The current line of vixen SD refractors (81 mm, 103 mm, and 115 mm) have been referred to by at least one well known reviewer as the “Rodney Dangerfield“ of refractors – lacking in the respect that they otherwise should get especially as they are compared to their Japanese counterparts built by Takahashi. Having owned and currently owning several of both I share his the opinion.
My herd of current Takahashi refractors include the FOA 60Q, FC 76 DC with extender, and FC 100DC. I own all three of the current Vixen SD refractors. I have had the chance to compare and consider the differences and, having finished this morning’s h-alpha (Lunt 60 double stack) and white light solar Vixen SD 115 (Lunt Wedge) observing and seriously dehydrating myself in the 90+ deg sun and heat, I am laying inside where it is air conditioned and musing on the long standing Vixen/Takahashi saga.
The Vixen/Takahashi duel goes way back. In the fluorite era, proponents of the rival fluorite doublets were equally divided as to which brand was better and, especially in Japan, the Vixens of this era remain in higher regard than the equivalent Takahashi.
My impression of back then? A coin flip as to optical performance with both sharing the same inherent flaw that continues through today, focusers that are not up to the rest of the scope.
How do things stand today? First, let’s consider the elephant in the room, the current pricing structure for both Vixen and Takahashi. Without getting into another long thread about this having already started one and watching it continue on ad nauseam, suffice to say that the distinction between buying a Vixen or a Takahashi it is fact that unlike Takahashi, who successfully restricts Japanese retailers from exporting to the United States, you can purchase Vixen refractors at far more reasonable prices from Japanese retailers who regularly export them to the United States.
The savings is considerable. I checked recently when I was contemplating a step up from my Takahashi and Vixen 4” models. The best price for the next larger Takahashi, the 120, assuming you can get one shipped here from Japan is $2681.47 plus shipping and Customs. The equivalent Vixen. product, the SD 115 SII (and I will deal with the aperture difference below) is $1689.97 plus shipping, etc. So is the Vixen a realistic and more reasonable alternative to the Takahashi and how about the better high end Chinese 115 refractors?
Now let’s consider the 115 Vixen to the 120 Takahashi. First what is the real as opposed to simplistic difference in the 5mm of aperture. Not much.
Most discussion of the benefit vs cost/weight of aperture treats the size progression by reference to diameter, a very misleading basis. The real difference is the increase of lens surface by reference to increase in diameter. The Vixen 103 has 12.915sq ” of lens surface. The increase of 12mm in aperture gained by stepping up to the 115 yields 16.1 sq “ of lens surface. The 120mm yields 17.53 sq” of lens surface.
Lens surface is the proper barometer of difference in light gathering, all other aspects of the two lenses being the same. Which, by the way, is why the 30mm of difference between a 5”and 6” refractor yields a benefit out of a simple ‘well it’s not that much larger if you consider the increase in diameter’. The lens surface area of a 150 is 27.39 sq “, a 10” increase for just a tad over 1” increase in diameter.
But as usual I digress. That means that the Vixen 115, a FPL 53 doublet with the traditional superb made in Japan Vixen optics (not Chinese made with a Vixen label) will give up a hardly noticeable inch of lens surface and light gathering ability to the Takahashi and even assuming you can get it from Japan, can be had with shipping etc for around $2000 or roughly $1000 less than the Takahashi. If you look at US prices the dichotomy is even more startling.
How about performance? No contest. I don’t own the current 120 Takahashi but have had the opportunity to use one belonging to a friend. I have also owned both an FS128 and an FC125. The Vixen finishes last — but by how much? Not enough IMHO to kick it out of bed for eating crackers. Or, putting it this way, contrast and clarity especially at higher magnification where the larger refractors come into their own for planetary/lunar/doubles is noticeable even by someone like me who no longer has young eyes. Night and day different (sorry)? No, the Vixen does not finish at the back of the pack but is alongside the Takahashi’s saddle at the finish line to quantify the difference in a more scientific terms. But, under truly bad conditions I recall my 5” Taks would show a bigger difference.
Comparison to a very well regarded higher end Chinese made 115, the AT 115 ED? Similar glass both well built doublets. I don’t own one but a good friend who owns and uses the heck out of his has borrowed my Vixen and had it side by side with his AT. He told me he thought it was a dead heat, with the slightly longer focal length of the Vixen giving it a slight advantage in it’s ability to accept magnification and the AT providing a tad more resolution on dimmer targets. He also said the difference might have well been subjective.
I intend to borrow his AT and repeat the test with my better sighted buddy to assist next month.
Okay, why did I buy the Vixen over other possible candidates? I am old school and aside from the optics etc I love the classic look of the current crop of the Vixen SD refractors. Crisp lovingly applied stark white finish, nicely anodized and carefully finished fixtures, traditional and excellent 7x50 lighted finder, classic Vixen graphics, and all in all looks pretty much like my vintage late production FL102S that will probably be the last scope I part with when the inevitable progress of time takes me out of this hobby.
Why buy it over the much cheaper and far more easy to get AT? No reason other than nostalgia for a scope probably not long for continued production.
Some pictures from watching a boat race after my solar observing are below:
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Edited by Dave Novoselsky, 29 June 2024 - 04:28 PM.
