Yes, it is a Canon EF-S lens.
The 24, assuming you have an APS camera, would be the 35mm equivalent of about 38mm, not what I would consider wide angle. Even the 17mm is only marginally wide angle on an APS camera IMO. I also have the Canon 10-22mm zoom when real wide angle is needed.
I have Canon equipment, and my "walk around" lens in the 17-55mm, f2.8. I use it probably for 90+% of my images, and use the 17mm range frequently. It equates fairly close to the old 28mm lenses we commonly used in the 35mm days. You may want to consider also carrying a wide angle zoom lens.
Ha. These things have been around a long time, but I never had or used one.
For truly candid photography, it is hard to beat old twin lens reflex cameras, such as from Rollei, Mamiya, and/or Yashica. They are used at waist level, and are extremely quiet. People today seem to notice or react only to eye level cameras, not cameras used at waste level. Have the camera preset for focus and exposure and most of the time the subject never knows a picture has been taken.
I don't necessarily recommend this because of slow focusing, but if silence is critical you could shoot in Live View. In live view, the mirror is locked up, which eliminates nearly all the noise.
JackM1943
Are you shooting in live view? My 60D is definately soft (inaccurate focus) in live view. Fortunately, it is easy to correct by magnifying the image and using manual focus. Then it is amazingly sharp because the mirror is locked up in live view.
In conventional view, it provides accurate focus with all lenses.
JackM
Randymoe; I haven't seen comparative lens tests, but the black lenses are obviously a more modern design than the older chrome lenses. I'm not certain about current prices, but guess that they have come down.
I have the 55, 80, 105, 135, 180, and 250. My favorites are the 55, 80, and 180. They also made a 65, but that just never made sense to me, too close to the 55. The 80 is a great macro lens provided you have the camera on a tripod fitted with a Paramender.
I have used it fitted with a porroprism, and mounted on a trigger grip with a Vivitar 283 attached, to shoot motorcycle races. It works very well for action photography because the focusing is quick and intuitive.
JackM1943
My first TLR was a Yashica 124G. One of the sharpest photos I ever took was with this camera. The crank mechanicals are a little weak, take it easy when cranking. I traded it for a Rolleiflex E3 Planar 2.8, which is a nice camera, also very sharp. Both of these cameras are very quiet, great for candid street photos.
I also have a Mamiya 330 outfit, with all lenses except the 65mm, and all accessories. Is my favorite TLR, but is very heavy. I consider it a tripod camera, not a "carry around" camera. With the 80mm and Paramender, it's a great macro camera. All the black lenses are very sharp.
JackM
I purchased the Canon 10-22mm EF-S lens with a Rebel, and am now using it with my 60D. It was designed for these APS Canons, and it is plenty sharp enough for most uses, and is moderately priced. I have been completely satisfied with this lens.
Focusing is slower because it uses a different method for live view. About half the time, my 60D does not focus accurately in live view. I consider it MANDITORY to use manual focusing when in live view. I really like live view for scenics when using a tripod because the mirror is locked up.
JackM