yup, its a universal truth. Pinhole (itty bitty aperture) cameras have, in theory, PERFECT focus for the entire field of view (infinite depth of field). As the aperture increases, depth of field decreases.
Check your cameras settings. Shutter speed has a big impact on exposure.
You should be struggling with TOO MUCH light in bright sun with any 35mm adapter. The problem I have is that I can only stop down to f5.6 (less with some lenses) before I can see the grain in my 35mm adapters ground glass. If I could stop down more, the DOF would increases and less focus woes.. funny, we bought the adapters cause we wanted shallow dof, but now that we have them, we lament the DOF is too shallow.. haha.. but its still worth it in my opinion.
My theory is that the smaller the aperture, the more of the light is coming in at an angle thus hitting the SIDES of the micro bumps on the ground glass, throwing part of the bump into shadow and the grain shows up..
I bought and ND filter for the front of the lens. This lets me reduce light without stopping down the aperture and thus able to get bright sun under control. I did NOT use ND filters for this shot as I was in the shade.. still though, I had the exposure compensation on my camera as LOW as it would go.. and if you look, the main subjects are in shade the entire time. Check the blown out white on the fences in the background.
