Over time,
the modular mount and Stiletto assembly may become dirty from everyday
use. In reality, quite a bit of debris can accumulate before
focusing becomes impaired. Do not conclude that the surface of the
ronchi screen needs to be impeccably clean f or
it to function properly. A stray fingerprint or minor dust will
have no affect on its usage at all. The ronchi screen is
sandwiched between two layers of optical glass which protect it from
inadvertent damage. A standard air duster spray is recommended to
eliminate the accumulation from the glass surfaces . To remove
a fingerprint or similar smudge, however, a cotton tip
lightly soaked with industrial grade acetone may be used. Take
care to use a minimal amount of acetone and avoid touching the plastic
bushing. Do not use too much acetone since it can dissolve the
ronchi screen if it penetrates around the protective glass.
The snap bushing housing the screen and optical glasses should never
be disassembled for cleaning.
When the modular mount is detached
from the Series IV body, take care to protect it with the body
and focusing tube caps supplied with the unit. Always store
your Series IV and mount in a cool, dry place.
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onchi screen which is mounted
in a helical focusing tube. The focusing tube rotates within the
modular mount and adjusts the distance from the ronchi screen to the
front of the mount. This distance should correspond precisely
to the film-plane distance of your 35mm camera, or to the backfocus
distance of your CCD camera. The ronchi screen itself is mounted
within a removable snap bushing and is protected on each side by clear
optical glass. A calibration mark is placed at the factory setting
for your particular camera to indicate the proper position as it left
our factory. Little or no adjustment should normally be necessary.
The following instructions are provided as guidelines should you prefer
to optimize your Stiletto assembly for a particular non-standard camera
setup or when using an unusual combination of mounting adapters.
aking
any adjustments, take note of the existing calibration mark so that
you can easily return to the initial factory position if necessary.
First, break the seal which keeps the focusing tube in place.
A small amount of medium-strength Loctite holds it in place. You
should be able to free the tube by gently turning it with your fingers.
If leverage is necessary, carefully use a pliers to grip the outer threads
of the focusing tube to turn it to break the seal. Take
care to avoid touching the surface of the delicate ronchi screen at
all times. Normally, only very small adjustments of the tube assembly
are necessary. A half-turn of the focusing tube in either direction
will make significant changes in the focus. The threads on the
focusing tube are 32 tpi. Normally, focusing tubes may be adjusted
a minimum of 2mm in or out. Making small changes in the position
of the tube will allow you to do A-B comparisons with either developed
film or the CCD images on your screen. Once you optimize the tube
position, be sure to mark the tube and the calibration circle
for future reference. Should you have any problems,
the modular mount may be returned to us for recalibration free
of charge (other than shipping). Please refer to the Series IV Instruction
Manual for complete details on the recalibration procedure.
screen
through flexing. Undue and uneven pressure may crack the delicate
optical glass which protects the screen from moisture and inadvertent
contact. Th
tside of the 
circumference
of the focusing tube. This step is essential to maintain the
proper film-plane distance or backfocus distance between changes to
different resolution ronchi screens or if installing the True
Knife-edge Option.