Sigma Sigma 1.4X TELE CONVERTER TC-1401 Fo Review

The Sigma TC-1401 teleconverter is a bit of a puzzle. It's a 1.4x multiplier, so it takes your existing lens and gives you more reach, but the data suggests it's a middle-of-the-road performer across the board. Its best percentile ranking is autofocus, and even that's just average at the 49th percentile. That means it's not going to be the star of your kit, but it might be a useful tool if you need a bit more zoom without swapping lenses.

Our data shows it's best suited for portrait work, scoring 23.7 out of 100, followed by wildlife and sports at 22.1. It's not a specialist, and it's definitely not for macro, where it scores a low 7.9. At $359, you're paying for the Sigma name and the convenience of extra reach, but you're not getting top-tier optical performance.

Performance-wise, this teleconverter is firmly in the 'it's fine' category. Its optical quality lands in the 33rd percentile, which means over two-thirds of similar products in our database are sharper. The aperture performance is in the 30th percentile, so expect some light loss and potentially softer images when you use it. The autofocus, at the 49th percentile, is its strongest technical point, but that just means it's average—it won't slow your system down dramatically, but it won't speed it up either.

There's no image stabilization built in, which sits at the 42nd percentile. That's not a huge deal since you'd rely on your lens or camera body for that anyway. But the overall picture is clear: this is a utility piece, not a performance enhancer. It gives you reach at the cost of some image quality.

At $359, the value proposition is shaky. You're paying for the Sigma brand and the convenience of extra focal length, but you're not getting great optics for your money. Since it's a teleconverter, its value is entirely tied to the lens you put it on—it'll make a great lens okay, and an okay lens worse. If you absolutely need that 1.4x reach and you're locked into Sigma's ecosystem, it's an option. But if optical quality matters, there might be better ways to spend $359, like putting it towards a longer native lens.

Looking at the competitors, this Sigma sits in a weird spot. The Viltrox 35mm f/1.7 is a prime lens, not a teleconverter, so it's not a direct comparison—but for similar money, you get a sharp, fast prime that excels in specific areas. The Panasonic 14-140mm is a superzoom; for versatility, it runs circles around the Sigma TC-1401. The Meike 55mm f/1.8 is another prime that likely offers better optical performance. The Sigma's advantage is purely functional: it multiplies your existing glass. But when stacked against actual lenses in its price range, its optical shortcomings (33rd percentile) become hard to ignore. You're trading image quality for convenience.

Here's the data-backed take: only buy the Sigma TC-1401 if you have a specific, compatible Sigma lens that you love and you desperately need more reach for occasional use. Its below-average optical scores (33rd percentile) and weak aperture performance (30th percentile) mean it's a compromise. For $359, you could find a used telephoto lens that will outperform this converter. If you're not already invested in Sigma's teleconverter system, skip it and put the money towards better glass.