Plus Corrector PH
Few things are more frustrating than the British weather – fantastically clear one minute, sodden and cloudy the next. To take advantage of any window of good conditions, no matter how brief, it’s a boon to have a fast scope with a reasonable aperture that is both quick to set up and allows you to capture good images. This is a role the Vixen R200SS Newtonian reflector with Corrector PH fills admirably.
The problem with fast reflectors has always been their ability to maintain good collimation. While their speed makes them attractive, it can also make them infuriating, as the slightest shift in the position of either mirror can result in a spoiled image.
Vixen has tackled this problem head-on, with a substantial spider vane and closed primary cell. The R200SS handbook boldly states that the scope has been factory collimated and shouldn’t need any further attention. After star testing the telescope, it has to be said that we were pleasantly surprised. Even at high magnification, its out-of-the-box collimation looked perfect. Vixen will provide a DIY collimation guide if required, or will recollimate it for you – details are available via its dealers.
The other element of this package, also available as an add-on for existing R200SS owners, is an exciting new corrector – the Vixen Corrector PH. It promises round stars right to the corners of the image, and takes the already speedy f/4 R200SS down to an impressive f/3.8, ideal for making the most of limited clear skies.
Expectations met
With an eyepiece in place we couldn’t resist trying a few visual targets, and the wide field of view was perfect for observing star clusters. Particularly impressive was the Double Cluster in Perseus, with sharp, pinpoint stars right to the edge of the view. Although this telescope is designed for astrophotography, it comes with a 1.25-inch eyepiece adaptor and offers rewarding views, especially of larger objects.
Just before putting the camera in place we had a good look at the optics. A Ronchi grating gave an almost textbook parallel pattern, and at high magnification the mirrors returned a smooth and precise Airy disk. There was the slightest hint of astigmatism at high magnification, but nowhere near enough to degrade the star image at focus, whether using an eyepiece or camera. Indeed,