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DGM OA-4.0 f/10 Off-Axis Reflector

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This is a very hard to find 4.0" DGM f/10 off-axis reflector. Unlike virtually all other reflecting telescopes, this one has the secondary mirror "off axis" so there is no obstruction in the light path. The process involves taking a much larger "parent" mirror and cutting it into asymmetric pieces. This unique process gives this scope the high contrast of a refractor, and color-free views of a reflector. That's what makes it so special!

Many owners of larger Newtonians sometimes mask off a large portion of their mirror to do planetary observing. The smaller aperature, lack of central obstruction and increased f/ratio can improve the image tremendously. An off-axis telescope like this one goes one step further, giving you one "piece" of the mirror, permanently mounted. The telescope can handle high power and shows great contrast.

There are some great reviews of this scope online from Ed Ting,, and others (search DGM Optics OA-4.0 Off-Axis) The design is difficult to execute, so only one other company (Orion) attempted to mass produce them. This telescope is about 20 years old but the optics are in excellent condition. The mount is made from furniture grade plywood and beautifully finished. The telescope excels at viewing the moon and planets.

This is a great scope for use in the city and very collectible.
Price: $500, OBO.  Pick up only, or can meet you within 100 miles of Seattle.