Dark patch when merging

[johnb]

So I'm merging a long and short exposure of M42 following an article on how to composite the two and it works fine, I find that when applying the Gaussian mask and blurring I find it hard to get the right balance. Anyone else use this technique ?

John B

[cosmojaydee]

soft brush, softer the better , you can intensify the effect by repeating the brush, the harder the brush the more intense the effect and do not clip the area you want to keep as it is