Flare of Prominent Nokton 50mm F1.5

[jsuominen]

I got my Voigtlander prominent with a legendary Nokton 50/1.5 few days ago and yesterday I developed the first test roll. It shows nice bokeh as I've heared. But under a back light conditon (it wans't too harsh), I found a serious flare from the picture. Please check bellow pics carefully. Does it normal?

I don't own a classic Nokton 50/1.5, but I liked a lot of your photos. The third portrait photo was very nice. Do you remember, what aperture did you use when you took that shot?