Opticron GS 52 GA ED telescope and HDF 12-36x zoom eyepiece

As optics technology has evolved, the image quality delivered by smaller telescopes has improved considerably. Opticron’s GS 52 GA ED is an extension of the existing GS range, which already includes 66.5 mm and 81.5 mm models, and its introduction marks the phasing out of the popular MM2 ED ‘mini scope’.

This new 52 mm model resembles nothing that has gone before in the MM range, nor will it win any beauty contests. The design brief, according to Opticron, was to encapsulate large scope technology in a compact body. The result is a somewhat uniquely shaped end product. The model resembles the back half of a full-sized scope, the front end appearing to have been sheered off with surgical precision. This appearance is further emphasised by the location of the tripod attachment sleeve immediately behind the objective; the shape of the full-size prism housing prevents positioning elsewhere. 

There is no retractable lens hood, although the objective is deeply recessed at 28 mm, and the fixed body length of 200 mm is a compromise between the MM2 ED’s 177 mm retracted and 217 mm extended lengths.

The body and rotating tripod attachment sleeve are lightweight magnesium alloy, but the full rubber armour adds weight, as does the larger prism system, which is used in the full-size GS 665 and 815 models, and the overall body weight is 750 g. Although this is significantly higher than the MM2 ED’s 468 g, it should be remembered that it weighs little or no more than many binoculars on the market.

I found the focusing mechanism among the smoothest and lightest I have used. The scope employs the split-wheel twin focusing system of the full-size GS models to allow accurate adjustment. The smaller of the two wheels appears to make fine focusing easier at higher magnification settings, but despite this I still found it difficult to obtain sharp focusing toward the top of the magnification range (36x) with the HDF zoom eyepiece.

It is worth noting that other eyepieces from the Opticron range, including the HR2 and the more expensive SDL, are compatible with this scope and the field of view is larger than the MM2 ED’s. Furthermore, all the eyepieces listed for the MM2 (excluding the MM2.HR items) are also compatible.

The HDF eyepiece produced extremely good images across a range of habitats. The colours and contrast, particularly up to 30x magnification, were excellent, and I was especially pleased with the vivid, feather-perfect image of my first Whinchat of the autumn, a juvenile.

A faint bluish colour cast was barely evident in what was a clean, bright image. There was some degree of chromatic aberration discernible across the whole of the field, but the consistent edge-to-edge sharpness and minimal curvature of field more than compensated for it. 

The depth of field is good, particularly at the lower end of the magnification range (as would be expected). The close focus at minimum magnification is quoted as 2.5 m – better than the MM2. I managed to squeeze 2.03 m out of it.

The GS 52 is a solidly constructed scope, with an attractive price point, retailing at only £10 more than the MM2 ED. It can be supported by a very lightweight tripod and is a ‘must see’ if you are looking for a scope which combines portability, ease of use and value for money. With such a broad range of eyepieces available for this telescope it is advisable to assess its performance in combination with a number of these before buying.