Foreword
First things first: I'm in no way related to any telescope vendor, manufacturer or whatsoever. I would happily accept bribes or sponsorship of any kind but so far have not been approached by any body ;-) I have had my fair share of telescopes ranging from a plastic Tasco refractor in the mid 80'ies up to big Newtonians and Schmidt-Cassegrains. I do have to point out that I am a passionate astrophotographer so my review may be biased towards that special area of interest.
The Small APO Disease
In the recent years small achromatic refractors (APOs) have had a tremendous raise in popularity caused by affordable prices and an increasing interest in wide-field photography using DSLR cameras. Many seasoned astronomers have wondered what good such small optics may be in the first place.
In my opinion small APOs ranging from 50mm to 80mm (maybe even 90mm considering the portable Takahashi Sky 90) make great all-round scopes. Those small APOs can be great grab-and-go scopes, travel scopes, guide scopes and make for some nice photo optics.
During the past few month I had been searching for an highly portable (that fit's into a Lowepro photo bag) telescope as a grab-and-go scope that may second as a wide-field lens. With those two requirements in mind APOs were a natural choice. I already own a William Optics Megrez ED II Triplet however it requires an extension tube to reach focus that I don't want to carry along and it uses a focuser without reduction. Another requirement I had was hence a 1:10 reduced 2” focuser mainly because of my photographic ambitions and the fact that I already owned high-end 2” diagonals and didn't want to buy 1.1/4” or SCT thread accessories.
Mechanics and Optics
When I unpacked the little APO for the first time I was amazed by it's professional loooks. It reminds my of the Takahashi FSQ – a look that I prefer over the more “shiny” looks recent telescopes boast. The William Optics Megrez 72FD is a fast apochromatic refractor using a doubled lens featuring an aperture of 72mm and a focal length of 432mm. The mechanics show the high quality we got used to from William Optics scopes. The retractable dew-shield, a 2” focuser as well as a built-in Vixen style mount come in extremely handy A word about the 2” focuser: Focusing with the 1:10 reduction is a breeze and the focuser supports also the weight of heavier camera equipment ( in my case a Tele Vue 0.8X Photo Flattener / Reducer and a Canon 40DH with battery grip). The whole scope isn't much larger or heavier than the various 66mm scopes on the market, yet it is remarkably more portable than a 80mm APO.
A look into the business end of the scope reveals very well coated optics and very black tube interior along with good baffling. The 72FD employs the new SMC-Coating that William Optics just recently introduced to it's line of telescopes if I'm not mistaken. While only a doublet the color correction appears to be very good for visual observers however I may not be too picky about it when looking through a scope. I am however picky about color fringes in photography and the 72FD has done good with the objects I took pictures of so far.
Visual Performance
Over Christmas my better half and I decided to spend a few nights in the mountains in order to to some hiking in the snow. The short vacation was clearly flagged as “non astronomical” and hence my obvious gear had to stay home. Luckily just a day before leaving a parcel containing the small Megrez 72FD had arrived. Along with a photo tripod, a Tele Vue diagonal and a 35mm Panoptic the small APO wouldn't really be suspicious. Once in the Swiss Alps I was able to steal myself away for 15 minutes enjoying the dark alpine skies. After a swift setup in the snow I put in the 35mm Panoptic and a UHC filter observing the North America Nebula, the Veil, the California Nebula, comet Holmes, H & Chi Persei, the Andromeda galaxy, the Plejades, the Hyades cluster and before anyone noticed I was back for dinner – that's what I call a “quick fix” ;-) Visually the scope does just great and you will get the typical APO sight of pinpoint stars on a velvet black background. The high contrast optics let you see lots of faint objects you wouldn't normally try with such a small aperture.
Photographic Performance
As stated in the introduction to this review astrophotography is my main area of interest and hence also where any telescope I use has to perform. Taking pictures with the small doublet is very pleasant. The 2” focuser causes little vignetting that can be easily corrected with a flat frame and the 1:10 reduction greatly improves focusing. The optics do show field curvature as to be expected by such an optical design. However a Tele Vue 0.8X Photo Reducer / Flattener I had around corrects the curvature pretty well. Stars at the very edge of the large DSLR sensor still are a little elongated but when reducing the image a little this is hardly visible anymore. If large printouts are your target you should be looking for a flattener more suited for these optics. Again color correction is very good and the blue halo in the sample photo is mainly caused by post processing (due to an asinh stretch).
Using a 0.8 field flattener / reducer the 72FD's focal length is reduced down to roughly 346mm - a focal length that is well suited for a multitude of wonderful targets in the night sky. With a reducer the already fast F/6 optics become very fast F/4.8 that will be greatly appreciated by any astrophotographer.
Verdict
The Megrez 72FD instantly won my heart and a place in my hand luggage. It has become my “take everywhere” scope and seconds as a nice APO for photography. For the price you get a very well designed and crafted scope that can be used in many different ways – clearly two thumbs up!
Pros
Great mechanics
Very portable
Rotable 2“ Focuser with 1:10 reduction
Good price
Cons
As a astrophotographer I might have wished for a triplet
Haven't found the perfect field-flattener for the scope yet
