In
the last issue we
looked at the JVC GY-DV500 camcorder from the perspective of two
other quite different cameras.
This time we look at it with its obvious rival, the Sony
DSR-300 DVCAM. It is
important to emphasize 2 things right up front:
-
The
Sony costs a lot more than the JVC, indeed around twice as much.
-
Cameramen
are notorious for their personal foibles, one man�s meat etc.
There
are several other reviews currently in print of these cameras, and I
would particularly recommend readers to look at the one
in the May edition of our US cousin, DV
Magazine. These
will give the features and basic performance descriptions, but I
would like to concentrate first on the actual image quality.
Both
cameras claim 800 lines resolution, and a sensitivity of f11 at
2000lux. The sensors
principally determine the basic imaging performance, and both
cameras use 3 of half-inch CCD chips, apparently both made by Sony
and with the same pixel count of 752x582.
This gives a useful amount of oversampling to derive the DV
line sample rate of 720. CCD
cameras need an optical anti-alias filter to avoid Moir� type
patterns with incoming image detail, and these are provided as a
pack of glass plates mounted behind the lens in front of the colour
splitting prism. They
are rather inefficient and will eat into the available sample size
of the chips, so any oversampling will help retain the required
codec resolution. I
suspect that these cameras use different filter packs since I found
slightly different effects when playing with a zone chart.
This is a collection of about 500 concentric circles that
give endless possibilities for aliasing effects as the lens is
slowly zoomed in and out. Neither
camera showed anything to cause any problems on real pictures, so
the filters are obviously working well.
It is the anti alias filter by the way that causes the
6-pointed star to be seen on bright highlights.
There
are �Lies, damn lies, and camera resolution specs� so the 800
lines figure should be dismissed as marketing nonsense!
Both cameras gave a very solid output at 600+ lines which is
plenty to fit in the 720 samples of the DV codec (use a 75% scaling
factor to align with normal broadcast practice).
Both
cameras use their own versions of Digital Signal Processing, or DSP,
which offer the virtues of accurate processing and easily adjusted
variables via menu control. Set
to the factory default set-ups, the JVC had rather more obvious
levels of aperture correction or �detail�.
This is artificial edge enhancement that is added to the
basic optical image to give a sharper appearance.
If it is overdone, ugly overshoots become too obvious as dark
or light haloes around objects. Both these cameras allowed extensive control of not only the
amount of correction but also the boost �frequency�. This observer would probably decrease the default detail
somewhat but they both produced attractive crisp pictures that would
be spot-on for many other users.
Pic.
1 - GY-DV500 with default set-up
Pic. 2 -
GY-DV500 with �Matrix� switched off
Pic. 3 -
DSR-300 with default set-up
Pointing
the cameras at a coloured still life scene revealed quite different
looking pictures with the default set-ups.
The scene was deliberately lit with a single key to produce a
deep shadow and strong contrast. The Sony is brighter in mid tones
and less saturated than the JVC.
After the last test I was advised to try turning off the
Matrix on the JVC and sure enough this reduced the colour saturation
considerably. Normally
a colour matrix is supposed to improve the accuracy of a camera�s
colourimetry but apparently this one is intended to appeal to
wedding videographers! It
does produce very rosy tones so some folk will like it�s cheerful
results. These initial
images produced are shown in the top row of the montage printed
above, the differences will be somewhat emphasized in print. Viewed on a Grade 1 broadcast monitor, the central JVC image
was the nearest to the truth, but all three images were quite
acceptable in isolation. Note
that the three images were all exposed for a white target, which has
been cropped off in these pictures.
Pic.
4 - GY-DV500 with preferred �detail�
Pic. 5 -
DSR-300 adjusted to approx match JVC in Pic. 4
The
JVC has a rather more limited selection of adjustments available in
the user menus. I
understand that this is something under continuous review and is one
of the benefits of DSP, it is relatively easy to add or change
functions with a software update!
The Sony has an extended menu available by holding down the
menu select switch on power up, and this offers quite an extensive
list of variables. I�m sure that should the occasion demand it would be
possible to match the pictures from both cameras with reasonable
accuracy. I very
quickly adjusted the Sony gamma, saturation and black level, and
managed to get the pictures a lot nearer to the JVC as shown on the
bottom row of the montage. I
also made a quick attempt to get a �detail� value that I liked
but this would need more realistic subjects.
Whilst I make no claims to exact matching, the exercise
proves that there is very little difference in the basic image
quality or colourimetry of either camera,
and despite the differences in cost there is no reason to
deduce that the Sony has any better quality DSP than the JVC.
Looking
now at some general operational matters, the Sony is a couple of
pounds heavier than the JVC but its gel type pad gives a very
comfortable fit, although it doesn�t feel quite as stable on the
shoulder as the conventional pad on the JVC. The Sony is probably very good for those folk who have a
non-standard slope on their shoulder and thus have trouble keeping
the camera level. The
viewfinder on the JVC suffers rather in comparison to the Sony,
which has a superior image quality, adjustment and apparent build
quality. I also found the Sony Zebra patterns much better but this
is definitely into personal preferences territory. The JVC did
produce a bigger image though, which was appreciated.
Since any viewfinder on the JVC is an option, it is perfectly
acceptable to buy the viewfinder from the DY-90E, which is a
straight replacement and would offer much better quality.
The handle on the Sony was a little easier to use for
handheld shots but like all current camcorders there is little
thought given by any manufacturers to this mode of use.
Both cameras appear to be solidly constructed with alloy
bodies and good protection for switches and connectors.
The Sony consumes a couple more watts of power than the JVC
and will therefore have slightly shorter battery life.
At
the end of the day, many users will decide on the basis of their
chosen tape format, although both formats have the same basic video
and audio performance. The
Sony uses the DVCAM format which does offer a few feature
advantages, whilst the JVC uses a slight variation on the basic DV
format. The JVC is also
limited to MiniDV cassettes and therefore a nominal 60-minute
duration. Both cameras
offer forms of scene identification that may well prove of great
value, but are not widely supported by editing software at the
moment. The JVC and the
more recent DSR-300AP version of the Sony also feature a Firewire
(IEEE-1394) port, but I will reserve discussion of this for another
day.
In
conclusion, for those uncommitted folk looking to buy a low cost,
fully professional digital camera then the JVC is tremendous value
for money. The Sony is
probably a little more solid and has more user adjustments
available, but the JVC can produce very similar picture quality for
a lot less investment and for many that will be enough.