不同焦距的监控镜头在聚焦调焦测试中，适用的测试距离会有所不同。

Different focal lengths of surveillance lenses have different applicable test distances in the focus test. 

The following are common focal lengths and recommended test distances for reference only:

镜头测试卡在不同焦距下的测试距离要求，仅供参考：

Test distance requirements for lens test cards at different focal lengths:

1.8mm - 2.8mm（广角镜头）：

推荐测试距离：1 - 3米

适用场景：较近的监控，覆盖宽阔的区域，如小房间、室内场所等。

1.8mm - 2.8mm (wide-angle lens):

Recommended test distance: 1 - 3 meters

Applicable scenarios: Close monitoring, covering wide areas, such as small rooms, indoor places, etc.

3.6mm - 4mm

推荐测试距离：3 - 5米

适用场景：中近距离的监控，适合走廊、房间、门口等。

3.6mm - 4mm

Recommended test distance: 3 - 5 meters

Applicable scenarios: Medium- and short-distance monitoring, suitable for corridors, rooms, doorways, etc.

6mm

推荐测试距离：5 - 8米

适用场景：中等距离，适合监控停车场、较大的室内场所等。

6mm

Recommended test distance: 5 - 8 meters

Applicable scenarios: Medium distance, suitable for monitoring parking lots, larger indoor places, etc.

8mm - 12mm

推荐测试距离：10 - 15米

适用场景：较远距离监控，如商店的长通道、露天广场等。

8mm - 12mm

Recommended test distance: 10 - 15 meters

Applicable scenarios: Long-distance monitoring, such as long aisles in stores, open-air squares, etc.

16mm - 25mm

推荐测试距离：15 - 30米

适用场景：远距离监控，如大门入口、车道或边界等。

16mm - 25mm 

Recommended test distance: 15 - 30 meters

Applicable scenarios: Long-distance monitoring, such as gate entrances, driveways or boundaries, etc.

不同的焦距对视角和覆盖区域有直接影响，在实际测试时，适当调整距离和镜头角度以获得最佳的监控效果。

Different focal lengths have a direct impact on the viewing angle and coverage area. During actual testing, appropriately adjust the distance and lens angle to obtain the best monitoring effect.

‌测试方法‌：

‌Test method:

‌放置测试卡‌：将测试卡放置在45°角的平整斜面上，确保测试卡稳定不动。

‌Place the test card: Place the test card on a flat inclined plane at a 45° angle to ensure that the test card is stable and motionless.

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