The Telescope Authority
Since 1947

View Shopping Cart

Your Cart is Empty

Baader UHC-S Nebula Filter - 1.25" Round Mounted


- Read
Add to Wishlist

Request stock alerts and we'll let you know when the item is back in stock

Got questions? Click for live chat

Product Details

  • The UHC-S Nebula Filter - 1.25-Inch Round Mounted by Baader Planetarium:


    This Baader Planetarium UHC-S Nebula filterexcels at delivering a high-contrast and natural view of emission nebula without excessive dimming and loss of background star fields. The perfect filter for viewing emission nebula from light polluted skies, or for boosting the contrast of nebula from dark sky sites. The advanced technology coatings enable the filter to achieve an outstanding transmission of over 97-percent across the entire pass band, with total blockage of prominent light pollution lines. This translates to maximum image brightness and contrast. Owners of 4 to 10-inch 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.

    The Baader UHC-S manages to improve on the contrast of the typical broadband or so-called "Deep Sky" filters. Sky background is darker, and contrast of emission nebulae are noticeably improved. Most other "UHC" filters tend to excessively darken the sky and star fields, leaving the nebulae looking artificial and flat, set against an empty background. The high transmission, sharp cutoffs, and more moderate 60nm pass band of the Baader UHC-S filter retains a more natural view, yet significantly boosts overall contrast. Imagers will appreciate the broader pass band and inclusion of an extremely efficient H-alpha pass band (>99-percent at 656nm), as well as the extreme optical quality.

    At the heart of the Baader UHC-S filters are their special fine optical substrate polishing process and advanced coating design. The result is a filter that imparts no image degradation, unlike other filters. To prevent deterioration from cleaning or exposure to moisture, some other filters even resort to sandwiching their delicate coatings between two layers of filter glass, resulting in potential blurred or double images. The combination of hardened coatings and fine optical substrate of the Baader UHC-S avoids this image degradation. A common misperception is that deep sky viewing is limited to low powers, and image resolution is not as important as in planetary observation. In reality, high magnifications are very common and useful in studying fine details, particularly for the brighter diffuse and planetary nebulae. Baader UHC-S filters can take high magnifications, and stars retain their pinpoint sharpness, even if the filter is used far ahead of the image plane (i.e. for imaging use, or ahead of a star diagonal or binoviewer). Baader filters fulfill the requirements of an ideal filter, to perform their filtration at highest efficiency without any other detectable effect on the image.


    Baader Planetarium UHC-S Nebula Filter Features:

    True Optical Quality: Baader glass substrates are of true optical quality. Most other filters are merely made from raw flame-polished, optically flat, or sometimes a top quality commercially polished filter glass (fine for camera filters), resulting in wavefront deformations that damage image sharpness and contrast when used with telescopes. Baader Planetarium filters are made from striae-free substrates, and actually fine optically polished flat to within 1/4 wave p-v over the entire surface, plane parallel to within 30 seconds of arc! This important and unique custom step adds cost - but the result is a filter that maintains the full wavefront quality of the telescope without double images or ghosting, even at high magnifications. Critical to maintaining this level of flatness are Baader's carefully balanced coating designs, which prevent coating surface stresses from warping the substrate. Such high flatness enables Baader filters to be used far in front of the focal plane, ahead of star diagonals and digital cameras. They are particularly well suited for attachment to the nosepiece of the Maxbright Binocular Viewer (other manufacturer's filters must be used in pairs, attached to the eyepieces).

    Filter Durability:Filter durability has always been a hallmark of Baader Planetarium. The multi-layer dielectric coatings are plasma-assisted and Ion beam-hardened using the latest technology (the coatings are harder than the glass substrate itself!). Baader filters withstand repeated real-world exposure to the elements and physical cleaning. Users need not leave their precious filters dull and dust encrusted to avoid cleaning - Baader filters may be used and cleaned without fear. We have heard sad stories from owners of other simpler soft-coated dielectric filters, who have seen their coatings degrade from normal exposure to moisture, or wiped away from routine cleaning. Some manufacturers even resort to sandwiching their delicate coatings in between two layers of glass (and risking blurred double images as well as eventual degradation from the edges inward). Baader Filters will truly last a lifetime.

    Stackability:Unlike other filters, Baader Planetarium filters are truly designed to be stacked and combined. This is possible due to the high optical quality and highly efficient anti-reflection multi-coatings. The ability to combine filters opens up many exciting possibilities, permitting unique spectral characteristics unachievable with any single filter.

    Special Filter Cell:Baader's special filter cell design offers unique features that enhance their reliability and usability. Though difficult to produce, the ultra-thin filter cell results in the maximum possible clear aperture, in order to minimize vignetting (the 1.25-inch Filter clear aperture is 27mm, the 2-inch Filter aperture is 45mm). The special threading has been designed to fit a wide variety of eyepieces and accessories (there is significant variation between the 1.25-inch filter threading used by eyepiece and accessory manufacturers). The front crown of the filter incorporates milled notches which make handling and threading the filter a more secure operation in the dark.

    Low cost:Despite high quality and advanced technology, Baader Planetarium filters are affordable. By leveraging high volumes across all filters in the Baader family, these filters can be offered at very reasonable prices.



  • specifications

    Free ShippingYes
    Integral Transmission0.97
    Warranty1 Year Warranty

Product Reviews

Customer Reviews
4.8 Based on 5 Reviews
5 ★
4 ★
3 ★
2 ★
1 ★
Write a Review Ask a Question

Thank you for submitting a review!

Your input is very much appreciated. Share it with your friends so they can enjoy it too!

Filter Reviews:
    Gerardo Diez Martinez C.
    Mexico Mexico

    Baader UHC-S Nebula Filter - 1.25"

    Simply amazing the quality of Baader's products, I had never used them before, but it was very nice to see the results I got. I highly recommend it

    United States

    Baader UHC-S Nebula Filter

    I have only had the opportunity to use this filter twice so far, but the results are very encouraging. There is a lot of skyglow from a nearby city in my southern sky, and this filter clearly compensates for it. Camera image backgrounds are much blacker than without the filter. It does require longer exposures as would be expected.


    If you buy only one nebula filter

    I've tried several different nebula filter of different brands over the years, and so far this has been my favorite. Unlike most UHC filters, many faint stars can still be seen using it and there is are no bright purple ghost halos on bright stars. This filter has a very nice balance of light blocking and throughput. There is only a slight blue color cast on stars, and nebula contrast is definitely improved. This filter improves almost all types of nebula when used in the city or even a dark sky. With my 8" SCT, using the UHC-S under dark skies, the Veil Nebula is astounding, with ribbon like detail visible, set in a beautiful star field. Under the skies of L.A., this filter is a must for the Orion and other bright nebula. It's even a good photographic filter when trying to image deep sky objects in the city (see attached), when properly color balanced.


    Filter of choice

    Having used the Baader UHC-S filter for more than a year I can say I am completely happy with it, and it is my filter of choice for most applications. I've used the filter in a 120mm F5 achromat, a 10 F4.7 reflector and an 18 F4.5 dob and it performs well at all apertures. I particularly like the 'natural' look to the FOV. Contrast and depth are enhanced, but the nebulae still appear against a backdrop of sky and stars.


    Really great filter

    Really like this filter, works great on Nubulae and not bad on galaxies and star clusters. I do so a noticeable blue in my background of my photos vs. the black you normally see. I've been using it in front of a ZWO ASI 1600 MC camera.