A 50 year old vintage lens from Germany is my favorite one for close-up photography.
It renders the out-of-focus areas with a creamy bokeh and tends to create "bubbles" on the highlights.
Mounted with extension rings it is often used hand held on my mirrorless cameras.
Often images look closer to watercolors than photographs; the shallow depth of field has blurry backgrounds with edges that seem to "bleed" softly into the next color.
The Meyer Optik Trioplan 50mm f2.9 is a manual focus lens, very small in size compared to modern lenses. Not exceptionally sharp, it might not please the perfectionist wanting to achieve details in every twig or grass blade but it is the lens that I regularly take on my outdoor trips to recreate the "feel" of a place more than just accurately record it.
Somebody once said: I am not interested in image quality, I am interested in quality images.