Takahashi FS-102 fluorite doublet APO refractor

The Experience

Well, it's only been 52 hours since I sent my Takahashi FS-102 on to it's new owner. As I'm writing this it's probably on a truck somewhere between Melbourne and Adelaide. I miss it already. That's not to say I regret selling it (I did need a change) but there were a couple of things that I really wanted to do with it, that I never got I chance to do for one reason or another.

One was to look straight at Venus at a really high magnification. My first look through a Takahashi FS series scope was with an FS-127 pointed at the large bright waning Venus. It was amazing, not because of what was there, but because of what wasn't. Every other time I had looked at this planet I got bored very quickly. Through an achromatic refractor, I felt like I was staring at some stupid blue bath crystals in a hippy incense shop. Through a dob, I might as well have been playing some silly astronomical version of noughts and crosses, that left me blind for hour. The much maligned Schmitt Cassegrain and humble Mak's faired the best, but the surrounding bright fuzz-ball just made it look like I was looking at the planet through a telescope, not looking at it with my own eyes.

The Takahashi was different. It was as if someone had got a big astronomical black texter (marker) and drawn a crisp black outline around the sparkling bright crescent. It was beautiful, almost 3D and completely mesmerising.

I had the same experience with the FS-102 but with stars mostly. My favourite thing was to put my 35mm panoptic in and point the scope straight at Sirius. The rich, deep, 3 degree wide view of thousands of teeny weenie pin pick stars, set a wonderful back drop for the most intensely bright and beautiful jewel. It's hard to describe why this view was so awesome but Sirius appears EXACTLY the same size as the background stars around it, but a million billion times brighter. I can't understand how such a tiny point can be so bright. It's as if one lone light sensor at the back of my eye is getting completely overwhelmed while the other ones right next to it received absolutely nothing. You can't compare this view with any other telescope type, as they all make Sirius look bigger, softer or bluer and just generally not nice. I will really miss this view.

The Build Quality

The FS-102 is built with no fancy over engineered parts. It's simple solid and practical. The white and lime green colours are conservative and kind of soothing and the blue rim between the dew shield and main tube is a bit odd without being out of place. The rack and pinion focuser is brilliant. It has no play in it whatsoever and the focus lock could hold my body weight without slipping. I think it was designed with astrophotography in mind, which makes it feel a little heavy. The thick grease on the gear is like an up-market version of the synta heavy-snot grease used on cheap achromats. I think I slightly prefer the focuser on the Teleview 101 as it is more suited to visual work because it has a little bit lighter feel. Both are ultra smooth and "crayford like" but without the slippage of course!

The lens cell in the FS-102 truly gives an image the is to die for. Admittedly, I struggle to spot the different between the TV101, FS102 and big triplets from Astrophysics. The only differences are minor and really not an issue, but I do think that the TV101 has a slighly flatter field and the triplet APO's appear a little more curved. But this is probably just my imagination. As far as brightness goes, I didn't really notice any difference between the doublet FS102 and the quadruplet TV101. Apparently there is, so I guess it must be small.

Currently the FS-102 is almost half the price of a TV101, which makes choosing between them really easy. If you need the super flat field, Takahashi do sell a field flattener which also reduces the focal length of the FS102 to near that of the TV101 and still comes in at significantly cheaper overall. The quality is not any worse though.

Positives and Negatives

This scope is the closest thing you can get to an expensive short focal length APO Petzval (like the Tak FSQ-106 and TV101). For most things the 820mm focal length is short enough and the whole setup rarely reaches a meter in length with the dew shield, diagonal and racked out focuser. Having said that it's not a small scope. You do need a good mount, at least an EQ5, HEQ5 or better. The visual images of planets are quite often better than what you will see in larger reflector because the image is more stable, much much sharper and it's not often you can push past 200x in normal seeing conditions anyway (so the advantage of much larger scope is not often seen).

The only down side is shared with most other refractors and that is the viewing height of the eyepiece changes quite dramatically, depending on where you are viewing in the sky. You can be on your tip toes like a ballet dancer and five minutes later on you knees like Monica Lewinsky. But apart from that inconvenience there's not much else to complain about really. It's a nice scope.

by stu

Edit (six months after initial review): Now when I look through other peoples apochromatic refractors, I get a shock because planets look so 3D. Not having an APO for a while, you forget about this trait. Seriously it looks like the planet is jumping off the black background.