Need help thinking through a lens decision.

<p>I've decided on two lenses to use as my walkaround zoom lens on my Canon T1i. The Tamron 17-50 2.8(non-IS version) OR the Canon 17-85mm IS lens. Basically, the decision comes down to either the constant 2.8 aperture of the Tamron OR the extra 35mm reach of the Canon lens. I know that there are other lenses that would fit the bill. But they are more expensive, and this stops them in their tracks. So, between these two lenses which one do YOU (personally) feel would make the top candidate? The one with the faster aprerture, or the longer reach? Which is more important in YOUR eyes for use as a walkaround lens? Thanks.</p>

<p>I got the Sigma version of the 17-50 as my primary walkaround lens, and have no regrets. Constant 2.8 was a big factor for me, as I like to shoot wide open and didn't want to lose light when zooming in, especially indoors. I also carry a 70-200 for reach, and I don't use it that often.</p>

<p>What lens do you use now, and do you find yourself shooting in the 50-85 range (or wishing you had it) enough that the 17-50 would be limiting?</p>

<p>If you need lower light capabilities, the Tamron would be the one, I guess.</p>

<p>However, on my older APS-C bodies, I bought the direct ancestor of the EF-S 15-85, namely the 17-85 lens. I still use it constantly. Its only serious flaw in my eyes was that it was just a little longer than I wanted on the short end - fixed, along with some other details, in the newer 15-85.</p>

<p>The IS is easily worth the difference in aperture (for things not moving, obviously). I shot flowers, by accident, I should say, at 1/10 of a second hand held and got usable results.</p>

<p>So my recommendation is for the EF-S 15-85mm; all the reviews say it's better than my old favorite.</p>

<p>The lack of IS on the Tamron disqualifies it for me.</p>

<p>It's not about IS. That feature is largely a red herring in a discussion of those two lenses. The 17-85 <em>needs</em> IS because it is soooo slow. Between one & two of the stop 'advantage' of the IS is used up just by the speed of the lens. The focus on 'IS', which is largely a moot point, distracts from far more critical issues in the lens.</p>

<p>Instead, I'd be considering the impact of two factors. FL (of course), and the IQ of output. The 17-50/2.8 <em>WO</em> is capable of sharper, better looking imagery the the 17-85 is capable of <em>at it's best</em>. It comes closest at f8. To put it another way, <em>the 17-85 @ f8 is almost as good as the 17-50 @f2.8.</em><br>

<em> </em><br>

The focal length is a seperate issue, and if you need the extended FL of the 17-85, the 17-50 is not a good choice. The impact of the difference between the two is most largely dependent upon what you shoot, and, w/o knowing that we'd all be negligent to offer a rational choice.<em><br /></em></p>

<p> </p>

<p>I'm with JDM on this one. The extra reach of the EF-S 15-85 would clinch it for me over the Tamron 17-50, particularly for outdoor use. My main walkabout lens is the 70-200/4 L IS, and I almost never find its maximum aperture too slow.</p>

Everyone has their priorities, but IS is very important to me.

<blockquote>

<p>sharper, better looking imagery the the 17-85 is capable of <em>at it's best</em>.</p>

</blockquote>

<p>I really doubt this very much. <em>Sharpness</em> has never been a problem for me, and I did recommend the newer lens in any case.<br /> The 17-85 has some warts, but these are in areas that rarely affect the sharpness of the image in practical use.</p>

<p>On modern cameras, the apertures are reasonably fast any how, if you're not a timid mouse about using higher ISOs.</p>

<p>Since you are asking for <em>personal opinions</em>, for <strong>me</strong> 50mm would be too short at the tele end. I used the 17-85 IS for some time as a walkaround lens on my 350D/XT, and still do, when I have to travel light. These days my walkaround is 24-105, and I still find myself wishing for a bit more length more often than a bit more width!</p>

<p>Personal Opinion between the two – Varying Maximum Aperture Zooms drive me nuts – so I would live with the lack of reach and crop in PP if necessary.</p>

<p>WW</p>

<p>I have both the lenses: Canon 17-85mm IS for several years and Tamron, for few weeks. Tamron with constant f2.8 is the better lens, specially if you can get a good copy. You can read reviews at photozone.de.</p>

<p>If you want to sell the lens later, Canon 17-85 does not have a used market after Canon introduced 18-55 IS and 15-85 IS, which are optically better than 17-85 . I have been trying to sell mine locally. The best offer I got was $200.</p>

<p>Sanath, there <em>is</em> a market, but there's no doubt the price is lower now.</p>

<p>However, the OP will be <strong><em>buying</em></strong> one at the reduced price, not worrying about selling it later. The latest eBay prices actually paid (as opposed to asked and not bid on) run from a high end of about $350US down to just around $200. That's what the OP would have to pay, less if patient.</p>

<p>For that price, this is still a better buy, I think, especially as the Tamron does not have IS. Otherwise, except for the nice aperture, it's just the old "kit lens" as a user in focal length.<br>

It (the 17-85) is just so HANDY.</p>

<p>Robert, I've got the same camera and went through the same decision. In my case I came up with a slightly different answer: a Sigma 17-70 f2.8-4. It's got Sigma's version of IS, it's faster than the 17-85 (and the 15-85) and while not equalling the constant aperture of the 17-50/17-55 lenses, it does have somewhat longer reach. I've had it 18 months or so and I'm happy. On a Canon APS-C camera it has more-or-less the same field of view as the old 28-105 lenses. I spent a long time during the 90s using one of those, so I feel very comfortable with it.</p>

