True coloursĭescribed as synthetic fluorite, the air-spaced apochromatic double lens in the ZS126 is produced using FPL53 glass, developed for its low refractive index while avoiding the issues inherent with natural fluorite lenses. Producing images and views as outstanding as its own appearance, the Williams Optics ZS126 looks set to become a favourite among observers and astrophotographers alike.
These extreme magnifications, though rarely practical, did demonstrate good, round airy disc patterns, revealing the quality of the lenses and lens cell in the ZS126. The Moon itself demonstrated the apochromatic nature of the objective lens, revealing a crisp, clear image with no discernible colour aberrations on the brightest lunar edge during steadier seeing patches.Ī quite enchanting, wide sky view with sharp stars right to the edge of our 21mm, 100° eyepiece (at 47x magnification) made us wish the nights were longer and darker, while our 10mm eyepiece produced a practical 97x magnification, allowing the wide, multi-coated objective lens to bring in views of M51, despite challenging skies at our site.ĭouble star enthusiasts would no doubt enjoy the views we experienced of Epsilon Lyrae, a good, easy split of the stars with perfect diffraction patterns.ĭuring one observing session the seeing and transparency improved to the point where we were able to use a 2x Barlow lens with our 4.5mm eyepiece, giving magnification of 430x, and even to double it again with another 2x Barlow, to 860x. With a dominant Moon, we started using the scope for visual observations. It is worth noting that the short tube design which aids portability, also means that extension tubes are needed when using a camera, and in fact, we also had to use a short extension tube with our 2-inch diagonal to focus with some of our eyepieces. The large controls had a bit of a new feel about them, and the action was a bit sticky at first, but fine focus control was exceptional, and combined with the integrated Bahtinov mask made focusing the scope a swift, simple affair. We found that this was highly adjustable, and held the weight of our equipment without slopping, or the image shifting when locked. Precise focusing, a pre-requisite for good results, is accomplished by a Crayford focuser. The Whirlpool Galaxy, M51, showed what the scope was capable of on galaxies, and we were impressed that the four small but more noticeable stars within the Ring Nebula, M57, were present and sharp.įor imaging, the ZS126 has great potential. Targets like globular clusters were nicely presented at a good scale, and we enjoyed our time imaging M13 and M92 in Hercules. This demonstrated that the doublet lens produced good, sharp, round star images, and that red, green and blue wavelengths came to close focus together.ĭespite the lack of a flattening lens, there was barely any sign of coma using our Sony 460 size CCD, so we decided to try a few imaging sessions using a one-shot colour version of the camera.
We didn’t have the flattener available but used the first clear sky opportunity to run basic tests with a mono CCD camera and filters. The lens is f/7.7, giving a focal length of 970mm, making the scope suited for observing, or astrophotography with an optional field-flattening lens. With this impressive appearance, we were keen to see how the ZS126 actually performed. Our review package included an optional 50mm guidescope, which made a beautiful set. The scope has an integrated handle and finderscope rail, which works together with CNC tube rings and a premium Losmandy-style dovetail bar to provide a reliable platform for the instrument.
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