Solar eclipse with binoculars?

[Craig_]

Like everyone else, tomorrow I'm hoping to view the eclipse. After watching a video from the stargazing live website I would like to use my Helios 15x70 on tripod and project the image.

Would this cause any damage to the binoculars ?

Thanks.

[Peter Drew]

Prolonged use could possibly melt the Canada balsam cementing the eyepiece lenses or any plastic bits that get focused on. Better to cover one or both objectives with solar film and use visually. 

[ronin]

Whatever you use you need solar film over the front all the time.

Even when 90% obscured up in Scotland it will fry things, especially eyes.

It is the eyepiece end that will suffer the most, that is where it is all concentrated and so it gets hot,

[Hallelujah]

Take a look at this:

http://www.exploratorium.edu/eclipse/how.html

Stan

[Craig_]

Thanks for the replies and the link. I remember doing this many years ago with some cheap 10x50 bins but was wary of using such expensive ones this time around. Strange how the video on the website doesn't mention that the instrument may get damaged ??

[MarySkater]

During the 1999 eclipse, I projected it with one side of a cheap pair of 10 x 25s.  Worked okay, nothing got hot, no damage to bins.  I spent a few minutes this morning setting up in full sun with my slightly more expensive waterproof 8 x 42s.  Nothing got hot, no damage to bins.  So long as the light is going through the optics and on to the screen, all seems okay.  My image was about 10 cm in diameter, so it's not a hot-spot.  I read a suggestion that if the alignment is lost, you might focus sunlight on the inside of the tube with damaging consequences, so I covered the bins except when I was actually attending to the image.  Maybe I've just been lucky, but it works for me.

Mary