This question already has an answer here:

Recently while browsing for a camera, I noticed that some cameras have this "DoF Preview" and some have none.

Now, can someone explain to me here the importance of this feature in a DSLR?

marked as duplicate by Michael C, NickM, mattdm, AJ Henderson, Imre Nov 27 '13 at 17:27

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • 1
    Importance varies from photographer to photographer. Better to ask what DoF preview does for you. See the link in Michael Clark's comment. – Esa Paulasto Nov 27 '13 at 9:23
  • I have read that post sir but nothing in there said its importance. Actually i have read it before I post my question. The post tackles "how it works?" but not "how is it important?". Hope you get my point. – Ulfric Stormcloak Nov 27 '13 at 9:27
  • 1
    The other question covers not just how it works but also what you would use it for, from which importance naturally follows. – mattdm Nov 27 '13 at 13:24

The importance is being able to see a closer approximation of what the image will look like. Normally when looking through a viewfinder (unless the lens has a manual aperture) the aperture is open all the way. This means what you see is a) very bright and b) has a very narrow field of view. This is done because it helps the autofocus work better and also makes it easier to see the subject.

By stoping down the lens to whatever aperture is selected for the photo, This makes it darker and harder to see the subject, but it also makes the correct depth of field to preview what will and will not be in focus.

Not the answer you're looking for? Browse other questions tagged or ask your own question.