50mm f/1.4 - What am I looking at here? (bokeh/aberration?)

hey guys,

I had a chance to do some video with a 5Dii recently (woot!) and my trusty 50mm.

Upon review of the footage later, I noticed that the "bokeh balls" towards the center of the frame (to the right side of the image below)
look different from the bokeh balls to the edge of the frame (left side of the image).

The image is a screen shot from the footage from the left side of the frame.
This was shot at 2500 ISO and f/2.2 or so IIRC.

Do the "football" shaped bokeh balls mean that my lens has something wrong with it,
or is this lens known for doing this?
What am I looking at here? Is this spherical aberration? Or is this just normal and I've not noticed it?

Here's a link that you may find useful: http://www.wlcastleman​.com …iews/aps-c_port/bokeh.htm

That is normal for the 50mm, step it down to change the characteristics.

rogue.guineapig wrote in post #16994442
Do the "football" shaped bokeh balls mean that my lens has something wrong with it

Basically, yes, it's not a $40k cine lens.

j/k aside, unfortunately it is normal for this and other fast primes (50L, 85L etc..) that are not $40k lenses - actually it might also occur with truly expensive lenses as well for all I know, but I wouldn't be surprised if it was less obvious.

Basically at the sides of the frame the round aperture of the lens looks oval rather than completely round, so the OOF highlights also have this shape. As you can see from the different lenses, it is a bit more complicated than just that, but in essence it is because of the geometry of the light rays. Longer lenses are less susceptible to this because of the narrower FOV.

Awesome! Thanks for the info...that makes sense. I just didn't know what exactly I was looking at there.

The examples that bob_r posted are great...they just don't look like mine exactly and I was curious.

I'll uhh...keep saving for that Cine lens to "correct" the problem hehehe...

I have heard of this being called bokeh chop. I don't know if that is the correct term or not, but that is what I learned and have always referred to it as.

Many times it's referred to as the "cat eye" effect.

Here is some more reading on the subject: http://toothwalker.org​/optics/bokeh.html

thanks guys! Good info to know and have!