Review - Takahashi FCT-76

The Takahashi FCT-76 is a fluorite triplet apochromat refractor.

Specifications

Aperture:  3 in. [76mm]

Focal Length:  19.2 in. [487mm]

Focal Ratio @ Prime Focus:  f/6.4

Prime Focus Photographic Field:  4.8°

Focal Ratio w/Reducer:  f/4.5

Photographic Field w/Reducer:  8.4°

Limiting Magnitude:  ~ 11.6

Resolving Power:  1.5 arc seconds

Lowest Useful Magnification:  11x

Highest Useful Magnification:  152x

Tube Diameter:  3.7 in. [95mm]

Tube Length:  17 in. [432mm]

Weight:  6.6 lb. [3.0 kg]

Field of View and Magnification

TeleVue 31mm Nagler: 4.9° @ 16x

TeleVue 22mm Nagler: 3.7° @ 22x

TeleVue 17mm Nagler: 2.9° @ 29x

TeleVue 12mm Nagler: 2.0° @ 41x

TeleVue 09mm Nagler: 1.4° @ 54x

Introduction

I saw this telescope on the Anacortes website and knew right away that it would be a special compact 3"triplet apochromat refractor that could be used for observing, imaging, or as an upscale guidescope.

My evolving philosophy about what makes a perfect high-quality portable telescope has been "experience modified," which is a way of saying I came to it by trial and error through purchasing various small telescopes in hopes of finding an ideal setup; nonetheless, the FCT-76 is an impressive contender. A special scope like this comes at a special price, ~ $1,600 - $1,800 USD while available [I paid at the low end of this range] and current used prices run higher ~ $2,100 - $2,500 USD, but I was relieved to pay up for some peace of mind.

Design

So what makes the FCT-76 so special? For starters, the OTA is beautifully crafted - light in weight and machined with top notch fit and finish, and can be coupled to popular alt-az mounts like the TeleVue TelePod, Takahashi Teegul, or any number of equatorial systems; and because of it's small dimensions, the Tak is an excellent travel scope. The FCT-76 is also a real rarity - only 40 OTAs and 30 photographic reducers were imported in the 1998 production run.

The telescope can be used in a variety of observing configurations; including straight-through or with a diagonal using 1.25" and 2" eyepieces, the Tak Extender-Q for better barlowing [which increases the focal length from 487mm - f/6.4 to 779mm - f/10.2], and with the Takahashi TwinView binoviewer for eyestrain free enjoyment.

Additionally, observing with a diagonal or binoviewer using the 60mm rotatable focuser allows for a more relaxing head and body positioning at the eyepiece, and negates the need for use with a dedicated Camera Angle Adjuster.

An excellent Takahashi 7x50mm illuminated finderscope can also be attached to the OTA in front of the focuser or to the tube itself to help with star-hopping.

As previously mentioned, the FCT-76 can function as a guidescope to another advanced telescope [usually a larger one].

Modifications

A minor drawback in the design of this model was the limited consideration given to observing with 2" eyepieces [as reflected in their older OTAs generally being longer than necessary; from what I've heard, the Japanese don't use 2" eyepieces to the extent that we do], so a special adapter constructed by Texas Nautical Repair Company must be employed to properly bring the telescope to focus. The original length of the adapter was too long to reach focus with the newer TeleVue Nagler Type 4 & 5 eyepieces, and had to be sent back so a centimeter or two could be taken off. The scope now reaches focus with all 2" Naglers and Panoptics.

Another slight design issue is the length of the dew shield - it's awfully short, which is great at a dark site, and not so great around street lights. I bought the FS-78's dew shield as a replacement since I never had any issues blocking stray light interference with it.  Unfortunately, the FCT series logo stickers aren't available to be placed on the new dew shield, so I left it stickerless.

One more design drawback is the location of the finderscope. The Taks are placed a bit too close to the back of their OTAs where they can come in close proximity to larger 2"eyepieces while observing with a diagonal. To avoid this pitfall, I've coupled the Takahashi 7x50mm Finderscope to the front part of my FCT-76 using an FS-78 accessory holder [95mm] and a BRC-250 7x50mm finderscope bracket. However, when I ordered the above mentioned accessories, I didn't realize that the BRC-250 bracket was painted white to match the scope it was designed for and not the FCT-76's limegreen [so Takahashi painted one to match mine]. Oh well, I guess you can't always have these things figured out perfectly! One additional plus to placing the finderscope at the front of the OTA is that I don't have to contort myself to look at objects near the zenith.

A Pelican 1600 Protector Case will provide the proper protection for road and air travel.

