Really Right Stuff LCF-103 for Sony 400mm f/2.8 FE GM and Sony 600mm f/4.0 FE GM

Really Right Stuff LCF-103, precise replacement foot for Sony super-telephoto lenses

If you’ve ever balanced your Sony 400 or 600 on a solid tripod head and thought “there’s still room for improvement in terms of stability,” then the Really Right Stuff LCF-103 is exactly where you can start. The LCF-103 is a precisely fitting replacement foot for the Sony super-telephoto lenses FE 400mm f/2.8 GM OSS and FE 600mm f/4.0 GM OSS and replaces the standard Sony foot with a significantly stiffer, lower, and more practical solution.

The LCF-103 was specifically developed for the following lenses: Sony 400mm f/2.8 GM OSS FE [SEL400F28GM] (2018), Sony 600mm f/4 GM OSS FE [SEL600F40GM] (2019), as well as the Sony 400mm f/2.8 GM OSS FE [SEL400F28GM]. Not a universal part, not a “sort of fits,” but a custom-tailored base for exactly these lenses, so you don’t have to deal with compromises in the field.

Made in the USA, solid construction from 6061-T6 aluminum

The LCF-103 is precision-milled in the USA from solid blocks of 6061-T6 aluminum. In professional photography and mechanical engineering, this material is something like the “gold standard” because it offers an excellent ratio of weight, stiffness, and durability. So you’re not getting a thin-walled casting, but a cleanly machined, torsion-resistant foot that won’t give way even with heavy setups including teleconverter, camera body, and gimbal head.

The surface is black anodized Type II, providing a robust, unobtrusive, and low-reflection finish. Especially for wildlife, sports, or reportage, it’s nice when nothing shines or attracts unnecessary attention. At only about 122 g, the foot remains pleasantly light, so your overall setup doesn’t become unnecessarily heavier.

Specifically designed for the following lenses, perfect fit instead of compromise

The LCF-103 is not a “sort of fitting” universal foot, but explicitly not universal. It is purpose-built for the Sony super-telephoto lenses that in professional everyday use often end up on monopods, gimbals, or heavy ball heads: Sony 400mm f/2.8 GM OSS FE [SEL400F28GM] and Sony 600mm f/4 GM OSS FE [SEL600F40GM]. Thanks to this specialization, the foot sits lower, brings the center of gravity closer to the tripod head’s axis of rotation, and thus provides smoother, more controlled panning behavior.

In practice, this means: less bouncing, less “nodding” when loosening the clamp, and significantly more pleasant handling when tracking fast subjects. Especially in sports or wildlife photography, when you follow a subject for minutes at a time, this improved balance makes a noticeable difference.

With QD strap socket, integrated secure carrying option

The LCF-103 features an integrated QD strap socket, more precisely a single QD-compatible strap anchor socket. This allows you to secure your Sony 400mm f/2.8 GM OSS FE or 600mm f/4 GM OSS FE directly at the foot with a suitable carrying strap, without additional adapters or rattling extra plates. This is particularly practical when you switch between tripod use and hand‑held shooting and still want to maintain a secure, defined carrying position.

To use this socket, you need a strap with suitable QD strap anchors. You can find more information here: QD strap anchors.

We would say: if you often carry your super-telephoto by the foot anyway, this integrated solution not only makes the setup safer, but also tidier, because you don’t have to attach additional eyelets or carabiners.

Arca-Style compatible, integrated dovetail for quick-release systems

The LCF-103 comes with a fully integrated Arca-Style compatible dovetail base. So you no longer need to mount an additional quick-release plate under the lens foot. This reduces the height, saves weight, and minimizes potential play or rattling points between the foot and the tripod head.

According to the manufacturer, the ARCA profile is compatible with a whole range of common 38 mm quick-release clamps and systems, including:

• Really Right Stuff lever clamps and Really Right Stuff screw clamps
• Wimberley clamps
• ProMediaGear clamps
• Jobu Design clamps
• Acratech lever clamps and Acratech screw clamps
• Kirk clamps
• FlexShooter screw cross clamp
• other Arca-Style compatible 38 mm quick-release clamps

So if your tripod head or gimbal is based on an ARCA system, you can clamp the LCF-103 directly. Additional notes on ARCA compatibility can be found here: Arca-Style compatible systems.

With QD strap socket and well thought-out mechanics, details that matter in everyday use

In addition to the QD strap socket, the LCF-103 offers several threaded holes on the underside to give you maximum flexibility for mounting. You’ll find:

• 1 x 3/8" UNC photo thread
• 2 x 1/4" UNC photo threads

This allows you, if necessary, to mount the foot directly on a tripod head without an ARCA clamp or to attach additional accessories. The combination of an integrated ARCA dovetail base and classic photo threads makes the LCF-103 a very versatile interface between lens and support system.

The dimensions are chosen with practical use in mind: approximately 14.6 cm in length, 3.8 cm in width, and 4.2 cm in height. This results in a comfortably grippable shape that can be held well even with gloves, without feeling unnecessarily bulky. A separate PMG strap socket is not present, which deliberately keeps the design clean and uncluttered.

Arca-Style compatible and safe, integrated safety stop screws

To prevent accidental slipping out of the quick-release clamp, the LCF-103 is equipped with 2 safety stop screws. These screws sit at the ends of the ARCA profile and engage in the corresponding recesses of many ARCA quick-release clamps. Even if the clamp is loosened too far, the foot will not simply slide forward or backward out of the clamp.

Especially with heavy telephoto lenses, this safety mechanism is more than just a “nice to have.” It protects your equipment from impact damage if, in the heat of the moment, the clamp is not fully closed or you are briefly inattentive while repositioning. We would almost say: this is one of those small details you don’t think about until it saves your day once.

Easy installation, from Sony foot to LCF-103 in just a few steps

Switching from the original Sony lens foot to the Really Right Stuff LCF-103 is intentionally straightforward and can be done with standard tools. You only need a 3 mm hex key and the four original screws from the Sony foot.

First, use the 3 mm hex key to loosen the four screws that hold the standard Sony foot to the lens and carefully remove the original foot. Then position the LCF-103 in the same place and fasten it to the lens again using these exact four original screws. No drilling, no modification, and no special tools are required—just careful work and a bit of attention when tightening the screws.

Once everything is correctly mounted, the LCF-103 sits free of play and stable on the lens and is immediately ready for use on Arca-Style compatible clamps, monopods, or gimbals.

Real-world benefits in the field: stability, balance, and handling

In real-world use, the LCF-103 primarily brings you three things: more stability, better balance, and more pleasant handling. Thanks to the lower profile and the integrated dovetail, the lens sits closer to the tripod head’s axis of rotation, which reduces vibrations and makes panning smoother. Especially at long focal lengths like 400mm f/2.8 or 600mm f/4, every small movement is immediately visible in the viewfinder; here the stiff, cleanly milled foot provides noticeable help.

The combination of ARCA-compatible base, QD strap socket, multiple photo threads, and safety stop screws ensures that you can flexibly adapt your setup without constantly having to mount new adapters or extra plates. Whether you’re sitting in a hide with a gimbal head, working on the sidelines of a sports field, or shooting from a car, the LCF-103 forms a robust, well thought-out interface between your Sony super-telephoto and the rest of your equipment.