What causes those "bulls eyes" on "bokeh"?

[Abby Rose]

On those little out of focus circles, what causes the bulls eye appearance that you get sometimes? How can you avoid it?

 

[kundalini]

Can you explain what you mean by 'bulls eyes'? Or better yet, give an example.

 

[Taylor510ce]

I think you are referring to lights in the background..... try putting some christmas lights up as a background and see what it does just as an extreme example.

 

[Big Mike]

The ones that you usually see, come from specular highlights (small bright areas). The shape of them reflect the shape of the aperture in your lens. Higher quality lenses often have more aperture blades, thus a rounder aperture opening, and some say...a more pleasing bokeh.

You can also shape the 'bulls eyes' by cutting out a shape in a card/paper and holding it in front of the lens.

from HERE

 

[Taylor510ce]

The ones that you usually see, come from specular highlights (small bright areas). The shape of them reflect the shape of the aperture in your lens. Higher quality lenses often have more aperture blades, thus a rounder aperture opening, and some say...a more pleasing bokeh.

You can also shape the 'bulls eyes' by cutting out a shape in a card/paper and holding it in front of the lens.

from HERE

I never knew that. So you just cut out a large shape and then make sure your subject is inside and then crop the edges?

 

[benlonghair]

Do you mean crappy bokeh like this?



I've been told that this is caused by VR working.

 

[benlonghair]

I never knew that. So you just cut out a large shape and then make sure your subject is inside and then crop the edges?

I was under the impression that took using a shaped aperture in a lensbaby or something. But Mike knows a lot more than me.

 

[Big Mike]

I never knew that. So you just cut out a large shape and then make sure your subject is inside and then crop the edges?

DIY - Create Your Own Bokeh | DIYPhotography.net

 

[epp_b]

Bulls-eye or doughnut bokeh is characteristic of mirror lenses.

 

[reznap]

Bulls-eye or doughnut bokeh is characteristic of mirror lenses.

^ This..

 

[Derrel]

Do you mean "onion" bokeh perhaps???

Bokeh

 

[Tee]

I never knew that. So you just cut out a large shape and then make sure your subject is inside and then crop the edges?

DIY - Create Your Own Bokeh | DIYPhotography.net

Thanks for that link, Mike. I am so going to try that tomorrow when I get home from work.

 

[Abby Rose]

THIS kind of bokeh... I'm sure I have a worse example somewhere, but I cant seem to find it and its noticeable enough here. See how the circles on the middle right are like a circle within a circle?

 

[Big Mike]

I'd guess that it's a property of that particular camera (more specifically, the lens).

 

[Abby Rose]

Mmm, I don't like it. Sometimes I just get normal circles, and sometimes I get those, and sometimes a combination, but for the life of me I can't figure out how to avoid it! It seems to do it randomly....