EF-S Conundrum: 17-55 or 15-85 and Sigma 30 1.4?

You mentioned that you wanted extra reach, are you finding your 18-55 not long enough? If you find your 18-55 not long enough then I would take the 17-55 out of the equation and go with the 15-85 as your primary zoom lens. If you do find the 18-55 to be long enough, I would add a flash first to your 18-55 and see if it works well enough for you in low light. If it works well enough, you can be sure that you don't need a fast prime lens for low light purposes and I would go with the 17-55 since you think it has the best IQ of the bunch. If the flash + 18-55 combo doesn't work well enough, then you know a fast prime is the only option for your low night needs.

Why not pick up a flash first and then maul over your options some more? Ultimately, I think you want to have a fast prime in your lens lineup but you seem to want to upgrade your primary zoom lens first and I would go with the one that makes you happy first.

MARK1992 wrote in post #13831579
Tough decision. You require low light performance which pretty much seals it for the 17-55, as with IS you can handhold shots with nothing moving and 2.8 to freeze motion.

But, the 15-85 + 30 gives you a lot more flexiblity. It's wider and longer and faster for when you might need it.

Personally, I'd go for a 15-85 and a flash, and pick up the 30 when you can.

^ +1

jrmy wrote in post #13831921
I'd like to be able to capture my 2 and 5 year-old nephews, indoors, occasionally. I do want to learn how to use a Speedlite, but I think I'd be happiest with a capable low-light lens.

That's screaming out for 15-85 and speedlight.

I love my Sigma 30. I have good AF performance out of mine, IQ is great, but 2yo & 5yo in low light is going to be hell. At F/1.4 you're gonna have to decide whether you want the nose, left eye or right eye in focus, and hope they're not moving much otherwise you wont nail it.

Furthermore low light use of the Sigma 30 is itself (like all lenses) much better when combined with flash. Better AF performance thanks to AF assist, and better lighting control.

Learning how to use a speedlight isn't as tricky as it may sound. A safe starter would be to point the speedlight at the ceiling, use M mode and set a safe shutter and the desired aperture (i.e. 1/100s F/4, ISO200) and let the speedlight light up the scene as much as required.

get the 30 1.4. I really loved that lens. Amazing shots wide open. I am addicted to fast primes there is no equal with zooms. 2.8 is simply not fast enough and the 30 is a perfect walk around length for crop.

I was in the same situation and decided to go with the 17-55. While it's true that you'll need a flash with either this or the 15-85 in many dim situations, there's certainly a reasonable amount of times where the 2.8 of the 17-55 is just enough for an indoor photo without a flash. All around, it is pretty useful and I am totally happy with it.

15-85 would not be a bad choice either though of course. Part of the reason these threads pop up so often is that it really is a tough decision between two good options. I doubt you'd be too unhappy with either choice.

if most of your shots are taken OUTDOORS during the day, get the 15-85.
the 15-85 has a wider focal range, but optically it's better suited outdoors.

otherwise, get the 17-55. it outperforms the 15-85 in every regard minus range, size/weight and flare.

but regardless of what you get i recommend getting the sigma 30.
the sigma will give be FAR SUPERIOR to BOTH zooms in low-light capabilities, stopping action, and bokeh.

i myself have teetered between swapping out my 15-85 for the 17-55 again and again.
but in the end, i'll take range.
if i need low-light, i'll slap on the 24L.

Lots of opinions, and they are all valid -- from the perspective of the responders.

However, which one is right for you?


I won't pretend my response is any more "correct" than others', but hopefully I can explain my reasoning clear enough that you can determine for yourself if my experience is relevant.

I have both the 17-55 and the 15-85. The 17-55 is the one I bring with me 99% of the time.

jrmy wrote in post #13831553
I'm shooting on a T2i, and though I feel my skills are beginning to yearn for a more advanced body, I'd rather spend the money on glass.

The fact that you are considering upgrading your glass before the body suggests you are somewhat serious about photography (i.e. not from the "kit-lens-till-I-die" masses). To me, this means you are going to build a multi-lens system like most of us, so you'll likely end up with a UWA and a telephoto at some point.

If you are going to be stuck on a deserted island with only one lens, the 15-85 will definitely give you more versatility in terms of focal lengths. However, when flanked by a UWA and a proper telephoto, the extra focal lengths of the 15-85 become meaningless, whereas the main advantage of the 17-55 (F2.8+IS throughout the range) will remain indispensable.

jrmy wrote in post #13831553
I don't really have a specific subject I focus on and my needs, or more accurately, desires, are: low-light performance, IQ, and reach -- all on a wide zoom.

