I have all or most of the original or L screens for the first two F-1 models. The one I use most is the LD. This is a grid type screen. While it can be used for copying and architectural photography, it is also very useful for macro work and using slower lenses and zoom lenses. The grid lines are a good visual sharpness reference and there is no central split image or mictoprism to black out. The D screens are my default ones. The C screens are plain matte ones. These are useful for higher magnification macro work and for portraits. Why portraits? The C screen will allow you to focus on an important area, like a person's eyes, without having to point the center of the screen at the area and then recomposing. I have a fleet of New F-1 cameras. These have different versions of most screens with different metering patterns. They are less plentiful than the screens for the earlier models and much more expensive. I do have a few D and C versions but most of my New F-1 cameras have E screens in them. For general picture taking, they are fine.