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Astronomik UHC Filter
Brand | Astronomik |
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Availability | available |
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Overview
Reviews
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Nov 23, 2009
Astronomik UHC filter
Pros:- best performance of all nebula filters
Cons:
- excellent quality- very expensive
Comments:
- hard to find
- may be best used on >4" apertureBefore investing in a filter to combat light pollution, I did a lot of research to try and decide which one was the best performer. I live in the middle of a fairly large city (~1million), so performance of the filter is important. Second of course is cost. I compared all the filters I found that were readily available on the market:
Bottom Line: Would you recommend this item? Yes
- Astronomik (UHC, OIII)
- Baader Planetarium (Moon & Skyglow, UHC-S, OIII)
- Lumicon (Deepsky, UHC, OIII)
- Meade (Broadband, Narrowband, OIII)
- Orion (Skyglow, Ultrablock, OIII)
- Televue (Nebustar, OIII)
- IDAP (LPS)
Note that based on the information I could find, the Celestron brand light pollution filters are made by Baader and so their performance would seem to be the same. As the point of comparison I looked at the spectral response data that was provided for each filter by the manufacturers or by third parties who have actually measured the response of the filters. I digitized and replotted all the data in the same scale on the same graph and compared. The objective of the filter is to reject the largest amount of light pollution wavelengths possible, and have the highest transmission possible in the bands of interest. Light pollution, including skyglow (a natural phenomenon), occupies a band from 400-440nm and 540-640nm. The desirable observation bands for nebulae are: H-beta 486.1, OIII 495.9 & 500.7, H-alpha 656.3, and SII 672.6.
Based on the data I collected, the Astronomik UHC is the best performing nebular filter, having excellent transmission in the bands of interest, and very sharp cut-off to nil transmission in the light pollution bands. The Televue was a close second except that it has little or no transmission in the Halpha and SII bands. A close third is the Baader UHC-S, which has a broader transmission band around the desired bands allowing a bit more light pollution in. This may however be desired for scopes with a smaller aperture (<4"). By the same token, the Astronomik UHC may be better suited to scopes with >4" aperture.
So based on my analysis I searched for and purchased the Astronomik UHC filter. It was hard to find in Canada, and expensive (~$200USD for a 2”). I am however extremely happy with my purchase. The filter is top notch quality, and it has performed for me on my 8” SCT as I expected it to. The filter is made in Germany, and it comes in a nice foam lined soft plastic case that closes securely…no chance of it flying open like other filter cases or cracking if stepped on.Aug 5, 2007An ideal "combination" filter!
Pros:High quality filter as compared to some of the other leading brands
Cons:Slightly more in price ($20?), but well worth it.
Comments:If you don't want to have two separate filters for O-III and light pollution, this is an ideal combination filter. It shows the Veil Nebula real well. I also use it on the Omega Nebula to bring out the details of the dust clouds and the emission clouds.
Bottom Line: Would you recommend this item? Yes
It comes with a five year warranty and is completely resistant to humidity and scratches. It passes nearly 100% of the O-III and H-beta frequencies and about 98% of the H-alpha frequency in a separate band.Sort by