Suggestions on using ND filters with Hasselblad

Perhaps I'm missing something, but I haven't found a way to manually stop down my C lenses.

 

This is done by pushing down on the little non-descript silver latch button located on the right side of all your "C" lenses, just below the EV/aperture tab. The lens will stop down to your preset aperture and remain stopped down (you don't need to keep holding the button, just push it once). You can try various apertures and see the effect in the viewfinder. To restore automatic stopdown mode, move the aperture ring to to wide open setting and the lens will reset. Note some very early silver C lenses do not have this depth-of-field preview button, so there is no way to check for focus shift or DOF with those. Aside from not having the button you can identify these by the different shape of their EV/aperture tab (small half-moon shape on the early lenses, wider and straight on lenses with the DOF feature). All black C lenses have the silver DOF button, newer CF, CFE, CFi and CB lenses have a large ribbed slider switch on their left side. The effect is less visible on the Acute Matte screens than the older ground glass.

 

Focus shift isn't usually a factor with Hasselblad lenses 100mm and longer. Some 80mm Planars shift a bit when stopped down from f/2.8, it depends on the individual lens. The old "C" 50mm Distagon has various issues with field curvature and focus shift, but it isn't always easy to see in the viewfinder (as Ed_Ingold said, no "live view magnification" for film, unfortunately). Overall it doesn't seem to be as big a problem as it is for smaller-format DSLRs: I don't think any of the wide Hassy lenses have focus shift as significant as, i.e., the Nikkor 28mm f/1.8 AFS-G.

Ed I guess I worry because it tends to be windy here in New Mexico, especially in spring.