Imaging

CCD photography is possible using either standard DSLR or medium format 645 cameras, but not with medium format 67 cameras [the focuser's too small].  When using the FCT-76's dedicated photographic reducer, a flat 8.4° field @ a fast f/4.5 is achieved [so I'm told, it's reportedly flatter than the FCT-100].

Observing

Optically this scope gives high-contrast, razer-sharp views and is so well corrected that it shows no false color halos on any object I've looked at. Here are some examples: Venus looks white, not purple-white; Mars looks orange, not red-orange; Sirius looks blue-white, not purple-blue-white. The limb of the Moon is pure white with black sky immediately adjacent to it [during early crescent phases, otherwise a light-reflected white glow] and colorful double stars on paper look colorful through the eyepiece. Deep-sky astronomy with the Tak in urban/suburban locations suffers a bit from light polluted skies where the brightness of magnitude 10-11 stars are dim, but what scope doesn't have a similar problem?

Under rural skies, the Tak is completely transformed, like a Jekyll & Hyde metamorphosis into a deep-sky mini-monster. Open star clusters come alive with exquisite beauty to the point that fainter Messier and NGC clusters are resolved beyond expectation - so the shock value of this scope is high. How high? Take a look at my notes from a trip I took to West Texas.

From March 2000:

I observed the Milky Way from Cassiopeia down to Vela under a 2-day old moon using my Takahashi FCT-76 [carried in a Pelican Case - model 1600] on a TeleVue Tele-Pod mount. To say I was pleased is an understatement. M 46/47 were amazing in a Nagler 17mm, where both fit in the same fov and were beautifully resolved into many dozens of stars. M 46 itself was more spherically resolved than I have ever seen at this aperture. NGC 2362 in Canis Major was ablaze with faint stars and NGC 2477 in Puppis was resolved across its diameter. NGC 2547 near Lamda Velorum also resolved well despite being only 11° above the horizon. The region around M 93 was so dense with stars and clusters that my dad and I spent several minutes sweeping through the Milky Way using a Nagler 22mm. I would estimate that the majority of Milky Way background stars visible through the eyepiece were of 12th & 13th magnitude and fainter, arriving at this conclusion by comparing the brightness of M 93's stars using no averted vision to the plainly seen surrounding field stars. This corresponds with what I saw in May 1999 near Big Bend under magnitude 7+ skies.

Fortunately, I was able to attend a star party at the McDonald Observatory the following night, and observed through a variety of popular telescopes which allowed me to evaluate how my own little refractor stacked up against the others. The first was an unfamiliar 8" Maksutov-Gregorian f/20 design with a central obstruction ~ 30% that showed a bright but washed out Jupiter - not what I expected from a Mak. The eyepiece didn't look cheap so it might have been the scope's collimation. The second scope was a Questar 3.5" on Saturn. I've heard great things about their performance but didn't see it through the eyepiece [same problem?]. Next came a Celestron C5 on the Moon - not bad. The last scope I looked through was a 24" Sky Designs Dob on M 42, the Orion Nebula. This scope showed excellent contrast and detail in the wispy outer region and small diffraction spikes on the trapezium stars - very nice.

So how did the Tak do? Contrast in the Tak appeared to beat out ALL of the other telescopes, just very closely edging out the Dob. My dad also reached the same conclusion despite not knowing anything about telescopes, saying he thought the Tak put the others to shame - now there's an endorsement! I believe however that the Dob could easily out do the Tak in many observing situations, although I can't help but marvel at how similar M 42 looked between them [contrast wise, not resolution wise].

Of course, it would be ridiculous to suggest that the FCT-76 has no limits; obviously, you can't see protoplanetary disks, spinning neutron stars, or gamma ray bursts... or can you? Maybe!

Truthfully, there is no singularly perfect telescope, just preferences and minimum standards that every owner sets - which is why I plan to get a larger 12" - 16" Dobsonian to compliment the Tak: different scopes with different functions, but always a means to an end - to see a small part of the universe with better clarity and understanding. That's my reasoning anyway.

Alternatives

Let me offer up some FCT-76 alternatives since you probably won't be able to acquire one yourself. The closest offering in the Takahashi product line today is the FSQ-85ED "Baby Q" extra-low dispersion quadruplet apochromat and the FC-76DS fluorite doublet apochromat. Both closely approximate the size, weight, and utility of the FCT-76. In many respects though, the FSQ-85ED is a more modern interpretation of what the FCT-76 was designed to achieve - high quality optics bundled in exquisite portability.

There are other companies that manufacture 70-90mm doublet and triplet apochromat refractors which are priced competitively and reported to be excellent performers. As to whether or not they reach the same threshold of excellence that Takahashi does is an individual determination.

Good luck!

FCT-76 Instruction Manual.pdf

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