How to focus to or on infinity with a digital SLR camera?

When reading manuals or photography magazines and books, you will come across the term, 'focus your camera to infinity'. You may also notice the word or infinity symbol on one of your camera lenses. This can usually be found when you turn your camera lens to manual focus (MF) and rotate the focus ring either all the way to the right, or all the way to the left. Nikon and Canon lenses work complete opposite to each other.

On the example lens on the left, notice there are two focus rings that can be rotated. If your DSLR lens doesn't have these, then it can't manually be set to infinity.

If your lens does have two rotatable focus rings, firstly change the AF/MF switch to MF (manual focus). Next, turn the smaller focal ring all the way to the right and then all the way to the left, until you see the infinity symbol.

Now look through your viewfinder and point your lens towards an object in the distance that you want to photograph. Rotate the larger ring with your fingers until the object looks to be in sharp focus. If doing this doesn't achieve sharp focus, you may need to physically move yourself closer to or further away from the object. Now take the shot.

This is the technique known as focus to infinity.

Another example showing how to focus on infinity, can be seen in the image below. A photographer could set their main focal point on the rocks and take the shot. Or alternatively, they could focus on the mountains in the distance. By which case, they would be focusing on infinity.

Other tips for focusing on infinity with a digital SLR camera

• When using this technique, it's more effective if you have your aperture f stop, set to the highest f number. For example f/22 or higher.
  
  
• Use a tripod, as you should with all photography where the aperture f number is very high.