Overview: This is a self-made rear soft filter for astrophotography (see photo 1). By attaching it to the rear of a wide-angle lens, it suppresses the streaking of stars in the four corners of the screen and has the effect of making bright stars appear larger. Since its release, this filter has been used by over 160 customers. Size and Material: Size: 105mm x 100mm Thickness: 125μm (0.125mm) Material: PET (more rigid than polyester and less prone to scratches) Actual Shooting Examples: Photo 2 shows a picture of the starry sky taken without a filter, photo 3 was taken with a LEE No. 3 filter, and photo 4 was taken with the self-made "Medium" filter. How to Use: This filter is used by attaching it to the rear of the lens. Cut it with scissors and fix the sides with double-sided tape. It can be used in either direction, regardless of front or back. Refer to photo 5 for how to attach it to the lens. (If there is a mount on the rear of the lens, insert it into the mount.) Compatibility: Please refer to the table in photo 6 for compatibility with filters sold by various manufacturers. Shooting Equipment: Camera: Canon EOS 6D Mark II Lens: Canon EF 16-35mm f/2.8L II Single shot Development software: Lightroom Classic Other: We manufacture with the utmost care, but please refrain from purchasing if you are looking for a perfect product. Shipping will be via regular mail, so please note that it may take about 5 days if it falls on a weekend or holiday.