Telescopes and Equipment

The primary imaging system is based around a Meade LX200 14 inch Schmidt Cassegrain optical tube for long focal length work and a new piggy backed Takahashi FS-60C for wide field views. Images are captured onto a Starlight-Xpress SXV-H9 cooled CCD Camera

Until recently the system sat on the original Meade LX200GPS fork mount. After a hell of a lot of hours of modifying, tweaking and measuring I concluded I wasn’t going to get the performance I wanted from it. I also decided it would be nice to actually get some imaging done in the brief clear spells rather than spend my time freezing in the shed with my hands covered in grease.

Everything is now mounted on a Paramount ME although the pictures here still show it on is original, albeit modified, fork mount. The Paramount is an absolutely superb piece of kit and allows imaging with all my heavy equipment bolted onto it and is not unduly affected by wind

After the Meade OTA the optical train starts with Paul Van Slyke’s (VSI) excellent Masterglide M3A focuser with Robofocus electronic control. Temperature compensation sensing is via a probe physically coupled to the main scope. A VSI Atlas Zerotator follows, allowing the rest of the optical train to be rotated whilst maintaining accurate coaxial and lateral alignment.

Following this is a Starlight-Xpress SXV-AO active optics device. Due to the mass of the rest of the imaging components this has been mounted within a custom designed and manufactured external bracing cage. This cage has eliminated the mechanical loading on the AO unit and reduced flexure across this component to almost zero. Since the move to the Paramount ME I not sure how much help the AO unit will be. Since this optical train usually gets enough light on the guiding chip for 0.1 second exposures giving effective correction rates of 7 to 8 Hz it might prove to be some use in correcting for gross atmospheric ‘seeing’.

A VSI Versa-Port Slider 2 Optical Manifold provides a pick off mirror to direct an off axis image to the guiding system whilst providing the functionality of a flip mirror system. This allows the image to be directed to the CCD Camera or easily diverted to an eye piece. This is a particularly nice feature as it allows an object to be studied visually, then the image can easily be directed onto the CCD without changing equipment.

Various focal reducers then reduce the effective focal length as required. A True Technology SupaSlim filter wheel provides automatic placement of Astronomicks Type 2c optical filters in front of the CCD.

Guiding is provided by a Starlight-Xpress SXV guide camera which receives it’s image from the pick off mirror of the Optical Manifold via a second telecompressor, usually a Meade 0.33x unit. This puts all of the light from the oversized pick off mirror in the VSI unit onto the guide chip, allowing faster corrections with the AO unit.

Click on image for closer view