The 40mm f/2.8 STM is a lens I rather like; it makes an excellent body cap, weighing only 125 grams, and is corrected optically in a pleasing way. At about $149 with instant rebate it’s a go-anywhere lens that fits into just about anything. Might as well use it over a body cap.
At 50 megapixels, the Canon 5DS R challenges any lens. So how does it do on a very simple pancake lens with only six elements?
This aperture series from f/2.8 - f/11 shows how many lenses are likely to perform on the Canon 5DS R. It’s an excellent target showing performance across the field. With entire-frame images up to 24 megapixels as well as the usual large crops.
Note that this is not a camera review piece; rather it is one of a number of lens review updates I have planned that I’ll be publishing across brands and focal lengths; as such it goes into the appropriate publication, in this case my review of the Canon EF 40mm f/2.8 STM in DAP (same publication as the review of the Canon 5DS R).