Before I decided to try a copy of the Sigma 56mm DC DN Contemporary, I had checked with Novoflex to see if their ASTAT-SL tripod collar, offered for the 24-90mm and 90-280mm SL lenses, would work with the 50mm Summilux-SL. The reply I received from Novoflex indicated that it was designed for use with the former two only.
Yeah, it would have have been an ergonomic anomaly on the CL, but, oh, that IQ! But for less than a tenth of the price, would the Sigma’s IQ even be in the same ballpark?
No, I didn’t test one against the other. I’m content to shoot the 50 ‘lux on the SL2, where it still looks a bit oversized. But I did manage a somewhat more fair comparison: the Sigma and the 18-56mm T lens at 56mm. I say “somewhat” because my copy of the 18-56mm is a KEH “BGN” sample that has obviously weathered some rough treatment externally, even though the optics show no signs of wear.
It was no surprise to see that the Sigma was a bit sharper, especially in the periphery. But what I didn’t expect to see is that color and tonal gradience of the Sigma are indistinguishable, even under close scrutiny, from that of the 18-56mm. To be fair, the Leica lens is at its weakest at the extremes of its focal length range, and renders with slightly more dimensionality from about 24-48mm.
It would have been enough for Sigma to offer their trio of fast APS-C primes in L-mount, among others, just to give CL/TL/TL2 users more options. That they do it at such a high level of quality is no surprise, considering the number of great lenses they’ve produced in recent years. It’s their prices, though, that have us cheering; and which will sooner or later thin their competition.