Best Teleconverters of 2026

Fit Canon's extender to the RF 100-500mm and the lens stops being a 100-500. It becomes a 420-700mm, because the extender cannot be used below 300mm on that zoom, and the entire 100-300mm range disappears while it is attached. That is the most useful thing to know before you buy, and it is the main reason to think twice. On the 100-400mm or the 600mm f/11, no such restriction applies.

Everywhere else, this is the extender we reach for on RF bodies. Autofocus and stabilization behave as though nothing has been added, images come back sharp with detail intact — feather structure, not just feather shapes — and the camera even reports the combined focal length in the display. The 222-gram, water-resistant barrel suits the way RF telezooms actually get used: in weather, on a monopod, at the end of a long walk.

Paired with the 600mm f/11 and an R7, it makes a genuinely light supertelephoto rig, the kind of combination that justifies owning an extender at all. It only earns its keep if you already own glass it fits, which is true of every converter here. For those shooters it is close to a free 40%.

Sony sells two converters for the same lenses, so E-mount shooters face a decision the other mounts do not. Take the 1.4x if you want reach you can leave mounted for a whole afternoon of birds; take the 2.0x only when the subject is genuinely out of range without it. The 1.4x is the one that behaves like the lens it is screwed to.

On a 100-400mm GM it turns 400mm into 560mm, and the files look like the lens at 400 — same color, same contrast, center sharpness intact. Autofocus speed barely moves in good light; it is in low light, where the missing stop bites, that the combination starts to feel its length. With the 70-200mm f/2.8 GM you get a 98-280mm f/4 that hand-holds all day.

Results are good rather than miraculous. The 1.4x is kind to a great lens and unforgiving of a merely good one, so pair it with the glass it was built for. Dust and moisture sealing carries over from those lenses, which matters on a converter that will spend its life outdoors.

Doubling focal length costs two stops, and this converter charges them in full: an f/2.8 zoom becomes f/5.6, an f/4.5-5.6 becomes f/9-11. Sit with that number before you buy, because it changes when you can shoot far more than the extra reach changes what you can frame.

What you get is 800mm from a 400mm, and in decent light that is a genuine gain — subjects that were specks fill the frame. The center holds; the corners soften and vignette, and flat light brings a haziness a bare lens would not show. Expect a supertelephoto look rather than a prime look, and stop down when the subject holds still long enough.

Autofocus is where it makes you work. In good light it locks quickly; at the long end, in low light, it hunts, and manual focus becomes the practical answer. That is the physics of the missing stops rather than a fault in the converter, but it is why we treat this as a specialist's tool — the one you fit when the alternative is going home without the shot.

It is also the converter for bodies that handle high ISO well, because you will be leaning on that. In bright conditions it delivers distance nothing else in the Sony line here can match.

On Nikon's 300mm f/4 PF this converter looks close to free money: 420mm at f/5.6, files that keep their bite, and autofocus that still finds a bird in flight. That pairing is why we keep recommending a converter Nikon has sold for years — the optics are simply clean, which is not something every 1.4x manages.

It does similar work two ways. Add it to a 200-500mm and you have a 280-700mm; add it to a 70-200mm f/2.8 and you get a 98-280mm f/4. Fluorine coating front and rear makes it easy to wipe clean after a wet afternoon, the barrel is weather resistant, and at 190 grams it is among the lighter converters here.

The caveat is autofocus with slow glass. On a 200-500mm or an 80-400mm the combination slows noticeably and gets less sure as the light drops — in daylight it is a non-issue, at dusk it decides whether you get the frame. DSLR autofocus modules want aperture, and one stop is one stop.

For the lenses that take it, this is still the most straightforward way to add reach to an F-mount kit, and the one we pack when the DSLR comes out of the cupboard.

Two times on a 300mm f/4 PRO means 600mm at f/8, which in Micro Four Thirds terms is 1200mm of reach in something you can carry up a hill. It also means the light has to be there. Bright mornings are this converter's home; a gray afternoon is not.

Build matches the lenses it was designed for — dust, splash, and freeze-proof, with nine elements in four groups and Olympus's ZERO coating keeping flare in check. At 5.28 ounces it disappears into a jacket pocket, and the included case clips onto a bag strap rather than rolling around loose at the bottom.

Where it costs you is focus. It is not as quick as the bare lens and hunts more at the far end, which you notice tracking birds and barely notice on perched ones. Sharpness holds up better than the f/8 figure suggests, and background separation survives; these files still look like the lens took them.

The alternative for a Micro Four Thirds wildlife shooter is a lens costing several times as much and weighing more than the body. That trade is why we keep one in the bag and accept f/8 as part of the deal.

The arithmetic is the whole pitch: this converter costs roughly half what Sony charges for its 2.0x, and it lists more Sony lenses as compatible, including the 200-600mm and the 400-800mm. If you have been circling a 2x and flinching at the price, that gap is the reason to look.

Viltrox fits electronic contacts for autofocus and EXIF, a dust- and splash-proof barrel, and a three-year warranty that runs longer than the camera makers give. Two times is two times, though: you lose two stops, an f/5.6-6.3 zoom becomes f/11-13, and suddenly the light matters as much as the reach.

Where we are careful is the optics. A 2x is the hardest job in this category, and a converter's faults get magnified along with the subject, so on a high-resolution body the gap between this and a first-party converter will show. In good light ours behaved respectably, but we treat it as the value pick rather than the equal of Sony's.

The three-year warranty is the reassurance. If you need double reach a few times a year rather than every weekend, that is a sensible trade; if wildlife pays your bills, buy the first-party glass.