Sigma TC-1401 1mm

The Sigma TC-1401 adds 40% more reach to compatible Sigma Global Vision lenses for $328 USD. Autofocus works up to f/8 and the build is weather sealed, but optical quality ranks at just the 33rd percentile. It's a niche tool that makes sense only if you already own the right Sigma glass.

The TC-1401 uses SLD glass elements to keep aberration correction in check, and in practice that means you're not sacrificing much sharpness for the extra reach. The aperture ranking sits at the 70th percentile, which is solid for a teleconverter. You lose one stop of light with the 1.4x magnification, so an f/4 lens becomes f/5.6, and an f/5.6 lens becomes f/8. The fact that autofocus still works up to f/8 on compatible bodies is a big deal, especially for wildlife and sports shooters who need that extra focal length without giving up AF.

The optical ranking is mediocre at the 33rd percentile, which is worth being honest about. Teleconverters always introduce some compromise, and this one isn't going to turn a budget zoom into a prime. But the bokeh ranking is above average at the 69th percentile, so background rendering stays pleasant when you're shooting portraits or isolating subjects. The stabilization ranking is underwhelming at the 34th percentile, but that's expected since the converter itself has no stabilization. It relies entirely on the lens it's attached to.

Stacked against the competition, the TC-1401 is a weird entry. The Tamron Di III 18-300mm f/3.5-6.3 is an all-in-one superzoom that covers everything from wide to telephoto without needing a converter at all. The Sony E 18-135mm f/3.5-5.6 OSS offers built-in stabilization and a much more versatile focal range. The Meike MIX Series 85mm F1.4 II is a portrait specialist with a much faster aperture. What the Sigma does that none of those can is extend the reach of a lens you already own. It's not competing on versatility or optical quality, it's competing on a very specific use case: getting more millimeters out of a Sigma telephoto without buying a new lens.

At $328 USD from a single US listing, the TC-1401 is priced like a mid-range prime lens, which feels steep until you remember what it does. It effectively turns one lens into two, adding 40% more reach to any compatible Sigma telephoto. If you already own a Sigma 150-600mm or similar, this is a lot cheaper than buying a second super-telephoto. But if you don't own a compatible lens yet, the converter is a paperweight. The value proposition hinges entirely on your current kit, and for the right shooter, $328 is a bargain compared to the cost of a longer lens.

The Sigma TC-1401 is a 1.4x teleconverter built for Canon EF mount, and it's a niche tool that does one job well if you own the right lenses. It's designed exclusively for certain Sigma Global Vision lenses, so compatibility is the first thing to check before you even think about buying one. The build is dust and splash-proof, which is a nice touch for a piece of glass that lives between your camera and a big telephoto. Our database puts its social proof at a strong level, with a 4.3 out of 5 rating across 311 reviews, so owners generally seem happy with what they're getting.

But this isn't a lens, and scoring it like one gets weird. Its best use case score is portrait at 56.7 out of 100, which tells you more about the lenses it pairs with than the converter itself. Macro is the weakest area at 23.4, and that makes sense, a teleconverter doesn't help you focus closer. The aperture ranking is above average, which is good news since a 1.4x converter costs you a stop of light. You'll still be able to autofocus up to f/8 with compatible cameras, and that's the real selling point here.

If you don't already own a compatible Sigma Global Vision lens, this converter is useless to you. The versatility ranking is mediocre at the 33rd percentile, and the macro score of 23.4 out of 100 means it's not helping with close-up work. Shooters who need stabilization should also look elsewhere, since the TC-1401 has none and relies entirely on the lens. And if you're picky about sharpness, the 33rd percentile optical ranking will probably bother you. This is a tool for reach, not for image quality purists.

The TC-1401 is a smart buy if you own compatible Sigma Global Vision glass and need more reach without hauling around a second massive lens. The autofocus support up to f/8 and the weather sealing make it a practical tool for wildlife and sports shooters. But the optical compromise is real, and the 33rd percentile optical ranking means you'll notice some softness if you pixel-peep. For $328, it's a calculated trade-off. If you're already deep in the Sigma ecosystem, this is a solid addition. If you're not, skip it and buy a lens that actually fits your camera.