Canon APS-C portrait lenses

Given that I happen to have all the lenses you mentioned, I highly recommend the Canon EF-S 17-55mm f/2.8 IS USM. It's a relatively old design, but it consistently delivers top wide-open performance across the zoom range. It sits on my 80D most of the time.

The Sigma 17-50mm f/2.8 EX DC OS HSM, a bit difficult to find now relative to the newer 17-70mm f/2.8 DC OS HSM "Contemporary", may be considered if you want to optimize your budget.

The Sigma 18-35mm f/1.8 DC HSM Art is optically phenomenal. No arguments if you must have f/1.8. I find out that I should slow down to insure proper AF or do MF myself. In other words, this lens excels in a controlled environment.

Keith Z Leonard wrote:

Kaso wrote:

The Sigma 17-50mm f/2.8 EX DC OS HSM, a bit difficult to find now relative to the newer 17-70mm f/2.8 DC OS HSM "Contemporary", may be considered if you want to optimize your budget.

There is no 17-70 f2.8 DC OS HSM C, it's f2.8-f4 sadly.

Typo. (I have both 17-50 EX and 17-70 Contemporary.)

Sigma 18-35mm f1.8

I've used a friend's 17-55 and it's lovely. I own the 35 f2 IS and use it on full frame and can wholeheartedly recommend that also. It feels solid, has quick and quiet focus, the IS works a treat and it's got a decent MFD.  The 24 has great reviews, would be nice and light and gives you the 35mm equivalent focal length which is ideal for street. You can't go wrong with either choice - the two primes or the zoom - it just depends how you want to shoot.

This should give you great versatility and excellent portraits (you provide the talent) with the 35mm lens in all kinds of trying conditions.

BAK

Although I should probably add that you might not want both primes, as 35 & 50 equivalent focal lengths aren't too dissimilar...

I can recommend the Canon 35F2IS and the Canon 85F1.8 for portraits on a crop. The shorter lens is great for any environment, and the IS helps when the light gets very low. The 85 is a nice lens, but is on the long side for indoor portraits. Of course, this depends on the size of your house and the sort of portraits you want. It works fine for head shots indoors, and is more flexible outside. The two lenses are sharp and very useful.

Both of these Canon lenses have very fast and accurate AF, even in low light. They are compact and relatively light.

I have never had an interest in large, heavy lenses, but that is a personal gripe. Even though the Sigma 18-35 zoom is reputed to be very sharp, the size and weight of the lens is a real turn off for me. Of course, people carrying a 7D with the 24-70 F2.8 II clearly don't have this view. There are People walking around with 1D series cameras and 70-200 F2.8 lenses. Size and weight preferences are personal. Some people thing that a Rebel is large and heavy, and carry small mirrorless cameras.