Ralph Chou - Observing the Transit Safely and Effectively
Spoiler
Ed ~ For cheap unaided visual (and potentially hazardous) observations of the Sun, or solar eclipse, an unprinted dense compact disk (CD) can be use - if held at arms length.
The CD must have a thick aluminium coating, so that you can barely see a 100watt light bulb filament through it - this will allow for temporary visual observing. A thick aluminium coating cuts the harmful level of transmitted invisible infrared radiation - to comparable levels found in commercial solar filters (in one transmission spectrum test it actually out preformed one brand); but, the 'silver' coating of different types of CD are non standard and vary considerably. Also, the optical image quality of the CD is rather poor.
Note: The compact disk should be held at arms length, and not be used with any magnifying device, such as binoculars or telescopes.
For slightly better, and potentially safer, solar image viewing, a grade 14 welder's glass is recommended. Pinhole projectors will also provide excellent images of the Sun, and are inexpensive to make.
Baader Planetariums AstroSola safety film is a specially manufactured streak- and blisterfree foil. It attains the optical performance of planeparallel glass filters. The base material is not "Mylar"!. The basic development of this film was made in laboratories for nuclear- and particle physics. High density coatings on both sides of the foil ensures a highly uniform filtering, while neutralising the occasional miscroscopic holes in the coating. The image of the sun is extremely contrasty and of almost neutral colour. The coating of the foil is subject to constant quality control. Its reflective property of over 99.999% has been tested by a German Republic bureau of standards and conformity with EU norm 89/686 is certified with the CE-symbol. We deliver AstroSolarTM safety film in sheets of 20x29.5 cm. For larger requirements, such as instruments with larger aperture or high-volume orders, it may be obtained in rolled sheets of 100 x 50 cm (approx. 4 Sq.Ft). Read more
Ed ~ A tip is to make a secure DIY mount for the safety film, so the film sits at a slight angle on the telescope; this will remove any annoying reflections. Loose film is a lot cheaper to buy than pre-mounted filters (that also unfortunately only sit at right angles on the telescope - with possible internal reflections).
A small tip with solar webcam capture is to treat the process with as much care as visual solar observing.
It is good practice to have a routine, or check-list, when setting up your telescope.
ie. 1) Fit the solar filter on with the telescope pointing away from the Sun. 2) Check the finderscope is covered. 3) Attach the webcam/camera. 4) Hook-up and boot-up the computer, and launch any capture software. 5) Point the telescope, etc.
It is all too easy to get involved in attaching the webcam and setting up the computer, and then swing the telescope towards the Sun... having forgotten to attach the Solar filter... This small mistake will probably instantly burn out the camera and possibly destroy any attached filters.
Sunspots 11391 and 11393
Spoiler
The Sun captured through a 60mm refractor and Vesta Pro webcam. Baader contrast filter + UV + IR filter.
We sell Solar, White Light, Sun, neutral density, Filters for viewing, photography of sun spots, eclipses, flairs, granulation. Fits Telescopes, Binoculars, Cameras, Refractors, View Finders, and Spotting Scopes. We sell Solar Eclipse Viewers and black polymer thin film sheets superior to Baader. Read more