DIY Solar Filter

[Scosmico]

This post is about what I did during the British Monsoon. I have not many techniques to share here. It just want to encourage others that want to be able to look at the sun with a low budget (£25) and safe Solar filter. I was able to make one filter for my scope (102mm) and two small ones for my binoculars (2x 50mm). Actually you can produce 2 sets and share the cost with a friend. Only £12.50 for a set of filters, scope and binos.

Materials

Baader Astrosolar Filter Film A4 size - £23

One thick cardboard - recycled

One thin cardboard - recycled from filter's posting package.

Bendable card - £1.29

Masking tape - daughter's school kit

One A4 sheet - daughter's school kit

Tools

Cardboard knife

Sealer tape

Scissors

One CD and tin

1- Cut the A4 sheet in half and use it as model to cut the thick cardboard, the thin cardboard and the baader film filter.

2- You only need to cut circles in the cardboards. They will be the film holders. You can use the film square as it is.

3- Use the CD (102mm) to draw a big circle and a can around 50mm diameter to draw the small circles. Spread the circles wisely so there is enough space for the film to cover the circle, and expands until close to the edge of the cardboard.

4- The film holder is going to be a sandwich of one thick cardboard, the thin cardboard and the film filter in the middle.

5- Before sticking the film to the holder, remember to remove the fine translucency plastic that covers the filter on the side that is not protected by the tissue paper that comes with it.

6- Cut three stripes in the bendable cardboard, two inches or 5cm each. And one stripe of one inch or 2.5 cm for the binos.Use these stripes to make a tube that will fit to the scope/ binos. Just tape it as you circle the aperture of your scope/binos.

7- Use the tapes to put together the film, film holders and tubes.

8- To avoid the filters touching each other, fit the filters in different levels in the binos objective.

I already tried it and I am very happy with the result.

Any question please let me know.

Kind regards

[Bart]

Nice, I did something very similar for my 150mm Newt. Please be careful the bino set doesnt come off, are they very secure?

Bart

[Gina]

Yes, I've made several solar filters too - Blue Peter Rules!

[Scosmico]

Thanks Bart. They are very secure. I took extra care. I need my eyes .

Nice, I did something very similar for my 150mm Newt. Please be careful the bino set doesnt come off, are they very secure?

Bart