So I'm planning on using my DMK21 and/or DMK41 with my PST to do some H-a solar imaging.
My question is, should I use an R, G or B filter with it, or should I be capturing straight luminance?
Using the Moon as an example, you can capture straight lum, but the image can be sharper with a R or G filter when the seeing is good. Is it the same for H-A solar imaging with the PST?
As you are already filtering the light to a huge extent, the addition of another filter will only reduce the amount of Ha available to the camera. I see no point in filtering the already sub nm filtered light.
As Stuart says Mike and you have remembered. It is already heavily filtered. You could add a blue, a green and a pink with yellow polka dot filter and it wouldn't make any difference. Those frequencies are already blocked. RGB solar colour is all false colour except for the red, specifically the 656.3 band.