VIDEO - How to make your own pinhole camera for viewing the eclipse.

Solar eclipse
Solar eclipse

The biggest solar eclipse since 1999 will cast much of Britain into darkness on Friday. Some parts of the country will see 99 per cent darkness — but for others the eclipse will be much less intense.

As with the huge eclipse 15 years ago, people will be heading across the country to find the place where it can be seen most clearly. And, in most cases, that will mean heading north — in the UK, the eclipse will be seen most clearly at the very north west of Scotland, and will get less intense towards the south east.

The very best place to see it in the UK is the Isle of Lewis in the Outer Hebrides, where the eclipse will reach 98 per cent coverage.

The eclipse will begin about 8am on Friday morning. It will peak at about 9.30 — varying by a few minutes depending on location — before the sun will come back at about 11am.

Wherever the eclipse is being watched from, viewers are advised never to look directly into the sun. Taking pictures of Friday’s solar eclipse on a smartphone could put people at risk of blindness, eye experts warn.

The College of Optometrists says the danger comes should people look directly at the Sun as they position themselves for selfies or other shots.

The eclipse will be spectacular because the Moon is closer to the Earth than it has been for 18 and a half years.

Dr Edward Bloomer, astronomer at the Royal Observatory Greenwich

Inadvertently glancing at the Sun - even briefly while setting up a shot - can lead to burns at the back of eye.

Experts advise indirect viewing, using pinholes and facing away from the Sun.

And, in an unusual twist, Friday’s solar eclipse will present a significant challenge for the UK’s electricity network and be an unprecedented test for operators of power networks.

Power demand is expected to fall and then surge.

As the moon obscures much of the sun, the electricity generated by solar panels is expected to drop by up to 75%.

But National Grid believes the overall impact will be “manageable”.

For details of how to make your own pinhole camera see our video.