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Photography Question 
Daniel Kasenda

What Does the DOF Preview Button do?

Hi, Can I ask what the depth of field preview button does in a Nikon F80? How does it exactly help you? Sorry, I am a beginner in photography :/ Thanks!

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5/2/2004 11:43:51 AM

Gregory LaGrange
BetterPhoto Member Since: 11/11/2003
  It makes the lens close down to what the aperture is set at, so you can see what the depth of field looks like before taking the picture. The aperture affects the size of the area that appears in focus of a photograph, so if you needed to check to see where and what was falling within that area, you use the DOF preview to see it.

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5/2/2004 12:59:43 PM

Robert Bridges   There is a simple answer, and then there is a more complex answer. The simple answer is exactly what Gregory gave you. The more complex answer, hopefully, follows.

DoF preview is an extremely handy feature to have - IF you are doing either macro work or needing to make sure that EVERYTHING is as sharp as it can be from foreground to infinity ... as in a landscape. Lastly, DoF preview has myriad creative AND can help immensely in your focusing.

First thing it "does" is it darkens your viewfinder but that's simply because less light is available to the view screen. What you have to do is train your eye to look THROUGH the darkened screen so that you can see the effect different F/stops are having on your image. This takes time and practice. It sometimes helps to open up the lens all the way and then with the DoF button pushed in SLOWLY stop down. You need to look that both what is immediately in front of and immediately behind your point of focus. Doing this will help you see what parts of your subject are MORE in focus at a given F/stop than a different F/stop. Generally speaking, you won't see much difference between 2.8 - 4.0 or 5.6. BUT you will see some major differences between 4.0 and 8 or 11 or 16 et al. Now for the tricky part. With the DoF button in, re-focus your image until you can get all or as much as possible of whatever it is (foreground, surround, and background) of the point where your focus is. When you can see those differences, then you can fine-tune your point of focus. Note that when you do this and you release the DoF button and look through the viewfinder it MAY appear as if nothing is in focus. Trust your camera at this point.

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5/4/2004 9:32:56 PM

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