Welcome to the photography section.

Not sure what u mean about flare lense, but i bought an 1100d with 2 kit lense only this year , so lense cant be dirty, r u reffering to the flare from the lights ? thats from the long exposure

 

I do long exposures when I do night time lapse and have no where near as much flare as that.
You can buy a filter lens that gives you that effect.
It usually comes in four six and eight star formats and would give the
Effect that you have there with every light source having six beams if light
From them.I use them sometimes to give a more arty effect with night photos.

 

The Nikon D5100 has star/flare effect in it's effect settings, results are fairly good on first attempts, i will post up pics when i have a shot i'm happy to put up

 

Iv a cheap ebay uv filter on it maybe that effects it

 

Don't use them mate, take it off. In my experience UV filters make the image worse, i never use them, apart from my 50 as it's cheap and plasticky.

 

Levin you hit the nail on the head.that's what is causing the flare.
I only use them during the day as you get the flare effect at night.

 

thanks for the advice lads , here's a few shots with the 75-300 kit lense

 

working last week at a wind farm in north wales, (again)