Currently I am considering these two lenses for my 30D. Is the IQ of the 17-55 better than the 24-70, or barely noticeable? I can buy the 24-70 for $1100 new and I don't have to pay extra for the lense hood or case. The 17-55 is around $1000 new and does not come with a hood and case and obviously can't be used if I switch to full frame. Does the IS really make a measureable difference? I welcome any opinions on which one I should choose. Thanks, Jason

Unless you are moving to FF in the next few weeks/months, then the 17-55 f2.8 IS lens is the better choice for the 30D. I have used it on my 30D and now 40D and it is an excellent choice. The difference from 55 to 70 is nothing, but the 17mm and IS on the 17-55 along with stellar image quality make it the better of the 2 for the 30D.

If you're going to use 1.6x for awhile the choice is 17-55 hands down. Most complain 24-70 gets from owners who use it on ff camera is lack of IS. The picture below will tell you if IS is useful. Shot with 17-55 atf2.8, 1/4sec, ISO800.

17-55 is a great lens. You could always sell it later if you pony up for FF.24-70 is no slouch but as heavy as it is and without IS it's an easy choice in my book.I love my 17-55....Bob

17-55/2.8IS...I wouldl take 24-70/2.8L IS the non-IS version if there was one... -- Mark

txbulldog03wrote:Currently I am considering these two lenses for my 30D. Is the IQ of the 17-55 better than the 24-70, or barely noticeable?In the comparisons I've seen, the 17-55 was noticeable better than the 24-70. Ofcourse, it's still both L quality. The 24-70 has the advantage of somewhat less vignetting.I can buy the 24-70 for $1100 new and I don't have to pay extra for the lense hood or case. The 17-55 is around $1000 new and does not come with a hood and caseThe hood is €39 so that's not an issue. And the lens will be your standard walk-around lens, that's always on your camera. Who cares for a case?and obviously can't be used if I switch to full frame. Does the IS really make a measureable difference?A really BIG difference. This 3-stop is no marketing. People don't feel the need to benchmark is, because the difference is so obvious. Even if it would be only a garanteed 2 stops... that difference is huge as well.Obviously, in daylight, you don't need IS at this focal length at all. But in very low light, or dark insides (castles, churches etc), it's incredibly valuable. Fare more valuable than I had ever anticipated.The 17-55 has the typical 'normal zoom' focal length. (27-88 equivalent). The 24-70 has this on a FF body, but is rather long on a crop body. (38-112 equivalent). Some people actually like that longer length. It depends on your typical subjects. I guess the the 14-70 would be preferable for portraits, because it better allows for a tight framing. But for city walk around, architecture etc, you'll dearly miss the 17-24 range. With the 24-70 you'll probably add a 10-22 to get some wide angle option. With the 17-55, you might be perfectly happy with 17mm, and not want a 10-22.

for 30D - probably should not be a contest at all - take the 17-55 IS and do not look backI had 400D and was making same decision - I went with 24-70.The only reason was I knew I am going to buy 1D body ASAP.

If you switch to full frame, will you keep your 30D as a backup body or will you sell it to finance the FF body? If the latter, then you might actually have a tough choice to make. If the former... the 17-55 is an amazing lens and I doubt you'd have any regrets. Plus, it seems to hold its used resale value very well, so if you really did switch, selling it should be almost a wash. And in the meantime, who knows, Canon might even come out with a 24-70L2.8IS to make FF users happy.I paid full price for my 17-55, plus hood. I lovelovelove it and consider it in a class with my 70-200L2.8IS and my 80-200L2.8. It's sharp and fast focusing, its IS works great, and imho it's the definitive wide to normal zoom for indoors, low light, close action, and portraits. Worth every penny.I don't have the 24-70, so I won't comment on that lens. -- A 'must watch' for forum participants everywhere! http://www.albinoblacksheep.com/flash/posting

