Masked stretch creates halos on combined image

[nickg]

I am trying to reduce star size and have ran into a road block. The imaging FL is 1800mm f/9 which produces some fairly large stars if left unchecked. I came across the masked stretch method, where the masked stretch image is combined with the high-contrast one using pixel math. The problem is I am getting halos, no matter what setting I use on the mask. I like the smaller stars also because they are not as saturated, and color is enhanced. Any way to cure this? Completely stumped at this point   I have attached example previews, one is with masked stretch and the other one without.

Thanks,
Nick

[Juan Conejero]

Hi Nick,

I see no halos at all, just an expected result from MaskedStretch (modulo any additional masking you may have applied).

The stars are IMO much nicer on the "with" preview than on the "without" one, although the MS result would require a color saturation increase to be comparable.