Sigma 50-120mm f/2.8 for video: what to check on FX30, A6700 and Canon RF

The Sigma 50-120mm F2.8 DC OS Contemporary is a 390 g APS-C telephoto zoom for Sony E, Fujifilm X and Canon RF, on sale since 22 October 2026 for €799 in Europe and $799 in the US. That's about 75-180mm in full-frame terms at a constant f/2.8, with 4.5 to 6.5 stops of optical stabilisation. For video, check four things before you order: the barrel extends as you zoom, Sony's Breathing Compensation doesn't list it, the filter thread is 55 mm, and the Canon RF version looks different from the other two.

We went through Sigma's product pages, the official photos of all three mounts and Sony's compatibility lists to answer the video questions. We haven't shot with the lens ourselves, so where a question needs a hands-on test that nobody has published yet, we say so.

What are the specs that matter for video?

The Canon version weighs 20 g more and is 2 mm shorter. Sigma lists the same 18 elements in 13 groups for all three.

The 23 cm closest focus at 50mm is the spec we'd use most. At 1:3 you can fill the frame with a watch face or a coffee cup for product inserts without a macro lens. Shooting tight at 120mm, you have to stand at least 55 cm back.

Does the Sigma 50-120mm extend when you zoom?

Yes. Sigma's own product photo of the E-mount version at 120mm shows an inner barrel sliding forward. The spec sheet gives a single length, 99 mm. On a tripod or handheld that's fine. On a gimbal, balance at 50mm, zoom to 120mm and the weight moves forward, so the motors work harder or you rebalance. If you live on a gimbal, pick one focal length per setup and balance there.

Sigma doesn't publish the extended length, so measure it in the shop if your gimbal plate has little room to slide.

Will Sony's Breathing Compensation work with it?

Not according to Sony. We checked Sony's official Breathing Compensation compatibility pages on 3 November 2026: the lists for the FX30, A6700 and the other bodies include only Sony lenses, with no Sigma models. So the FX30 menu option won't do anything with this lens.

Sigma says the optical design itself keeps breathing low, "with little change in composition". That's a design claim. We haven't found an independent measurement of breathing yet, on any mount. If you pull focus on camera between two faces, test it in the shop or wait for a breathing test before you plan a narrative shoot around it.

What changes from one camera body to another?

Body stabilisation changes how much the lens OS gives you. Sigma rates OS2 at 6.5 stops at 50mm and 4.5 at 120mm, measured on an APS-C mirrorless camera. Sigma doesn't say how the lens OS combines with each brand's IBIS, and we haven't seen a test that measures it.

With no switches on the barrel, you can't flick to manual focus mid-take, so put AF/MF on a custom button before the shoot. The same goes for turning OS off on a tripod: it lives in the camera menu now.

Which ND filter size do you need?

The 50-120mm and the 18-50mm both take 55 mm filters. The 10-18mm takes 67 mm. If you own the trio, one 67 mm variable ND with a 55-67 mm step-up ring covers all three. That's cheaper than our usual advice of buying 82 mm and stepping down, which we explain in our variable ND guide, but it only makes sense if you stay on small APS-C zooms.

Prices are the lowest listings on heise Preisvergleich on 3 November 2026, for the Sony E versions. Black Friday is close, so they may drop.

Sigma 50-120mm vs the usual APS-C tele options

If you wanted f/2.8 at the long end on APS-C, the choice used to be the heavy Fuji zoom or a full-frame 70-180mm or 70-200mm on a crop body.

The Sigma is less than half the weight of any of them and the cheapest. You give up reach: 120mm is short if you film wildlife or sport from the stands. The Tamron and Sony start at 70mm, which on a crop body is already a 105mm look, so they can't double as an interview lens across a small room the way 50mm can.

Who should buy it, and who shouldn't?

Pros and cons for filmmakers

If you're still choosing the body, our look at Sony Monitor & Control on the A6700 and ZV-E10 II covers what those two can do from a phone on set. On full frame, Sigma's other autumn launch is the 375 g 50mm F1.4 CL DG, with its new RDD autofocus.

Questions people ask

Sources

• Sigma, launch announcement of the 50-120mm F2.8 DC OS | Contemporary (8 October 2026): release date, mounts, OS rating, focus breathing claim, removed switches
• Sigma, 50-120mm F2.8 DC OS product page: specs per mount, product photos of all three versions and the extended barrel
• Sigma product pages for the 10-18mm F2.8 DC DN and 18-50mm F2.8 DC DN: filter sizes and weights
• Sony, Breathing Compensation compatibility information, checked 3 November 2026
• Sony, FE 70-200mm F4 Macro G OSS II specifications
• Fstoppers, hands-on with the Fujifilm X version and comparison with the XF 50-140mm
• Calumet and heise Preisvergleich: Sigma 50-120mm prices and stock in Germany and Austria. All other Europe prices are the lowest listings on heise Preisvergleich. Both checked 3 November 2026
• Fstoppers and Newsshooter: US price and launch coverage
• Weights of the Fujifilm XF 50-140mm and Tamron 70-180mm G2 from the makers' published specs, as listed by Photography Blog and Adorama
• Cover and product photo: Sigma press images, graded by 4FILMMAKERS