18-55 IS really better than the 17-85 IS?

I don't know but I tend to think the 17-85 is the better lens. I like the focal range better for one. The 18-55 IS is a nice lens for the buck and for sure better than the 18-55 non IS.

17-85 IS on a 20D :

I can't answer your question, but I will say that the 18-55 IS is a very annoying lens. Every time I want to upgrade to some lens in the $400 - $600 range I inevitably find numerous comments saying that it will not be much better than my kit lens, if it is better at all! This is a very frustrating feature when you are hankering to spend money on lenses that you probably don't need.

Here's a link to a good review of the 17-85 and other lenses :

http://www.the-digital-picture.com …5-5.6-IS-Lens-Review.aspx

The 18-55 IS is sharper, has less distortion, less CA, less vignetting and has shorter MFD. The 17-85 IS has USM and 30mm more reach. You choose.

I don't know of many people that think the 18-55 IS is the better lens. Most say the 18-55 IS is just as good optically and is a lot cheaper. With the new 15-85's releas, though, the 17-85 has dropped a lot. You can get them for like $250 now if you look hard enough. At that price, the extra range and ring USM make it a good upgrade IMO. It used to be closer to $450 and at that price, it was hard to justify

qbfx wrote in post #10023713
The 18-55 IS is sharper, has less distortion, less CA, less vignetting and has shorter MFD. The 17-85 IS has USM and 30mm more reach. You choose.

right, and if you believe review sites like www.photozone.de the 18-55IS is the better lens for sharpness, image resolution, etc. compared to the 17-85. The 17-85 gets some of the worse reviews !

IQ is not much different, however, you do gain 1mm on the wide end and 30mm on the long end (in which the long end is very sharp on the 17-85), as well as USM and better build.

For $250-300, I think it is worth it. Not much more then that though.

watt100 wrote in post #10023752
right, and if you believe review sites like www.photozone.de the 18-55IS is the better lens for sharpness, image resolution, etc. compared to the 17-85. The 17-85 gets some of the worse reviews !

According to photozone, the 18-55 IS is as good as the 24-70 and 24-105 L lenses, too. And supposedly it is sharper than my Sigma 30mm at 30mm. Having owned the 18-55 IS, it is a "good-for-the-money" lens, but not excellent in any sense of the word. My 30mm is considerably sharper than the 18-55 IS at 30mm, so I don't know what to beleive.

mpix345 wrote in post #10023669
I can't answer your question, but I will say that the 18-55 IS is a very annoying lens. Every time I want to upgrade to some lens in the $400 - $600 range I inevitably find numerous comments saying that it will not be much better than my kit lens, if it is better at all! This is a very frustrating feature when you are hankering to spend money on lenses that you probably don't need.

haha, that's exactly my thought process too o.o

tkbslc wrote in post #10023768
According to photozone, the 18-55 IS is as good as the 24-70 and 24-105 L lenses, too. And supposedly it is sharper than my Sigma 30mm at 30mm. Having owned the 18-55 IS, it is a "good-for-the-money" lens, but not excellent in any sense of the word.

excellent in the sense of the words "sharp on crop models" !
at www.photozone.de you cannot directly compare some lens like the 18-55IS and Sigma 30mm because there is no comparable focal ranges in their "MTF" resolution tests. But I'm glad sites like photozone exists, it seems there are lots of conflicting opinions on the question "what lens is sharper" !

watt100 wrote in post #10023847
excellent in the sense of the words "sharp on crop models" !
at www.photozone.de you cannot directly compare some lens like the 18-55IS and Sigma 30mm because there is no comparable focal ranges in their "MTF" resolution tests. But I'm glad sites like photozone exists, it seems there are lots of conflicting opinions on the question "what lens is sharper" !

There is 30mm vs 28mm and both at 8MP, so I think it is pretty comparable. And I would still call the 18-55 IS only slightly above average for sharpness. It's not at amazing as the charts lead one to beleive.

I use photozone all the time for checking out lenses, it is just that sometimes I wonder if certain lenses are less optimized for charts and more optimized for real world shots. The 18-55 IS does fantastic at the lens charts, but only average in real world. The 30mm Sigma is the opposite.

watt100 wrote in post #10023752
right, and if you believe review sites like www.photozone.de the 18-55IS is the better lens for sharpness, image resolution, etc. compared to the 17-85. The 17-85 gets some of the worse reviews !

Umm, yeah, the 18-55 IS really is better in sharpness. The 17-85 IS is also notorious for its barrel distortion and CA issues, and when you consider it sells for close to $400 new, it does deserve bad reviews. I don't say it's the worse lens in the universe, but provided the 18-55 IS sells for 4 times less, and is at least on par with the 17-85 IS IQ wise, I don't see why anyone would want to "upgrade" that way.

watt100 wrote in post #10023752
According to photozone, the 18-55 IS is as good as the 24-70 and 24-105 L lenses, too. And supposedly it is sharper than my Sigma 30mm at 30mm. Having owned the 18-55 IS, it is a "good-for-the-money" lens, but not excellent in any sense of the word. My 30mm is considerably sharper than the 18-55 IS at 30mm, so I don't know what to beleive.

I don't know if it's sharper than the 24-70L or the 24-105L, but it is damn sharp and that's a fact. Then again, that's not throughout the whole range, and L lenses have other qualities like contrast, color rendition, bokeh rendition, flare performance, build quality, AF performance, etc.

The Sigma 30 F1.4 is sharp but not the sharpest lens. In fact its corners are far from sharp. Don't get me wrong, it is one of the best primes for crop.

I dont know how you judge sharpness but I don't think you'd get much difference on a 10mpx sensor - both the 18-55 IS and the Sigma outperform it.

tkbslc wrote in post #10023768
According to photozone, the 18-55 IS is as good as the 24-70 and 24-105 L lenses, too. And supposedly it is sharper than my Sigma 30mm at 30mm. Having owned the 18-55 IS, it is a "good-for-the-money" lens, but not excellent in any sense of the word. My 30mm is considerably sharper than the 18-55 IS at 30mm, so I don't know what to beleive.

I know that most lens will have a better copy of it, sometimes you get lucky and get one of the best copies, closest to perfection and it's hard to beat by even 10 times more expensive lens.

You probable have a great copy of a Sigma 30.

Have you guys just not used a nice lens or something? 18-55 IS was fine, decent, good enough, but never awesome, "damn sharp", wow, amazing, etc.

I dont think you can go wrong with either lens. I just orderd a 17-85 becuase it has a longer range and USM. According to the digital picture --"The 18-55 IS is a better value - more lens for the money - but the 17-85 IS is a better lens - especially if the longer focal lengths are important to you." Either one will do the jo IMO...I just prefer the extra reach and the USM is a bonus on inexpensive glass.