School me on SL1 lens options

[AlpiNord]

An Xmas Canon SL1 w/EF-S 18-55mm f/3.5-5.6 IS STM lens has me trying to get up to speed on lens options as a DSLR newby. The EF-S 55-250mm f/4-5.6 IS STM seems like the natural next choice for telephoto options, but the the EF-S 17-135 f/3.5-5.6 IS STM (or comparable) and DSLR to SLR lens equivalences have me wondering about how to approach building a lens quiver.

Among the questions I haven't found answers to yet:
1) To develop a sense of capabilities for DSLR vs SLR lens equivalences, how realistic are they?
2) How advantageous is IS STM vs IS? Worth the additional cost?
3) Are EF-S lenses the only options for SL1 bodies?
4) Could the 17-135mm fully replace the 18-55mm and provide enough range for skiing, touring and hiking as a compact one lens DSLR option vs the 18-55mm plus 55-250mm options?
5)......

TIA, Terry

[geomorph]

I don't quite know what you mean by #1, but you have a 1.6 crop factor relative to 35mm, so multiply your lens length by 1.6 to get the equivalent 35mm length. Your camera will take both EF and EFS lenses. STM I believe is mostly important for autofocus during video. It is also a bit faster and quieter than the standard autofocus, but not as fast and quiet as USM. I don't have any specific experience with that lens, so can't comment on that.

[AlpiNord]

Thanks. You answered #1. I've got an old SLR and lens that I know what type shots relative to zoom ranges I could take. Looks like I need to understand 'crop factor'.

So what does the 'S' signify relative to EF-S lens? What are the pros & cons of EF vs EF-S lens?

[smmokan]

2- From my understanding, the STM lenses thus far (18-55, 18-135, and 55-250) are all MUCH better than their predecessors in both image quality and focus speed. I just picked up the 55-250, so I'll let you know what I find out.

3- No, EF lenses work as well.

4- In a word, yes. The new 18-135mm STM lens gets great reviews when it comes to IQ and focus speed, and it makes a great one-lens quiver. I see it regularly compared to the Canon 15-85mm with regards to those attributes, which is saying a lot. It would make a great one-lens solution for what you're talking about.

[AlpiNord]

That's encouraging. I'm definitely curious about your take on the 55-250. The 15-135 is more costly than the 55-250 so simply adding the 55-250 would be the 'better' economic choice at the moment. Plus I need to get out and spend more time getting to know the camera and current lens.

5) Is there any market for (and what value) the week old 18-55 STM to help offset the 18-135 STM if I continue to rationalize it's acquisition?

[Tye 1on]

if you're thinking quiver, i wonder about the 80-200 that is for sale a few posts down. Not the new technology, but it L-glass, and f2.8...

[smmokan]

^^^ However, given the size of the "magic drainpipe", it kind of offsets the benefits of the tiny SL1.

And yes, I think there's a market for the 18-55 STM... I think you can get over $100 for it on POTN and elsewhere.