Key Takeaways:
- An Ultra Wide Angle lens, with field views up to 160°, is crucial for capturing expansive scenes and intricate details.
- Their complex design includes negative front groups and positive back groups for deflection and correction.
- Aspherical lenses improve image quality and compactness, while digital correction addresses distortions.
- Wide-angle lenses are essential in photography, security surveillance, automotive systems, and aerial imaging.
Wide Angle Lens Overview
A wide-angle lens, with its short focal length and broad viewing angle, captures expansive scenes, making it ideal for landscapes, buildings, and large outdoor vistas. It emphasizes the foreground while encompassing a wide background, creating unique visual effects. In addition, widely used in photography, wide-angle lenses are also prevalent in security surveillance, automotive systems, and aerial photography, enhancing real-time coverage, safety, and convenience.
Key specifications include
- Field of View: Ranges from 80° to 120° for wide-angle lenses, over 120° for super-wide, and near or above 180° for fisheye lenses.
- Focal Length: Less than 38mm in traditional photography, and typically under 10mm in security applications.
- Wavelength: Covers visible wavelengths, with short-wave infrared for poor lighting conditions and night imaging.
- Chief Ray Angle: The alignment with the detector’s angle is crucial to maintain image quality and illumination.
- Distortion: Wide-angle lenses exhibit “Pincushion” distortion, often corrected digitally, enabling the broad application of ultra-wide and fisheye lenses.
Design of Ultra Wide Angle Lens
EFFL | 2.5mm |
F number | 3 |
Wavelength | visible light |
Image height | 7.2mm |
Vertical FOV | 120° |
Diagonal FOV | 160° |
F-theta distortion | <5% |
This lens is designed to have a field of view of 160°, which is an ultra-wide-angle lens. Moreover, wide-angle lenses are usually composed of a negative front group and a positive back group of lenses, with the structure being relatively complex. In order to achieve their purpose, wide-angle lenses need at least one or several negative lenses as the front group to achieve the deflection of light in the field of view. Additionally, in general, the complexity of the front group is determined by the size of the field of view of the lens. The diaphragm is usually placed in the middle of the rear group. In most cases, double-bonded lenses for chromatic aberration correction are set in the latter group.
MTF&Spot
In order to prevent the occurrence of purple edges during imaging, the lens coverage band is 435nm-656nm. Considering the tolerance of component processing and assembly, the MTF can reach >15%@250lp/mm, which can meet the sensor use of 2um pixels.
The object image relation is image height=f ‘θ, and the F-theta distortion is less than 5%.
A total of 10 pieces of glass are used in the design, including 8 pieces of spherical lens and 2 pieces of aspherical lens. The lens image quality is good. The use of aspherical surfaces can improve the image quality, simplify the structure, and help to compress the overall size. The overall size of this lens is small, with a length of 28mm, which is conducive to integration in actual use.
Versatility of Ultra Wide Angle Lenses
In conclusion, wide-angle lenses, with their short focal lengths and expansive fields of view, are indispensable tools in both traditional and modern imaging applications. They excel in capturing wide landscapes, intricate architectural details, and large vistas, making them essential for photographers. Furthermore, beyond photography, their utility extends to security surveillance, automotive systems, and aerial photography, where they enhance coverage, safety, and convenience. Moreover, the sophisticated design of wide-angle lenses, incorporating multiple glass elements and aspherical surfaces, ensures high image quality and compact form factors. The integration of advanced features like short-wave infrared compatibility and digital distortion correction further broadens their applicability. As demonstrated, by lenses with up to 160° field of view and meticulous design considerations to optimize image quality and minimize distortions, wide-angle lenses continue to evolve, meeting the diverse needs of various imaging disciplines.
At Avantier we can produce custom wide angle lenses in many configurations, including wide angle low distortion lenses with built-in correction. Contact us today to set up your initial consultation or to discuss your next project.
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