Plenty of structures here for the AF to see. Handheld. |
When I started
making pictures with the FZ1000, I noticed that quite a few shots taken at the
long end of the zoom were not quite sharp.
I carried out systematic chart testing of the lens at all
focal lengths and discovered that the lens is not quite as sharp at E400mm as
it is at shorter focal lengths but it is still very good and should be capable
of making convincingly sharp photographs.
I noticed that some of my pictures at E400mm looked
impressively sharp when printed at 400x600mm in size while others were only fit
for the trash bin.
I had previously had
very much the same issues with the Lumix
100-300mm lens (E200-600mm) on Micro
Four Thirds and the long end of the E25-600mm lens on the Panasonic FZ200.
What's going on? I think the same issues apply to each of
these lenses at the long end.
1. If some pictures are convincingly sharp and others are
not the problem is most likely either
a) focus variation or
b) user technique variation
or
c) subject variation
I have come to the view that all three factors are in play.
2. The lens loses local contrast (a.k.a. microcontrast) as
it is zoomed out. I can easily see this in my test chart photos. In addition in
each case there is slight loss of resolution.
3. Due to the above, the camera's contrast detect autofocus
system has more difficulty achieving focus at the
long end.
4. The effect of camera shake is progressively magnified towards
the long end and this is not fully
compensated by OIS, even the excellent 5 axis type in the FZ1000.
My impression is that OIS is very good for compensating
relatively slow shake cycles but not so effective for compensating the fast
cycles which are a significant cause of unsharpness due to camera shake with very
long lenses.
5. I have noticed that the problem of intermittent
unsharpness is most apparent with subjects at a long distance from the camera.
6. Observation of photos taken at long distance clearly shows
the deleterious effects of haze and atmospheric distortion. The latter is a
phenomenon caused by swirling air currents within which the refractive index of
the air varies enough to affect photographs, sometimes to a marked degree.
7. Both the above
factors make the task of the contrast detect AF system even more difficult.
In response to the above observations and impressions I have
worked out a set of guidelines for improving sharpness at the long end of the
zoom.
Settings
Mode Dial S with shutter speed at 1/400sec or faster for
static subjects, 1/800 sec or faster for moving subjects. This will usually see the aperture at f4. OR
Mode Dial M with aperture at f5 or f5.6 and shutter speed as
above, Auto ISO in each case.
This can be useful for static subjects as the lens performs
slightly better at f5 than f4. For
moving subjects combatting shutter shake and achieving accurate focus are more
important.
Focus Mode AFS or Manual with peaking for static subjects,
AFC for moving subjects. Manual focus works best on tripod as the camera needs
to be reasonably still to enable viewing of the enlarged image with peaking.
Autofocus Mode 1 Area, AF box sized to match the subject but
larger = more sensitive, smaller = more precise. I usually have the box at around
size 5/15 counting up from the smallest.
Shutter type, mechanical.
The FZ1000 does not have a shutter shock problem so the mechanical
shutter is OK.
Technique
Hand Held:
Stand, sit or lie comfortably and relaxed.
Look through the EVF with the camera steadily braced against
the skull bones.
Practice breathing technique. Mini meditate to slow the
heart rate and reduce muscle tremor. Squeeze
the shutter button just at the end of a slow exhalation.
Place the AF box over a part of the subject which is
reasonably light in tone, has good contrast and if possible has strong vertical
lines (camera in landscape orientation). Note that Panasonic AF (and possibly
others, I don't know) will not focus on a non textured subject with lines
running only horizontally.
Make the box as large as possible without extending outside
the main subject so focus on the background is prevented.
Tripod:
Use Timer 2 sec or remote shutter release.
Lowest possible ISO for the conditions.
Manual focus where possible.
Subject For distant
subjects try to photograph on a day with low air pollution and low haze. In
most locations some seasons/wind directions are usually better than others.
Try to have the subject in cross lighting for maximum
definition.
Early mornings usually see the least air turbulence of the
day.
Summary The FZ1000 can make very good or just
mediocre photos at the long end of the zoom. In most cases good results can be
attributed to correct settings, subject selection and optimal technique.
I have taken my own advice and the results are improving.
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