Clairmont Camera has modified the Sony F900 cameras to make them
more user friendly for people used to working with film cameras. As
the camera comes from Sony, it makes sense to be as light as possible
and for the controls to be located where they are for ENG work from
which this camera evolved. For the type of work required, shooting
movies, TV movies, TV series, and commercials, the ergonomically
relocated controls are more user friendly.
The lens mount and integral frame which holds the 'Optical Head
Block' (the prism and it's three attached CCD imagers) is not rugged
enough for cine style work. This lens mount/frame is made of die-cast
aluminum and subject to burrs. These burrs prevent the lenses from
seating squarely against the lens mount and result in back-focus
errors and uneven focus across the frame. The F900 utilizes 2/3"
imagers and when compared to 35mm academy format, we use lenses 2 1/2
times wider to accomplish the same field of view. This is of concern
considering that wide angle/short focal length lenses are very
critical regarding back-focus. The other concern with the die-cast
aluminum is it's expansion and contraction due to temperature changes.
The F900 produces enough internal heat that it requires two internal
fans to reduce temperature. This expansion and contraction of the lens
mount/frame causes changes in back-focus as well. Clairmont Camera has
machined a new lens mount/frame from a 'space age' stainless steel
alloy utilizing the existing B4 mount specifications. This new mount
is much harder than die-cast aluminum and resists deformation and
burrs exceptionally well. This lens mount/frame is also 'thermally
stable' from -100F to +400F and back-focus changes due to thermal
expansion and contraction have been eliminated within the camera. We
reassemble the Optical Head Block to the new lens mount/frame,
precisely aligning optical centering and flange depth. All filters in
the filter wheels are checked for precise thickness and optical
refraction index. This eliminates any back-focus change occurring
during filter wheel changes due to variances in the filters.
The camera's stock front plate, to which the lens mount/frame and
Optical Head Block are attached, is manufactured of thin die-cast
magnesium. When this plate flexes, as it does when the camera is used
on a shaky platform like a helicopter, the images are not steady due
to the lens moving around. Clairmont Camera manufactures this front
plate out of a much thicker and harder material than the original
plate. Inside the camera we add reinforcements to the camera's
original top and bottom horizontal frames. These reinforcements are
tied to the vertical plate making for a very rigid front plate and the
attached lens mount/frame. This front plate has a large button to stop
and start the onboard video recorder and is placed in a more
accessible location. A protective guard has been added around the
filter selection knobs to prevent inadvertent movement of the filter
wheels.
The original controls for menu selection, shutter control, and
white/black balance, have been ergonomically relocated to the new
Clairmont carry handle. This makes room for the Arri mini-rod bracket
on the front plate allowing use of Arri 16SR style follow focus and
matte boxes. Motors for remote focus and iris can also be attached to
these rods.
Clairmont's new carry handle has been designed to make the camera
more rigid. The carry handle contains the earphone outlet, menu
control, shutter control, and white/black balance controls,
ergonomically relocated for fast, easy use. Clairmont's new video
eyepiece bracketry is manufactured from stainless steel for strength.
The top of the handle has 1/4x20 and 3/8x16 steel insert threaded
holes to accept Steadicam mounting plates and other onboard
accessories. This new handle has been designed to be Steadicam
friendly, and has three 12 volt power outlets for accessories such as
lens lights, Cinetape Measure, onboard video monitors, transmitters,
remote focus, iris, zoom controls, etc. We've also added two 12 volt
power outlets to the camera's side cover. This gives the camera a
total of five 12 volt power outlets with 8 amps (96 watts) capacity.
Each connector is rates at 1 1/2 amps not to exceed 8 amps total.
There are four additional 12 volt power outlets on the onboard Evertz
HD/SDI F9 adapter. This F9 adapter provides for NTSC down converts as
well.
The camera mounts onto a Clairmont manufactured balancing plate
which allows use of Arriflex matte boxes, follow focus, lens support,
focus motors, iris motors, and anything else that will fit on Arriflex
15mm rods. This balancing plate has a quick release for the camera so
the camera can be removed easily and quickly and an improved
rear-mounting pin for positive locking.
