The Daystar Filters Imaging FlatCap FC140 is a diffuser designed for capturing flat-field calibration frames in solar imaging. The device is temporarily installed on the front of the telescope when taking reference images used to remove dust spots, vignetting, and filter non-uniformity from the final image. The Gaussian diffuser strongly blurs the Sun so that the reference frame records only imperfections in the imaging train, which can then be corrected during image processing.

Key features

• diffuser for capturing flat-field calibration frames in solar imaging
• helps remove vignetting, dust spots and optical system non-uniformity during processing
• Gaussian intensity distribution diffuser
• mounted on the front of the telescope during flat frame acquisition
• construction with spun aluminum mounting ring and polymer diffuser
• designed for telescopes or optical components with an outer diameter of 130-139 mm

Kit contents

• Daystar Imaging FlatCap FC140
• felt pads for fitting adjustment

Technical specifications

• manufacturer: Daystar Filters
• model: FlatCap FC140
• diffuser type: Gaussian
• divergence angle: 4° FWHM
• maximum field of view: 1° with Sun backlight
• wavelength transmission range: 350-800 nm
• exposure time adjustment factor: approximately 100×
• operating temperature range: -10 to 100°C
• compatible tube outer diameter: 130-139 mm
• mounting ring material: aluminum
• country of manufacture: USA
• SKU: FC140