.

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Cinematic imaging
The DJI Ronin 4D is designed to function as a movie camera, which can be used in film shooting settings.

001 Resolution
It comes with two versions: Zenmuse X9 6K and Zenmuse X9 8K, both of which are full-frame with a dynamic range of 14+ stops. The 8K version has higher resolution and focuses on details, which is suitable for shooting detailed objects and scenes, such as forests, crowds, artworks and artifacts.

While the 6K version is more focused on the tones of imaging, and can cope with complicated lighting environment and low-light scenes as well, producing works with fine tones and rich details.

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002 Encoding Formats
Both versions support internal recording of Apple ProRes RAW, ProRes 422 HQ, and H.264 video. H.264 is suitable for long-time recording, ProRes 422 HQ provides solutions for editing and grading, and Apple ProRes Raw can maximize post-processing space.

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H.264 format is so versatile that can support most players and post-processing software, while ProRes 422 and ProRes RAW requires higher performance computer and exact software. Three editing softwares including Finalcut, commonly used Adobe Premiere and AVID support the direct import, preview and editing of ProRes RAW; as for grading, three editing tools including Scratch, Misitka and Baselight support ProRes RAW files. However, the Da Vinci system does not yet support the direct editing of ProRes RAW files before transcoding.

003 Frame Rate
The 6K version supports up to 6K 60p, 4K/120fps, while the 8K version supports up to 75fps, which indicates their different market positioning. The 8K version is mainly designed to facilitate cropping and secondary composition, as well as deliver better results for keying and other processes needed by special effects users.

Both versions support full-frame 4K video recording, which can provide oversample image quality finesse and uncropped perspective composition. The in-camera S35 mode is also available to meet the needs of cropped shooting.

And it should be noted that all of the above resolutions and frame rates support autofocus as the DJI Ronin 4D applies a LiDAR focusing system.

004 Gamma
DJI Ronin 4D supports D-Log, Rec.709 and HLG modes. Under the D-Log mode, the maximum dynamic range can be achieved. Under the D-Log or HLG mode, changing to Rec. 709 mode for monitoring is allowed.

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005 ISO
Both versions support dual native EI and have a dynamic range of 14+ stops, with the 8K version supporting EI800 and EI4000 and the 6K version supporting EI800 and EI5000.

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006 Built-in ND Filter
X9 has 9-stop built-in ND filter (ND 0.3 to ND 2.7). All ND glasses have been strictly selected to minimize the chromatic aberration between stops as much as possible.

With the built-in ND filter, there is no concern about using a large aperture in strong light. While ensuring the depth of field, it avoids the adverse effect of adjusting shutter speed and EI on imaging performance.

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LiDAR Focusing System

The camera applies a LiDAR range finder. The principle of LiDAR focusing system is different from that of the phase focusing. Specifically, the former can focus faster, without compromising the image quality or relying on the surface texture of the subject. This is especially useful in low-light environments. The speed of autofocus can maintain even in fast motion.

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The LiDAR focusing system is also suitable for manual focusing. The visualized focus assistance technology displays the ranging points on monitors in a simplified top-down view, with a distance scale on the right. This provides groundbreaking and intuitive manual focusing assistance. Even operators with little or no experience can become adept at manual focusing quickly.

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With the LiDAR focusing system, plus a mechanical focusing structure, many manual lenses can also apply to autofocus, which greatly expands the choice of lenses.

DJI Ronin 4D has three focus modes: single-point focusing, wide-area focusing and smart focusing, which can be switched in the menu. The principle of single-point focusing is the same as that of other commonly-used focusing mode. After testing, we have found that the changing of focus between objects is very fast and accurate.

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Wide-area focusing takes the center of the frame as a priority (in the yellow box) and the subject within the area can be focused well. We tested the focus mode with two people in the frame. We could see that the focus position was still prone to the center, and even if the person in front appeared in the yellow frame but yet reached the center, the focus would still be on the person behind.
This is because in wide-area autofocus mode, the system will focus on people first. So once there are people in the yellow frame, the system will also exclude interference from edge objects or people.

