Well, filters are not usually a good option for comets, because the time shift between acquiring different channels results in artifacts given the object's motion. So some sort of one-shot color cameras are generally best, if not absolutely essential. But I'll stand by my assertion that DSLRs generally give poor color on astronomical objects- something that hasn't improved with newer models, and is unlikely to ever improve. The color filters built into the sensor simply have the wrong band pass for too many common emission lines, and in addition they are fairly leaky to out-of-band signal.badsocref wrote:I don't disagree that a dedicated CCD and color wheels are a superior imaging set-up, but newer DSLRs do a pretty decent job with color and sensitivity.
That's not to say they can't produce "decent" results, of course. My point was really that people (one person in particular <g>) shouldn't get too hung up on what constitutes "accurate" color, given that no instrument or display device matches the human eye, and the choice of camera will impact how the final color appears, and no instrument will see what the eye sees.