FIXME **This page is not fully translated, yet. Please help completing the translation.**\\ 
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====Exposure Time====
**1. What is Exposure Time?**\\
In layman's terms, exposure time is the time interval from pressing the shutter button to releasing it, measured in seconds. From a professional perspective, exposure time mainly refers to the photosensitive duration of the sensor. The longer the exposure time, the brighter the image, which is suitable for low-light conditions. Conversely, the shorter the exposure time, the darker the image, which is suitable for well-lit conditions. There is no absolute good or bad for exposure time; it depends entirely on the specific requirements. For example, if you are capturing star trails, a very long exposure time is needed (possibly up to several hours), as shown in Figure 1. Since stars are only visible at night when light is poor, the exposure time must be extended for night scenes. However, if you are capturing a clear image of a speeding car, only a very short exposure time is required (usually a few thousandths of a second), as shown in Figure 2. This is because a faster shutter speed can freeze moving objects, resulting in a sharp image.
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^                                      Figure 1                                             ^  
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^                                      Figure 2                                              ^
**2. How to Test Exposure Time?**\\

**2.1 Test Equipment:**\\
**Image capture card, camera module, fill light (LS-CCXL-2S06-IR), Timer (time tester), gray card, image capture software, etc.**\\
Among these, the Timer is used for testing camera frame rate timing, exposure time, and flicker. The Timer is a device featuring a 10x10 LED matrix on its panel. During the subsequent image capture process, it needs to be photographed, as shown in Figure 1.

|{{ http://ydadmin.rdbuy.com.cn/ueditor/php/upload/image/20230815/1692061383146737.png }}|
^      Figure 1  [[https://www.yanding.com/product/detail?id=1551|IS-Timer101 Time Tester]]   ^

The **image capture card** is a device capable of capturing images, as shown in Figure 2. Its hardware consists of a circuit box, power adapter, USB 3.0 cable, and coaxial cable, as shown in Figure 3. During shooting, it needs to be connected to the camera module, and then the image capture software is used to activate the module and acquire real-time images to capture the desired scene.

|{{ yanding:屏幕截图_2025-07-24_142656.png?direct&400 |}}|
^      Figure 2  [[https://rdbuy.com/product/productdetail?model_id=10260|Image Capture Card]]   ^

|{{ http://ydadmin.rdbuy.com.cn/ueditor/php/upload/image/20230802/1690952754783964.png }}|
^      Figure 3  [[https://rdbuy.com/product/productdetail?model_id=10260|Hardware Composition of Image Capture Card]]   ^
The **LS-CCXL-2S06-IR vertical multi-color temperature fill light source** is a lighting device equipped with color temperature and brightness control panels. It allows you to set the required color temperature and brightness according to your needs, as shown in Figure 4.
|{{ http://ydadmin.rdbuy.com.cn/images/product/e45576951feea2ca81a4bc985b66aac2.png?direct&500 }}|
^     Figure 4  [[https://rdbuy.com/product/productdetail?model_id=1204|LS-CCXL-2S06-IR]]   ^

**2.2 Test Procedure:**\\
**1. Environment Setup**\\
Set up the environment and switch the Timer to exposure time mode. At this point, the LEDs on the Timer will be flashing in a cycle. Adjust the unit time to find the appropriate unit time for the current module (here we use milliseconds as an example; generally, the unit time is 1 millisecond).\\
**2. Capture Process**\\
Adjust the brightness of the fill light to the level corresponding to the required illuminance. Use the image capture card and image capture software to activate the module, save 10 images in BMP format (as shown in Figure 5), and record the unit time displayed on the Timer.\\
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^      Figure 5    ^

**3. Calculation of Exposure Time**\\
The exposure time of the module can be calculated by counting the number of lit LEDs in the image and multiplying it by the previously recorded unit time. That is, the number of lit LEDs multiplied by the corresponding unit time yields the exposure time of the module.\\
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**See More**\\
[[:camera测试用例]]、[[:测试用例]]、[[:riqa简介]]