Sigma Lumix S AstrHori AF 85mm F1.8 II Full Frame Lens Upgrade Review

So, you're looking at the Sigma Lumix S AstrHori AF 85mm F1.8 II. It's a full-frame prime lens for Leica L-mount cameras, and it's priced around $329. On paper, it's a classic portrait lens with an 85mm focal length and a fast f/1.8 aperture, which should give you nice background blur. It also has autofocus and image stabilization, which is pretty rare at this price. But right away, there's a weird thing: the specs say it's an 85mm f/1.8, but the product name lists 'f/85' as the max aperture. That's clearly a typo, but it's a confusing start. We'll assume it's f/1.8 for this review.

This lens is a bit of a mixed bag, and the benchmark scores tell the story. Its autofocus is in the 96th percentile, which is excellent. It's fast, quiet with that STM motor, and the face/eye detection works well. The image stabilization is also strong, landing in the 89th percentile. That's a huge plus for handheld video or low-light photos. But the optical performance is where it stumbles, scoring only in the 33rd percentile. That means sharpness and overall image quality are just okay, not great. The bokeh quality is in the 2nd percentile, which is shockingly low for a portrait lens. So while you get a blurry background, it might not be the smooth, creamy look you're hoping for.

At $329, it's one of the cheaper autofocus 85mm lenses you'll find for full-frame. The value proposition hinges entirely on how much you need that great autofocus and stabilization. If you shoot a lot of video or need to track moving subjects, those features are worth the price of admission. But if your main goal is getting the best possible portrait image quality, your money might be better spent elsewhere, even if it means giving up AF or IS.

Let's name some names. If you're on a Leica L mount and want an 85mm, your main alternative is the Sigma 85mm F1.4 DG DN. It's more expensive, but its optical quality and bokeh are in a different league. For Panasonic shooters, the Lumix S 85mm f/1.8 is another native option that will likely have better integration. If you're open to other focal lengths, the Viltrox 35mm f/1.7 for Z-mount or the Meike 55mm F1.8 Pro are competitors in a similar budget AF lens category. They might offer better overall image quality, but you lose the 85mm focal length and the dedicated portrait look. The AstrHori's biggest selling point against them is that combination of AF and IS, which they often lack.

Should you buy this? It's a very specific tool for a specific need. If you need a budget-friendly, stabilized autofocus lens for video work, vlogging, or situations where you absolutely must have reliable AF on moving subjects, this AstrHori lens makes a surprising amount of sense. But if you're a portrait photographer buying an 85mm lens primarily for its image quality and beautiful bokeh, this is an easy skip. The optical performance just isn't good enough for that job. Look at used versions of more reputable brands instead.