Quote:
Originally Posted by blink138
thanks terry
how are falts taken? i know they are photos taken with a dusk sky..... but do they need to be taken prime focus or can they be done hand held? what exposures / speed / quantity need to be done?
pat
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You will have to google for full detail regarding flats, but basically they have to be taken with the camera left on the ota in the same position as the lights were taken with a white cloth or light source over the objective. Flats help to remove any blemishes in the imaging train such a dust spots and in your case uneven field illumination "vignetting" caused by using a too large sensor for your imaging train. Great effort otherwise and my guess with the m27 pic is that your camera has rotated on one or more subs. You could always crop the pic a bit to reduce the vignetting.