The Ross London 17-inch (430mm) f/6.3 Teleros lens is a distinguished example of early 20th-century optical engineering. Known for its exceptional quality, precise craftsmanship, and versatility, this lens has earned its place in the annals of photographic history.
The Teleros is a telephoto lens made by Ross of London. It was introduced in 1922 and replaced the Telecentric. It was made until at least 1938. It was made in a wide range of focal lengths, from a 4-inch Leica-fitting lens to a 40-inch lens intended for 8½x6½ inch plate cameras. It was available as an f/5.5 with a magnification of two (i.e., the back-focus is one-half of the focal length) or an f/6.3 with a magnification of three.
In this article, we will explore the lens’s history, design, technical specifications, and legacy, offering a comprehensive overview of its significance and enduring appeal.
The Ross London 17 Inch F6.3 Teleros Lens: A Detailed Examination
Introduction
The Ross London 17 Inch f/6.3 Teleros lens is a distinguished example of early 20th-century optical engineering. Known for its exceptional quality, precise craftsmanship, and versatility, this lens has earned its place in the annals of photographic history. In this article, we will explore the history, design, technical specifications, and legacy of the Ross London 17 Inch f/6.3 Teleros lens, offering a comprehensive overview of its significance and enduring appeal.
History of Ross London
Origins and Early Developments
Ross London, founded in 1830 by Andrew Ross, was one of the foremost optical firms in Britain. The company gained a reputation for producing high-quality lenses and optical instruments, catering to the needs of both photographers and scientists. Ross’s commitment to innovation and excellence positioned the company as a leader in the field of optics throughout the 19th and early 20th centuries.
Development of the Teleros Lens
The Teleros series of lenses was introduced by Ross London in the early 20th century, during a time when the demand for high-performance telephoto lenses was increasing. These lenses were designed to provide photographers with the ability to capture distant subjects with clarity and detail, making them ideal for landscape, wildlife, and portrait photography. The 17 Inch f/6.3 Teleros lens, in particular, became one of the most popular models in the series, renowned for its optical precision and versatility.
Lens Design and Optical Characteristics
Optical Design
The Ross London 17 Inch f/6.3 Teleros lens is a telephoto lens, characterized by its long focal length and relatively compact design. The telephoto construction allows the lens to achieve a greater focal length than its physical length, making it easier to handle and use. The Teleros lens employs a multi-element design, carefully arranged to minimize optical aberrations and deliver sharp, high-contrast images.
Lens Elements and Groups
The Teleros lens typically features a configuration of four to six elements in multiple groups. This design helps to correct for various optical distortions, such as chromatic aberration, spherical aberration, and astigmatism. The precise arrangement of the lens elements ensures that the images produced are sharp and free from significant optical defects.
Aperture and Depth of Field
With a maximum aperture of f/6.3, the Ross London 17 Inch Teleros lens offers good control over depth of field. The relatively fast aperture allows photographers to achieve a shallow depth of field, which is particularly useful for isolating subjects from their backgrounds in portrait photography. Additionally, the lens performs well in lower light conditions, providing versatility in various shooting environments.
Technical Specifications
Build Quality and Materials
The Ross London 17 Inch f/6.3 Teleros lens is constructed from high-quality materials, ensuring durability and longevity. The lens barrel is typically made from brass or aluminum, with a finely machined focusing mechanism that allows for smooth and precise adjustments. The use of premium optical glass for the lens elements further enhances image quality and ensures consistent performance.
Coating and Treatment
Many Teleros lenses feature anti-reflective coatings on the lens elements, a relatively advanced feature for lenses of this era. These coatings reduce flare and ghosting, improving contrast and overall image quality. The anti-reflective treatment is particularly beneficial when shooting in challenging lighting conditions, such as direct sunlight or backlit scenes.
Mounts and Compatibility
The 17 Inch f/6.3 Teleros lens was produced with various mounts to accommodate different camera systems. Common mounts include the D-mount and C-mount, making the lens compatible with a range of large format and medium format cameras. This versatility made the Teleros lens a popular choice among professional photographers who required high-performance telephoto capabilities.
Applications and Usage
Landscape and Wildlife Photography
The Teleros lens’s long focal length and sharp optical performance make it ideal for landscape and wildlife photography. Photographers can clearly capture distant subjects, bringing far-off scenes and elusive wildlife into sharp focus. The ability to isolate subjects against a blurred background adds to the aesthetic appeal of the images produced.
