Opticron GS 665 User Manual

Telephotography

Telephotography using SLR cameras (digital or film). In this system

the camera lens is substituted for the telescope + telephotoadapter
or telescope + eyepiece + photoadapter. To convert your GS
fieldscope to a 750mm
40215 telephotoadapter. Alternatively connect a suitable push fit
photoadapter to your viewing eyepiece.
connect the assembly to the camera body.

Notes. Focusing is facilitated on the telescope. Camera may need to be operated in
manual mode with shutter locks disengaged where necessary. The high magnification
to aperture ratios result in slower shutter speeds compared with conventional
telephoto lenses so choose an IS0 setting of 400. For 35mm SLRs 400 ASA film is
recommended. If possible use a cable release or remote control to reduce camera
shake when operating the shutter.

1

This is an approximate figure based on 35mm SLR cameras. D-SLR cameras use
different sized image sensors compared to 35mm so an equivalent telephoto conversion figure must be calculated separately.

2

For information on push fit photoadapters visit our Telephotography pages at www.opticron.co.uk

Digi-scoping with digital compact cameras and camcorders

5x. To get the best results you will also need to fit a low magnification wide angle eyepiece to your telescope or use a zoom
eyepiece set at minimum. To find out more about bespoke digi-scoping kits and universal mounts and brackets visit the
Telephotography pages at www.opticron.co.uk or contact Sales on [phone].

Opticron

©

1

/f.11.3 telephoto lens, you will need a

2

A T-mount is required to

Shooting high magnification photos and video through your telescope is possible if you have a suitable
camera or camcorder. To find out how suitable or not your camera is for digi-scoping, position it up to the
viewing eyepiece and see if an image appears on the screen. You may have to position the camera a few mm
away from the eyelens of the eyepiece and increase the zoom to get a full frame image.

The most suitable cameras are those with a lens diameter of 20mm or under and zoom range no greater than

Opticron, Unit 21, Titan Court, Laporte Way, Luton, Beds LU4 8EF UK.

2013. All equipment and specifications illustrated are subject to change without prior notification.

Camera body

T-mount

1. Telephotoadapter or

2. Photoadapter +
eyepiece (inside)

GS Telescopes

User Guide

GS6650513

Models

GS 665 GA

GS 665 GA/45

GS 665 GA ED

GS 665 GA ED/45

Getting Started

Your GS telescope will open up a whole range of new and exciting
impressions, whether for general use or specialist study. To focus at
different distances, simply turn the main focus wheel in conjunction
with the 9:1 ratio accurate focus adjuster until the image being
viewed becomes sharp. To minimise image shake caused by high
magnification the instrument should be supported using a suitable
tripod or mount connected via the tripod socket located on the
tripod sleeve. If the eyepiece being used has a fold down or
retractable rubber eyecup it should be used in the down position
when wearing glasses. This ensures the maximum available field of
view is obtained. Be sure to return the eyecup to the up position if
you or anybody else wants to view without glasses. The retractable
lens hood should be extended when viewing in bright sunlight.

Rotating sleeve
and tripod socket

Eyepiece

Main focus wheel

9:1 ratio accurate
focus adjuster

Retractable
lens hood

Specifications & Eyepieces

Specifications 665 665/45 665ED 665ED/45

Product Code 40960 40961 40962 40963
OG Dia (mm) 66.5 66.5 66.5 66.5
Min Focus (m) 3.8 3.8 3.8 3.8
Length (mm) 326 326 326 326
Weight (g) 976 980 1049 1053

EYEPIECES • SDLv2 • HDF • HR/HR2

Product Code 40936G 40810G 40809G 40858G 40860G 40861G 40862G 40930G 40931G 40933G*
Magnification 16-48x 18xWW 25xWW 35xWW 60xWA 80x 16-48x 21xWA 27xWA 18-54x
Field/1000m 41/25 50 47 35 19.5 12.5 42/20 49 39 38/20
Eyerelief (mm) 20-18 22 18 17 15 16 22-17 18 17 18-14

* 40934G eyepiece adapter required

Care & Cleaning

To clean outer glass surface of the eyepiece and objective lens, gently remove excess dirt and dust using a compressed
air device or blower brush. Caution. Hard and persistent rubbing of dirty surfaces can cause abrasive scratches on the
surface of the glass which may distort viewing. Breathe on exposed glass surface and then wipe with an optical
cleaning cloth (code 30277) in a circular motion until the surface is clean again. Do not attempt to dismantle the
instrument as this will invalidate the guarantee.

WARNING. Never under any circumstances use a telescope to view the sun. Doing so will cause serious damage to
your eyes.

Whenever possible store in a stable dry atmosphere away from moisture. For extra protection, use the gift box or one
of the optional cases available.

Waterproof Cases

Stay-on-the-scope waterproof in Black. Water resistant multi-layer padded cases individually

designed to fit each model. Protects instrument while fitted to a tripod and in use. Includes
removable end caps and adjustable carry strap.

Stay-on-the-scope waterproof in Green (angled models only). As Black models but supplied
with a fully adjustable neoprene carry strap for extra comfort.

Traveller semi rigid case (not illus). Manufactured from water resistant material with central zip
fastener, adjustable straps & loop attachments to carry a tripod.