Laser-Precise Focus at Night

Get precise manual focus on stars and planets with the Kase Bright Star Professional Bahtinov Focus Filter. Designed for astrophotographers and photographers who use compatible camera lenses, this laser-etched Bahtinov focusing filter creates a diffraction pattern that makes precise nighttime focusing fast and repeatable.

Unlike a clip-on Bahtinov mask, the Kase Bright Star attaches to a compatible 77mm or 82mm filter thread using a magnetic adapter system. Install the adapter ring once, then attach and remove the Bahtinov filter magnetically whenever you need to focus.

If you've ever spent hours trying to manually focus a camera on the stars at night, you know the struggle. A Bahtinov focus filter turns that guesswork into a visual focusing process that can be completed in minutes.

Why Choose the Kase Bright Star Professional?

The Kase Bright Star is designed for photographers who want a threaded, magnetic Bahtinov focusing system rather than a clip-on mask.

Key advantages

• Laser-etched Bahtinov pattern for precise diffraction-based focusing
• Magnetic attachment allows the focusing filter to be installed and removed quickly
• 77mm and 82mm filter-thread options for compatible camera lenses
• Durable optical material with a hardened protective top coat
• Water, oil, dust, fingerprint, and scratch resistance
• Lightweight design at approximately 1 oz (28g)
• Protective storage case included
• Designed specifically for camera-lens astrophotography and nighttime focusing

The magnetic system is particularly useful for photographers who frequently switch between focusing and shooting. Once the adapter ring is installed, the Bahtinov filter can be attached for focusing and removed without repeatedly threading the focusing filter onto the lens.

Who Is This Bahtinov Filter Best For?

The Kase Bright Star Professional is a good choice for:

• DSLR and mirrorless camera photographers
• Astrophotographers photographing stars, planets, and the night sky
• Photographers using telephoto or other compatible lenses with 77mm or 82mm filter threads
• Photographers who want a fast, repeatable method for manual focus
• Users who already use threaded filters or magnetic filter systems
• Photographers who prefer a threaded filter solution over a clip-on Bahtinov mask
• Anyone who regularly needs to refocus a camera lens during nighttime photography

Especially useful for telephoto astrophotography

Bahtinov focusing becomes particularly useful when precise focus is difficult to judge through the camera's normal Live View display. Longer focal-length lenses can make small focusing errors especially noticeable, making a diffraction-based focusing aid a valuable part of an astrophotography setup.

Who Should Consider a Different Bahtinov Mask?

The Kase Bright Star is not the best choice for every camera or telescope setup.

Consider a clip-on Bahtinov mask instead if:

• Your lens does not have a 77mm or 82mm filter thread
• You want a mask that mounts based on the exterior diameter of the lens barrel
• Your lens uses a different filter-thread size and you do not want to use a step-up ring
• You frequently switch between lenses with substantially different front diameters

For telescope users or very large optical systems, a telescope-specific Bahtinov mask may be a better choice.

For very wide-angle lenses, Bahtinov focusing can be more challenging because the diffraction pattern may be smaller or less distinct. A brighter focus target, such as a bright star or planet, can help produce a clearer pattern.

Kase Magnetic Bright Star, Wolverine Series

Get precise focus on stars and planets with a laser-etched Bahtinov pattern.

This filter uses a standard threaded filter connection rather than sizing by the outside diameter of the lens barrel.

Check the filter size marked on your lens, usually on the front ring or inside the lens cap. It will commonly appear as a diameter symbol followed by a number, such as:

Ø77 = 77mm filter thread

Ø82 = 82mm filter thread

Choose the version that exactly matches your lens's filter-thread size.

Important: A 77mm or 82mm filter size refers to the lens's filter-thread diameter. It is not the outside diameter of the lens barrel. This is different from our clip-on DSLR Bahtinov masks, which are sized according to the exterior barrel diameter.

Durable Optical Construction

The Kase Bright Star uses shock-resistant tempered optical material with a hardened, easy-clean protective top coat.

The surface is designed to resist:

• Water
• Oil
• Dust
• Fingerprints
• Scratches

That makes the filter well suited to astrophotographers working in remote locations, dark-sky sites, and outdoor environments where equipment is exposed to the elements.

Lightweight Design

At just 1 oz (28g), the Kase Bright Star adds minimal weight to a camera setup and is designed to avoid unnecessarily disrupting rig balance.

Its lightweight construction also makes it practical to keep in an astrophotography bag and install whenever precise focus is needed.

Protective Storage Case Included

Each Kase Bright Star Professional Bahtinov Focus Filter includes a storage case to protect the filter when it is not attached to your lens.

Keeping the filter in its case helps protect the optical surface during transport and makes it easier to keep your astrophotography accessories organized.