Need Help Picking A Lens For 30D

[Jesse Williamson]

Thanks for the help everyone. I think I'll be going with the 17-55. It doesn't have quite as much reach as I'd like, but I think the f/2.8 will make up for that for me. Now I just have scratch some cash together.

[clemmb]

I checked the ISO charts for 28, 35 & 50mm. The 24-105mm looks sharper to me.

You did not perform the comparison correctly. Read the [url="http://the-digital-picture.com/Help/ISO-12233.aspx]Chart Help Page[/url] where it says this:



<p style="padding-left: 30px;"]Lenses should be critically compared to each other only with test samples from the same camera body..


(Emphasis mine.) This is really important, because the 24-105 would look much worse if the chart had a 50D body. For example, look at the 28-135. On that lens, both bodies are available in the test:


[url="http://the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?FLI=0&amp;API=0&amp;Lens=116&amp;FLICom p=0&amp;APIComp=0&amp;LensComp=116&amp;CameraComp= 474&amp;SampleComp=0&amp;Camera=453]28-135 on 1Ds3 @ 28mm f/3.5 vs 28-135 on 50D @ 28mm f/3.4[/url]


See how much worse the 50D looks? If the chart for 50D+24-105 was available, you'd see that it is worse than 50D+17-55.
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I hear what you are saying and it makes sense so I did a test of my own.


First I looked at Bryan's ISO chart comparison between the canon and tamron 17-55. It looks to me like the tamron is a little sharper than the canon.


I own a tamron 28-75, tamron 17-55 and two canon 24-105s. My 17-55 is a little sharper than my 28-75. I think I have a good copy.


I tested the tamron 17-55 and my 25-105 both on my XTi(same body). Both lenses wide open(tamron at f2.8 &amp; 35mm, canon at f4 &amp; 35mm), same ISO, etc...


The 24-105 is noticably sharper.


I know my test is not scientific but I have always gotten sharper photos from my 24-105.


Mark

[Daniel Browning]

I tested the tamron 17-55 and my 25-105 both on my XTi(same body). Both lenses wide open(tamron at f2.8 &amp; 35mm, canon at f4 &amp; 35mm), same ISO, etc...


The 24-105 is noticably sharper.


I know my test is not scientific but I have always gotten sharper photos from my 24-105.

Interesting. Thank you for sharing your results. The only time I had the 24-105 was back when I had the 20D and 5D. On the 20D, I got sharper results from the Tamron 17-50 than the 24-105 (at 35mm anyway... 17mm on the Tamron has a lot of field curvature). It's possible that I've been wrong about the 17-50 being sharper than the 24-105 all this time. (The 20D doesn't have liveview, so it's difficult to be 100% certain of critical focus, even when taking a lot of shots with focus bracketing. That may have affected my results.)

[Jon Ruyle]

Both lenses wide open(tamron at f2.8 &amp; 35mm, canon at f4 &amp; 35mm), same ISO, etc...


The 24-105 is noticably sharper.

Wait, though- it isn't surprising that the Canon would be sharper wide open. Correct me if I'm wrong, Daniel, but when you said the 17-55 was sharper, did you not mean that it would be sharper at the same f number?

[Daniel Browning]

Wait, though- it isn't surprising that the Canon would be sharper wide open. Correct me if I'm wrong, Daniel, but when you said the 17-55 was sharper, did you not mean that it would be sharper at the same f number?

Actually, I meant both. I found the 17-55 and 17-50 to be so much sharper that even at f/2.8 they could beat the 24-105, and at f/4 it was an even bigger difference.

[clemmb]

Wait, though- it isn't surprising that the Canon would be sharper wide open. Correct me if I'm wrong, Daniel, but when you said the 17-55 was sharper, did you not mean that it would be sharper at the same f number?
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I shoot weddings. When I was shooting weedings with the XTi and Tamron 17-50, I was very pleased with the results but when I upgraded to the 24-105 I saw that my shots were overall sharper. I would shoot the tamron at f4.0 with flash and I would shoot the canon at f4.5 with flash and IS off. Always on tripod.


I did run into issues with 24 not being wide enough so I would have to switch to my tamron.


I purchased the 24-105 and then later another 24-105 as a kit lens with my 5D. I now wish I had originally purchased the 24-75 f2.8 so now I would have both. Hindsite is always 20/20.


Mark

[scalesusa]

In the almost 3 years I've owned my 17-55mm lens, it has zero visible dust. It is the only lens i keep a filter on, just because of the stories. I also have a 24-105, and its good on a crop camera, but not wide enough. My 17-55mm IS lived on my 40D until I sold it last week.


I'll sell it now, but do not regret buying it and using it for almost 3 years. I won't lose much if any money selling it, since prices have went up on new ones. I also have a 17-40mm thatI bought for my FF. It takes nice images on my 5D MK II, but never gets used on my 40D, the 17-55 is much better.