By now you've probably heard of the solar eclipse gracing our skies this Thursday.
You know what it is, where to see it, when to see it, who's going to see it, what it will look like and why it's so rare.
But questions remain. Like, how do I see it without losing my eyesight?
And can I get it on video without damaging my gear?
Every eclipse, some people stare at the Sun and suffer serious and permanent eye damage. Others end up damaging their camera sensors.
So here are the dos and don'ts (but mainly don'ts) of watching the eclipse.
Can I photograph the Sun with my smartphone?
Yes, but it will look terrible.
According to Phil Hart, an award-winning Australian astrophotographer, there's little risk to your smartphone from photographing the Sun, since the lens aperture is small and lets in relatively little light.
But, equally, there's not much point in taking that risk.
"It's not going to fry the sensor on your smartphone, but it's also not going to take an interesting picture.
"All you risk is harm [to your camera] and you're not going to get anything useful."
Plus, you risk accidentally frying your eyes.
If you want to record the eclipse on your phone, make a projection
How much of the Sun is eclipsed depends on where you are in Australia. People in Perth and Darwin will see at least a 70 per cent eclipse, while those in Melbourne and Sydney will see about 10 per cent.
For a 70 per cent eclipse, you can observe its progress with a simple pinhole projection.
Make a pinhole in a piece of card, and, with your back to the Sun, project the spot of sunlight onto a wall, the ground or a piece of paper.
During the partial eclipse, the round spot will become crescent-shaped, and you can can easily record the changing shape with your phone.
But for a 10 per cent eclipse, it'll be hard to observe any change in shape.
An alternative option is to use a telescope or a pair of binoculars to project a larger spot of sunlight.
This is a similar procedure to making a pinhole projection, but with the lens of the telescope or binoculars in place of the hole in the card. Here's a guide to setting it up using cardboard and scissors.
Remember, when lining up your binoculars or telescope with the Sun, never look through the eyepiece at the Sun.
Also, don't hold the piece of paper that you're projecting the light onto too close to the lens, or it will catch fire.
In the early 1990s, Jonti Horner, who is now an astronomer at the University of Southern Queensland, accidentally demonstrated the power of the Sun's focused rays, when he almost burnt down an observatory in West Yorkshire.
He'd pointed a telescope with an 18-inch aperture at the Sun, intending to project the Sun from the viewing end of the telescope and onto the side of the dome that housed the equipment.
But he'd forgotten a crucial piece of equipment. An eyepiece was meant to be fitted to the telescope, to make the rays diverge.
Instead, the telescope focused the rays upon a small spot on the wall.
"The dome started smoking," he said.
He rapidly realised his mistake and swung the telescope away from Sun, preventing a solar-powered inferno.
Don't look directly at the eclipse without eclipse glasses
Because some of the Sun is covered, you may be tempted to stare at it directly.
Even when the Sun isn't bright, your exposed eyes will be damaged by its ultraviolet radiation, which you can neither see nor sense as pain.
In fact, it can take days before you even realise that you've damaged your eyes.
The medical term for this damage is solar retinopathy, which is where intense light energy damages the back part of the eye. Looking at the Sun for as little as a few seconds can result in permanent loss of vision.
Fortunately, there's a handy solution: eyewear especially designed for safe viewing of the Sun, known as solar shades or eclipse glasses.
What about when the Sun is completely covered by the Moon?
According to the Royal Australian and New Zealand College of Ophthalmologists, it is safe to look at the Sun without proper eye protection only in the brief period when the Moon completely covers the Sun during totality.
But solar shades must be worn at any time the Sun is still visible during the partial phases. Even when 99 per cent of the Sun's surface is obscured, the remaining crescent Sun is still intense enough to cause retinal burn.
Getting the timing wrong can cause permanent eye damage, so some people may prefer to wear their solar shades throughout the entire eclipse.
For almost every Australian, the April 20 eclipse will be a partial one, meaning only part of the Sun is covered.
