Comment sélectionner la meilleure résolution de objectif pour la taille des pixels de votre caméra
Lors de la sélection d'une objectif pour votre caméra industrielle, il est important de considérer que la résolution de la objectif correspond à la taille des pixels de votre caméra industrielle. Le objectif de lentille est mesuré en paires de lignes par mm (lp/mm). Cela garantit la performance optimale de votre caméra industrielle. Cet article explique le principe de la résolution de la objectif en paires de lignes par mm (lp/mm) et comment calculer la compatibilité avec votre caméra industrielle.
Table of contents
Lens Resolution and Pixel Size: Key Factors in Digital Imaging
Both lens resolution in line pairs per millimeter (lp/mm) and camera pixel size play significant roles in digital imaging. The lens resolution, measured in line pairs per millimeter (lp/mm), helps gauge the spatial resolution of a camera or lens system. Pixel size, on the other hand, refers to the physical size of a single pixel on the camera’s image sensor.
What is Lens Resolution?
Lens resolution is defined by the number of black-and-white line pairs that can be distinguished per millimeter of image space. A higher line pair count (lp/mm) corresponds to greater spatial
resolution, enabling the camera or lens system to capture finer details in an image.
For example, a lens with a resolution of 100 lp/mm can resolve up to 100 pairs of black and white lines per millimeter. This allows the industrial camera to detect objects as close as 10 microns apart. Please note, the actual physical performance may vary, and the stated values are theoretical.
What is Pixel Size?
Pixel size refers to the physical dimensions of an individual pixel on an industrial camera’s image sensor, typically measured in micrometers (μm). The overall resolution of the camera is determined by the total number of pixels.
For instance, the MER2-160-227U3M camera has a resolution of 1.6 MP (1440x1080), consisting of 1,555,200 pixels. Smaller pixel sizes generally require lenses with a higher lp/mm to achieve optimal resolution.
Relationship Between Lens Resolution and Pixel Size
The formula for calculating the relationship between lens resolution and pixel size is as follows:
- ξ = (1lp / (2*s)) * (1000µm / 1mm)
Where s is the physical pixel size.
For example, a 9MP camera (ME2P-900-43U3M) with a pixel size of 2.5 microns would require a lens with a spatial resolution of 200 lp/mm.
Lens Resolution (lp/mm) Overview
To determine the appropriate lens resolution (lp/mm) for your camera's pixel size, refer to the lens table. Fill out the form to gain access to our Download Page, where you can find a comprehensive list of lenses in our portfolio along with their corresponding lens resolutions.
Lens Resolution: Center vs. Edge Performance
The table above illustrates the variation in lens resolution, measured in line pairs per millimeter (lp/mm), between the center and edges of the lens. This difference directly affects the image captured by your industrial camera, with the center of the image typically appearing sharper than the corners. When selecting a lens for your camera, the lp/mm value at the center is generally used for calculations, as it more accurately represents the overall resolution.
Recommendations for Matching a Lens with an Industrial Camera
Use the lens table as a guide to match the lens resolution (lp/mm) with your industrial camera’s pixel size. In certain cases, a lens with a slightly lower lp/mm than what is typically required may still be suitable for your camera sensor:
- If you are working with a limited budget and cannot afford a higher resolution (more lp/mm) lens.
- When you require a highly light sensitive lens with an f/1.8 aperture or lower, which may not be available in a higher resolution lens.
- While a lens with lower resolution may result in a slightly less sharp image, this may still be acceptable depending on the specific demands of your application.
