The wiggles seen even on long-term charts obscure the trends we are trying to find so we need a way to cut through the clutter. Computerized filters using such complex concepts as fractals, wavelets and noise reduction can help, but only if you have the algorithms and understand how to apply them.
Most technicians use either bar, candle or point and figure charts in their work.
These movements can be knee-jerk reactions to news or market conditions rather than illustrative of the actual trend or technical pattern in force at the time. Using only a closing line chart, or even a low interval moving average of the closes, reduces the resolution of the chart but it also reduces the visual clutter. This makes trends and patterns easier to spot. On the bar chart, the corrective pattern from August 1995 to January 1996 is a triangle. On the line chart, the pattern is a rectangle.