1.25" UHC Narrowband filter


Availability: In stock

This Celestron ultra high contrast (UHC) light pollution filter has improved contrast when compared with the wider passband of a broadband filter, making it easier to pick out faint nebulas . . .
Our Product #: CUHC1
Celestron Product #: 94123

Product Description

The 600 Ångstrom passband of this new Celestron 1.25" ultra high contrast (UHC) light pollution filter provides improved contrast when compared with the wider 900 Ångstrom passband of the typical broadband filter. The filter has excellent transmission at the visually important emission lines of hydrogen-beta at 4861Å and doubly ionized oxygen at 4959Å and 5007Å. This combines with the narrow passband to make faint emission nebulas such as the Helix, Rosette, Veil, and North American stand out briskly against a dark sky. Brighter nebulas (such as the Omega, Dumbbell, Lagoon, etc.) stand out well under city lights. It can also be very useful in hunting down and enhancing very faint nebulas from a dark sky observing site.

The filter's advanced technology multilayer dielectric coatings let the filter achieve an outstanding transmission of over 97% across the entire passband, with a total blockage of the prominent light pollution lines. The improved transmission translates to maximum image brightness and contrast. Users of smaller 4"-11" telescopes will especially appreciate the high efficiency, and larger scope users will love the rich star fields and detailed subtle nebular shadings that are left intact. Ion beam hardened coatings provide excellent durability and resistance to scratching. The high transmission, sharp cutoffs, and more moderate 600 Ångstrom (60nm) passband of the UHC/LPR filter retains a more natural view, yet significantly boosts overall contrast. Imagers will appreciate the broader passband and inclusion of an extremely efficient 6563 Ångstrom H-Alpha passband. Comes in a protective clear plastic case. A ribbed rim makes it easy to thread in and remove the filter from an eyepiece in cold weather when wearing gloves.

Enter your telescope focal ratio in the formula box to the right to see what focal length eyepieces will work best with this filter.

Tech Details

Max City Exit Pupil 4mm
Max Dark Site Exit Pupil 6mm
Min City Exit Pupil 1mm
Min Dark Site Exit Pupil 2mm
Size 1.25"
Weight 1 oz.


Review by:
This filter does a decent job of making emission nebulas more visible in light polluted areas. The filter does distort the colors of stars quite a bit, particularly with smaller stars. (Posted on 11/27/2018)
Review by:
What a difference! I have gone from not being able to see a nebula at all to easily being able to find them. Living in Florida is tough seeing conditions anywhere but being within 30 miles of a large metro area makes it very frustrating to pull out much more than the planets. This filter helps a lot! (Posted on 11/25/2018)
Review by:
I have used this filter extensively for imaging under light polluted conditions. If you have primarily sodium (orange) light pollution in your area, this filter will be especially useful. Optical quality is great too. Most used filter. (Posted on 11/22/2018)
Review by:
If you’re a visual observer and you want to see more nebula a UHC filter should be your first purchase. Even with moderate light pollution this filter will help you see more nebula. It will enable you to see more detail on nebula you can already see and allow you to see. Ones you couldn’t see before. Add an Oiii filter later and you should be set for a very long time (Posted on 11/3/2018)
Review by:
Defiately a nice addition to my kit. Living in a ifht polluted area it is a necessary filter to have. (Posted on 10/6/2018)
Review by:
Definitely provides a noticable difference when viewing deep space objects in light polluted areas. Living in urban Southern California, light pollution is a constant problem and deep space observation is normally problematic. When using this filter fainter details are definitely more noticable (and more easily observed) and skies appear darker with greater contrast. I have also noticed some better surface definition when viewing Mars through this filter (this was actually the filter I used most for visual observation during Mars' opposition). If I remember correctly (don't quote me on this, though) this is basically the exact same filter as the Baader Planetarium contrast booster filter, just with the Celestron name. Build quality is great, and because of the noticably high durability of the glass coatings, you don't have to worry as much as some other brands about scratching it when a cleaning is required. However, one thing to keep in mind is that like most filters, it does impart a slight color change to the image, giving a yellowish tint to objects viewed through it. However, it isn't noticable on faint or deep space objects. If you live in a light polluted area and tend to do (conditions permitting) a lot of deep space observation, I think it is well worth the price. (Posted on 10/6/2018)
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