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The smart focusing mode is best for shooting people, as it will automatically recognize faces, bodies and autofocus on the recognized people in a fast and persistent way. Combined with a smart following function, it places the recognized person in the center of the frame, ensuring the composition of the frame while moving the camera quickly.

The focusing mode ensures that people are always in focus, and the smart following function ensures that people are always within the range of the frame. The combination of the two is ideal for shooting high-speed sports, street dance and people-tracking activities. And we will share with you the skateboarding and street dance shooting experience in the next article.

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The laser focusing system, although good, has some problems. Owing to its focusing principle, it will fail to focus on transparent objects or on other objects through the glass. For example, if we shoot a glass, it will not be able to focus on the glass, while switching to another non-transparent objects, it will be able to focus very well.
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4-Axis Stabilization
In addition to the consumer-targeted RS2 and RSC2, there is also the film-grade RSC2 included in Ronin series. The 3-axis gimbal design and manufacturing are undoubtedly trustworthy.

The gimbal principle and usage of DJI Ronin 4D follow those of DJI RS2/RSC2, so people who are familiar to this type of stabilizer can learn quickly.

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Most importantly, the newly-added Z-axis can minimize the vertical shaking which traditional stabilizers fail to decrease. In the process of walking, running and a wide range of movement, without the need for an exact pace, you can also decrease the vertical shaking and simulate slider or professional stabilizer, and get a fairly stable result.

Actual shooting scenes and results

Some people may ask whether the Z-axis can lift up and down. Actually, it hasn’t this kind of function as it is mainly designed to reduce the vertical shaking of the Z-axis. But it can compensate for the vertical shaking to ensure a persistent composition in a photographer handheld shooting with up and down movement.

Actual shooting scenes

Nowadays, a majority of crews need to be equipped with a camera operator and assistants. Sometimes it takes a long time to adjust the slide in order to achieve a slide effect which is time-consuming and labor-costing. Fortunately, DJI Ronin 4D may serve as a perfect solution.

In the process of car-following shooting, the shaking brought by uneven road and the moving car can be well eliminated, with the smart-following function, the shooting task can be completed easily.

Shooting samples

However, due to the working principle and high sensitivity of the bottom downward-looking sensor and ToF sensor, in the case of Z-axis Lock, once the vertical direction of the body changes, the Z-axis will suddenly move and the center of gravity of the body will change, so be careful to protect the safety of the body when holding.

Wireless Transmission

DJI Ronin 4D uses the brand-new DJI O3 Pro Video Transmission technology, which offers better shooting experience that is not included in the standard version.
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The transmitter of the system is installed in the middle of the body and the battery pendant, (the extend unit behind the body are modular, which can be stacked layer by layer), and four antennas are needed here.
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The receiver is a 7-inch wireless video transmission, which has a higher resolution of 1920 * 1200, 1500-nit high bright, up to 1080p/60fps. In short, it’s a wonderful experience! Through it, you can have a good experience of monitoring and playback.
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In addition, it can also be achieved through an external control handle to follow the focus, control the gimbal, start and stop the recording and adjust the camera parameters.
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With the technology, the staffs of focus following, camera directors and other staffs on the shooting site as well as the representatives of customers can improve work efficiency and monitoring experience.
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In addition, there is a version with SDI, time code interface and XLR audio interface.
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Integrated Design
The look of the DJI Ronin 4D is unprecedented, pioneering in separating the body from the sensor and lens mount, and designing a four-axis mechanical part in the middle to directly integrate recording with stabilization and motion.

Let's divide the camera into several parts and analyze them one by one.

