Sunday, December 21, 2014

{Photography} How to nail focus

One of the most frequently asked photography questions, which was asked by Tara last week, is how to get crisp, sharp, in-focus photos.  Focus is a result of several different components.  If one of these components is off, you're probably not seeing the photos you thought you were taking.  If you seem to be having a focusing problem, here is what I suggest you evaluate:
  1. How is your camera set to determine the focus point?
  2. What aperture (f stop) are you using?
  3. What's your shutter speed?      
Focus point

99% of the time, I use auto-focus on my camera.  This is not the same as using the auto setting, which is the green AUTO on the dial on top of the camera.  I always shoot manual mode (where I determine the ISO, f stop and shutter speed) but my camera is set so that it focuses for me.  The D7000 has a few different options for how it determines what to focus on.  I have it set for single-point AF.  This means that when I look through the view finder, I see one little box (focus point) and I move it around to where I want the focus point to be.

In this photo


the focus point was on Emily's face. (ISO 160, f/6.3, SS 1/100)

If a subject is closer to me, I usually set the focus point on the subject's eye nearest to me.

Aperture or f stop

I feel like it was a trend a few years back (and maybe it still is now) to shoot wide open, which means using the smallest number f stop.  You may think that you need to shoot with an f stop of 1.4 or 1.8 to achieve bokeh or an out of focus background but that's only part of the equation.  For example, you also need to consider the distance between your subject and the background and which lens you are using.  But this post isn't about bokeh or an out of focus background.  

Most lenses are not sharp at their widest.  I've seen reviews of professional lenses that do produce tack sharp images at their widest but most lenses do not.  So if you are using the 35mm, f/1.8 lens and shooting at 1.8, you probably are not going to get crisp images.  I have this very lens and it tends to back focus on me so I rarely shoot wider than 3.2 or 3.5 with it.  In addition, when you shoot wide open, you are narrowing your depth of field and giving yourself a smaller area that will be in focus.

This photo


was taken with an f stop of 3.5

This photo


was shot with an f stop of 8.0.  Don't be afraid of shooting with those bigger number f stops.

Shutter speed

This is something that folks may not think of but keep in mind that slower shutter speeds are more difficult to shoot with the camera hand-held.     


Tara said...

Thank you so much for doing this post. Yes, I definitely need to shoot with a bigger f-stop.
Thanks again! -Tara

Laurie said...

I absolutely love that photo of the castle! Great perspective.