Reference Guide

10
Advanced EOS·1 Technology ~"
Superior Reliability
The new EOS-I has been designed specifically to handle
the heavy-duty work loads
of a professional photographer.
Performance
is ensured from -4 °F (-20 °C) up to 113 °F
(45 °C) at 85070 humidity.
1. Thicker Body Material
Composed of extra-tough, glass fiber-reinforced
polycarbonate, the body cover
is approximately 25%
thicker than other models. A base plating composed
of
nickel and copper adds support, while a black chrome
plating completes the camera body, making it tough enough
to withstand rough handling. Thick sections
of non-slip
rubber make holding secure.
2. Moisture-resistant Design
The camera is also highly dust- and moisture-resistant,
thanks to a cover sealing mechanism and the use
of push
buttons,
levers, and revolving dials that are more effective at
preventing water from entering. (Much better than conven-
tional external slide switches.) Rubber seals and guards
protect all possible moisture entry areas.
Even if moisture should enter, important electrical
contacts are placed so
as not to be affected. Shutter blades
and important electrical-contact areas are coated with a
water-repellent lubricant, too.
3. Double Electrical Contacts
All important electrical
contacts have double terminals
to ensure proper operation.
Surfaces
of data-transmitting
contacts are gold plated for
optimum contact.
4. Self-diagnosis Functions
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All camera sequence control operations are monitored
by the main microprocessor to ensure reliability.
If trouble
is detected, the sequence is halted and a "be" warning
appears on the display panel. (Other cameras may not offer
this safety feature, which prevents improper operation.)
There's no problem with power, either. Automatic
battery checks are done during sequence operation to ensure
adequate power for finishing a process. Moreover, pressing
the battery check button under the palm door
gives an
instant readout
of battery power on the display panel.
Other warnings also ensure real reliability. The display
panel presents a row
of blinking dashes as a warning if the
film
is not loaded properly, for example. And a row of
dashes coming out of the cartridge symbol indicates correct
film advance and film rewind.
TTL·CT·SIR AF Ranging System
The TTLCT-SIR (TTL Cross-Type Secondary Image
Registration) phase detection system determines focus
by
driving the lens after completing a sophisticated process of
signal detection and calculations. The system splits light
rays into four beams - two horizontal and two vertical -
that form images on the surfaces
of four sensors. Focus is
determ.ined first by analyzing horizontal and vertical image
data. This extra information speeds up the focus process.
Once this has been completed - a matter
of microseconds
- the lens motor focuses the lens.
S U ~ j ~
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Film Pl ~ a' l C~ ,,~ ""'"
. ' . .::>. '--Horizontal
, . sensor
. ~~ .. '" [ Yertical sensor
/ J Secondary Imagmg
. Le ns
Cross Ranging Sens or BASIS
The new BASIS (Base-Stored Image Sensor) was
created to be accurate enough and reliable enough to meet
the standards
of professional photographers. The result of
extensive research, it consists of two, 47-bit horizontal line
sensors and two, 29-bit vertical line sensors, plus associated
amplifier circuitry that
is housed in a clear-molded package.
By integrating an amplifier with each individual element of
the sensor instead of just having an amplifier section at the
output stage
as CCDs do, BASIS preserves signal integrity
by amplifying the electrical signals before they are read out
through switching. Signal purity
is thus maintained, with
minimum noise and minimum loss
of information. In addi-
tion, the
new BASIS is equipped with an extra circuit that
boosts the signal ten times in order to improve sensitivity
and SI N ratio. The sensor pitch is also 10% finer than that
of previous BASIS sensors, providing improved narrow-line
detection ability. Also, anti-reflection film coats the sensor's
light-sensing areas in order to stabilize signal detection.
Innovations like the cross
Th e Dif f e ren ce Between BASIS an d CCDs
ranging sensor BASIS BA SI S: Sequential readout through sw itching
result in improved
accuracy and better effi-
ciency, makiQg possible
reliable low-light
level
operation down to EV-I,
light dimmer than most
people can see clearly.
~
Amplifier Out put
ce D s: Se qu ential readout through charge transfer
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