001 Main Body
The main body, in a rectangular shape, has the overall size comprising the length, width and height of about 309 × 290 × 277mm (including the gimbal), or 235 × 115 × 160mm (excluding the gimbal). It’s excellent in workmanship as proven in delicate molded and CNC-processing parts, the uniform and smooth appearance of the paint layer.
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With the lens installed, its overall weight is about 5kg, well, not really a light type. While with the combination of DJI’s excellent ergonomic technology, the carrying handle and left and right handles to facilitate a comfortable operation, the body is not too big to operate when dual-handed.

On the left side (from top to bottom, left to right) are: a Power button (press 1 second to turn on, 3 seconds to turn off) (about 4-5 seconds of starting time), a Lock toggle (after locking other buttons and menu will not respond to avoid misuse), a REC recording key and an ON-OFF button of Z-axis.

The middle of the left side panel is about gimbal, including an OFF button (turning off the gimbal), a Lock button (three-axis fixed, not following.) and a Follow button (opening the following mode); and the opening of the following mode covers another three modes including PF pan following, PT pan and tilt following and FPV first person three axis following. As for the bottom two custom buttons, you can specify their functions in the menu, and by default, they are used to control the gimbal back to the center and the fourth axis.

On the right side is a focus dial and a Type-C port for computer activation of the device, firmware upgrades, connection to external storage and so on.
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At the bottom is where the disk is installed. We used the original DJI PROSSD 1TB to install, which slides into self-locking and connects using the Type-C port; the original PROSSD supports all recording specifications. In addition, it supports a CFexpress Type-B slot as well as USB3.1 Type-C port, but these two cannot meet the needs of the highest recording specifications.
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The right side of the body(from top to bottom) are the interface of the body monitor, 3.5mm microphone interface (with locking thread to prevent accidental disconnection), headphone monitor port and full-size HDMI interface, and the above interfaces are covered with plastic covers, with waterproof and dustproof function; the bottom is the DC-IN 12-30V power supply interface, DJI Ronin 4D can be used while charging.

Connecting the capture card through the HDMI interface, you can directly use the computer for live-streaming or recording. The HDMI cable can also be linked to other monitors, the ATOMOS Ninja V we use for recording, for example.
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The front side is a four-axis mechanical structure, we are not yet clear about its weather resistance, so it is best to adopt waterproof and dustproof measures. In addition, the bottom of the front side has two forward-looking binocular sensors.
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The bottom of the body has two downward-looking binocular sensors and two ToF range sensors, which can be used to detect changes in the vertical direction to abate vertical shaking. A base plate is attached to the bottom for Z-axis fixation and extension, with 1/4" and 3/8" size of screw holes in the center (the production version has two 3/8" size of screw holes in the bottom), and only one 3/8" size of screw hole in the bottom of the body itself. The bottom plate is hollowed out at the sensor, which does not disturb the sensor's work.
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The rear side of the body is used to install the battery snap-on plate. The DJI Ronin 4D uses the same TB50 battery as that of Ronin 2 and Inspire 2.
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This part can also be installed with other extend units, such as the wireless transmitter, which can be installed on the body to complete wireless monitoring and remote control to set the menu, follow the focus and other activities. (The O3 Pro wireless video transmission is not included in the standard version)
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002 Control Handle and Left/ Right Handles
The control handle is located on the top of the body and is removable. The grip is covered with hard rubber and the front end is slightly protruding, making it easy to use.
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The front of the handle has cold shoes on the left and right sides, which can be used to install external devices such as monitors and microphones; on the top is the tilt axis control lever and the M sport mode button, pressing the button to turn on the sports mode, and vice versa. The top and right side of the rear of the carrying handle have a 3/8 and 1/4 interface.
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The left/right handles are mounted with a slide-in double locking quick release structure, allowing for quick and safe mounting and removal, and can be adjusted to a mounting angle of approximately 120 degrees to accommodate a variety of high and low angle shooting positions. A press with your thumb on the inner dial can adjust the installation angle, which is labor-saving, efficient and science-based.
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Both sides of the handle have been ergonomically designed, which allows you to grip better. And there are also a lot of functional buttons fixed on both sides in order to complete many more quick operations while keeping a comfortable grip.

