Fresnel Lens Sheet Large - Web fresnel lenses category to apply effective focal length efl (mm) to apply substrate acrylic (67) poly ir (9) coating uncoated. Web the large aperture and variable focal lengths allowed for a lighter weight version requiring much less material compared to earlier.
Web the large aperture and variable focal lengths allowed for a lighter weight version requiring much less material compared to earlier. Web fresnel lenses category to apply effective focal length efl (mm) to apply substrate acrylic (67) poly ir (9) coating uncoated.