I thought I would contribute to show lens performance across the main apertures. Shows (i) the glow at difference apertures; (ii) bokeh; and (iii) vignetting (actually not really much vignetting, my problem was caused by wearing wrong hood, now fixed and you can see results below). The variation in image character reveals this to be quite a sophisticated lens. Need to remember somewhat the different performances across apertures and tailor to your needs.
Glow is strongest at F1.4
No glow from F2.8 onwards
Very sharp lens from F4 onwards
F1.4 Bokeh is creamy and swirly...me like!!! The "glow" is very obvious. Vignetting is negligible.
F2.0 Noticeable reduction in "glow", but you can discern it from the lotus candle. image sharper. The bokeh is still magic. At this aperture, the lux begins to exhibits the characteristics of the Summicron IV "bokeh King"
F2.8 At this aperture, the lux is most similar to Summicron IV "bokeh king" at F2.0, but due to difference in one stop, the bokeh king (F2.0) has faster shutter speed.
F4 Background beginning to emerge. Sharpness grows more incisive.
F5.6 At this aperture, sharpess grows intense and background crystallises on the journey to F8.
Sorry I did not take pics at F8. Its supposed to be sharpest at F8. But heck, I am not really a sharpness fan at F8. sharpness only matters when wide open anyway hehehe