Although white light viewing of the Sun can be accomplished easily and safely by eyepiece projection from a refractor or by using inexpensive filters (see Solar Filters), to view prominences and surface detail in the chromosphere (the active surface just above the bright photosphere) it is necessary to filter the sunlight in a small section of the light emitted by Hydrogen Alpha activity at the 656.3 nanometre wavelength. The very narrow (around 0.7 Ångstrom) slice of the spectrum required to obtain reasonable contrast necessitates the use of specially manufactured filters which are expensive.

Although I have always been very impressed by the images produced, I did not feel the result justified the cost for occasional viewing. But fortunately a gentleman who through ill health was no longer able to use his telescope offered it to me at a very reasonable price. Thank you very much, John. The Coronado Helios 1 telescope was originally manufactured in the Isle of Man, and mine is one of these. A forerunner of the MaxScope 70, it is a self contained telescope with a 70 mm objective, and the bandwidth of 0.8 Ångstrom produces good viewing with a 'sweet spot' around the central area of the field of view.

The results are thrilling, and my first good photograph of a substantial prominence was taken at the Scarborough Starfest, August 14th. 2004. See here.

But eventually I realised that although the Helios 1 gave good images, the more recent developments gave a better viewing experience. The Helios had a 'sweet spot' for visual, although the whole disc was resolved in CCD images.

So having now got the Hydrogen Alpha 'bug', I took the plunge and bought new a Solarview 50 from Solarscope. This is still manufactured in the Isle of Man, but uses a different optical system with a full aperture filter, giving superb views of the entire disc. It has a slightly narrower bandpass of 0.7 Ångstrom which gives better definition of surface features.

 It also has matched well with my Artemis CCD camera, and images can be seen on my Solar page.