Tripod thread and lens thread

The world of thread standards is a fascinating balance between standardization and specialization. In most applications, it's convenient to work with the same standards repeatedly, allowing your equipment to serve multiple projects. On the other end of the spectrum are the specialists. Thread standards designed for a very specific use-case and found only in that context.

In this blog post, we dive deep into one such highly specialized area: special threads in photography. Professional SLR cameras utilize unique thread types in two significant places. Can you guess where? We're talking about the tripod thread and the lens thread. Although, in the realm of lenses, a newer solution has been gaining traction for years. But, let's start at the beginning.

A Small Screw with a Big Responsibility: The Tripod Thread

Let's start with a thread that can be easily overlooked due to its positioning - the tripod thread, located at the base of the camera body. Its role is paramount, as this tiny thread must provide secure support when using a tripod during photography.

Secure in Every Situation

A tripod thread has a tough job. If you've ever held a DSLR camera, you're aware of their potential weight. Especially when paired with a large lens, the device can be quite heavy to handle freely. Tripods are used when the camera needs to remain particularly still, e.g., during long exposure shots. The weight rests on a small, inconspicuous screw connection. This thread must be resilient, especially as the center of gravity shifts forward with larger lenses. In fact, very large lenses have their own tripod thread for additional stability.

Professionals Craft Their Tripod Threads

While amateurs might take the tripod thread for granted, professionals place significant emphasis on this component for a couple of reasons. Firstly, a professional setup, including a lens, can easily reach a price range of several thousand euros. Naturally, photographers want assurance that the tripod thread is reliable and won't allow their equipment to fall. Additionally, for long exposure shots, even the slightest movement can ruin a shot. The camera's mirror can cause vibrations when it flips up, which is why a stable tripod thread connection is crucial. As a result, many photographers don't rely solely on the manufacturer-installed components and prefer to craft their tripod threads.

DIN 4503 or UNC Thread?

Tripod threads have their own standard, DIN 4503 (Camera and Accessory Tripod Connections). However, their dimensions are so similar to the UNC thread that the two can almost be considered interchangeable.

Two tripod threads are prevalent in photography:

• 1/4" - 20 UNC (small photography thread)
• 3/8" - 16 UNC (large photography thread)

The smaller tripod thread is primarily used in rangefinder cameras, Single Lens Reflex (SLR) cameras, medium format cameras, flash rails, quick-release plates, and tripod heads. In contrast, the larger tripod thread is used in most medium format and nearly all large format cameras, as well as most connections between tripods and tripod heads.

The Lens Thread: A Specialist with History

Cameras with interchangeable lenses, like SLRs, need a mechanism to secure the lens to the camera body. This connection must be stable, as dropping or misaligning the lens can cause significant damage. Moreover, this interchange should be quick and simple, making it practical for everyday use.

M39, M40, and M42 Lens Threads

Historically, lenses were always attached to the camera body using a screw thread. The M39 lens thread, often known as the Leica thread, is particularly famous. Nowadays, conventional lens threads like M39, M40, and M42 are less common outside the realm of analog photography. For most purposes, lens threads have been replaced by bajonet connectors, which are known for their ease of use, allowing photographers to change lenses quickly with a single hand motion.

C-Mount Thread for Camera Lenses

Though traditional lens threads have largely given way to bajonet connectors, there are areas where screw connections remain preferred. The C-Mount is a standardized lens thread introduced in the 1920s for film technology, and it's still widespread today. The lens thread has an external diameter of 1 inch with a pitch of 1/32 inch. The flange focal distance is 17.526 mm.

Derived from the C-Mount lens thread is the CS-Mount with a flange focal distance of 12.526 mm.

S-Mount Thread for Mini Lenses

Another common thread is the S-Mount, used for mini or board lenses, ideal for space-saving applications.

Filter Threads for Professional Gear

Then, there are the filter threads. Filters are thin glass or plastic plates placed in front of the lens to achieve specific effects, analogous to Instagram filters but in a physical form. Filter threads are quite short, requiring only 1.5 to 2 turns for attachment. Filters should be easily interchangeable and are, by nature, lightweight.

Whether you're a professional photographer wanting a secure connection between your camera and tripod, or a hobbyist interested in vintage film equipment, the first question often is where to find the necessary tools. In the online store of BAER, the tap manufacturer, you'll find threading tools for rare and unique thread standards. Whether it's special threads in photography like tripod or lens threads, BAER has the appropriate screw taps and thread cutting dies for you. Explore our offerings!