Question about DOF/aperture

Started Feb 6, 2013 | Discussions
aap292
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Question about DOF/aperture
Feb 6, 2013

Beginner question on a Sony NEX.

If I'm taking a shot of an object at a fairly close distance with a 50mm/1.8 I know that I can select a higher f/number to get more of the object in focus in aperture priority mode.

But while I'm doing this, do I have to be aware of anything other than what parts are in focus when I'm going to this higher f/number? (I know that the camera will have to adjust the shutter speed for the available light etc.)

Mark Scott Abeln
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Re: Question about DOF/aperture
In reply to aap292, Feb 6, 2013

aap292 wrote:

But while I'm doing this, do I have to be aware of anything other than what parts are in focus when I'm going to this higher f/number? (I know that the camera will have to adjust the shutter speed for the available light etc.)

If you stop down the lens a lot — say f/16 or a larger number, although it depends on a lot of things — then you risk diffraction in your image, which means that everything will be fuzzier or less sharp. This can be corrected somewhat on the computer with sharpening.

Longer shutter speeds mean that your image might be blurry because of camera shake, but a sturdy tripod or more light should help. Your camera might also raise the ISO sensitivity, giving you more digital noise, particularly in the shadows.

Just exactly where to focus can be somewhat of a problem, and usually you ought to focus on the most interesting point. If you have a whole range of things that ought to be more or less in focus, then focus halfway between them in depth: that is, if you have something 10 feet away, and want it to have the same focus as something 20 feet, then focus at 15 feet. This might be a bit difficult these days since most new lenses don’t have a focus scale.

Another alternative focus point would be at the edge of your subject. Having a sharp outline of a subject often looks better than having a fuzzy outline.

 Mark Scott Abeln's gear list:Mark Scott Abeln's gear list
Nikon D200 Nikon D7000 Nikon AF-S DX Nikkor 35mm f/1.8G Nikon AF Nikkor 50mm f/1.8D Rokinon 85mm F1.4
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aap292
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Re: Question about DOF/aperture
In reply to Mark Scott Abeln, Feb 7, 2013

I'll have to do some more experimenting but thanks for the tips!

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Dragonborn67
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Re: Question about DOF/aperture
In reply to aap292, Feb 8, 2013

Jump on to YouTube ....there are countless hands on tutorials on all aspects of photography including dof and aperture. I am a novice and have learned an amazing amount from this method. Good luck!

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umanemo
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Re: Question about DOF/aperture
In reply to aap292, Feb 9, 2013

I found this when researching Focus Stacking. Explains it better than I have read anywhere before.

http://www.cambridgeincolour.com/tutorials/hyperfocal-distance.htm

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