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In preparation for the shooting of
Pablo Valiente’s short film we have done a series
of tests with the Panasonic’s Ag-DVX100 MiniDV
camera in co-operation with InfoTv, Madrid Film and
Liquid Productions. The MiniDV format was chosen due
to its reduced cost and the fact that it was the most
adequate to represent the script.
The test was done at the InfoTV facilities using the
following equipment
Panasonic Ag-DVX100 25P Camera 1/25 Cine-Like scene
Wave Monitor/Vectoscope
Sony 9” Monitor
ESSER TEST CHARTS TE 105 TE 125 TE 166 TE 222 TE 223
TE 106 (Some cards are transparencies lit by an LV5
spherical format)
Filmed with Arrilaser on KodaK 5242 intermediate and
printed on KodaK Vision
Within the miniDV format, the DVX100 stands out thanks
to its high quality and specially its 25P feature, with
real progressive scan, as well as to the possibility
of adjusting gamma, colour, detail and many other factors
that make this camera an excellent tool for certain
types of cinematographic work.
What follows are in-depth analyses of the cameras features.
Latitude:
In order to compare the camera’s latitude in both
the cine-like and the default settings, we overexposed
and underexposed on an 18% grey card.
In *
(Fig.1), we can see the characteristic X-shaped wave
that is formed where the blacks are higher than usual.
We can see that the signal in the normal system is more
compressed
* (Fig.2), the blacks are darker and with
less detail although in the area of whites we can see
how the higher values are lower than those in the cinelike
curve; this curve captures more detail in the shadows
and mid-tones at the expense of losing some detail in
the high lights as we can see when we compare the two
gamma curves, resulting in a generally softer picture.
* (Fig.1)
* (Fig.1)
*
(Fig.2)
Comparison between Normal(Pal)
and Cine-Like
In the comparison between normal gamma curves and cine-like
we can see how with the same input signal (see the high
light values), the cine-like outputs a lower signal
than normal, which implies more detail in the shadows
and mid-tones as well as in the high lights, being incapable
of reproducing the information under extremely high
light, whereas the normal curve can still handle it.
The footage in intermediate can be seen in
* (Fig. 3) as well as the print.
*
(Fig.3)
*
(Fig.3)
Greys shot on intermediate and
printed at 32-36-19
We can conclude that with the cine-like feature the
camera maintains a latitude slightly over 5 F-stops,
3 F-stops under the median grey and 2 1/3 over, which
is enough for this format while being far from the latitude
attained by other video formats, such as HDCam, which
reach up to 9 F-stops, and of course film negative which
reaches up to 11 F-stops. In view of these results it
is necessary to light very carefully to ensure that
everything in the shot lies within the range that the
camera can reproduce correctly. For the short film we
had to choose very carefully the actors’ wardrobe
so there were never in the same shot actors with contrasting
clothes, and the set walls have had to be painted darker
than usual. Another aspect to take into account has
been the treatment given to skin tones, as we had to
constantly touch-up the actors’ make-up to avoid
that the reflection from their faces, falling outside
the camera’s latitude range, was reproduced as
burnt-out spots. Using the cine-like set-up clearly
makes the original image smoother than normal and it
therefore requires a colour grading process that adjusts
the blacks, the whites and the gamma in general.
Seq. 2 shot 2 T :4 Lens: 32mm
(relative to 35mm) Filter ND3
In the image we can see the range of latitude, controlled
in this case by lighting the shadows and the choices
made during the shoot.
The camera's sensitivity using the cine-like setting
with a 1/25 shutter speed is around 500 Asa, and 300
Asa at 1/50.
In the previous table we could observe how the luminosity
and the V response is very similar with very wide apertures,
which made me decide to work on 3.4 throughout the majority
of the film. In the grey scale we can notice this, with
the card's luminosity remains almost identical all the
way until Open (1.6). For that reason the optimal highest
aperture is 2.8 and the lowest one is 16
Sharpness
One of the most significant improvements in terms of
image sharpness has been the camera's ability to shooting
with a real progressive scan, thanks to which we can
really see the camera's 440.000 pixels of resolution.
In the following cards we can see the camera's definition,
which, despite being far from professional format performance,
is very good for its range, making it possible to consider
transferring the image to 35mm as long as one is aware
of the existing limitations.
Resolution card in Cine-Like
mode
In the following images we compare the camera's definition
with that of a professional format to illustrate the
importance of definition in the quality of the final
projected image. It is of utmost importance to choose
the format on the basis of the story being told, and
although this camera is perfect for the work we Pablo
Valiente's project, it might not reach the necessary
standard for other kinds of productions, despite whatever
some producers might suggest, based on economic considerations
rather than artistic decisions. The camera's definition
makes the use of this camera recommended for very specific
work if it is going to be for shown in big screens.
In our case, and given the film's story we decided that
the look of the film required a certain "roughness"
provided by this slight loss of sharpness.
Notice the difference in resolution in the edges of
the image as well as the centre
Comparison between HD resolution
and MiniDV, with a 300% zoom.
Colour
Another camera feature worth mentioning is how it transforms
the colour towards tones closer to emulsions than to
video. In FIG 7 we can see the difference in colour
between normal settings and the cine-like feature, the
latter having the reds slightly corrected using the
phase so they did not tend so much towards magenta.
Macbeth card in Cine Like and
Pal Normal formats. Notice the difference in saturation
as well as the difference in the tones, specially in
the reds
The final look has a more natural colour, less shrill
than that of normal video. In the images we can see
the differences in colour and the results after colour-grading.
It should be noted that the camera in preset 3200 gives
an excessive red dominance that can be easily corrected
during colour-grading.
Original frame
Colour-graded frame. Notice the
original deviations towards red as well as the smoothness
of the image.
Resolution comparison between
colour HD and MiniDV
Colour resolution close-up
Seq.4 shot 1 T: 3.4 Focal 32mm(correspondencia
con 35mm) 1/25
Lens:
An excellent Leica Dicomar lens without noticeable anomalies,
if anything a very slight decrease in light uniformity
with apertures under 2.8. Absence of geometric distortions
in either the widest angle or the longest tele. The
lens has excellent and great sharpness without noticeable
chromatic anomalies. Other considerations:
The camera makes it possible to modify many parameters
that affect the image. To attain a more professional
level, the camera would need a few improvements, such
as adding marks to the focus ring (instead of the no-end-stop)
and a remote focus control. In addition, the diaphragm
adjustment has to be done in half F-stop units, which
is not very comfortable. Another inconvenient was the
RECORTE that both the view-finder and the LCD screen
DO on the sides of the frame, hiding considerable amounts
of the image on both the left and the right sides. This
problem can be solved taking a monitor with underscan
on-set, but we didn’t always have that chance.
Access to the menus was quite simple and comfortable.
The menu allows us to slightly modify the levels of
detail, chroma and the phase amongst others.
Conclusion: In my opinion this camera offers a standard
of quality high enough to be used in professional projects,
with very good results in every aspect, although one
should never attempt to use it as a substitute for professional
formats. Quoting cinematographer Tamí Reiker
“When you shoot in MiniDV instead of asking yourself
how you are going to make the images beautiful you have
to ask yourself: How am I going to make these images
aceptable?"
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