The top of the left handle is mainly the gimbal lever, which controls the pan and tilt rotation of the gimbal; one side of the lever is the lock toggle, the same as the lock toggle on the left side of the body; the bottom is the exposure assist tool and smart follow button. Long press is to turn on/off smart follow and short press is to select/unselect the tracking object.
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The left index finger controls the plate key, which plays different roles in different modes and long/short presses ways. The most commonly used is to double-click the gimbal back to the center, long press to turn on the gimbal-locking mode; in the inner side of the left handle, there is a M sports mode button, with your middle finger pressing continuously to turn on the sports mode in which the gimbal lifts with the accelerated speed and releasing to turn off.
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The dial on the top of the right handle can be used for focusing, aperture control and menu selection. The bottom from left to right are mode buttons (you can quickly select to adjust the aperture, EI and ND), peak assistance, recording key (red light on when recording).
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The right-hand index finger is responsible for the board button, which mainly controls the fourth axis. With a double click, you can turn on or off the fourth axis; the inside of the right-hand grip is the AF focus mode switch button, through short press to switch between auto/manual focus.
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003 Gimbal
The gimbal is symmetrical in shape, which makes leveling easier and also enables to improve the motor strength in the tilting direction to support lenses with changing center of gravity when focusing.
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Leveling is required before start-up and also after lens replacement. The leveling logic is similar to that of the Ronin S-series stabilizers, except that the cross-roller axis of this gimbal can be free from leveling, and all three axes are equipped with axis locks and leveling scales.
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The fourth axis, the Z axis, extends from the front of the body to the slanting bottom, using a carbon fiber arm to maintain the strength and reduce weight at the same time.
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The fourth axis is connected to the three-axis gimbal using a specific bayonet and is removable, and that is to say, there will be more possibility for DJI Ronin 4D.
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004 Camera mount
In the middle of the three-axis structure is the sensor and the camera mount. Ronin 4D is equipped with Zenmuse X9, DJI’s flagship full-frame camera and a 35mm full-frame CMOS sensor. The native mount is DX mount, and other mount components are supported for alternatives.
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It comes standard with DJI-produced DL mount kit, which supports three native DL mount full-frame lenses 24/35/50mm F2.8. In addition, it also supports replacement with DJI's official M-mount and third-party E-mount, with such a short flange distance lens mount assembly, then a large number of E-mount and M-mount lens can be applied.
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Except for the native DL mount lens, other lenses with autofocus need to be calibrated in-camera after installation to enable focus adjustment. After calibration, the relevant data can be stored in the camera, and the saved data can be called directly after replacing the lens, without a need to readjust each time. The lens without autofocus function need to calibrate after the installation of a follow focus, then the autofocus function can be achieved.
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The movement of the fourth axis has a certain weight limit of 2000g, and the weight of the three-axis gimbal already accounts for 1040g, so the weight of the lens must be lower than 960g, which puts requirements on the volume and weight of the lens, and further limits the choice of the lens. In addition to the original DL port lens, we also used E-mount components with Sigma 24mm F2 and 90mm F2.8 lenses, which features compact size and excellent image quality. As a result, they match well.
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005 LiDAR Range finder
DJI Ronin 4D adopts a LiDAR focusing system, and the LiDAR rangefinder installed at the center of the mount, directly above the lens position. It can focus and follow focusing in a fast and smart way.
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The native DL port lens communicates directly with the camera body through the bayonet electronic contact. The focus area can be adjusted directly without the need to install the follow focus gear and the focus calibration, which is a major advantage of the lens.

