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Cooled CCD cameras of G4 series contain detectors with 36 × 36 mm area, which is 50% more than photographic “full-frame” format. G4 camera dimensions are the same like dimensions of G3 series, with the exception of camera head thickness—G4 cameras are somewhat slimmer, because they do not contain internal filter wheel. Also camera handling, software control, power supply and connection to the host PC using fast USB 2.0 interface is the same like in the case of G3 cameras. Filter wheel for 50 × 50 mm square filters (round filters of 50 mm diameter cause vignetting on such large CCD chips) cannot be placed inside the camera head due to limited space. But it is possible to connect external filter wheel for 5 large filters to the G4 camera, the camera head already contains connector for external filter wheel control.
G4 cameras contain Full-Frame CCD chips OnSemi KAF. These detectors are equipped with so-called “anti-blooming gate” (ABG), which drains the over-abundant charge from saturated pixels. ABG ensures the round images of bright stars, without disruptive blooming spikes. On the other side, compromising of the CCD linearity by ABG is only negligible. G4 cameras can be used for astrometric and photometric applications as well as for astrophotography.
No matter if your target is reliable scientific data or beautiful images of deep-sky objects, G4 CCD cameras are able to provide both.
