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CHANGING POWER
To change magnification, rotate the Zoom Power Change
Ring to the desired power as indicated by the white
engraved scale.
As you zoom from low power to high power under low light
conditions, you may notice a decrease in image brightness.
This is normal. All magnifying optical instruments show a
decrease in image brightness as magnification is increased.
HOW TO USE YOUR DISCOVERER AS A 1 0 0 0 M M
TO 4000MM ZOOM TELEPHOTO CAMERA L E N S
With the addition of 2 inexpensive accessories, the
Discoverer will attach to a 35mm single lens reflex camera
that has a removable lens. It then becomes an integral part of
the camera’s optical system and functions as an extra
powerful zoom lens.
The two accessories needed for this are; a #22-3030
Telephoto Camera Mount and a Camera Body Adapter that
matches your particular camera (see listings under
accessories at the end of these instructions).
TO A S S E M B L E
1 . Turn the spotting scope’s Telephoto Adjustment Control
Ring clockwise all the way until it stops, then screw the
Telephoto Camera Mount over the eyepiece.
2 . Screw the Camera Body Adapter to the other end of the
Telephoto Camera Mount.
3 . Remove the standard lens from the camera and attach
the body to the Camera Body A d a p t e r.
TO USE
1 . Films with the highest ISO ratings are recommended.
The faster the shutter speed, the sharper your picture.
2 . Mount the spotting scope on a sturdy tripod or shooter’s
stand. A car window mount is also available but it is
recommended that the camera not be operated while the car
motor is running since the slightest tremor at even the
spotting scope’s lowest magnification can ruin image
sharpness. Shield the scope from wind as much as possible
and always use a cable release or the camera’s self-timer to
make an exposure.
3 . After setting up, locate the subject through the camera’s
viewfinder in the usual way with the spotting scope at it’s
lowest magnification. This gives the widest field of view. Once
located, you can frame the picture as desired with the Zoom
Power Change Ring in the same manner as when using it as
a spotting scope, then use the focusing system of the spotting
scope to bring the subject into sharp focus. Minimum focus
distance as a telephoto lens is 80 feet.
LENS CHARACTERISTICS
Coupling the spotting scope to a camera creates a
completely new lens system, the essential characteristics of
which are controlled largely by the scope-with one exception:
the Discoverer does not incorporate a variable aperture
(f/stop) control. In this new system, each of the scope’s 7
power settings has its own effective f/stop as shown on the
Telephoto Camera Mount, and any increase or decrease in
the amount of light transmitted to the film at any one power
setting must be made by a change in the camera’s
shutter speed.
HOW TO DETERMINE SHUTTER SPEED
The following reference chart can be used for shutter speeds
only under bright, sunlit conditions.
If your camera’s shutter speeds do not match these
calibrations and if the difference is very slight, the next higher
speed indicated on your camera’s dial should be used.
Underexposure in both black and white, and color film
(particularly color film) is recommended.
CAMERAS WITH BUILT-IN METERING SYSTEM
Set the camera’s film speed dial to the ISO rating of the film
being used. Turn the Zoom Power Ring on the spotting scope
to the desired magnification (telephoto effect) and check the
chart printed on the Telephoto Camera Mount for matching
f/stop, determine the shutter speed in the usual way.If the
c a m e r a ’s meter will not give a reading, increase the film’s ISO
setting until it does. Remember to make a note of this higher
setting - the laboratory will need to know it when you bring in
the film for processing. Also keep in mind that all subsequent
pictures on the same roll must be taken at this same ISO
rating - roll film cannot be processed by individual frames.
Spotting Scope/Telephoto
Adjustment Control
Telephoto
Guide
Telephoto
Camera Mount
Camera Body
Adapter
35mm
SLR
Camera
ZOOM TELEPHOTO LENS ADAPTATION FOR SINGLE
LENS REFLEX CAMERAS WITH REMOVABLE LENS
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