If you google canon crop - portrait lenses - you will come up with a huge collection of links, ranging from amateurs to the pros, and everything else in between, giving you advice on which portrait lens to get.
The more advanced sites, will differentiate between a crop and FF sensor camera.
Anybody who starts to get serious about their photography begins to realize, that shooting "things" and shooting "people" is quite different. With people you want a natural moody look. Unlike "things" where often sharpness, colors, and contrast are the emphasis.
Of course, even within the portrait "look" different photographers prefer their own nuance of style.
In other words, a recommended portrait lens, means a lens that gives the "look" you are seeking, which is very subjective.
The acceptable focal length for portraiture is opx 85mm FF equivalent. This gives a natural look to the facial features, avoiding the protruded look of a short FL distorting the facial features, pulling out the nose, and making the ears look like they are way back.
This of course is assuming you are getting a head shot style portrait.
Today, the net is full of more environmental casual style portraits, which include half or full body shots, shown within a chosen environment. This could be a child at home playing with toys, an adult in his work area, a woman sitting on the beach etc. Such a "portrait" would be taken with a much wider FL then the traditional 85mm.
So your choice of a "portrait lens" is a function of quite a few factors:
- The "look" of the lens as far as softness and color rendering of the face.
- Choosing a FL for the KIND of portrait you are taking - head shot, or more half / full body.
- Obviously the type of camera you have FF as apposed to crop
I find, my particular style of people shots, more head shot oriented. Or maybe head and shoulders. Its hard to get a clean appealing environmental shot in a home setting (unless you have an area in the house you can use as a quasi studio). Hence for my canon crop t2i - I find myself using the Canon 50mm 1.4, and surprisingly the Samyang 85mm 1.4 - even though it is MF only.
The 85mm on my crop gives me a working distance equivalent of a 135mm on FF. This allows me to be somewhat obscure when shooting candid shots of my kids, as I can stand somewhat "away" and catch spontaneous moments. Obviously with a MF lens this is challenging.
When I need a lens that focuses real quick and sharp, for a faster paced kind of shoot, like a guest who is just leaving, or an event where people are on the move, I use the 60mm macro f/2.8. This lens delivers a pleasant shot, and has a FL equivalent of 96mm on a FF.
For portraits with the 60mm macro I would suggest setting the EV to +1 , and possibly bumping the contrast and saturation in the picture style. The lens tends to give "quite" colors and this can spice it up.