The problem is, timecode alone, while sufficient to provide syncing points for post production, may not be a reliable way to keep devices in sync with each other. With timecode, unless the cameras or recorders are re-jam-synced frequently, their timecode will start to drift apart. The problem is that the quartz crystal (or other piezo-electric material) clocks used in many cameras and quite a few audio recorders are too imprecise for critical applications.
Roller Naps. Paint roller nap sizes range from 1/4 to 1/2 inches in length. When painting a ceiling, the selection of a roller nap size depends on the surface of the ceiling. In general, a ceiling with a matte, flat, or eggshell finish calls for a roller nap of between 3/8 and 5/16 inches. If the ceiling is more textured, however, a longer nap may be called for.
Nap Roller Covers. The term nap refers to the length of the fibers covering the center tube. Consider the material the nap is made of as you are deciding which one to purchase. They come in both synthetic and natural fibers. Synthetic fibers are ideal for latex paints and all surface textures. The longer the nap, the more paint the roller cover will absorb. Smooth surfaces generally require a nap of 3/16 to 1/4 inch. Medium, semi-smooth surfaces require a nap of 3/8 to 1/2 inch. Semi-rough surfaces, such as stucco, require a nap of 3/4 to 1 inch.