I was trying my best today to make the most out of a seaside photo taken at dusk, which required quite a long burn compared to the rest of the picture. The base print exposure was 26 secs. The sky required an additional 26 secs to give it just a touch of density.

For me, this is quite a big jump in difference between the base and the burn. The first one had really serious halo's, which I suspect was from not moving the mask enough (I had also burnt in the sky for 40 secs, which was a tad too much). The second one was substantially better, but there was a touch of darkening along one edge.

Can anyone give me a run through on the best technique to avoid such issues?


(PS. I'll scan them in and post once they are dry)