It should strike you as odd that I am using the words “wildlife photography” and large format in the same sentence. This lens, in combination with my Graflex Series D 4×5 SLR camera, is my wild horse photography gear.
Portrait Photography
The Teleros lens is also well-suited for portrait photography, thanks to its ability to produce pleasing background blur (bokeh) and its fast aperture, which allows for shallow depth of field. Portrait photographers appreciate the lens’s ability to render subjects with sharp detail while creating a smooth, creamy background that enhances the subject’s prominence.
Scientific and Technical Applications
Beyond artistic photography, the Teleros lens has been used in various scientific and technical fields. Its precision and clarity make it suitable for tasks that require detailed observation and documentation, such as astronomical photography and technical imaging.
Legacy and Collectibility
Impact on Photography
The Ross London 17 Inch f/6.3 Teleros lens has had a significant impact on the field of photography, particularly in the realms of telephoto and long-distance imaging. Its exceptional optical performance and versatile applications have made it a valuable tool for photographers seeking to capture detailed and impactful images.
Collector’s Item
Today, the Teleros lens is highly sought after by collectors and photography enthusiasts. Its historical significance, combined with its superior build quality and optical performance, makes it a prized addition to any collection of vintage photographic equipment. Collectors value the Teleros lens not only for its technical capabilities but also for its role in the evolution of telephoto lens design.
Conclusion
The Ross London 17 Inch f/6.3 Teleros lens stands as a testament to the ingenuity and craftsmanship of early 20th-century optical engineering. Its long focal length, precise optical design, and versatile applications have made it a cherished tool among photographers and collectors alike. Whether you are exploring the rich history of photographic equipment or seeking to enhance your collection with a piece of optical excellence, the Teleros lens embodies the enduring legacy of Ross London lenses.
Additional Info
The Ross Teleros telephoto and Ross Telecentric telephoto lenses are both products of Ross Ltd., a British optical company known for manufacturing high-quality photographic lenses. When I was doing my research, I wanted to understand the differences between these lenses beside them sharing the same focal length.
Here’s a detailed comparison of the two lenses:
Ross Teleros Telephoto Lens
Production Period:
- The Ross Teleros lenses were produced primarily in the early to mid-20th century, roughly around the 1920s to 1950s.
Optical Design:
- The Teleros is a traditional telephoto lens, which means it uses a configuration that includes a positive front group and a negative rear group. This design shortens the physical length of the lens compared to its focal length.
- The Teleros lenses were typically designed for large format cameras and were known for their ability to provide a long focal length without the excessive bulk and weight of traditional long lenses.
- These lenses were appreciated for their relatively compact design and the ability to provide good image quality with decent contrast and resolution.
Ross Telecentric Telephoto Lens
Production Period:
- The Telecentric lenses came later than the Teleros, with most production occurring in the mid to late 20th century, likely around the 1950s to 1960s.
Optical Design:
- The Telecentric lens design is more complex and aims to keep the chief rays (rays passing through the center of the aperture) parallel to the optical axis. This design minimizes distortion and keeps the image scale constant regardless of the distance from the lens.
- In practical terms, telecentric lenses are used when consistent magnification and low distortion are crucial, such as in scientific and industrial photography.
- These lenses usually feature a more intricate arrangement of lens elements and groups to achieve the telecentricity. This often results in a larger and heavier lens compared to traditional telephoto lenses but with superior optical performance in specific applications.
Key Differences
Purpose and Application:
- Teleros: Primarily designed for general photography with an emphasis on reducing the size and weight of telephoto lenses for large format cameras.
- Telecentric: Designed for specialized applications where low distortion and consistent magnification are critical.
- Optical Design:
- Teleros: Uses a simpler telephoto design with a positive front group and a negative rear group.
- Telecentric: Employs a more complex optical system to maintain parallel chief rays, minimizing distortion and ensuring consistent image scale.
Size and Weight:
- Teleros: More compact and lighter compared to its focal length.
- Telecentric: Generally larger and heavier due to the more complex optical design.
- Image Quality:
- Teleros: Good overall image quality with decent contrast and resolution for its time.
- Telecentric: Superior performance in terms of distortion correction and consistent magnification, making it ideal for technical applications.
These differences reflect the evolution of lens design and the varying needs of photographers and industries over time.