solar projection as an alternative

[Mark at Beaufort]

I am keen solar observer and have a PST and also use my Astro Tech 4" APO frac with an Orion solar filter. The best white light observing is done using my binoviewers.

From time to time I show individuals the view of the Sun and there is sometimes a worry by some to look through the eyepiece. Clearly if the filter is old and faulty the Sun will blind you so I always check the filter before use.

Recently I saw a solar projection kit advertised second hand on eBay and because it was so cheap I bought it to use with my William Optics SD66 frac. Today is clear so after viewing with the PST I thought I would set up the projection screen to see how good it is. I attach photos showing the setup and another of the Sun projected onto the screen.

You can easily see the Sunspots 1649, 1650, 1652 and the large group 1654.

Clearly a useful procedure for group presentation and at about £16 a pleasing purchase.

Mark

[michael.h.f.wilkinson]

Projection has its advantages (several people can watch at the same time), but the contrast is low, in my experience. At about £16 it is a good deal (you can also make suitable screens yourself, but they will probably not be much cheaper). I am getting a Herschel wedge for my frac for more detail.

[Bizibilder]

Its a good method as long as you dont have any plastic parts in your scope! This includes the focusser/baffles/dewcap/eyepiece etc. It is also a good idea to get yourself a non-cemented type of eyepiece (Ramsden for example - cheap and cheerful). Don't use your best Plossl - they have a cemented element and the cement will melt/degrade and ruin it!