<p>To sum up (in my own words): if most of your photos are taken outdoors during the day, buy the 17-85. Otherwise, buy the 17-50.</p>

<p>Wow. As with many gear questions and choices, this question is turning out to be anything but conclusive. So let me toss a couple of other thoughts into the mix. If I were to acquire the Canon 17-85mm lens, it would be at the expense of trading my Canon 35 f2 for it. So there goes my best lower light lens. <br>

Zack.....I'd be using which ever zoom I end up with about 90% in the day light. <br>

Is the IS (or whatever Tamron calls theirs)all that important on the 17-50? It isn't a very large or unwieldy lens anyway.<br>

I have the 17-50 2.8 lens, but was thinking that I could use the extra stretch of the 17-85, making it a bit more practical for general, walkaround shooting. I purchased the Tamron to upgrade my Canon 18-55IS. But other than for the constant 2.8, I'm not so sure this was much of an actual upgrade. My brief experience with the Tamron has demonstrated it's good IQ. But then it was shooting things not usually shot with the kit lens. So sort of hard to compare the Tammy to the kit lens.<br>

The one thing that continues to linger in the back of my confused brain is the extra reach of the 17-85.<br>

And finally, after comparing these 3 lenses on the lens comparison site, it appears to demonstrate that the lenses fall in this order: #1) Tamron, #2) 18-55IS, #3)17-85IS: with #1 and #2 surprisingly close together, and 17-85 a definite #3.<br>

So maybe I should just use the kit lens, and keep my 35mm f2 for lower light, and be done with all this.</p>

<p>WW +1</p>

<p>Constant max aperture is a must for me too.</p>

<p>I don't understand your reasoning-- you'd have to give up the 35mm f/2 to get a $200 lens (the 17-85)? But <em>not</em> have to give up your 35mm to get the Tamron? Or have I misunderstood?<br>

I certainly would not give up the 35mm f/2 either way- as you know, it's a superb low light lens.</p>

<p>I really don't find the lack of a constant aperture to be a problem, and in practice, I use my EF-S 17-85 on my APS-C bodies as I do my EF 24-105mm (constant aperture) on my 35mm sensor bodies. My shooting is mostly scenic rather than portrait, to be sure.</p>

<p>IMPE, the added reach is convenient, but I've also found that the improved sharpness more than makes up for it, as, w/ the increased performance comes (especially w/ modern crop sensor resolution) the ability to crop far more effectively.</p>

<p>When using the 17-85, for example, I found that <em>any</em> significant cropping led (due to the limits of the lens) to a noticeable decrease in the IQ of the final output. When using the 17-50/2.8, even though the focal range was more constrained, the improved absolute sharpness of the lens made it so I could often crop down to nearly 1:1 (or 100%) without a significant decrease in output appearance (other than some contrast fringing). It really was amazing to me just how much control I could gain w/ the improved optics of the 17-50 - Then I went FF, and learned to deal w/ a whole different set of problems... ;-)<br>

As a side note, I've owned two copies of the 17-85 (figuring my first was simply 'bad'), both required stopping down to (at some points) f8-11 to get optimal (for them) results. When I could get the same, <em>or better</em> results from the 17-50/2.8 WO, it really negated any benefit from the IS (which does work for about a 2 stop improvement).</p>

<p>So, in a nut shell, while the 17-50/2.8 isn't nearly as long as the 17-85, the increased sharpness and clarity allows far more effective cropping, giving you (with a crop) the same or better end result...</p>

<p>Marcus,<br>

Your last sentence hit the nail on the head. It's something that I was thinking about all along, but few admitted to it. That's the statement that I'll take to the plate, and likely favor the shorter 17-50 2.8 to the longer (and quite possibly more convenient) 17-85 at this time.<br>

THANKS to everyone for weighing in on this question. Your thoughts and opinions are important to me even if I don't always agree with all of them.</p>

<p>FWIW, I bought a Canon 17-55mm f2.8 for my 60D. After using it for awhile I discovered that for every time I needed the f2.8 fixed aperture there were at least 10 times when I needed more reach. I sold the 17-55mm f2.8 and bought the 15-85mm EF-S and it has been a much better choice for me. Which is best in your case depends on your style of shooting and the subjects you prefer.</p>

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<p>I bought a Canon 17-55mm f2.8 for my 60D. After using it for awhile I discovered that for every time I needed the f2.8 fixed aperture there were at least 10 times when I needed more reach. I sold the 17-55mm f2.8 and bought the 15-85mm EF-S and it has been a much better choice for me.</p>

</blockquote>

<p>My experience exactly. For walkabout use, reach trumps speed (almost) every time for me.</p>

<blockquote>

<p>I bought a Canon 17-55mm f2.8 for my 60D. After using it for awhile I discovered that for every time I needed the f2.8 fixed aperture there were at least 10 times when I needed more reach. I sold the 17-55mm f2.8 and bought the 15-85mm EF-S and it has been a much better choice for me.</p>

</blockquote>

<p>The difference between 55 and 85mm isn't all that great, a step or two forward, and if you want "real" reach you have to go longer. I'd personally favor the IQ and speed of the Tamron over the convenience of the 17-85. The 15-85 is a different dog, however, being significantly <em>wider</em> and very, very sharp.</p>