SingAstro

Equipment Brand: William Optics
Equipment Model: Megrez 80 II ED triplet apochromatic refractor telescope (sold)
Clear aperture: 80mm
Focal length: 560mm (F/7.0)
Objective lens: air spaced triplet, center element made by Schott FK01 ED glass
Focuser: 2” crayford style with 1.25” adapter

Real Name: Liu Ming
Contact Number: 67904202 (weekdays)
Email Address: biuliuming@yahoo.com

Condition of Item (as per guidelines): 10

Package include: (info in bracket indicates condition)
Item 1: OTA (optical tube assembly, lens (mint), tube (9/10)) + 2” mirror diagonal (97% reflection, 10/10) + 25mm Plossl eyepiece (10/10) + 6 X 30 finderscope bracket (mint) + backpack style carrying case (9/10)(all are original William Optics made except for eyepiece)

Additional Comments:
Important Note: The scope is an update from WilliamOptics’ Megrez 80II, not Megrez 80 fluorite version. I got the ED triplet lens from W/O factory in this Aug. and installed it on megrez 80 II tube.
Performance: 160 X magnification is easy (50 X per inch of aperture), cleanly split double/double in Lyra in Singapore sky.

Links:

http://www.excelsis.com/1.0/entry.php?s ... ntryid=573

http://www.buytelescopes.com/product_list.asp?m=49&d=1 (see item 1)

http://www.astronomy.com.cn/bbs/viewtop ... highlight=

http://www.astronomy.com.cn/bbs/viewtopic.php?t=26879

My review on W/O yahoo group:
“Kept my old Megrez 80II tube and bought the new ED triplet lens
(F/7) from WO, a two inch extender tube is needed to provide enough
back focus. The service of WO is quite good and speedy.

1. the lens coating is much better than my old megrez 80 II, the
reflection is same as that of Fujinon's EBC(electron bombardment
coating) coated lens. Not sure if the coating quality is consistent,
I hope it does not vary from batch to batch.

2.color correction: much better than megrez 80 II, can be easily
pushed to 160 X (2 D) with trace green halo discernable. Even at 336
X, the image of high contrast object didn't break down.

3. Vega shows a little bit halo at 140 X, double-double at lyra is
cleanly split at this power, which is no easy for my old megrez 80
II.”

Review from an experienced amateur (quoted from yahoo group):

"Color correction is obviously much better than the MII doublet was,
looks like a solid ED-class performer. Not zero color like the much
more expensive zero-color fluorite triplets, but at half the price,
something of a bargain.

Most importantly, the star test is very good indeed, very round
fresnel rings with ruddy-fringed rings inside of focus, essentially
perfect correction of spherical abberation. In focus, the airy disk
is hard and round, with a single dim red diffraction ring, on
moderate brightness stars. I do not see how you could ask for a
better result at this price.

Cosmetic quality of the glass is very clean indeed. It does not look
like the cell is collimatable like the doublet, then again mine
doesn't need it like the doublet did.

I haven't had a chance to do critical comparisons yet, but it looks
like this is William's answer to the Orion ED80.
On A-B nighttime star tests, initial impression, I would estimate the
color error about 2x the color of the TV76, primarily a little excess
red.

I once compared the Orion ED80 to the TV76 and the former had a
little more red excess than the latter, lets say 1.5x. A Tak FS78
beat them both, again in the red, but not by much, just to give you
an idea of the level of performance we are talking about here. All
these scopes have many times less color than an achromat.

Vignetting is not an issue, either at the foam ring baffles, which
can be scooted against friction if necessary, nor at the focuser body
or extender tube.

Next comparo: I estimate the TV Ranger (Pronto) has a good 4x the
color of the MII/EDT.

The color halo around stars is quite obvious on the Ranger, with a
actinic mixture of red and blue. Switching back to the MII/EDT is a
dramatic improvement, the airy disk changes from yellow to off white,
and the halo goes from a bright violet 3+ diffraction rings to 1 dim
red.

The MII/EDT color error reminds me of the original TV Genesis I once
owned, and also the TV Oracle, the under-appreciated and short lived
75mm F7.4 triplet. The colorful rings of the Ranger are due purely to
the color defocus, as it has a superb star test otherwise.

My tally from most color to least:

Achromat
Ranger/Pronto/Megrez doublet

TV Oracle
MegrezII EDTriplet
Orion ED80 APO
TV76

FS78 fluorite doublet

80 TMB F6 fluorite triplet
80 TMB F7.5"

More astronomy stuff for sale:

1. Antares Speers Waler wide angle eyepiece (condition: 9/10)
82 degree field of view, 8 element design, 14mm focal length, 12mm eye relief
S$ 180

2. 32 mm focal length Plossl eyepiece, with screw bottle(condition: 10/10)
S$ 50

3. Vixen 3X barlow lens (condition: 10/10)
S$ 60

New low price for the telescope package: S$ 1700 (FYI: the package cost me 1300 (megrez II package)+500 (lens upgrading) + 350 (mount and tripod)= S$2150)

Wat brand and series is the item2? How do u do transaction? :idea:

Are u refering to the 32mm PL ep? I bought it several months ago from harlequin at S$100, used only for few times. The invoice only indicates "super plossl (taiwan)", but the quality is good, you can test it on your scope before you buy.
I live in clementi, can accept cash or ATM transfer.

new low price S$1550 for the 80mm Apochromatic telescope package, self collect at clementi

just curious, what is the minimum length of the ota with diagonal removed and dewshield retracted?

cls,
arief

ariefm71 wrote:just curious, what is the minimum length of the ota with diagonal removed and dewshield retracted?

cls,
arief

Hi Ariefm 71, The length measures at 15 inches. That's base on my megrez 80II.