Odd Looking Specular Highlights And Bokeh

[68lbs]

Quick query...

I'm getting quite obsessed with shallow DoF, bokeh and specular highlights. I understand that when you're shooting wide open the bokeh is circular, and when stopped down you can see the shape of the aperture depending on the number of blades.

But what causes funny shapes, like the ones below? I've had them more pronounced than this too... like a vertical 'eye' shape.

 

[PauloWanClift]

Are they all towards the edge of the pic? Lens distortion maybe. Not that I know enough about lenses to know if bokeh can get distorted.

 

[HoppyUK]

It's off-centre light, which sees the aperture as an oval from the side, plus some clipping as it gets chopped off by the lens barrel with some low f/number lenses.

 

[68lbs]

It's off-centre light, which sees the aperture as an oval from the side, plus some clipping as it gets chopped off by the lens barrel with some low f/number lenses.

Ah, that makes sense... thanks Hoppy.