TS-Optics 1.25" UV & IR Cut Filter - Low Profile Filter Cell

Written by Aaron Urquhart
on 2025-07-22

"I mount this filter directly in front of my guide camera to prevent star bloat and improve guiding precision. Without it, infrared sensitivity in CMOS sensors can blur or distort star shapes—especially when using refractors or lenses that don’t fully correct IR. This filter sharpens the star profiles, making it easier for the guiding software to lock on and stay accurate during long exposures. Recommended For •Astrophotographers using mono guide cameras (e.g. ASI120MM, QHY5L-II) •Guiding with refractors, telephoto lenses, or achromats •Anyone experiencing inconsistent guiding due to bloated or fuzzy stars •Ideal for compact setups or filter drawers with limited space Quality & Optical Performance •Passes visible light while sharply cutting UV below ~400?nm and IR above ~680?nm •Improves star sharpness and centroid stability during guiding •Low-profile housing fits any 1.25” adapter without impacting back focus •Coated optical glass resists reflections and does not introduce halos •Threading is clean, and the build is solid despite the lightweight frame Regularly recommended on forums as a go-to fix for bloated stars in guiding setups. Especially effective with fast scopes or when using low-cost guide scopes where chromatic correction is minimal. No impact on brightness in visible spectrum, and noticeable improvement in guiding graph stability. If you’re guiding with a mono camera and seeing bloated or distorted stars, the TS-Optics 1.25” UV/IR Cut Filter is an easy and effective upgrade. It’s inexpensive, fits cleanly into any standard setup, and delivers better guiding performance by removing unwanted light outside the visible spectrum. Highly recommended for all guiding setups—especially with refractors or fast optics "

Written by Hubert Elsner
on 2023-11-25

"Gutes Produkt, tut was es soll..."

Written by Steffen Lamprecht
on 2023-10-21

"-Für ASI Fotografie einfach unverzichtbare erweiterung. Qualitativ, das was ich erwartet habe. :)"

Written by Jakub Lach
on 2021-07-10

"Nach dem ersten Gebrauch ist es mein Lieblingsfilter"

Written by Michel Willemin
on 2021-05-20

"Very nice quality. "

Written by Krzysztof Grzelczak
on 2020-11-05

"Es funktioniert gut."

Written by Hans-Jürgen Becker
on 2020-10-14

"Gutes Produkt."

Written by Bernd Spier
on 2020-10-08

"Einsatz als Sperrfilter für meine ZWO ASI120mini Astrokamera um Störungen im UV und IR-Bereich zu unterdrücken. "