Developed around an all new optical system featuring objective lens sizes of 66.5mm and 81.5mm plus the option of straight-through or 45° angled viewing, GS Fieldscopes set a new benchmark in affordable lightweight telescopes for birdwatching and general wildlife observation.
All six models in the range aim to meet the three main requirements demanded by today's active Fieldscope user; 'high end' optical performance and value, usability and reliability.
'High end' optical performance and value
The GS series takes the two size model range concept a stage further by increasing the 65mm OG model to a 66.5mm OG model and the 80mm OG model to an 81.5mm OG model without any noticeable gain in size or weight. As a direct result, the GS 815 gains 4% surface area over a standard 80mm OG and GS 665 5% over a 65mm OG. The increase in the amount of light entering the instruments coupled with an all new optical configuration, new prism units and revised multi-coating results in significantly higher levels of optical clarity over preceding models. Images are extremely bright whilst retaining excellent colour saturation so important for accurate identification.
Models: GS 665 GA · GS 665 GA /45
Warrant serious consideration for users wanting
optimum size & weight to performance ratios
Models: GS 665 GA ED · GS 665 GA /45 ED afford even greater light transmission and sharper images over 35x (when compared to standard model) plus higher colour fidelity especially noticeable in extreme light conditions. A natural choice for those wanting to experience the 40935 SDL eyepiece, the GS 665 GA ED will perform against the very best.
Models: GS 815 GA · GS 815 GA /45
The preferred choice for those wishing to maximise light transmission at magnifications over 35x
Usability
'Ease of use' and 'functionality' are all important when using an instrument in the field and the GS series is designed to provide class winning optical performance seamlessly in an array of different outdoor conditions.
As telescopes need to be used with a solid tripod for image stability, any weight saving is crucially important. Constructed using lightweight materials where at all possible, the GS 665 weighs under 1000g, and the GS 815 under 1300g. In addition, model GS 815 is perfectly balanced on a tripod when fitted with any HDF eyepiece to eliminate 'drop forward' syndrome common place with many large objective telescopes.
GS Fieldscopes are protected by 'full body' natural rubber armour with a textured finish to the top half of the main body prism housing. The centrally positioned focusing wheel allows easy access for both right and left handed users and is also rubber covered - delivering 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. Housed within the same mechanism for convenience is a 9:1 ratio accurate focus adjustment.
Having access to full range of different magnification eyepieces is also important. The GS series are fully compatible with Opticron SDL, HDF & HR eyepieces including; 40862G HDF T 16-48x (665) / 20-60x (815) 40809 HDF T 25xWW (665) / 32xWW (815).
Designed to enable rotation around the main axis of the instrument for use on a bipod or in a hide with a high window, GS fieldscopes feature a solid die-cast tripod sleeve with -/+ 90 degrees each-way action with 45° incremental 'stops.'
To avoid problem of reflected light on the objective lens in bright sunlight all models are fitted with a retractable lens hood extending 28mm (665) and 40mm (815).
Reliability
Extensively tested for continuous trouble free use in varying temperatures, the
models are fully nitrogen gas filled and waterproof and come with the assurance of a
30 year guarantee.
Read about alternatives to the Opticron GS Field Scopes in the Optics section for telescope reviews, microscope comparisons, binocular reviews and guides to spotting scopes.
