In fields such as security monitoring, in-vehicle imaging, and intelligent transportation that have extremely high requirements for low-light imaging and dynamic capture, Sony's Starvis™ series of image sensors have become industry benchmarks with their outstanding performance. Among them, the IMX678 and IMX585, two 4K sensors belonging to the Starvis2 technology camp, are often used in high-end imaging equipment, but there are clear distinctions between them in optical design, performance focus, and application adaptability. Many users are easily confused by their "same series + same resolution", but in fact, their differences are the key to accurately matching the needs of different scenarios. From a popular science perspective, this article will detailedly analyze the core differences between the two sensors and provide clear selection suggestions.
I. Common Foundation: Core Capabilities Endowed by Starvis2 Technology
Both the IMX678 and IMX585 are equipped with Sony's proprietary Starvis2 back-illuminated pixel technology. This technical architecture has laid a common high-performance foundation for the two-ultra-high sensitivity, excellent near-infrared imaging capabilities, and artifact-free HDR performance. As sensors for professional imaging fields, their core imaging specifications are highly consistent: both are 4K resolution (recommended recording pixels 3840×2160, effective pixels about 8.3 million), support 10-bit/12-bit RAW format output, are equipped with CSI-2 serial data interfaces (supporting multi-channel configurations such as 2/4/8 lanes), and can realize functions such as horizontal/vertical 2×2 pixel binning and window cropping, adapting to the needs of different imaging specifications.
In terms of core technical characteristics, both support the Clear HDR function. By simultaneously capturing low-gain (adapting to bright areas) and high-gain (adapting to dark areas) images and synthesizing them, it solves the artifact problem when traditional multi-frame HDR captures high-speed moving objects, which is particularly suitable for clear capture of fast-moving targets in scenarios such as traffic monitoring and dashcams. At the same time, relying on the special pixel structure of Starvis2 (convex-concave incident surface design), both have excellent near-infrared light absorption rate, which can achieve high-quality imaging in night infrared supplementary lighting scenarios and reduce the energy consumption and heat generation of supplementary lighting equipment. In addition, both adopt a three-way power supply scheme of analog 3.3V, digital 1.1V, and interface 1.8V, balancing low power consumption and stable performance.
II. Key Differences: Precise Division of Labor from Optical Design to Performance Focus
Although the core technologies are homologous, the design positions of the IMX678 and IMX585 are significantly different. The core differences focus on three major dimensions: optical format and pixel size, frame rate performance, and packaging form. These differences directly determine the boundary of their application scenarios.
1. Core Difference: Optical Format and Pixel Size, Decisive Factors for Low-Light Performance
Optical format (sensor size) and pixel size are core indicators affecting the low-light imaging capability of image sensors-the larger the sensor size and the larger the single pixel area, the more light received per unit time, and the better the signal-to-noise ratio (image quality purity) and imaging brightness in low-light environments. This is the core distinguishing point between the two sensors:
The IMX585 adopts a large 1/1.2-inch optical format with a diagonal length of 12.84 mm and a single pixel size of 2.9μm×2.9μm. The larger pixel area endows it with extremely strong light capture capability in low-light environments. Combined with Starvis2 technology, it can suppress noise and clearly restore object details even in extreme low-light scenarios such as dark alleys without street lights. At the same time, its near-infrared sensitivity is outstanding-the sensitivity at 850nm wavelength is about 1.7 times higher than that of the previous generation product, which can greatly reduce the demand for supplementary lighting equipment during night infrared monitoring.
The IMX678 adopts a 1/1.8-inch optical format with a diagonal of only 8.86 mm and a pixel size of approximately 1.45μm×1.45μm (calculated based on optical format and resolution). Compared with the IMX585, its sensor size and pixel area are significantly reduced, and its light capture capability in low-light environments is slightly weaker. However, the smaller optical format enables it to adapt to more compact lens modules, providing possibilities for the miniaturized design of terminal equipment.
