THE SOLAR SCOPE
A solar telescope does not need much aperture—6 inches (150 mm) is ample, and good observations can be made with apertures of 2 to 3 inches (50 to 75 mm). Because sunlight usually creates poor seeing, cannot use the higher resolution afforded by a larger scope.
To reduce the effects of bad daytime seeing, try observing in the early morning, before the Sun has had a chance to heat up the surroundings. Erect your telescope on a grassy area, avoiding pavement, rooftops, or any other heat-absorbing surface. Another solution is to view the Sun across a lake, where the water helps to keep the air relatively settled.
The only safe way to view the Sun directly is to use a solar filter that fits over the entire aperture of the telescope. An aperture filter reduces sunlight to safe levels before it enters the scope. This keeps the optics cooler and improves the viewing.
Most solar filters are made from Mylar plastic or glass; both kinds will show sunspots and faculae. Expensive filters that isolate narrow wavelengths, such as Hydrogen-alpha (H-alpha), can show other surface details and spectacular prominences.