RESOLUTION SOLUTION
The Canon Magazine 89
EOS S.O.S
Break the resolution rules
The old rules for shake-free photos are challenged by high-resolution cameras
E
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ver since I read my first book
on photography there’s been
one rule for sharper photos that
always holds true – keep everything
still. For the times you hand-hold the
camera, the rule is to use the reciprocal
of the focal length to avoid the chance
of camera shake. So, if you use a
100mm lens, then you’ll need 1/100
sec shutter speed, and for a 500mm
lens 1/500 sec.
But with the advent of hi-res digital
sensors and larger screens we’ve
stopped judging the sharpness of a
10x15cm print. My 24-inch monitor is
50cm wide and there’s 1920 pixels in
those 50cm. Zoom in to 1:1 on a 24Mp
image and it’s like looking at a print
that’s 1x1.5ms. It’s no surprise that you
see more faults looking at digital
images at full-size on a monitor.
When the first EOS-1D was updated
to the EOS-1D Mark II and the resolution
jumped from 4.1Mp to 8.2Mp, many prosports photographers found they
needed to use faster shutter speeds to
achieve the same level of sharpness.
Fast forward to the 24Mp and 30Mp
cameras commonly in use and you
should realize that the old rules might
have stopped being as effective.
With the current crop of cameras,
solid tripods or faster shutter speeds
are needed to freeze miniscule
movements of subjects. I’ve been using
the reciprocal of twice the focal length
as my guideline for years. For portraits
I do my utmost to use a minimum of
1/100 sec regardless of the lens.
If you use Program or Aperture
Priority with Auto ISO, your camera will
do it’s best to achieve the traditional
hand-holding speeds for your lens by
raising ISO. The more advanced models
include custom settings to select 1, 2 or
3-stops faster shutter speeds than the
rule would dictate. You can even set a
fixed minimum speed too. From theEOS 80D, EOS RP and higher models
this capability is found in the ISO Speed
settings, and if you use Auto ISO with
Program or Aperture Priority I suggest
you go and update the usage of this
rule for sharper shots.Setting the camera for faster shutter
speeds suitable for the lens being
used ensures sharper action shotsManual min shutter speed delivers sharper
portraits with a shutter speed of 1/125 sec