Exmouth and a small part of the surrounding peninsula in Western Australia will see a total eclipse, with periods of partial eclipse on either side of the total eclipse.
The period of total eclipse will last for 58 seconds.
After that, the Sun comes back out, and the risk immediately increases.
Don't use scratched or damaged eclipse glasses
You may have a pair of eclipse glasses that have been bumping around the house for 10 years, purchased for the 2012 total solar eclipse.
Don't wear them. They probably won't protect you. If eclipse glasses have any scratches or damage, they won't shield your eyes. They'll only give a false sense of safety.
"If they have a slight scratch, that's enough to damage your eyesight," Professor Horner said.
"Get brand new ones and double check they're still in perfectly good condition."
In fact, due to this risk, the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) has warned against using eclipse glasses for viewing the eclipse.
The Department of Health recommends ensuring eclipse glasses meet Australian standards and were purchased from a reputable retailer.
Eclipse glasses that meet Australian standards should have an "ISO" or "CE" mark on the side.
You can also check the glasses come from a reputable retailer, and were made by an approved manufacturer.
And in case you're thinking of giving it a go, regular sunglasses won't protect your eyes from solar retinopathy.
Don't look directly at the Sun through unfiltered telescopes or binoculars or cameras
Because optical instruments intensify the light, looking at the Sun through an unfiltered telescope or binoculars is very dangerous.
If you have a camera with an optical viewfinder, don't use that to look at the Sun either.
The exception to this is if you're using a solar filter, which sits on top of the lens and blocks most of the sunlight to avoid damage to the eyes.
According to photographer Phil Hart, if you haven't arranged to get a solar filter yet, don't bother trying.
"It's too late to buy proper solar film online and have it shipped," he said.
Don't photograph the Sun with a telephoto lens and no filter
You can destroy your camera.
In 2017, employees at an a Iowa photo store demonstrated what would happen if you try and shoot a solar eclipse with a telephoto lens and no filter.
They hooked up a DSLR body to a 400mm lens (the type of beefy telephoto lenses used for sports photography) and set the shutter to six seconds.
In that time, the light began to melt the camera's innards.
"If you're using a telephoto lens, you've got a big aperture that's gathering a lot of light, and that does create a risk for the camera," Mr Hart said.
Wider angle lenses are lower risk, but then they're also not worth using to photograph the Sun, since the subject will appear too far away.
If you have the right lens and filter, use a tripod and remote shutter release
This is more of a precautionary suggestion.
When taking a picture, many of us glance at our subject around the camera to frame the shot. When that subject is the Sun, you risk burning your eyes.
You also don't want to be stuffing around with camera settings during the eclipse.
"Set it up beforehand ... so you can just ignore the camera and enjoy the eclipse," Mr Hart said.
Do marvel at the weird light effects of the total eclipse
Mr Hart is lugging "several hundred kilograms' worth of kit" to Exmouth to view to the total eclipse, but not all of it will be trained on the Sun itself.
Some will be used to record what happens on the ground.
If you're in the Exmouth area for the total eclipse, you'll see some "crazy changes in light", he said.
"There's great twilight colours around the horizon.
"You're as much interested in twilight colours and changing light and the reactions of people watching it."
If you're taking this advice, he recommends using a tripod and heavily under-exposing before the eclipse, so that it will be the right exposure during the eclipse.
"For a time lapse of the scene, it would be exposure settings of 1/15 shutter speed, aperture of f4, and ISO100, and with the camera in burst mode."
"Start a few minutes before the eclipse, let it run through the eclipse and capture a very true sense of how light changes within the scene."
There are more advanced tips in this comprehensive guide written by another experienced astrophotographer and recommended by Mr Hart.
If you don't manage to catch this week's eclipse, you'll probably have another chance in five years time.
In July 2028, a total solar eclipse will be visible throughout a much larger area of the continent, from the Kimberley in the north-west to Sydney in the south-east.
Might be time to order those solar filters.
