NZPhotographer Issue 23, September 2019

SUNSET OVER MT NGAURUHOE
F11, 1/6s, ISO 64
than enough for everything they would ever use it for,
including A3+ prints. The number of megapixels your
camera has, only impacts sharpness if you intend to
make huge prints of your photographs.
Lens – I think lens quality is a more important factor
to consider when it comes to image sharpness. A
camera body only records light; it is the lens that
controls the quality (sharpness) of this light and
focuses it onto the sensor. There is no point owning
a camera with a 45MP sensor and using a cheap
lens that is only capable of 12MP sharpness, and
some low-quality lenses would not even be capable
of rendering this sharpness. Even the very best fullframe
lenses available today are still not capable of
resolving 45MP in terms of sharpness, but some do a
much better job than others.
The DXOMARK website is an excellent resource for
lens tests and saves the work of testing them yourself.
Coming back to my earlier point about the 40MP
phone and why this is a bit of a joke, I doubt the tiny
optics on its lens would be able to resolve much of this
resolution sharply.
Sharpest Aperture / Diffraction – All lenses have a
sweet spot, and you need to test your lens or use a
website like DXOMARK to find out this information.
This will differ from lens to lens. As a go to for most
full-frame camera lenses, your sharpest aperture
will be around f8, with f11 only having very minimal
diffraction. With each aperture narrower than this
(e. g. f16, f22) you will lose noticeable sharpness in your
image due to diffraction.
CORRECT FOCUSING TECHNIQUES
Focusing in the right place and obtaining enough
depth of field to get both your foreground and
background in sharp focus is critical for most
landscape images. A slightly out of focus image
on your camera will be extremely noticeable when
viewed at 1:1 zoom later on your computer and even
more in a large scale print.
AF Point – People tend to rely on their camera’s Auto
AF point selection mode. While using AF is not a
problem we need to take control of the AF system
and where it focuses; by using the Auto AF point
selection, the camera would focus on the closest
subject it can find, and this would likely leave the
background out of focus. By manually selecting our
AF point, we can still utilise the AF system but decide
where we wish the camera to focus within the image
to obtain the best depth of field.
September 2019
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