Originally posted by Class A I don't agree when it comes to apertures near f/1.4.
For instance, the Pentax FA 50/1.4 is not that great near f/1.4 and many other fifties are similar.
What is the "purpose of having a 50mm"?
I believe the purpose of a lens should be to give the photographer a large range of options. Many lenses force you to stop down to get decent sharpness and/or bokeh and hence limit your options.
The new Pentax DA 20-40/2.8-4 is a case in point. It seems to be made for the benefit of photographers themselves with its small size, weight and beautiful build quality.
In contrast, lenses like the Zeiss Otus or the new Sigma Art lenses seem to be made for the viewer. Sure, the photographer will have to deal with a larger, heavier lens, but when it comes to the image viewing, only quality counts. The weight you had to carry around or the size you had to deal with will be irrelevant at this point.
If a lens can be kept compact and still deliver stellar IQ, great. But if it needs to be made large then so be it. I prefer that to a small beauty that limits your options.
I like your thinking, but I would like to add that the image is the result of the shooting process. So everything that shooting process consists of, have an impact on the final result.
Sharpness, bokeh, CA control etc are specs that are very important in the shooting process, but the thing that is often forgotten is -
the joy of photographing. I believe it is one of the most important (more important than sharpness)
ingredients for making a tasty photo.
The thing why Ltd's are so loved are because it is a joy to use them. Of course, they are good optically, but that is not their strongest part. The first lenses I got after kit lens were DA Ltd's and at that time it was all about the joy of photography for me.
With the Sigma the situation is totally different. When I started to make some from photography, occasionally I found myself in the need of faster lens. So I got, Sigma 35mm. Results are fantastic, but what I also found is that photography became less about joy, more about getting the result (for the client). That is a
big red flag.
I've seen wedding photographers that take photography as their job. No more. People who once were taking their cameras with them whenever they can because they enjoyed shooting, now only shoots when someone pays.
So, what I am trying to say, it is not only about sharpness, bokeh etc but how much excitement and joy you will feel using that particular lens