Discovery RFT 90mm

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Date: NA
Price: $329.00
Design: 90mm refractor operating at f/5.5 for a focal length of 500mm
Description: Small refractor on an equatorial mount. It ships with two Plossl eyepieces (26mm and 10mm) and a 6x30 finder scope along with a 45 degree diagonal.  The package also includes a 2x Barlow lens, soft case, and a table top mount.

The Review

We bought this one right before Christmas as a traveling scope.  It is the same Chinese scope that is sold by Orion as the Short Tube 90.  Discovery had the best package deal, so we went with them.  It arrived in five days.   Here's what we got.  The OTA with 90mm slightly coated objective; 6x30 finder; 2 brand-X Plossls; 45 erect image diagonal; EQ mount; aluminum tripod; brand-X Barlow and a soft carry case that fits everything.  The case is about as big as a brief case, but twice as think.  It is carry-on luggage size.  It is not tough enough for airline baggage handlers.

The first thing I did was replace the 45 diagonal with an Orion mirror 90 diagonal.  Every review I have ever read about this scope states that it only performs to capacity with a good quality diagonal and eyepiece.  The supplied Plossls are okay, but I prefer my University Orthos.  The tripod is adequate, but I recommend not extending the last section of leg and viewing seated. With the EQ head, the whole thing is quite top-heavy.  The EQ head works.  Personally, I find EQ heads annoying, so I replaced it with a DIY wooded alt-az head similar to the project in Oct.2000 S&T.  It saved much weight.  At a dark site, this scope does surprisingly well.  The wide field of view includes all of Orion's belt with a 32mm Pl.  The Trapizium was cleanly split. The false color is not bad, though I suspect this is because the aperture might be slightly stopped down by the focuser.  The Jupiter and Saturn are easily resolved as is Venus (that had false color!)  I have not made a very extensive test of this short refractor, because it has been very cloudy this winter (Ohio).  Nevertheless, for its size it does very well and is at least 85% as good as a Pronto.  It is a far better beginner scope than anything available at Walmart.

Submitted by Russell Hopkins - rah4@hotmail.com - NE Ohio

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