For non-native bayonet manual focus lenses, a mechanical follow focus device is required to complete the focus control. The data cable of the follow focuser is plugged into the gimbal axis arm on the side of the lens for data and command transmission. This function makes it possible for many manual focus lenses to autofocus.
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006 Highlight Monitor
DJI Ronin 4D is equipped with a 5.5-inch, 1000nit highlight monitor with 1920*1080 resolution and 60Hz refresh rate, which is installed with the left side of the top carry handle by default, but can be changed to the right side, and the menu of the monitor also supports mirror flip. Its built-in small gimbal can be flipped in omnidirectional angle, which gives you a better experience than other ordinary side flip screens.
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It is fine in image quality and supports full-screen touch. Controlling settings, focusing, playback and other adjustments can be completed by touching the screen. The monitor indeed brings convenient experience to users, and we will explain it in the next article when we analyze the function points of DJI Ronin 4D in detail.
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The monitor provides exposure tools such as waveform, false color and so on, and also has focus peak function. In addition, in terms of focusing, users can open the LiDAR focusing for manual focusing assistance.
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Manual focus with LiDAR focus oscilloscope on the monitor
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007 Battery
The DJI Ronin 4D uses the same TB50 battery as the Ronin 2 and Inspire 2. The battery clasp plate is well designed, inserting and removing the battery being very simple as the removing operation only requires pressing the release button on the left side.
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As with other DJI products, the battery comes with its own power indicator light to keep track of power information. A TB50 battery can last for about 1.5-2 hours, and the actual length of use varies depending on the gimbal and recording format and other smart function. Besides, it has higher charging efficiency, only 20 minutes or so to fill the battery.
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Some problems

During usage, we also found some problems with the DJI Ronin 4D.

First of all, good as the autofocus is, sometimes it is too sensitive to adjust more naturally. However, the AF autofocus will be better in the following firmware version, said DJI officers, so it’s solvable and expectable.

In the AF autofocus mode, the center position focus changes obviously.
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In terms of monitoring, the exposure waveform has two ranges to choose from (1/3 or 1/4), but even 1/4 accounts for a slightly larger area of the overall picture, which will block a lot of the screen and is not conducive to composition and monitoring; the indication of the focus peak is not intuitive, and it feels like all parts of the frame are focused on. Of course, we merely received a beta version and these issues will be solved consistently in the following production version, said DJI technicans.

The waveform area is too large to achieve a good composition (illustrated as 1/3)
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Focus peak is not intuitive (it feels like all the subjects in the picture are focused on)
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In addition, there is a trickier problem or maybe no problem at all. Due to the limited weight of the Z axis, the size and weight of the lens is restricted. It is not a problem to users who are not in needs of professional cine lenses, ultra-telephoto or ultra-wide angle lens. We have texted 24, 35 and 90mm lenses without any negative effects.

Moreover, the applied scenario of zoom lens is also very limited: one is related to the calibration, the other to the zoom center of gravity.

Overview

The DJI Ronin 4D is an unprecedented movie camera. We are delighted to witness such a unique and advanced product with a China-based brand emerging in the videomaking field. DJI does not compete with other brand with only body size and recording specifications, but put what users need into the primary consideration of its product design. For example, it originally combines recording and motion, and adopts a thoughtful design and practical performance.

A variety of technologies from different sources through developing and accumulating are finally concentrated on DJI Ronin 4D, for example, technologies including camera system, wireless transmission system, downward- and forward-looking sensor and battery from DJI drone, the laser focusing technology from Ronin stabilizer and so on, reflecting the strong influence of DJI ecology. Furthermore, the modular design empowers the camera to a wider range of application, and expectedly, there will be many useful accessories produced in future!
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It can be concluded that DJI Ronin 4D is a disruptive and landmark movie camera, evolving the core tool of shooting video from a single camcorder to a comprehensive system including "caputuring plus motion", and empowering users great autonomy in autofocus. It provides video creators with better creative tools and truly brings us more abundant and flexible ways to create.

With its cinematic image quality, 4-axis gimbal, advanced autofocus technology and wireless video transmission, the DJI Ronin 4D is perfect for small teams and individual creators.