Photo Levelling?

[Dazbo5]

I've had a photo rejected for being unlevel and wondered if anyone could give me some advice on levelling it. I've always used vertical objects, such as the mast in the background to level photo's rather than horizonal objects, such as the runway in the background. How would you level this photo? If I use the horizon, the mast looks like its about to topple over but when I levelled it like this, I got it reject for unlevel. Any advice would be appreciated.

Darren

[philip]

0,5 degrees ccw (left) should do the job

[Dazbo5]

Thanks for that. I tried 1 degree and it looks better. The mast is leaning to the left slightly but at least the houses are level and it looks a little more balanced.

Darren