Question for science teachers....

[teacherwith2kids]

Trivial one really. Teaching light to upper primary (light in straight path, changing height of shadows with the position of light and object, effect of lenses and prisms etc), but suspect that the same issue arises in secondary.

To work well, these experiments need reasonably bright torches, quite small, with a single point light source. So many 'educational' torches are now LED ones, with multiple LEDs that make these experiments really hard to do accurately. We had some nice little cuboid torches, size of a couple of AA batteries, that were brilliant, but have come to the end of their lives.

Anyone out there found the perfect solution, quite cheaply? Or am I going to have to do lots of complicated things with 'masks' / slits for LED torches?

Secondary teacher here. We have rayboxes for that kind of experiment. Can you cover the end of the torch with black sugar paper. Pierce a hole with a pencil so that the light shines through a smaller area.

Thanks Jesses. Rayboxes would be wonderful, but are a bit out of our price range. The black sugar paper trick (or rather something similar with a thin slit) is what we already do with our current torches to get a thin ' beam' of light - but the extra step to also block out the multiple light sources will make things like the height of shadows experiment very tricky in a normally-darkened multi-use primary classroom, because we will have to block out so much of the available light.

(Perfectionist ex-scientist here!)

Do they need to be white? Or would 101 finger lights do?

How about a demo with a laser pointer. Taking care that the pupils are not in the reflected/refracted line. They can carry out with torches.

Ah, I do the demo with laser pointer. It's the equipment for 'carry out with torches' that is foxing me at the moment, given the shift to LED torches that seems to be happening at the moment, especially for small ones.

However, I think that :
these may fit the bill, with a little black card modification here and there.

I could only find things like:
these with 6 LEDs earlier.

I'm also not sure that even the ones that may be OK have 1 light source - there is no photo that gives me a good view of what is inside the front lens.