On the German Forum Dslr-forum.de Sigma 30mm f/1.4 lens owners spotted a specific issue: The lens takes unsharp pics when shooing at f/2.0 aperture with AF-S focusing via the EVF. Sigma germany acknowledge the problem and is working to fix it.
I am sure Sigma will fix that issue as this sounds a lot like a software issue. There is really no reason to not buy this lens also because it’s the best APS-C E-mount lens to date according to DxOmark.
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