How to use correct aperture?

Question by Tereca: How to use correct aperture?
If I shoot a line of objects around 10ft apart, what would be good to shoot? I live in a small town and cant seem to find anything interesting. I want to be more creative, but can’t seem to find the right thing.

I want to shoot something close up and then something other that is further away in the backround, around 10 feet apart.

Any ideas????

Best answer:

Answer by EDWIN
Apparently you are trying to work with Depth of Field (DOF) which is the area in focus in front of your subject to the area in focus behind your subject. DOF can be deep or shallow or anywhere in between.



There are only three factors that affect your DOF*:

1) The focal length of the lens.
2) The aperture used.
3) The subject distance.


You can use the DOF Calculator at to compute your DOF for any combination of the three factors imaginable.

* I’m purposely ignoring compact digital cameras that have a tiny sensor that actually affects DOF and makes it more difficult to achieve a shallow DOF. Just concern yourself with the three factors listed.

Know better? Leave your own answer in the comments!

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3 Responses to How to use correct aperture?

  1. Hondo says:

    Why don't you just try it? Use several different apertures and look at the results?

  2. priangshu says:

    If u r looking for a blurred background then go for the smaller number of aperture like f/2.8 or 3.5 look for the smallest number if your lens provides u a wider aperture. Depending on the light condition.
    If u want all ur photo sharp then go for a larger aperture number like f/9 or f/11. Depending upon the light condition.
    Bigger f number+ slower shutter speed+ low ISO = all sharp photo
    Smaller f number+ faster shutter speed+ low ISO= Blurred background.

  3. Mark says:

    We can’t always say that there is a “correct” aperture for any given photo. It comes down to what you want the picture to look like. In your example, you could do a number of things.

    1) Focus on the first object, set the aperture to its widest (the lowest number) and shoot. You will get relatively shallow depth of field. Then, keeping the aperture the same, move closer to and further away from the scene and take a few more shots. You might be surprised at how different the results are.

    2) Same as above, but set a higher aperture like F8 or 11. Again, look at the results. You are training your eyes to see how aperture affects things.

    3) Focus on the middle object, or the object that is around a third of the way into the scene. Shoot with the widest aperture you can get, If you can get it right, you will have blur in the foreground and background, and a sharply focused object in the middle. This is an interesting effect to play around with. Something like a row of trees is good for this kind of experiment.

    Once you start to see how changing aperture affects the scene, you will start seeing more things to shoot, even in a “small town”. Combine this with experiments in shutter speed and you’ll broaden your artistic palette quite nicely.

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