AltairCapture has a “live” flat frame subtraction feature, which you can use to remove dust artefacts and uneven illumination effects.

Live Flat Frame Subtraction Correction is available in the following modes:

File Format:	Camera Mode:*	Live Flat Frame Subtraction available?
.SER	RAW only	No
.AVI	RGB only	YES
.TIFF/.PNG	RGB only	YES
.FITS	RGB	YES
	RAW	NA

* “RGB mode” can also be used with mono cameras.

Note: This article only concerns “Live video” or the display of “Live stills” in AltairCapture. In the course of normal imaging you can capture flat frames, save them and stack them into a “master flat” and apply them to your light frames later, in any mode or imaging format, which is the general way this is done in post processing of astro images.