Pick the best lens to optimize image quality for your megapixel camera.
With analog and VGA-quality systems, most lenses off the distributor’s shelf would usually provide acceptable image quality, because the resolution of the camera was not high enough to require a higher quality lens. But as the resolution and pixel density increase, use of a substandard lens introduces issues such as aliasing and other issues related to the modular transfer function in megapixel cameras.
There are no standards for specifying “megapixel”, meaning “megapixel” quality lenses from two manufacturers can have vastly different specifications for line pairs per millimeter (lp/mm). While these settings provide some measure to compare two lenses, they are often not disclosed in the manufacturer's specifications. Physical pixel size can also vary for different imagers, meaning a lens rated with a high lp/mm for a 1/2” imager may perform differently on a 1/3” imager.
This can make it difficult to find the right lens for your camera.
Lens A vs. Lens B: quality and image clarity can vary greatly with lenses of equal specifications:
You can find the right lens on the ArecontVision product page for your camera. Arecont Vision offers three lens lines that represent different quality and pricing: LENS, MPL, UHD.
- LENS lenses are a low-cost option and good for 1.3 and 2MP cameras. Depending on the application this line could meet the needs of a 3MP or 1080p camera.
- MPL lenses are cost-competitive and higher quality than the LENS line. MPL lenses support 1.3, 2, 1080p and 3MP cameras, and also act as a mid-range 5MP lens.
- UltraHD or UHD lenses are the flagship line specifically for the 10MP resolution. For critical 5MP applications, this line is recommended.
ArecontVision lens models and applications
When looking at lenses, you should pay attention to the angle of view, the focal point or focal length of the lens, and the depth of field
The angle of view determines the width and height of the image captured by the lens. This is often referred to as the field of view or FOV. The angle of view on a given lens is directly related to:
- Focal length: The distance between the focus point and the camera sensor, specified in millimeters (e.g. 10mm).
- The size of the sensor that the lens is rated for (e.g. 1/3”, 1/2”, 2/3”)
- The size of the sensor that is actually used.
|Angle of view and focal length examples|
In the camera, the image sensor is placed at the focal point of the lens. Some lenses have fixed focal points; others are vari-focal lenses — lenses that can be adjusted through a range of focal points, called a focal length. Vari-focal lenses are usually specified using the lowest and highest focal lengths they support, e.g. 8-16mm. The higher the focal length in millimeters, the tighter the angle of view; the smaller the focal length (8mm) in millimeters the wider the angle of view.
The depth of field refers to how well objects in the foreground and background are focused at the same time. The depth of field is affected by the F-stop and the focal length. The F-stop, or aperture, is the measurement of the light gathering ability of the lens. The larger the F-stop, the greater the depth of field. The F-stop or aperture is controlled by the lens iris. You can open or close the iris to allow more or less light in, depending on your application and light level.
Use the settings above to determine the right lens for your application; you can find lenses on your ArecontVision camera's product page.