GS 665 Fieldscopes
GS 665 GA, GS 665 GA ED
Specifications & Pricing I Eyepieces I Cases I Telephotography I Photo Gallery I Accessories
Introduced in response to demand for high quality lightweight waterproof telescopes the GS 665 GA ED sets the standard for people wanting to take-out and walk-about with their equipment whether for birdwatching or general wildlife observation. Available in straight-through or 45°, the models are designed and manufactured to meet the three main requirements demanded by today's active fieldscope user: high-end optical performance, usability and reliability.
'High end' optical performance and value
The GS 665 GA ED uses a 66.5mm dia objective lens without any noticeable gain in size or weight over a 65mm. With a 5% more light entering the telescope, more light is emitted, resulting in brighter images compared to a standard 65mm throughout the magnification range. 100% designed and manufactured in Japan using high quality glass and other materials, each GS 665 GA ED produces high resolution images with minimal edge distortion and accurate color reproduction.
Usability
The GS 665 GA ED is designed to provide class winning optical performance seamlessly in even pretty harsh conditions. Protected by full body natural rubber armour, the centrally positioned focusing wheel allows easy access for both right and left handed users and is rubber covered to deliver a positive feel with or without gloves. The focusing system is designed to allow adjustment from infinity to 50 metres in just a 270° turn with close focus set at 4m. Housed within the same mechanism is a 9:1 ratio focus adjuster, providing greater focusing accuracy at top end magnifications.
More often than not, telescopes need to be tripod mounted for image stability so any weight saving is crucial. Constructed to be as light as possible, the GS 665 GA ED weighs just 37oz (w/o eyepiece) and as a result can be used comfortably on a standard ‘non fluid’ panhead often found on Clamps or Travel Tripods. In addition each GS is fitted with a -/+ 90° rotating die-cast alloy tripod sleeve with 45° incremental 'stops'. This feature enables the scope to rotate around its’ central axis for accurate positioning when mounted to a bipod or on a clamp in a Hide or Blind. To avoid problems of reflected light on the objective lens in bright sunlight models are fitted with a retractable lens hood with integrated objective lens cover.
Having access to full a range of eyepieces is also important. The GS 665 GA ED is fully compatible with Opticron SDL and HDF T eyepieces including the 40862G HDF T 16-48x and 40809G HDF T 25xWW.
Reliability
Extensively tested for continuous trouble free use in varying temperatures, the models are fully nitrogen gas filled waterproof and come with the assurance of a 30 year guarantee.
| Specifications | 665 | 665/45 | 665 ED | 665 ED/45 |
|---|---|---|---|---|
| Product Code OG dia (mm) Min Focus (m) Length (mm) Weight (g) Price £ inc. VAT |
40960 66.5 3.8 326 976 299.00 |
40961 66.5 3.8 326 980 299.00 |
40962 66.5 3.8 326 1049 499.00 |
40963 66.5 3.8 326 1053 499.00 |

A wide range of eyepieces are available for use with GS fieldscopes and choosing the best eyepiece will depend on price and application. The eyepiece is an integral component in the system and a higher quality eyepiece will deliver a superior viewing experience.
SDL v2 Eyepiece CLICK FOR IMAGE
5-group 8-element ‘super’ zoom, the SDLv2 eyepiece maximises the performance gains inherent in Opticron ED objective lens fieldscopes at higher powers while maintaining superior cross-field definition coupled with exceptional viewing comfort. Model features twist-type retractable eyecup. Supplied in soft case. 10 year guarantee.
| Eyepiece Code | 40936G |
|---|---|
| Magnification Field/1000m Price £ inc. VAT |
16-48x 41/25 289.00 |
HDF Eyepieces CLICK FOR IMAGES
The preferred choice for image quality, HDF eyepieces are long eyerelief giving full field of view with or without glasses and have large diameter eye lenses for viewing comfort. Fixed magnification eyepieces are wide-angle and offer a unique visual experience for the discerning user looking for maximum clarity and field of view. Models marked (*) feature alloy twist type retractable eyecup to enable individual eye to eyepiece distance adjustment. 10 year guarantee.
| Eyepiece Code | 40810G* | 40809G* | 40858G* | 40860G | 40861G | 40862G* |
|---|---|---|---|---|---|---|
| Magnification Field/1000m Price £ inc. VAT |
18xWW 50 139.00 |
25xWW 47 159.00 |
35xWW 35 179.00 |
60xWA 19.5 99.00 |
80x 12.5 99.00 |
16-48x 42/20 199.00 |
HR Eyepieces CLICK FOR IMAGES
Good choice as either supplementary eyepiece in combination with HDF or single eyepiece for the more value conscious requiring long eyerelief. HR 40933 zoom eyepiece is an excellent choice for 665 models giving 18-54x. Models marked (*) feature a twist-type retractable eyecup. 5 year guarantee.
| Eyepiece Code | 40930G | 40931G | 40933G*(1) |
|---|---|---|---|
| Magnification Field/1000m Price £ inc. VAT |
21xWA 49 57.00 |
27xWA 39 57.00 |
18-54x 38/20 149.00 |
(1) Requires 40934 adapter to connect to telescope body
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.

| Code | Model | Price £ inc. VAT |
|---|---|---|
| 40970 40971 40975 |
GS 665 GA (65) Black GS 665 GA / 45 (66) Black GS 665 GA / 45 (66G) Green |
65.00 65.00 75.00 |
Telephotography, (taking high magnification photographs) is now easier then ever to enjoy using Opticron telescopes in conjunction with either D-SLR / SLR cameras, digital compact cameras or camcorders. CLICK HERE for more information on telephotography with GS scopes.
Accessories
CLICK HERE for information on Storage cases and Eyepiece cases
CLICK HERE for information on Tripods and Mounts
CLICK HERE for information on the 2.5x Universal Tele-adapter for SDL, HDF and HR eyepieces



