Burgess 127mm f/8 Achromatic Refractor

Geoff Gaherty
Toronto Centre RASC

 Burgess refractor

Bill Burgess of Burgess Optical announced early in 2003 a new line of achromatic refractors which he planned to import from China. I learned of these in March and placed my order then at a special introductory price of $299 USD. That price included an 8x50 finder, a 2" diagonal, a 2" to 1.25" adapter, a pair of tube rings with Vixen-compatible dovetail, and a 40:1 fine focus adapter. The price is now $489 USD, but that includes an aluminum case and two eyepieces. My telescope, serial number 47, finally arrived on December 13.

Although some members of the Burgess Yahoo group had reported shipping damage, my scope arrived safely double boxed via parcel post.

The tube wall is of noticeably heavier thicker aluminum than the typical Chinese refractor, and is painted white. It has several knife edge baffles installed inside. The objective cell screws onto the tube and has three pairs of push-pull bolts for collimation, although mine arrived in perfect collimation. The metal dewshield, also painted white, is machined with microbaffles (grooves) on the inside, and screws onto the objective cell. The dewshield is fitted with a plastic cap with a smaller aperture with separate cap. This dewcap is slightly small for the dewshield and tends to fall off. The objective has deep green coatings that appear very evenly applied.

Burgess objective

The focuser screws into the other end of the tube and is beefier than those found on other Chinese refractors. It also is free of that nasty sticky grease that characterizes so many Chinese telescopes. The drawtube and 2" to 1.25" adapters are both fitted with compression springs, rather than having bolts acting directly on the eyepiece barrels. The finder mounts in a dovetail groove on the focuser, as is typical on many refractors today. This places the finder’s eyepiece uncomfortably close to the main telescope eyepiece. Its alignment is adjusted by six bolts in two rings rather than the more common two bolts and opposing spring, which I find much more convenient. The finder’s objective cell is plastic and is glued onto its tube; mine immediately came unglued. The removable dewshield on the finder is also plastic. The finder focuses by adjusting the eyepiece in a helical fitting; mine was jammed on arrival and required considerable force to free. The crosshairs are extremely fine and not located in the focal plane of the finder eyepiece; they disappear completely against the sky. This finder is the only component to get a low mark.

I already own an excellent Antares 120mm f/8.3 achromatic refractor, which consists of an objective made in Japan to Vixen specifications mounted in a Synta tube assembly. I was curious to see how the Burgess would compare with it, since the two have similar apertures and focal lengths. Physically the Burgess was the clear winner, with its heavier tube, focuser, and collimatable cell, though the Antares’ Canadian-made finder was superior to that on the Burgess. Even though the Burgess is only half an inch longer and half an inch larger in tube diameter than the Antares, it weighs 6.6 kg (14.5 pounds), more than 50% more than the Antares’ 4.3 kg (9.5 pounds). This says a lot about the solidity of the Burgess’ construction.

First light through the Burgess showed it to be a formidable performer. Even though Mars had shrunk to only 9.4 seconds in diameter, I could clearly see the tiny South Polar Cap and considerable detail on the gibbous disk using a 4mm Radian eyepiece at 250x. There was a slight purplish haze around Mars, characteristic of the chromatic aberration found in short-focus refractors like this. Turning to the Orion Nebula, I was easily able to resolve the four main stars of the Trapezium at 250x, and then discovered that I could also see the fifth star, known as "E." The sixth star, "F," wasn’t visible. Saturn showed more chromatic haze, and was difficult to focus accurately at 250x.

On New Year’s Eve I was finally able to set up the Antares and the Burgess side by side under good seeing conditions for a careful comparison. The Antares was mounted on a Super Polaris on a Vixen pier while the heavier Burgess was on a GP-DX and HAL 110 tripod. I used Tele Vue diagonals and Radian eyepieces in both scopes, since I had not yet received the Burgess 2" diagonal. The 40:1 fine focus adapter is also still on its way from China.

First up was Mars using my 5mm and 4mm Radians for 200x and 250x. Despite Mars’ minute 8.4 second diameter, both scopes showed the Mare Cimmerium and the North Polar Hood clearly on the tiny gibbous disk. The Burgess appeared to have less color around the image, but the Antares' image was crisper, had more contrast, and snapped into focus more clearly. Round one went to the Antares by a hair.

Second round, the Moon just past first quarter at 250x. The highlands appeared yellow in the Burgess with purple shadows while they were more a pale yellow green in the Antares with neutral shadows. The Straight Wall was perfectly placed and looked like an antique military sword in both scopes. Neither scope showed the Rima Birt parallel to the Straight Wall. The large ruined crater Deslandres lay just to the south of the Straight Wall. It is filled with craters, rilles and rubble, which were revealed much more clearly in the Antares. So round two also went to the Antares.

Third round, star test at 250x with green filter and no diagonal, using Rigel as a target. As I've seen before, the Antares delivers an almost perfect star test, very symmetrical on either side of focus, and a tight Airy disk in focus surrounded by a few faint rings. The Burgess had dim inner rings surrounded by a bright ring inside focus, and a very blurry pattern outside focus indicating spherical aberration. I removed the filter and examined the in-focus image in both scopes. Rigel is a very unequal double star, the primary being a brilliant 0.1 magnitude and the secondary a faint 6.8. They are separated by 9.5 seconds, but the faint star can be easily lost in the glare from the bright primary. Both scopes showed the smaller star very clearly, but the image in the Antares was much cleaner and "refractor-like" with a tight Airy disk surrounded by faint rings. So the Antares won the third round as well.

All of this isn’t as bad for the Burgess as it may sound. The Burgess 127 f/8 is in fact a very good telescope–it’s just that the Antares objective is in a different class altogether. Keep in mind that when this objective was available for separate sale from Sky Instruments, it cost nearly twice as much for the glass alone (not including even the cell) as I paid for the entire Burgess scope! If I hadn’t had the Antares alongside for comparison, I would have been very impressed by the Burgess’ performance. I would expect it to easily equal or exceed the optical performance of refractors with similar specifications from other Chinese manufacturers selling for much more, and, as I remarked earlier, its mechanical construction is outstanding. All in all, the Burgess 127 is an excellent bargain.
 

2004-03-29