Photographing from impressionable viewpoints can already be tricky, but then to also be able to see through the viewfinder is sometimes an added challenge. If, for example, you start shooting from a high or very low vantage point, you will soon be unable to reach this. You can use an angle finder for this, this will increase the distance you can have to the viewfinder. Note that a Canon angle finder is not compatible with a Nikon angle finder. So be aware of which camera you have and whether your favourite fits this well. More about
Photographing from impressionable viewpoints can already be tricky, but then to also be able to see through the viewfinder is sometimes an added challenge. If, for example, you start shooting from a high or very low vantage point, you will soon be unable to reach this. You can use an angle finder for this, this will increase the distance you can have to the viewfinder. Note that a Canon angle finder is not compatible with a Nikon angle finder. So be aware of which camera you have and whether your favourite fits this well. More about
An angle finder is a tube with an angle in it. A prism and lens allow you to see through this angle the image you are about to photograph. A camera that fits this has a rubber rim around the viewfinder, which you can take off. Now you have a ledge around the viewfinder that you can slide the angle finder over. When you have it on your camera, you do still have to focus it. You do this by correcting the diopter. There is a small ring next to the viewfinder that you can turn to get the desired sharpness. After you have it all set up properly, you can start shooting!
Generally, an angle finder is used in macro photography. In macro photography, you need to get close to your subject, which sometimes means shooting from unusual angles. For example, the camera may be on the ground to get that close to a flower, or even slightly buried. Then you can no longer reach this with the eye, where the angle finder comes into play so you can still see into the viewfinder from above.
An angle finder can also magnify the image, up to 2x, for example. In macro photography, this allows you to see even better when your image is in focus and exactly where the focus is.