by The Bolton Group
No sooner were the 12-inch binos finished then Gerald looked around for a new project. The aluminium cut outs from the 12-inch binos were big enough for 8.5 inch ones so the temptation was too great. The 12-inchers are great for a star party or serious observing but for just carrying out easily for a quick view something lighter is needed. Hence these ultra-lights!
Brian made the optics (6 mirrors) and Gerald the tube assemblies although Brian did make some of the parts including the focuser.
The binos have been designed to be ultra-light. The total weight including optics is around 65lbs.
All design goals have been met, ie:-
1. Ultra stable
They dis-assemble into 4 components for easy transport and storage. All assembly thumb-screws are captive to avoid loss or accidents!
The views are stunning with pin-point stars and that magical 3-D effect! Just sweeping the Milky Way is a never to forget experience.
Being the 3rd pair made by the group the design is now much refined and improved. The following pictures give some idea of the amount of work and precision that has gone into this unique instrument..
The optics are f/6 and all the mirros were made Brian. They are as usual to his very high standards - if they are not perfect he will not let them out of his workshop! Brian has made many many mirrors of all shapes and sizes. He recently completed a commercial contract for a large test mirror for a company specialising in lasers.
In this new design, the azimuth and altitude axis shafts have been left exposed for the possible option of fitting digital setting circles.
I hesitated to show this new idea. Our
original 8-inch binos featured crayfords for adjusting
the inter-ocular distance. Low and behold when commercial
binos appeared a couple of years or so later they too had them! Coincidence?
The designers/makers - Gerald and Brian