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Message: <blockquote data-quote="Binastro" data-source="post: 3170205" data-attributes="member: 111403">. This morning I received the March edition of Sky at Night Magazine.There is a free solar specs with a protective wrapper included with the magazine.I presume that the magazine will be in the shops soon. They state that if the free solar specs are not included you should ask the newsagent for the free solar specs. The classic test in visual light for the correct density of a solar filter is that one can just see the tungsten filament of a 60 W clear tungsten bulb. Unfortunately nowadays these are not usually found although I have some. I just tested the free solar specs and I can just see the centre of a pearl 60 W tungsten bulb either the round classic type or the candle bulb.One can still get, so called, rough service 60 W tungsten bulbs, but these are pearl.There are full instructions in the magazine regarding observation of the partial eclipse.Included are instructions regarding colander projection and also pinhole projection.I did not mention these before, because people have received permanent eye damage from looking through pinholes.You must never look through a pinhole at the Sun.You must never look through the holes in a colander at the Sun.However, using a colander to project the Sun on a light surface, you will see multiple images of the Crescent Sun during the partial eclipse. This can be viewed by a group of people. You will only be able to see the Crescent and not smaller details such as sunspots as the resolution is not high.The same applies to mirror projection, where large groups of people can see the partially eclipsed Crescent Sun, but again the detail is not good enough to see sunspots. However, you can follow the progress of the moon across the Sun very easily with these methods.With my binocular projection method, I use this indoors, such as the kitchen yesterday.There are real advantages in viewing the projected Sun indoors. You are inside a camera obscura, although it is only partially dark. I.e. darker than outside. If anybody has ever seen the projected sun inside a real camera obscura, you will never forget the observation.In the sky at night Magazine, it shows binocular projection outside.For this, they are showing a 10×50 binocular probably.They have constructed a shade for the front of the binocular, as this is completely necessary to see the projected image of the Sun outside. The problem then is that it is more difficult to find the Sun as you cannot easily reduce the shadow of the binocular to a minimum in order to find the images.Although I said I use a 10×25 binocular, this is from indoors.If you are outdoors you can use a small binocular but at a short projection distance.For use outdoors a cheap 10×50 Bresser, Meade or Celestron Porroprism binocular costing about £20 or £25 or a similar offering from Aldi or Lidl may cost only £15.You can mount these on a tripod, and take the risk of damaging the eyepieces or any internal plastic, which might melt. However, as the eyepieces are probably three element, with only one cemented pair, you may be lucky and they may survive intact. But for the price one should consider them throwaway binoculars for this purpose. It doesn't really matter if they are collimated or not as you will still get an image. The magazine recommends that you cap one barrel, and this may be necessary to stop the images overlapping with this larger aperture binocular.</blockquote>

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