Daystar Instruments FLAT CAP Imaging Diffuser
Taking a Flat field reference image removes the effects of dust spots, vignetting, and filter uniformity.
The DayStar FlatCap is a Gaussian diffuser that is temporarily installed over the front of your telescope when taking flat field reference images. By strongly blurring the Sun, the only details you will see in the reference image are from defects in your imaging train that can be removed in software.
Specifications:
Construction: Spun Aluminum mounting ring with polymer diffuser
Intensity distribution: Gaussian
Divergence angle: 4 degrees FWHM
Exposure time adjustment factor: 100x longer
Maximum field of view: 1 degree with Sun backlight
Wavelength transmission range: 350-800nm
Operating temperature: -10 to 100°C (14-212°F)
• Warning: The Daystar Flat Cap is NOT a solar filter.
Not for use in a concentrated beam, FlatCap must be the first component to encounter light.
This is a not a solar filter, eye or equipment damage will result unless used in combination with a safe solar filter or solar telescope.
This product is manufactured in the USA.
| Model | Fits |
|---|---|
| FC90 FlatCap | Fits 80-89mm tube OD or 63mm ERF  |
| FC100 FlatCap | Fits 90-99mm tube OD |
| FC110 FlatCap | Fits 100-109mm tube OD or 80mm ERF |
| FC120 FlatCap | Fits 110-119mm tube OD or 90mm ERF |
| FC130 FlatCap | Fits 120-129mm tube OD or 100mm ERF |
| FC140 FlatCap | Fits 130-139mm tube OD |
| FC150 FlatCap | Fits 140-149mm tube OD |
| FC160 FlatCap | Fits 150-159mm tube OD or 130mm ERF |
| FC170 FlatCap | Fits 160-169mm tube OD |
| FC180 FlatCap | Fits 170-179mm tube OD or 150mm ERF |
| FC190 FlatCap | Fits 180-189mm tube OD |
| FC210 FlatCap | Fits 190-209mm tube OD |
FlatCap is sold by inside diameter of the mounting cap. Measure the outside diameter of the frontmost component of your telescope or ERF, and then round up to the next larger size. For example, a telescope with a 160mm front should use model FC170, and then optionally install the included felt pads for a secure fit.
Daystar Recommends SharpCap imaging software
Note: Newton’s Rings or intereference fringes will not be corrected by flat fields; use our Interference Eliminator adapter to remove these before performing flat field correction.