Aperture Fever - best avoided.

I blame star-parties for this affliction. TheBaker Street IrregularAstronomers meet each month in Regent’s Park to stare up at low cloud cover or light-polluted skies. No, that’s not fair comment; clear skies do present themselves in which a surprising amount of celestial objects are observable, bringing delight to all who attend the star-party.

I first attended the Hub, the BSIA’s meeting spot in the park, in the Autumn of 2010 soon after the group was established. Without a telescope, just a remembered boyhood love of astronomy instilled by Patrick Moore’s commentaries on the Apollo missions, I pitched up to an early meeting. Soon I was fascinated with the various telescope types members had brought along and the varied views each ‘scope provided. I remember particularly being shown by one of the founders of BSIA my first view of the double star, Albireo, now my favourite binary (thanks Ralph). As a gemmologist who looks at gem colour for a living, I observed a beautiful image of turquoise blue and topaz yellow through the eyepiece. The eyepiece was at the end of a William Optics GT-81. I succumbed to the first symptom of fever: I HAD to buy this telescope!

William Optics GT-81

This refractor was manufactured by William Optics, for some reason, as a limited run of 100: a ‘limited edition’.  I managed to secure number 35 (as attested on the base plate of the focuser) when spending time in the Canaries. On the island I mount it on an HEQ5Pro to enjoy the exceptional skies above the cloud level. 

During first set-up on the HEQ5Pro before ascent to 2300m

Easily transportable in its well designed back-pack, the OTA makes regular appearances at the Hub and the Cwmdu AstroCamp aboard a light, manual alt-az mount, a Sky-Watcher AZ4. This combination of scope and tripod is perfect for quick grab’n’go observing in central London: at the Hub I can set-up in minutes and be observing and showing observing targets to others while other star-gazers are still star aligning and perhaps cursing at their GOTO computers.

Set up  on the AZ4 at the Hub before night falls.

But that aperture fever takes hold of a weak soul. Soon or later one yearns for a something better, bigger and more expensive. There is no antidote: one simply MUST buy something else. Being in close contact at star-parties with other ‘scopes is, of course, the reason why this fever spreads indiscriminately, affecting young and old, the tyro and the ‘old hand’. At one Hub meeting when we were enjoyed exceptional skies a fellow Irregular showed me the double cluster  through his APM refractor (thanks Mathew). It reminded me of two groups of diamond melee scattered on a black gem cloth! So beautiful and all from light polluted Central London skies. I HAD to buy an APM refractor!

After my disappointment with the performance of the Crawford focuser on the GT-81 forcing me to replace it with a WO rack & pinion I vowed my next ‘scope shall have the well respected Feather Touch focuser. I love the optics of the GT-81 but its original focuser did let the scope down and I notice the latest WO scopes have R&P focusers as standard. APM provides the option for a Feather Touch focuser. And now I have learnt about the Russian glass used for the optics in many APM scopes.  This glass is considered by many users to be better than the Japanese glass found in most apo-refractors.

APM Apo-refractor

So the decision has been made: not by my cool head but by the aperture fever burning within. I shall order an APM 100mm apo-refractor. The WO GT-81 will be my UK scope and the APM my Canaries scope. And damn the expense!