You list low-light performance first. The 17-55 is two-third of a stop faster at the wide-end (F2.8 vs F3.5) but two full stops faster at 55mm (F2.8 vs F5.6). This is the #1 reason for me to choose the 17-55 over the 15-85.

I find IQ "good enough" for both that it's rarely the deciding factor. (I sometimes wish the 17-55 is more flare-resistant, but its many advantages make me overlook this shortcoming.)

The 15-85 obviously has more reach, but remember one can always crop to simulate extra reach, but it's much harder to fake extra "width" (stitching panorama only gives you a wider angle-of-view, but cannot reproduce the wide-angle perspective). The extra "2mm" on the wide end translates into a 12% difference in angle-of-view (84 degrees vs 75 degrees). It is definitely a noticeable difference, but that difference becomes almost laughable when compared to a real UWA.

The 15-85 will definitely give you more reach (15 vs 23 degrees in terms of angle-of-view), but visually it's not really that much. I own the 85/1.8 (which is an excellent lens), but I find myself pairing the 17-55 with the 100L or the 70-200 more often because when you want more reach, you want much more reach....

jrmy wrote in post #13831553
I could pick up the 15-85, which has excellent IQ, and gain the reach but at the expense of low-light performance. That's where the Sigma 30 1.4 comes in, fulfilling that need.

About the Sigma 30/1.4. You already have the 50/1.8, so you probably know from first-hand experience that a wide-open prime is not always the answer in low-light. Sometimes you actually want a bit more DOF -- a multi-person portrait, for example. Not to mention, 30mm on your T2i is not wide at all. Sadly, Canon does not have an affordable wide-angle prime for crop-sensor DSLRs. So until Canon (or one of the 3rd-party manufacturers) come out with an EF-S 17/2.8 or equivalent, the 17-55/2.8 remains the only low-light, wide-angle choice.

Flash is definitely useful, and I love bounce-flash. Regardless of your lens choice, strongly consider getting yourself a flash with bounce/swivel capability. (If money is tight, consider a Sigma flash -- it will do just about everything a Canon Speedlite can do, for a fraction of the cost.)

jrmy wrote in post #13831553
I'm keen on the 17-55, as it offers wide angle, low-light performance, and the best IQ of the bunch, though it lacks reach and covers the same range of my 18-55 kit lens.

The second-generation 18-55 kit lens is much better than the first-generation 18-55 I got with my Rebel XTi/400D. However, neither come close to the 17-55 (or the 15-85) in terms of IQ, build quality and focusing speed. I don't even know when I lost my 18-55 -- don't miss it at all.


Anyway, I know it's not an easy choice. I went through the 17-55 vs 15-85 struggle a few years ago, and ended up with both. Even to this day, I can't bring myself to selling it -- if I ever go on that African safari I've been thinking about forever, the 15-85 and 100-400 will be an excellent duo....

BigBadWolfie wrote in post #13832642
You mentioned that you wanted extra reach, are you finding your 18-55 not long enough? If you find your 18-55 not long enough then I would take the 17-55 out of the equation and go with the 15-85 as your primary zoom lens. If you do find the 18-55 to be long enough, I would add a flash first to your 18-55 and see if it works well enough for you in low light. If it works well enough, you can be sure that you don't need a fast prime lens for low light purposes and I would go with the 17-55 since you think it has the best IQ of the bunch. If the flash + 18-55 combo doesn't work well enough, then you know a fast prime is the only option for your low night needs.

Why not pick up a flash first and then maul over your options some more? Ultimately, I think you want to have a fast prime in your lens lineup but you seem to want to upgrade your primary zoom lens first and I would go with the one that makes you happy first.

This is a very sensible suggestion and one I'm now seriously considering. I've been planning on adding a Speedlite (580 or 430) for sometime and only discounted it because I assumed it's overkill for the casual, inconspicuous shooting I prefer.

I'm not dying for extra reach and quite often the 18-55 covers it. However, I do like to travel and with a visit to Italy approaching, I'd like something that covers the wide and gives me a bit of reach when desired. I've been to Italy before; I think 15-85 will handle most of my needs.

The desire for a fast prime isn't out of necessity; I don't often shoot children or pets running around in dimly lit rooms, but I'd love to know it's there when I want it.

Thanks, everyone, for your thoughtful contributions thus far. This thread is proving very helpful.

I was in the same predicament as the OP, 3 months back. Finally went with 17-55. Will pick up a speedlite soon.

You'll find that adding a good flash unit will do far more for your indoor photography of moving subjects than a new lens. With a good flash, any capable lens will do. Without the flash, assuming your indoor light is around average brightness even the fastest lens may not be fast enough to give you the shutter speed (and, as someone noted above, the depth of field) you need unless you also go to a pretty high ISO.