Visual Performance of the GSD 400 T


With its enormous aperture of 400mm the GSD 400 shows myriads of deep sky objects in detail. You have nearly twice the light gathering power of a 300mm Dobsonian. Several objects will already begin to show colour. For example, the Great Orion Nebula will glow in a fascinating greenish hue.

At the same time the excellent parabolical primary mirror offers excellent images of the moon and the planets, only limited by atmospheric seeing conditions. Under good conditions you will be able to see details invisible in smaller telescopes.

"A lifetime of observing isn't enough to see everything this large telescope has to offer on the night-sky!"

Truss Tube Design

Above a certain size telescopes can no longer be considered portable. This sets an upper limit for the useful aperture of classic telescope designs. At the same time the old rule "aperture can only be replaced by even more aperture" dictates that a telescope should be as large as possible for maximum light gathering power.

The solution for this problem is the truss tube design. It allows you to split the telescope into smaller, more compact parts that can be transported more easily.

The new GSO Truss Dobsonians use this principle and thus offer a greater aperture than would be considered portable in a conventional tube design. On the whole the 400mm Truss Tube Dobsonian can be transported just as easily as the classic 300mm Dobsonians.

High Quality 2" - 1:10 Micro Crayford Focuser

... a high quality, high performance Crayford-type focuser with 1:10 dual speed micro-focusing knob allows you to fully use the excellent optical quality the GSO Dobsonian has to offer. The focuser has a 2" brass compression ring. An adaptor for 1.25" eyepieces is included - of course also with 1.25" compression ring.