UV/IR Cut Filter
UV-IR cut filter is designed for ultraviolet and infrared wavelength blocking to improve sharpness of the image as most of the optics are designed for the visible spectrum, because it’s very difficult to create a lens with the same focal point for the visible and IR spectrum.
  • Description

  • Specification

1. Optolong UV/IR Cut Filter Introduction

UV/IR Cut filter is designed for ultraviolet and infrared wavelength blocking to improve sharpness of the image as most of the optics are designed for the visible spectrum, because its very difficult to create a lens with the same focal point for the visible and IR spectrum.

It is used on a digital camera and the video, which do not have an IR protection filter toward an image sensor or were remodeled. This is important because unfiltered CCD and CMOS sensors are extremely susceptible to UV and IR rays just outside the visible spectrum that can have a very negative impact on image quality

Main Use and Performance

⚪Suitable for color CMOS and CCD cameras and modified DSLRs.

⚪Use with monochrome CCD for astrophotography.

⚪Available to assist in focusing.

⚪Act as an outstanding dust shield, which prevents the possibility of dust settling on the lens during long time exposure.

WARNING: The filters of Optolong are not designed for sun observation. DO NOT LOOK AT THE SUN WITH OPTOLONG FILTER. You would be BLIND if you fail to observe the warning.


2. UV/IR Cut Referance Spectrum



How to read the chart?

▲The horizontal axis is the Wavelength in Nanometers(nm).

▲The vertical axis is transmission in %.

▲The RED line shows the transmission of the UV/IR Cut filter. 


3. Optolong UV/IR Cut Filter Feature & Retail Price


Optolong UV/IR Cut  Specifications Applicable Model Unit Price in US$
1.25" /1 1/4" mounted M28.5*0.5 $44
2" mounted M48*0.6 $65
31mm unmounted CCD filter wheel $55
36mm unmounted CCD filter wheel $56



4. Manufacturing Technology

⭐High-precision grinding and polishing to make sure the substrate parallelism is greater than 30" and the surface accuracy is better than λ/4 ;

⭐Purified water ultrosonic clearning is aim to effectively remove impurities and dust from the substrate surface.

⭐Electron-beam gun evaporation with Ion-assisted deposition coating technology for durability and resistance to scratching, as well as stability on CWL(central wavelength) no deviation affected by temperature change; IAD not only consolidates membrane compactness, increases film firmness, but also changes vacuum coating material characteristics.

⭐Planetary rotation system offers precision and homegeneity of coating ensuring high value on transmission of pass-band and Optical density of off-band;

⭐Non-cementing optical substrate coating;

⭐Quality Control: each filters is examined by Spectrophotometer for spectrum characteristic, and Laser Interferometer for surface accuracy.



5. Packing


2019 NEW package

※NoteWe are now in the transition from the old to the new packaging style, ship is random.



6. UV/IR Cut Filter Performance

I. NGC 4565, shot by Astrodoc Ron Brecher

NGC 4565, The Needle Galaxy, lies about 30-50 million light years from Earth in the constellation Coma Berenices.  It has a diameter of about 100,000 light years, similar to that of our own Milky Way galaxy.  Its length appears about half the Moon’s width in images, and somewhat less through the eyepiece.  Although it is classified as a barred spiral galaxy, the central bar isn’t visible in this image, because the galaxy is edge-on to our line of sight.  However, its presence is evident from Spitzer Space Telescope data.  Several other galaxies also appear in this field.  The most prominent is NGC 4562 at upper right. There are dozens of faint galaxies in the field, marked in the annotated image.  The faintest of the marked galaxies, PGC3096164, has a blue magnitude of +21. There are also many unmarked galaxies, including many off the lower right tip of NGC 4565.

Luminance: Sky-Watcher Esprit 150 f/7 refractor and QHY 16200-A camera with Optolong UV/IR filter
Chrominance: Takahashi FSQ-106 ED IV @ f/3.6 and QHY367C one-shot colour camera with Optolong L-Pro filter

Luminance:      58 x 10m = 580m
Chrominance:  244 x 3m  = 732m
Total: 21hr52m
Image scale 1.15 arcsec per pixel (based on Luminance)
Data Reduction and Processing
Preprocessing: The WeightedBatchPreProcessing script was used to create a Luminance master frame (from the mono camera) and a RGB master frame (from the one-shot colour camera).




II. NGC 1977, The Running Man Nebula, shot by Astrodoc Ron Brecher

The Running Man Nebula, a.k.a. NGC 1977 and Sh2-279, is part of Orion’s Sword, an asterism of star clusters and nebulae below Orion’s Belt. It sits about a little more than the width of the Moon north of the Orion Nebula. The Running Man Nebula includes pink HII emission regions, and blue reflection nebulae. Dark dust throughout gives the area surrounding the bright nebula a smoky texture. This complex lies around 1,500 light years away, and is about 7.5 light years across. I have imaged the whole sword previously, showing the Running Man Nebula in context. My 2010 image of this object is one of my first astrophotos. It’s amazing to me how far I have come in this hobby.


Acquisition, focusing, guiding and control of Paramount MX mount with TheSkyX. Focus with Optec DirectSync motor and controller. Automation with CCDCommander. Equipment control with PrimaLuce Labs Eagle 3 Pro computer. All pre-processing and processing in PixInsight. Acquired from my SkyShed in Guelph. Minimal moonlight, above average transparency and average or better seeing. Data acquired February 21-March 1, 2020.

Luminance: Sky-Watcher Esprit 150 f/7 refractor and QHY 16200-A camera with Optolong UV/IR filter
Chrominance: Takahashi FSQ-106 ED IV @ f/3.6 and QHY367C one-shot colour camera with Optolong L-Pro filter

Luminance:      40 x 10m = 400m
Chrominance:  154 x 3m  = 462m
Total: 14hr22m

Image scale 1.15 arcsec per pixel (based on Luminance)


(2nd.April 2020)Today's Image of the Day goes to Ron Brecher



Optolong UV/IR Cut Filter features 4 sizes:

★1.25"(1 1/4" mounted), 2" mounted for eyepiece

★Round 31mm unmounted, 36mm unmounted for filter wheel