abstract:An internal focus lens (sometimes known as IF) is a photographic lens design in which focus is shifted by moving the inner lens group or groups only, without any rotation or shifting of the front lens element. This makes it easy to use, for example, a screwed-in polarizing filter or a petal shaped lens hood.
Thereport talks about the principles, structure, accuracyanalyses, maintechnicaldata, characteristics, adjustmentandapplicationofanew typeinternalfocusingdevice for centring.
To accomplish this, the agency has fundamentally altered internal procedures by focusing more on fixed-price contracts and reducing its day-to-day oversight of commercial space companies, like SpaceX.
After spending time focusing on internal issues, and with the new PPS organization largely in place, a period of stability will enable HP to rebuild momentum.