James Parker

Hi Thanks for the response. I followed the instructions and they do work thanks. So I can remember in future what is the bit with creating the spare channel doing and also why is the mask layer not visible in the normal way as a child to the (brightness/contrast) adjustment layer?

I am trying to create a mask (to use on an adjustment layer) from an image. I have imported the image, converted it to a pixel layer using rasterise, but whatever I do (following the various guides on this forum and elsewhere) I cant get it to convert properly to a mask which can then be applied to an adjustment layer. The obvious 'rasterise to mask' just results in a completely black mask as does 'apply as mask to below'. Attached is the selected mask layer (its a 'star mask' - ie it masks the areas identified as 'stars' in a stacking program'). The end goal is to 'bring up' the stars in a sky scene of comet Neowise (second attachment) without over-exposing the sky or the comet.