Zeiss 15/2.8 Distagon: Aperture Series (Mossy Log Over Creek)
Just published in my Guide to Zeiss ZF / ZE Lenses is an aperture series from f/2.8 through f/16 for the 15/2.8 Distagon with high-res entire-frame images as well as various crops.
This series allows a very good understanding of sharpness and contrast, bokeh, vignetting and overall visual impact across the aperture range.