Usability
Terms like 'ease of use' and 'functionality' are all important when using an instrument in field conditions 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.
The importance of having access to full range of different magnification eyepieces is also important. As with most Opticron fieldscopes, the GS series are fully compatible with existing Opticron HDF/HR eyepieces including the 40862G HDF zoom 16-48x (665) / 20-60x (815) and 40809 HDF 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 the 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.