Sigma 30mm f/1.4 vs Sony 35mm f/1.8 OSS: Your Camera Body Changes the Answer

Both are obvious candidates for a first prime lens on a Sony APS-C body: close enough in focal length to compete for the same job, but different in aperture, size, and stabilization. Which difference matters most depends heavily on the camera they're mounted on.

The aperture difference

The Sigma's f/1.4 maximum aperture is about two-thirds of a stop wider than the Sony's f/1.8, giving it a wider maximum aperture for low-light shooting and somewhat greater control over depth of field. At roughly 45mm equivalent on APS-C, it sits closer to a natural walk-around focal length than the Sony's 35mm, which gives a 52.5mm-equivalent view, slightly tighter for portraits and subject isolation but a little less flexible indoors.

Why OSS changes with the camera body

The Sigma has no optical stabilization, while the Sony has Optical SteadyShot built into the lens. On the a6700, which already provides 5-axis in-body stabilization, the Sigma's lack of OSS is less consequential because stabilization is available at the camera body. On the ZV-E10 and ZV-E10 II, neither body provides mechanical sensor-shift stabilization. Both offer electronic Active stabilization for video, while the Sony 35mm adds optical stabilization at the lens, making OSS a more important distinction on these bodies than it is on the a6700.

The Sony is much smaller; the Sigma tests sharper

The Sony weighs just 154g versus 265g for the Sigma, and measures only 45mm long versus 73.3mm. On a small ZV-E10-series body, that difference is substantial. Independent optical testing by DPReview found the Sigma notably sharper than the Sony, including wide open, although the Sigma showed substantially more barrel distortion.

Which lens fits which setup

On an a6700, the Sigma makes a particularly strong case. The body's IBIS reduces the penalty of choosing a lens without optical stabilization, while the Sigma gives you the wider 45mm-equivalent view, brighter f/1.4 aperture, and lower price. On a ZV-E10 or ZV-E10 II, the Sony's OSS becomes a bigger part of the decision, particularly for handheld shooting, and the lens is substantially smaller and lighter too. Photographers who care more about the Sigma's wider framing, brighter aperture, and stronger tested sharpness can still reasonably choose it and accept the lack of OSS.