Soft to 5.6 or 8 and has lots more distortion than any Leica 50 ever made.
I completely disagree, and so does the Leica lens expert Erwin Puts!
The pre-asph 50mm is an excellent lens, albeit the current asph 50mm has more contrast and resolution. However, in no way can the pre-asph be called “soft”! Also, the pre-asph 50mm has the advantage of being extremely flare-resistant.
It’s my favourite lens - I wish all my lenses were this good! Never selling it, and most certainly not replacing it with an asph version!
Erwin Puts says of the pre-asph 50mm that it “performs as a Summicron (III) lens opened up one stop”. As for distortion: “absolutely zero”. Generally, he describes the centre performance as noticeably better than that at the edge.
This is what Erwin Puts wrote when he compared the pre-asph lens with the asph:
“If you are familiar with Dutch painting, one could say that the older Summilux paints like Rembrandt, whereas the new one paints like Vermeer. This is an especially apt comparison, as both painters lived in the same period. Rembrandt is famous for his atmospheric and emotionally charged paintings. Vermeer, on the other hand, has been called the first optical painter, as he painstakingly captured the finest possible detail with his brushes and used special techniques to bring specular highlights to life.
On a more quantitative level ... the new design is almost four stops ahead of the previous version [at f/1.4]. This is an incredible result, given the fact that the older Summilux got very high praise in the past for its performance.
Comparing photographs from the two lenses, the difference in resolution and contrast extends, not surprisingly, to out-of-focus areas. This can lead to the bokeh in some photographs taken with the aspherical Summilux appearing harsh and over-dominant.”
Dick Gilcreast wrote in 1998:
“[T]he 50mm f/1.4 pre-aspherical Summilux is still perhaps the best compromise between high speed and portable size – and definitely, if price enters the equation. Excepting the aspherical Summilux, only the full-stop-faster f/1 Noctilux has slightly better edge performance at f/1.4, but at the expense of considerably greater size and weight. Any one of these lenses from 1968 to the present makes an excellent all-purpose 50 mm lens for amateur or professional.”
In short, the asph 50mm is razor sharp, probably one of the sharpest lenses you can buy, but there’s more to lens than ultimate sharpness. It may be technically better than the pre-asph 50mm, but the pre-asph is no slouch.
Having compared photographs from the two lenses on my Leica M8, I prefer the pre-asph: in practice, the extra performance of the newer lens had little impact and was often indiscernible except below f/2. But what was obvious was the very high contrast and harshness of the asph lens - its images seemed sterile and lacking in emotional impact compared with pre-asph images.