2. Detailed Difference: Frame Rate Performance and Dynamic Capture Adaptability
In terms of frame rate performance, the two sensors have been fine-tuned for different dynamic capture needs. In the full-pixel (3840×2160) scanning mode, the maximum frame rate of both is the same at 60 frames per second (fps) when outputting 12-bit, which can meet the needs of conventional 4K video recording; but there is a difference when outputting 10-bit: the maximum frame rate of the IMX585 can reach 90 fps, while that of the IMX678 is 72 fps. A higher frame rate means that the IMX585 can more accurately capture the continuous movements of fast-moving objects (such as high-speed vehicles and running pedestrians), reduce motion blur, and is more suitable for scenarios with extremely high requirements for dynamic capture accuracy, such as traffic monitoring and high-speed event capture.
3. Integration Difference: Packaging Form and Terminal Adaptability
The packaging form directly affects the installation space of the sensor and the difficulty of integrating terminal equipment. The IMX585 adopts a ceramic LGA package with a size of 20.0mm×16.8mm. Although the package volume is large, it has stronger stability, which can meet the long-term stable operation needs of fixed equipment such as security cameras. In addition, the ceramic material has better heat dissipation performance, making it suitable for all-weather outdoor working environments.
The packaging information of the IMX678 is not clearly marked, but combined with its 1/1.8-inch small optical format and application positioning in small equipment such as in-vehicle and mobile phones, it can be inferred that it adopts a more compact packaging design (most likely Chip Scale Package, CSP). The smaller package volume enables it to be easily integrated into space-sensitive equipment such as dashcams, small in-vehicle cameras, and mobile phone secondary cameras, adapting to the lightweight and miniaturized trend of terminal products.
III. Selection Suggestions: Matching Core Advantages According to Scenario Needs
The two sensors are not in a "high-low configuration" relationship, but a precise division of labor targeting two major demand directions: "low-light performance priority" and "miniaturization priority". The core logic of selection is: first clarify the core demands of the application scenario-whether to focus on imaging quality in extreme environments or on the miniaturized integration of equipment, and then comprehensively judge in combination with dynamic capture needs and installation environment.
1. Scenarios Where IMX585 is Preferred
- Outdoor security monitoring: Especially in night scenarios without supplementary lighting or with weak supplementary lighting (such as suburban roads and remote factories), the large pixel size and high near-infrared sensitivity of the IMX585 can ensure clear imaging. The single-exposure dynamic range of 88dB (up to 106dB in multi-exposure mode) can cope with complex scenarios with backlight and strong light-dark contrast;
- High-speed traffic monitoring: When it is necessary to capture details such as license plates and vehicle conditions of high-speed vehicles, the high frame rate of 90 fps of the IMX585 can reduce motion blur and improve AI recognition accuracy;
- Fixed-installed professional imaging equipment: Such as industrial monitoring cameras and large security dome cameras, the high stability and heat dissipation of their ceramic LGA packages are suitable for long-term all-weather operation, and there is no need to consider miniaturization needs.
2. Scenarios Where IMX678 is Preferred
- Miniaturized in-vehicle equipment: Such as dashcams and in-vehicle surround-view cameras, the small optical format and compact packaging of the IMX678 can adapt to the limited installation space in the car. At the same time, the 4K resolution and Clear HDR function can meet the imaging needs of scenarios such as backlight (tunnel exits) and night driving;
- Portable smart devices: Such as small UAV aerial cameras and handheld professional recorders, which are sensitive to equipment volume and weight. The miniaturized design of the IMX678 can reduce the equipment burden, and the frame rate of 72 fps can meet the capture of conventional dynamic scenarios;
- Indoor medium and low-light monitoring: Such as indoor scenarios with basic lighting such as shopping malls and office buildings, which do not require extreme low-light performance. The imaging quality of the IMX678 is sufficient to meet the needs, and its miniaturization advantage can reduce the design difficulty of the camera module.
IV. Summary
As 4K sensors of the Starvis2 series, Sony's IMX678 and IMX585 share the core technical architecture and basic imaging capabilities, but through the differentiated design of key parameters such as optical format and pixel size, they form a clear division of application: the IMX585 takes "large size + high frame rate" as its core advantages, focusing on professional imaging in outdoor extreme environments and high-speed dynamic scenarios; the IMX678 takes "miniaturization" as its core selling point, adapting to space-sensitive in-vehicle and portable equipment. In actual selection, you only need to grasp the two core demands of "low-light performance priority" and "equipment volume limit" to quickly match the appropriate sensor and maximize the imaging advantages of Starvis2 technology.
