Peter Karbe, expert Leica lens designer, says that Leica lenses are designed to be shot wide open. Karbe says:
“…shoot the lenses wide open. Do not stop down for exposure control. STOP IT. Use an
ND filter if it is too bright out and please only stop down to control the depth of field...”
Should you shoot all lenses wide open? Or is Leica advertising Leica? Should you blur the background in all your photos? If you spend a lot of money on an f/1.4 or f/2.0 lens, why not shoot it wide open? Otherwise, maybe you've wasted your money. The best lens in my bag is a Zeiss Milvus 35 mm f/2.0, which is a manual focus lens.
Karbe's comment prompted a project: shoot 500 keepers on the Zeiss at f/2.0. A few things were evident. Vignetting is a feature of the lens at f/2.0. See the photo of the stone wall below. Vignetting can be can be strong or almost imperceptible, depending on the light. It brightens the center of the image and creates depth. For static photos, it's a tool for calculated use. For perfect focus, you need to go into live view at maximum magnification and focus precisely on the subject. At infinity focus, there is a little blur in the foreground, but you're generally OK in the rest of the frame. In dynamic situations, when people are moving, f/2.0 is hard to use. Conclusion, use f/2.0 selectively for conscious effect. Otherwise, stop down to keep things sharp.
The lede photo is a good example of the sharpness of the Zeiss at f/2.0 with strong lighting and a blurred background. Notice that Jefferson's columns on The Lawn are made of brick. The plaster surface was an aesthetic choice. Some recent restoration of the columns exposed the structures before they were restored and painted.
Below is a sampling of frames from the Zeiss at f/2.0. More to come next time.
Gear Photos were shot with a Nikon D750 and Zeiss Milvus 35 mm f/2.0.