There are two types of films for observing the Sun in the 100-240 range: one is solar filter film, and the other is Baader film. Both are very safe for observing the Sun. Introduction to 100-240 Solar Filter Film: Film Material: PET + Aluminum Foil Coating Frame Material: ABS Plastic Screws: Equipped with 6 screws (suitable for astronomical telescopes with 150MM-240mm objective lenses) The solar film adopts PET + aluminum foil coating, which is sturdy and durable, not easy to be damaged, and has passed the certification of the National Aeronautics and Space Administration (NASA) (the same material as the lenses of solar observation telescopes).
### Introduction to 100-240 Baader Film: - Film Material: Imported Baader Film - Frame Material: ABS Plastic - Screws: Equipped with 9 screws (suitable for astronomical telescopes with 100MM-240MM objective lenses) ### Safely Observe the Sun and Protect Your Eyes Baader film is a type of solar filter. What distinguishes it from other similar products is that while reducing light and harmful radiation, it does not lower the contrast of the subject being photographed. That is to say, using Baader film as a solar filter can achieve better image quality and even easily record sunspot activities on the solar surface. Baader film is a silver-colored thin film in appearance. An astronomical telescope must be equipped with Baader film or other light-filtering devices to observe the Sun; otherwise, it will burn the eyes and the instrument. The Sun is very bright, and even with Baader film installed, it is still easy to find the Sun in the telescope.
Warning: Do not look directly at the Sun with the naked eye or through a telescope, otherwise it may cause permanent and irreversible damage to your eyes. (A telescope must be used with a suitable solar filter to observe the Sun.)