Verdict

The Sigma 65mm f2.0 DG DN is the longest lens so far of Sigma’s new I-series of compact prime lenses with moderate focal ratios, a full metal body, and a ring to control aperture from. Optically the 65mm f2.0 DG DN is very sharp at least in the APS-C image circle, shows little longitudinal color aberrations and low vignetting and distortions (through lens profile). 65mm might not be a focal length you see often with lenses designed for full-frame sensors but it has it’s advantages sitting in the “middle” between 50mm and 85mm lenses: Its reach is 30% longer than from a 50mm lens allowing you to either stay further away from your subject or get a tighter crop with better background isolation. Compared to a 85mm lens it offers an 8 degrees wider field of view (37 vs. 29 degrees) capturing more context around your subject. So if you’re thinking about getting a 50mm or a 85mm aperture prime (or both) why not go for the Sigma 65mm f2.0 DG DN which also produces a Bokeh pretty close to a good 50mm f1.4 lens? And lest we forget: Sigma offers the unique option to get the lens mount swapped (at a cost) between Sony’s E-mount and Leica’s L-mount.

What’s not to like? First and foremost AF on my copy of the lens consistently was off a bit from perfect focus – which sadly could not be corrected by dialing in some amount of AF Micro Adjustment. Then there is some field-curvature softening the extreme corners of flat or distant subject a bit and the lens shows quite visible focus-breathing which might be distracting when shooting videos. On a more personal remark: I don’t like the full metal body plus lens hood: It makes the lens heavier than it need be, is freezing cold in your hands at temperatures well below zero, and does not look very elegant to me personally, although Gordon was quite fond of the design. And the magnetic lens cap does not solve a user problem: It can be as easily lost as any pincer-type cap, is much heavier, and cannot be dismounted with the lens hood attached. I’d rather have better weather sealing on the lens. One final gripe: Adobe’s RAW converter (again) does not recognize the distortion compensation from the lens profile at the time of writing.

This may look like a long list of faults but only the first point (AF) is a major deficiency, and it could be an issue with my test copy or may be resolved with firmware updates. Let’s put this into perspective and have a closer look at how the Sigma 65mm f2.0 DG DN compares to some alternatives.

Compared to Sigma 50mm f1.4 HSM Art

The Sigma 50mm f1.4 DG HSM Art is a fitting member of Sigma’s renown Art series offering very high optical performance with a 10 degrees wider angle of view than a 65mm lens. It delivers very good image quality in the center even wide open at f1.4 but shows a gradual softening toward the corners which makes it overall less sharp than Sigma’s 65mm f2.0 DG DN. As a legacy DSLR design the 50mm f1.4 HSM Art is also much bigger and heavier than the 65mm f2.0 DG DN – but it has the benefit of a one stop brighter focal ratio. Comparing Bokeh between both lenses is a pretty tight affair: At f2.0 it is almost undistinguishable and only at f1.4 there’s a slightly softer rendering from the 50mm f1.4 HSM Art. Until Sigma comes up with an original mirrorless design for a 50mm f1.4 lens that is much smaller and lighter than the current 50mm f1.4 HSM Art I’d rather go for the 65mm f2.0 DG DN for my mirrorless camera body.

For more details see my Sigma 50mm f1.4 DG HSM Art review where it came Highly Recommended.

Compared to Sigma 85mm f1.4 DG DN Art

The Sigma 85mm f1.4 DG DN Art is originally designed for full-frame mirrorless cameras and available in E-mount and L-mount versions. With its relatively low weight and small size it handles well on a mirrorless camera body. At 85mm focal length it has 30% more reach than the 65mm f2.0 DG DN and with its one stop brighter focal ratio it not only delivers better background isolation but also a better Bokeh than the 65mm lens. The 85mm f1.4 DG DN Art is optically the best 85mm f1.4 lens I’ve tested so far. It is roughly 50% more expensive than the 65mm f2.0 DG DN. But packed with additional features like better weather sealing, de-clickable aperture ring, lockable lens hood, and focus-lock button the Sigma 85mm f1.4 DG DN Art looks reasonably priced.

For more details see my Sigma 85mm f1.4 DG DN Art review where it came Highly Recommended.

Sigma 65mm f2.0 DG DN final verdict

The Sigma 65mm f2.0 DG DN achieves a convincing balance between quality, size, and price. It’s very sharp at least in the APS-C image circle, shows little longitudinal color aberrations and low vignetting and distortions (through lens profile), and produces a nice Bokeh. Its size makes it a good fit for a mirrorless camera and the full metal body leaves the impression of solid build quality and ruggedness albeit making the lens heavier than need be. Be aware though that despite the presence of a rubber grommet at the mount, the lens has no complete weather sealing, focus breathing could be lower, and field curvature softens the corners of flat or distant subjects a bit. All-in-all though – assuming that the AF problem is an individual glitch on my copy of the lens or fixable in firmware – I’d reward the Sigma 65mm f2.0 DG DN a Recommended!

Good points:

• Very sharp across a high-resolution full-frame sensor even wide open.
• Low longitudinal CA.
• Minimal light fall-off and distortions (through lens profile).
• Solid build quality.
• Can swap mounts (at a cost) between Sony E and Leica L-mount.

Bad points:

• AF fails to nail focus exactly – at least on my test copy.
• Some field-curvature makes stopping down mandatory for high-quality shots of flat (or distant) subjects.
• Focus breathing could be lower.
• Full metal body and hood makes the lens relatively heavy.
• Not weather-sealed except for rubber grommet on lens mount.
• Adobe’s RAW converter as of version 13.1 does not recognize distortion compensation from lens profile.