For onboard batteries, Clairmont Camera selected the Pag batteries
and chargers. Clairmont decided to use Ni-Cad and Nickel-Metal Hydride
batteries as we do not feel Lithium batteries have been proven yet.
Clairmont did not get the largest onboard batteries as we feel the
cameras will be hand held only a small part of the time and the
batteries should be light for this. The Pag Ni-Cad and Nickel-Metal
Hydride batteries are flat, keeping the length of the camera down. For
most shooting on sticks or dolly, the cameras will be powered by block
batteries using a 14 Volt 25 amp battery.
All Clairmont Camera Sony F900 cameras come with a high resolution
eyepiece, resulting in a better edge to edge eyepiece focus and lack
of distortion when compared to the standard eyepiece. The Sony
telescoping extension eyepiece is available. This extension finder
works with either the Arri or the Clairmont quick-release type
eyepiece leveling rod.
Clairmont Camera adjusts all lenses for proper back-focus
according to the B4 back-focus standard that the lens manufactures
prescribe. With the Clairmont Camera B4 lens mount and all the lenses
set to this B4 standard, there is no need to change the back-focus on
the lenses as they are changed for another focal length or put onto
another camera converted by Clairmont. To be able to check this
back-focus, Clairmont Camera came up with the idea of having a video
collimator. This makes back-focus checks much quicker and easier than
putting a chart in front of the camera and using a tape measure. After
making a test collimator to prove that this theory would work,
Clairmont went to Century Precision to manufacture these and Century
improved on the device. This collimator has been tested down to 0
degrees F (-17C). Unknown to Clairmont Camera, Zeiss in Germany was
designing the same item at the same time. In Clairmont's opinion, both
brands work well.
Clairmont Camera has carefully selected the lenses for our HD
cameras. For prime lenses, we found the Fujinon lenses have excellent
resolution. The focus scales are user friendly, and there is almost no
breathing while focusing. The Fujinon lenses have back-focus
adjustments that Clairmont can standardize easily. There is an
excellent selection of focal lengths with the Fujinon lenses. The
newest Canon prime lenses also have all these same qualities although
Clairmont feels the Canon focal length selection needs to be improved
so they have not purchased any of these lenses. Clairmont Camera also
has Zeiss Digiprime lenses that are excellent. These lenses have the
best focus scales and no breathing at all when focusing. All the Zeiss
Digiprimes are the same size and length for ease of use. Their optical
quality can not be beat. The Zeiss Digiprimes have a back-focus scale
with numbers. When the lens is properly adjusted, this scale is set to
0. This means when you change the lenses, all you have to do is set
the lens back-focus adjustment to the same number as the lens you have
just removed from the camera. This would be 0 if the camera is
adjusted properly, otherwise the error can be adjusted with the
back-focus of the lens.
Clairmont Camera has purchased the Pro35 lens adapter that allows
the use of 35mm motion picture lenses on the Digital cameras. This
adapter fits onto any camera with the B4 lens mount. It moves the lens
forward six inches and raises it about 1 1/2 inches. The Pro35 has an
iris at it's rear exit pupil that is used to control the amount of
light falling onto the CCD imagers. This iris will not effect depth of
field and can be used in conjunction with the camera's ND filters to
control exposure. The iris on the taking lens controls the depth of
field. At this time, our first tests indicate that you do not want to
close the taking lens iris to an opening smaller than T2.8 . Smaller
openings tend to make the ground glass visible. The Pro35 gives you
the same field of view and depth of field you would expect from the
taking lens if used on a 35mm motion picture camera. The image from
the taking lens falls onto a ground glass inside the Pro35 that is
oscillated so that grain on the ground glass is not visible. A
thumbwheel controls the speed of the ground glass oscillation. Power
and VTR start/stop functions to/from the Pro35 are supplied by a cable
connected to the camera's lens connector.
