This auction is for a 1995 Orion (Hoya or Kenko of Japan) 1.25-inch SkyGlow Broadband filter. It will come with an aftermarket, 2-inch class plexiglass storage case.
When Orion began their expansive catalogs campaign back in the 1982-84 years, a great deal of their products was not their own, but that of other companies. They had their own line of eyepieces by this time, and their forever trustworthy AccuTracks were heavily advertised and printed in ads. But for the most part, Orion carried other brands; like Celestron, Meade, Edmund Scientific, Tele Vue, and Lectra.
In the case of nebular-style and light pollution reduction filters, the SkyGlow had yet to appear. For now, they were selling Celestron's.
It wasn't until the end of 1987 or Jan-Feb of 1988 that we first see the Orion SkyGlow Broadband (Wideband) and UltraBlock (Narrowband) appear in the catalogs as Orion's own approach to the nebula filter market.
Model: SkyGlow
Threads to: 1.25-inch eyepieces
Design: mercury and sodium vapor wavelength elimination filtration;
enhanced incoming hydrogen alpha/hydrogen beta wavelength transmission
Optics: multiple layer interference filters in glass
Clear aperture: 25.8mm
Materials: anodized aluminum and glass
Weight: 0.2 ounces
When the first set of SkyGlows came to the catalogs, only the 1.25-inch, 2-inch, and Schmidt-Cassegrain (threads to their visual back) models were available. It is not until sometime in 1992 that we first see the .965-inch models arrive (1992 is the earliest year I can prove).
In early fall of 2001, the .965-inch model was dropped for good, mainly because by this point in time, in which many of the Japanese manufacturers' contracts were being replaced by those from China. Japan was LARGELY a 1-inch class purveyor of small focusers on small telescopes, whereas with China, even small telescopes would now be coming with 1.25-inch accessories.
The SkyGlow filters from the dawn of their existence in sales until 2002 were Japan-sourced. Then there was a short period where they came from Focus Optech Co, a Korean firm. By 2007-onward they were from China. None of the Japan-years SkyGlows experienced ANY generation changes; thus these filters from 1987-2001 look the same.
And as one would not be surprised to learn, the SkyGlow models from 2003-to date (2024) look identical. The difference here, however, is that by 2018, the only way to acquire the SkyGlow Broadband filter was to get it in the "Orion Deluxe Stargazer's 1.25" Eyepiece Filter Set" or with the "Orion 1.25" Deep Sky Explorer Telescope Accessory Kit".
In terms of performance and comparison, the Orion SkyGlow is in the same class as the Parks ALP, Celestron LPR, Meade Nebular, Lumicon Deep Sky, and Hutech IDAS-D1; though I feel the Hutechs and Lumicons are the top of top class, and they are considerably more expensive.
Though these filters have subtle differences here and there, they all do one thing in particular; reduce key bandwidths of light responsible for light pollution; primarily sodium, mercury, and ionized oxygen.
When this "pressure" or "noise" in the sky is reduced, the object of interest becomes enhanced via contrast; a bright light source immediately surrounded by blackness or very little-to-zero haze. It can be a stark difference between seeing regions of detail in M51, M31 or even the Fish's Mouth of M42 and not seeing any intricate detail at all.
Now a primary misconception, definitely a signature of an intermediate observer, is that these SkyGlow filters will magically allow you to see all these wondrous, knotted, molted, glowing details in nebulae and galaxies that was entirely invisible without the filter. On the contrary, there is nothing magical about what the filter does; it is filtering out very specific wavelengths of light so that your brain doesn't have to stress trying to separate images you are not interested in seeing. In fact, this filter will darken everything, not make it brighter. ONLY an increase in APERTURE can increase your brightness (unless we argue about the legendary Collins I-3). But what it will do is allow you to see finer, subtle details in the object. It can definitely be the difference between seeing M76 avertedly versus looking at it directly.
Generally, I would say these filters are intended for telescopes in the 6-inch and larger class, especially since apertures in the 2.4-inch to 4.5-inch are already light-starved and have enough of a time getting the Messier list on their own. Yet there is a reason why even small telescopes that can accept the 1.25-inch SkyGlow will find it more than works for them, and that is if your observing sit is smack in the heart of urbanization; like Los Angeles, NYC, Chicago, Miami. In this situation even your 60mm to 90mm refractor CAN BENIFIT from this light-blocking filter.
On a final note: it is important to note that this filter will not thread to any 1.25-inch eyepieces branded "Criterion", "Bausch And Lomb", "Vernonscope", or "Questar". These eyepieces will have brand-dedicated threads and only their brand of filters will thread to them.
You may also discover the very earliest Tele Vue plossls of pre-"NJ Japan" years will not allow complete attachment as their thread counts are off slightly. The filter will fit to them, but only a 3/4ths of 1 rotation will be allowed before risk of stripping the male threads of this SkyGlow unit.
When you cannot escape the streetlights and washed-out skies from the nearby shopping center, the SkyGlow will come to the rescue and make your observing session less futile and more fun.
This auction ad was completely, organically written by Veradale Mobile Observatory, not an A.I. software device; an actual honest-to-goodness, real human with over 20 years experience with now over 1000 telescopes made from today and all the way back to 1948.
Packed with great care.