Hence there is no stress build-up extended onto the film as it shrinks with temperature variation.
The film itself will not be harmed by temperatures between -50°C up to +50°C. Below the film will become stiff and further below (- 100°C) even brittle. Above 50°C the adhesive that fastens the film onto its mounting-ring may start to become soft - in case that temperature persists for longer than 24 hours.
Manufacturer Baader Planetarium SKU (#) 2459286 Weight (kg) 0.02 Usage Visual solar observation and imaging AstroSolar Film AstroSolar Safety Film Optical Density 5.0 Inner Diameter / Clear Aperture (mm) ca. 20 x 29 cm Solar Wavelength Whitelight (integral light)