Seymour Solar Helios Glass Binocular Solar Filter Kit – Slip-On Front-Mounted Solar Imaging Accessory (Pair)

Description

View the Sun in high-contrast detail with the Helios Glass Binocular Solar Filter Kit by Seymour Solar. This matched pair of ND5 white-light filters uses metallic-coated optical glass in precision slip-on aluminum cells to reduce the Sun’s brightness by a factor of 100,000, delivering a warm yellow/orange solar image suitable for white-light binocular observation and imaging when correctly installed.

Key Features

• Matched Pair of Helios Glass Filters: Two identical ND5 filters ensure both binocular barrels receive the same optical performance and image brightness.
• Optical Glass Substrates: Rigid, metallic-coated glass maintains figure and focus across the field, supporting crisp views of major solar features.
• Slip-On Aluminum Cells: Machined aluminum housings slide over the front of your binocular objective housings within the listed outer-diameter range for a secure front-mounted fit.
• Warm White-Light Solar Image: Helios glass produces a pleasing yellow/orange solar disk that highlights sunspots, limb darkening, and large-scale surface structure.
• Made in the USA: Designed and assembled by Seymour Solar in Avon, North Carolina.

What You’ll See

• Sunspots and active regions
• Overall solar disk structure and limb darkening
• The Moon’s silhouette during partial and annular eclipses
• Planetary transits (when visible)

Material Characteristics

Helios Solar Glass: Optical-quality glass with a durable metallic coating that reduces visible sunlight by approximately 99.999% (ND5). The rigid substrate supports consistent focus and contrast across the field, with a warm yellow/orange tone that many observers find comfortable and easy to view for short solar observing sessions.

Sizing & Fit

This kit includes two matched filters, one for each binocular objective. Each filter slips approximately 1 inch (25 mm) over the front of the binocular housing.

• Measure the outer diameter (OD) of each objective housing at the widest point within the first inch in front of the glass.
• Select the filter size whose listed OD range includes your measurement.
• For the best fit, confirm that both barrels of your binoculars fall within the same OD range.

Click here to measure your binoculars and choose the correct size.

Safety Information

These Helios glass filters are designed for front-mounted white-light solar observation with binoculars. Always install and secure both filters before pointing your binoculars anywhere near the Sun.

• Inspect filters before each use; do not use if the glass or coating is cracked, chipped, or visibly damaged.
• Confirm that each cell is firmly seated and cannot be dislodged by light pressure or a gust of wind.
• Never use these products as handheld eclipse glasses or place them directly in front of your eyes.
• These binocular filters are accessories for optical instruments and are not certified under ISO 12312-2, which applies to direct-viewing eyewear.

FAQs

• Why do I need a matched pair?
  Binoculars must always be filtered symmetrically. A matched pair ensures both barrels deliver the same brightness and image quality, preventing eye strain and protecting both eyes equally.
• How tight should the fit be?
  The cells should slide on with firm, even pressure and stay in place without wobble. If a size feels loose or can be knocked off easily, do not use it—select a size with a more secure fit.
• Can I use these instead of eclipse glasses?
  No. These filters are intended to be mounted on binoculars. For naked-eye viewing of eclipses, use appropriate direct-viewing solar eyewear that follows the ISO 12312-2 standard.
• Are these suitable for photography?
  Yes. When mounted on binoculars attached to a camera or used with suitable binocular mounts and adapters, the ND5 attenuation and rigid glass substrate support white-light solar imaging of the disk and sunspots.