dust issue of 17-55 (even if it doesn't affect IQ - it still looks ugly and upsetting to have a glass in that state (seen on some pics))not EF-Smore versatile zoom than 17-55mm (17mm is not enough on 1.6x crop body for real wide angle shots. so it's better to avoid it than approximate with its 27-ish resulting mm).24-70 is better as a workaround zoom.IS on this zoom is questionable (it's light, it's possible to handhold). would even question its use on other zooms. but it's me.cost as you mentionedRegards, Kirill

everything is relative. - 24-70 is not heavy at all. the only lens that is heavy is 500L (don't even mention 400 F2.8 & 600 F4).a bit more on weight issue - there are hundreds of posts that say that 70-200 F2.8 IS is heavy. didn't listen to them & good job. the lens is light (for a fit person, of course). people like to exaggerate.

For me, the biggest concern with 17-55 is the dust issues. Many say that after just a few months of shooting there is so much dust inside the lens, that it is clearly vissible on the images. For that reason alone I would not consider it. I would rather get a Sigma 18-50 2.8 Macro (the new version) wich is excellent.

What are you trying to prove? Show me just one case that people can attribute bad image of the lens to dust. I have never seen one. It's impossible for a few dust in the lens to affect the image in any noticeable way. My 300 4L bought about the same time actually got more dust than my 17-55 but I'm not concerned at all.Per Zangenbergwrote:For me, the biggest concern with 17-55 is the dust issues. Many say that after just a few months of shooting there is so much dust inside the lens, that it is clearly vissible on the images. For that reason alone I would not consider it. I would rather get a Sigma 18-50 2.8 Macro (the new version) wich is excellent.

IS, and wide? 17-55! solid build and beautiful Bokeh? 24-70You'll love eitherBTW, my 17-55 never had any dust -- Everyone is entitled to my opinion.

HI, not responding to the ignorant comment.....kid of harsh for a friendly board. Regarding the 24-70 and 17-55; I have both and love both. I use the 24-70 on my Mark 11n, great bokah, and I do not think its heavy. The 17-55 on my 30D is the best lense for everyday use. I could not be happier. It has been in Spain, Italy, Nascar race pits and NO NO NO dust. I was going to sell the 30d and get a 5D FF, but cannot see myself giving up the 30D/17-55. It a very sharp lense and IS really works......well worth the invesment......

Jesus, take a pill will you? I only stated what I have read in these forums! If dust is in fact not an issue for most, then great!carlkwrote:What are you trying to prove? Show me just one case that people can attribute bad image of the lens to dust. I have never seen one. It's impossible for a few dust in the lens to affect the image in any noticeable way. My 300 4L bought about the same time actually got more dust than my 17-55 but I'm not concerned at all.

You read it or made it up? Be man enough to be reponsible to what you said. I was just askining you to show proof.This is what you said. Totally baseless with no purpose other than trying to spread fear."Many say that after just a few months of shooting there is so much dust inside the lens, that it is clearly vissible on the images"No a single person can show or prove dust in the lens can actually affect IQ.Per Zangenbergwrote: Jesus, take a pill will you? I only stated what I have read in these forums! If dust is in fact not an issue for most, then great!carlkwrote:What are you trying to prove? Show me just one case that people can attribute bad image of the lens to dust. I have never seen one. It's impossible for a few dust in the lens to affect the image in any noticeable way. My 300 4L bought about the same time actually got more dust than my 17-55 but I'm not concerned at all.

http://forums.dpreview.com/forums/read.asp?forum=1029&message=24716740However I have since read that those who keep a filter on the lens permanent seems to avoid the dust issues.

Did you read the entire discussion follow that post? It is pretty much settled what bighand saw was caused by dust on sensor. Dust in the lens would never create image like that. Anyone with some knowledge of lens optics should know that right away. This really exemplifies the issue that a lot of times people will turn an innocent question into a horrible rumor. It can be just ignorance or sometimes with malicious intent. I’m not saying what is your intent but the end result is misinformation that will cause a lot people to make a bad decision.Per Zangenbergwrote:http://forums.dpreview.com/forums/read.asp?forum=1029&message=24716740However I have since read that those who keep a filter on the lens permanent seems to avoid the dust issues.