ladysue wrote:
Thank you for this very comprehensive summary of the camera's features. I think I will keep it. Unfortunately, I did sell the 17-55 lens. Would the 15-85 be similar or the 24mm 2.8 preferable for a "walk around"? The 15-85 would give 24mm field of view; the 24mm lightweight.
It really depends upon what you want for your "walk around"...
The EF-S 15-85mm f/3.5-5.6 IS USM zoom is quality, versatile lens. On an APS-C camera like the SL3 it gives an approx. 24mm to 135mm full frame equivalent angle of view. Note that the variable aperture range is 2/3 stop to 2 full stops less than the EF-S 17-55mm (which has an approx. 27mm to 88mm full frame equiv. angle of view). Although slightly smaller and lighter than the EF-S 17-55mm, it is a moderately large lens that uses 72mm filters and weighs about 4X what the following lens does.
The EF-S 24mm f/2.8 STM "pancake" is extremely compact, protrudes from the camera less than 1", is very light weight at just over 4 oz. and uses 52mm filters. On a small, light SL3 it borders on "pocketable". Note that unlike the 15-85mm and 17-55mm, this lens does not have IS and it uses quiet, quick but slightly slower STM (stepper motor) focus drive instead of USM (ultrasonic motor). It has the same f/2.8 aperture as the 17-55mm, but is a full stop faster than the 15-85mm's variable aperture when zoomed to 24mm focal length. On an APS-C format SL3, the EF-S 24mm "pancake" will give an approx. 38mm full frame equiv. angle of view.
FYI, there are two other Canon 24mm f/2.8 lenses that have been discontinued, but can be found used:
EF 24mm f/2.8 IS USM was only recently discontinued. Compared to the "pancake" above, it is considerably larger and over twice the weight at about 10 oz. Still, it's smaller and lighter than the 15-85mm and 17-55mm zooms. Of course, even though this lens is able to be used on a full frame Canon DSLR, on an APS-C like the SL3 it will render the same approx. 38mm full frame equiv. angle of view. To me that makes it a "slightly wide normal lens". Some like this as a small, simple walk around kit. Only you can say if it's the right thing for you. (Note: The EF 24mm f/2.8 IS USM was announced alongside an EF 28mm f/2.8 IS USM and an EF 35mm f/2 IS USM. All three of these lenses replaced and improved upon earlier models that lacked IS and USM.)
EF 24mm f/2.8 was discontinued quite a few years ago, but can still be found used. It lacks IS, uses slower, noisier micro motor focus drive and isn't as well built as the EF 24mm f/2.8 IS USM that superseded it. It is moderately smaller and lighter weight than that lens. While this lens isn't bad at all, the newer version that replaced it has was optically improved for a little better image quality and slightly closer focus ability.
Canon also made two versions of 24mm f/1.4"L" that are big, heavy and expensive... as well as two versions of 24mm f/3.5 "TS-E" tilt shift/perspective correcting lenses which are also big, heavy, expensive AND manual focus only.
NOTE: If you are wanting equiv. to 24mm angle of view on your SL3, you will need a 15mm and there simply aren't many of those available. Canon did make an EF 15mm f/2.8 but it is a rectilinear fisheye lens, with heavy distortion of straight lines in images. That lens was discontinued and replaced with an EF 8-15mm f/2.8 fisheye zoom that has similar distortion. Besides the EF-S 15-85mm zoom, another option might be slightly wider EF 14mm f/2.8L USM, which there have been two versions of over the years. They are fairly pricey. Samyang/Rokinon 14mm with AF also are available. The fisheye and the 14mm lenses all have strongly convex front elements, built-in lens hoods and no means of mounting screw in filters (they may have slots for gel filters at the rear element).
You might find The-Digital-Picture website helpful... Bryan Carnathan has extensive reviews, information and tests of virtually all modern and recent Canon get there, as well as a smattering of other brands that might be compared. [/url]www.the-digital-picture.com[/url]