Regarding the issue of shutter lag in compacts, a lot of that has to do
with AF acquisition time, all compacts and mirrorless cameras use a
contrast detection AF system utilising data from the sensor, that up
until now that has been quite slow. Panasonic were the first to develop
a contrast detection system that was a match for lower end DSLRs. DSLRs
use a phase detection system for AF with a dedicated AF sensor which up
until now has been leaps and bounds ahead of the contrast system in
compacts. The latest Panasonic can shoot at 4 frames per second and has
AF to match. They also have very good EVFs. Here's a review of the
latest Panasonic:
http://www.techradar.com/reviews/cameras-and-camcorders/cameras/digital-slrs-hybrids/panasonic-lumix-dmc-gx1-1044318/review?artc_pg=1
If you have a compact there are some things you can do to reduce lag,
including activating options like continuous AF, so the lens is focusing
at whatever it's pointed at not waiting for you to half press the
shutter, not all cameras have the option of course. MF also reduces
lag but it is normally so fiddly to activate it doesn't help much. The
problem with the super zoom compacts is that the AF and image quality at
the long end is a compromise, the lens is slow (about f5.9) at the long
end and the image quality is a bit average. The other problem I believe
is that they focus in steps, not continuously. This hidden at shorter
focal lengths by the large Depth of field inherent in small sensor
cameras, but not when DOF drops at large focal lengths. In fact
theonly reason they do what they can as well as they can is the small
sensor, it's a lot easier to design and build a compact lens that is
sharp across 4mm x 6mm sensor than it is to get it harp across a full
frame DSLR.
Nikon have also release a mirror-less "DSLR " the V1 that is reported to
be very good with AF, though in Aus is is pricey and the sensor is quite
small. It can use Nikon SLR lenses with an adapter that maintains full
functionality.
One thing that is of interest for bird photography with micro 4/3
cameras like the Panasonic above is the availability of adapters for
other lenses. Of particular interest is an adapter for the old Canon FD
lenses, that system was orphaned 20 years ago and some excellent optical
quality lenses can be picked up for a song. The beauty of the EVF with
these lenses is that you use the MF assist system quite easily and it
gets around the manual aperture on these lenses by allowing focus with
the lens stopped down as the EVF automatically adjusts the brightness.
Something like the Canon 500mm f4.5L lens which is a sharp as today's
$10,000 EOS lens goes for about $1000 on Ebay, allowing you to get
1000mm effective focal length with superb optical quality for a song.
I have one of these lenses from my film days and was using it adapted
to my EOS DSLR until I upgraded recently to the Canon 500mm AF lens.
I'll be trying to sell it soon as these new micro 4/3rds cameras have
opened up a market for such a lens.
Chris Ross
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