They pass the lines the gas emits and block the rest · review
A 1.25 in UHC filter with a precision-polished substrate and double-sided multi-layer coating, sold for raising nebula contrast — with no wavelengths published.
The bottom line A carefully made piece of glass sold under a name that says nothing about what it passes.
Substrate polished on both sides for parallelism. Multi-layer coating on both faces, with a broadband layer at the rear to reduce internal reflection. A rigid case. Those are genuine manufacturing claims, and parallelism in particular matters: a filter that is not flat degrades the image at high magnification.
The passband. A nebula filter is defined by which wavelengths it lets through and how much of each. Emission nebulae radiate at specific lines, and a filter’s value is the match between its window and those lines. No wavelength and no percentage appears anywhere in this listing.
One of the three UHC filters here publishes its passing wavelengths outright. Against that, a filter described only as “ultra high contrast” cannot be compared — which is exactly the situation the designation page on this site describes.
Under a suburban sky, on emission nebulae, at low to medium magnification. Nothing gets brighter; the background darkens and the contrast rises. An observer expecting more light will read that as failure.
German, French, Italian and Spanish Amazon stores ran from 31 € to 40 € on the day of the survey.
American and British Amazon stores list it in local currency, which the euro range above sets aside.
Figures as Keepa reported them on the day this page was last updated. Stock and pricing shift without warning.
Prices quoted in this text were read on 17 September 2026. The live price is at the top of the page.
| Bandpass and type | UHC — a market convention, not a published standard · The listing gives none: no wavelengths and no transmission percentage appear |
|---|---|
| Line transmission | Not published by the maker. |
| Blocking outside the band | Not published by the maker. |
| Thread size | 1.25 in, screwing into an eyepiece barrel |
| Glass flatness | Precision polished on both sides for parallelism, per the maker |
| Coatings | Double-sided multi-layer, with a broadband layer on the rear per the maker |
| Amazon reference | DE B0746J8KDP · US B06XKRSH6X · GB B06XKRSH6X · FR B06XKRSH6X · IT B06XKRSH6X · ES B06XKRSH6X |
| EAN | 0609378744273 |
Nothing published. It is a market convention describing an intention — a window wide enough to include several emission lines. The width of that window and the transmission at each line vary between makers, and neither appears here.
The maker says so. Visual filters are designed around the eye’s response, and a band that suits a sensor may leave little visible at the eyepiece. Where a maker specifies which use a filter is for, this site reports it — here it claims both.
UHC · passes 486, 496, 501 and 656 nm · 1.25 in
A 1.25 in UHC filter that publishes the emission lines it passes: hydrogen at 486 and 656 nm and oxygen at 496 and 501 nm, blocking everything else.
Best for: An observer who wants to know what a filter passes before buying it
≈ £58 / €58
UHC · 1.25 in · no passband published
A 1.25 in UHC filter from Omegon’s Pro range, sold on the contrast improvement it brings to nebula observing, with no wavelengths published.
Best for: A nebula filter bought on the maker’s reputation rather than on published data
≈ £57 / €63
114 mm mirror · 900 mm focal length · alt-azimuth mount
A 114/900 Newtonian on a simple alt-azimuth mount, supplied with three eyepieces, a 6x30 finder and a 1.5x erecting lens, recommended by the maker from age eight.
Best for: A family telescope where nobody wants to learn polar alignment
≈ £150 / €142
