This page is a chapter in the book New To Photography Book.
Keep both eyes open when looking through the viewfinder!
This might sound odd, as it seems humans naturally close the other eye, when looking though things like viewfinders (maybe it is a learned thing, remember back to your childhood and looking into microscopes/ kaleidoscopes etc) Keeping both eyes open when using a D/SLR viewfinder is a good technique to learn. This generally helps to get a perspective of what you are looking at and keeps you focused on your subject.
Try keeping both eyes open as an experiment and I will tell you why it could come in handy.
Let's say for example you are photographing a moving object, or something that is a bit unpredictable like animals or a sports event. If you are looking with just one eye through the viewfinder, you are limiting your field of vision to what you see in the viewfinder, you might miss an exciting bit of action happening just to the left of what the viewfinder sees, and therefore more likely to miss a great photographic opportunity.
Looking through the viewfinder whilst keeping both eyes open however, takes practice, and you can learn to watch and see more action. You see something out of the corner of your left eye (or the one not looking through the viewfinder) that you would normally have missed, you can quickly turn the camera and click, you got it!
So you like shooting landscapes, they don’t have ‘action’ so why should you keep both eyes open?
Well, you are shooting a lovely lake scene, the light is almost right, the clouds look great, there are some sun rays peeking through the clouds, creating a beam of light onto a small dinghy with fisherman in the middle of the lake. You take your shot, just as a bird flies by about 3 metres from your camera. Looking at the LCD, you have a lovely lake scene with a big blurry black blob in the middle of it. You delete the photo, curse, look up and the beam of light is gone. If you have kept both eyes open, you would have seen the bird coming, and either taken your shot a second or two earlier or later, and you would have the scene you hoped for.
Strangely enough, when photographing people, it can also put your subject at ease. If you are looking at them through the viewfinder and they cannot see either of your eyes, it can be quite unnerving for them. If they can see one of your eyes, then they can see that you are looking at them and that eye contact is important for humans. Even some domestic animals will lose interest in what you are doing when they lose eye contact.
And, if you do a lot of photography, by keeping both eyes open, you will not be scrunching one up all the time, and avoid ending up with lop-sided wrinkles!?!