Portrait lens help?

[sarahr_7]

I'm looking for a portrait lens (I know there is no "specific" lens that is for portraits only but just one that will be good). I am looking to do all types of portrait work (head, full body, etc)

I currently have a Canon 70D & Canon 50mm 1.8

I was really interested in the Canon 135 f/2 but I'm afraid it'll be too long on my cropped body, any opinions? I also like the 85mm 1.2 or the 70-200mm 2.8 but I just don't know! I'm trying to spend under $1000 on a used lens. ANy sugestions or advice would be much appreciated! 🙂

Attached are some photos I've done with my nifty-fifty:

[ScottyP]

Blocky blades or too few blades vs. 8 or 9 curved blades will mess up bokeh for sure, except if you are shooting wide open when it doesn't matter because the blades are fully retracted and not in the shot.  My old nifty fifty with the 5 flat blades made ugly distracting pentagons out of all the bokeh balls but wide open they were at least nice and round.  Not necessarily great bokeh, but perfectly round. 

Of of course you can't shoot wide open all the time. Can be too bright in the daylight even at max shutter speed, and way too little depth of field for a lot of shots. 

[TTMartin]

BOKEH is the quality of the OOF area. Bokeh does not need highlights. And example of lenses with a poor bokeh are reflector lenses, the OOF is often 'nervous' with donut shaped highlights.

When the EF 50mm f/1.8 II is wide open the aperture blades are fully retracted and it has a nice bokeh. Stopped down and the straight aperture blades impact the quality of the bokeh. The EF 50mm f/1.8 STM has more aperture blades and the are curved so it's bokeh is far superior.

[ebiggs1]

All lenses used wide open, provided the aperture blades fully retract, some don't, show circular out of focus points in the center of the image. However, not all lenses have good bokeh. You do get the uniform circular defocused area shooting wide open but the defraction is still there and the other aberrations.  This is what causes the onion effect.  The lighter ring appearing on the outside of circular highlights.

Bokeh is noticed more on bright points of light but it is actually present on all OOF objects.  Just less noticeable.

Another type of blur known is called Gaussian blur. Ideally this is what you would like.  It is a more smooth consistent transition from focus to OOF.  This is what really makes for good bokeh.