First try at sun with homemade filter, safe?

Hi i used the binoculars for this, i took 2 3,5" magnetic disk. I THINK they block visible light and passes only ir? I had a quick peak and my eyes are just as bad as they always has been so no damage done.

Hi Erik,

I am not sure if it is a good idea to use a floppy as a filter..From the NASA site

"No filter should be used with an optical device (e.g. binoculars, telescope, camera) unless it has been specifically designed for that purpose"

Might I suggest that you get your hands on BAADER AstroSolar film and knock up some safe filters. this is available from a lot of online retailers.

i wasnt planning to use it eighter (for observing), as i dont know the safty lvl of it.

search the net and floppy is beeing used by some but its not good for your eyes and might damage camera. As it passes most of the IR.

search the net and floppy is beeing used by some but its not good for your eyes and might damage camera. As it passes most of the IR.

I agree. Not safe! Using this type of filter on a camera might not damage the camera immediately (most modern digital cameras have a dichroic IR blocking filter to prevent IR from screwing up your colour balance, but all that heat has to go somewhere???)

But viewing through an IR pass filter such as a floppy (or photographic film) is a bad idea!!! If you peeked through the device and don't notice any holes in your vision, consider yourself lucky.

Old silver based (black) black and white negatives were used as solar filters in the past but modern films (and floppy disks) can pass 1/2 of the infrared energy. Invisible infrared light can cause at least as much damage as visible light, possibly more because it doesn't trigger pain, blinking, pupil contraction and other natural protection reflexes.

If you have a camera with the IR dichroic filter removed (nightshot cameras or ones you've modified yourself), you might want to try taking landscape photos through exposed (black) photographic film. You'll see that trees, grass and people are very brightly reflective in infrared. But I would never recommend using this for viewing the sun.

You are playing with fire there Eirik.
There are no pain or heat receptors in your eye, so you will no be aware of any damage until you start going blind.
Your eye is like the inside of an egg in thats its fairly transparent, but just like when you apply heat to the egg, its goes white and so will your eye.

Many people cut cost corners in many parts of astronomy, solar filters is not one of them.