Protect your eyes and lens
The first rule of taking photographs of a solar eclipse — or the sun in general — is to never look at it with your naked eyes. Permanent damage to your eyes may result. Always wear certified solar viewing glasses.
Never point a camera at the sun unless the lens is fitted with a certified solar filter. This is of utmost importance. Lens optics magnify the intensity and brightness of sunlight, and this can damage your camera. The only time you don’t need your lens is during the brief totality portion of this eclipse.
Never point an unfiltered digital camera at the sun and use live view or an electronic viewfinder; this may damage your camera’s sensor.
You do not need a professional DSLR camera to take good photographs of the eclipse. Any camera will do, but it depends on how you want to capture the event. You just need to take the proper precautions to protect your eyes and the camera.
Consider some extra gear
The sun is bright, so, when photographing the partial phases of an eclipse, you don’t technically need a tripod to avoid camera shake because your shutter speeds will be very short.
During totality, however, the sun is blocked, which means you are photographing in darkness and shutter speeds need to be longer.
Mostly, however, it will spare you from having to hold your gear for the entire event. I highly recommend using a tripod for this event.
A cable release, electronic release or a mobile phone app release will aid when it gets dark and your camera shutter speeds fall.
With these releases you can trigger your camera remotely to prevent camera shake and blurred images.
Leave your flash in your bag. It’s not needed for this.
Use the right settings
To get a sizable image of the sun, a focal length between 500mm and 1,000mm show the sun large enough in the frame.
For those who do not have lenses with those focal lengths, fret not. You can use normal focal length lenses to place scenery in the foreground of your image during the eclipse. You won’t have the tight shot of the event, but you will still need to take the same precautions as mentioned earlier.
You camera’s ISO should be set to its lowest.
Have plenty of memory ready so you can shoot RAW files.
If using a DSLR, use mirror lockup to minimize vibration.
During the total solar eclipse, the light will change from bright daylight to near darkness, but most of this time the brightness changes slowly, allowing camera settings to remain pretty much static until totality.
During totality the light will be changing fairly quickly, and you must be ready to make necessary adjustments to your exposures. Don’t forget to bracket your shots.
During totality, after you have removed your solar filter from your camera, begin bracketing your shots heavily, shooting many different exposures.
Keep an eye on your histogram, and use the blinking highlights on image review if your camera has that setting. It shows you where your highlights are “blown out” in your image. Don’t be afraid to underexpose.
Take your certified solar filter out with your camera beforehand and get plenty of practice shots before the big day.
Do some location scouting while you’re at it if using shorter focal lengths.