I have just upgraded to a 20D and am visiting the States in a couple of months, Colorado to be exact. I want a good walk around lens to replace the kit lens. Is there a huge differance between the quality of Sigma and Canon lenses, at least to cover the extra cost of Canon ? I fancy a Sigma 17-70 DC macro but wonder if I would be better off with the canon 18-125. Any help would be greatly appreciated.

janetr wrote: Canon doesn't make an 18-125. Sigma makes one though, and it is not fast and produces average image quality.. Canon's 17-85IS is a good walkaround lens. It's not fast either, but has IS which can substitute for a tripod in some situations.

I don't know much about the 17-70, but I know it is fast at the wide end, and has a great focal range.

Chris M
www.imagineimagery.com

I too have the 20d with the 17 - 85mm IS USM lens. It is a great all purpose lens and does quite well even in low light situations, only when the subject is NOT moving. If they are you may get some blur, depends of course how fast they're moving. Shooting a clear shotwith this lens in low light is based on timing.

style="BACKGROUND-COLOR: #000000"Below, I was watching my dog enjoy his rope toy so there was some head movement which, if I took the shot during that time would have been blurred. I waited until he momentarily stopped and took the picture. This is alsowithout a flash.

Awesome dog shot!

Here is another one from tonight playing darts with my son...or rather he's throwing the darts. Looks like this one's heading for bullseye!

20D, 17-85mm IS USM, 1/2000, 4.0, ISO 3200

tamron 28-75 is very good and fast at 2.8. i don"t understand why anybody needs IS for a lenses that only goes up to 85 . 17-85 is good but not for all the extra $$.

Some of you looking at the specs above in the dart pic might be wondering how I got a 1/2000 shot with my 17 - 85mm 4.0 lens. Well I managed to find 1400 watts of light andpointed it at the dart board.

The one thing with this 4.0 - 5.6, 17 - 85mm lensin low light is to enhance the light by anymeans possible, (try not to use the flash, it causes shadows) direct it in such a way to avoid shadows and you should be able to reach fast shutter speeds.This concept is for all 4.0 and up lenses shooting low light.

This next action swimmingpic is again in alow light settingbut I tookadvantage of the large bank of windows on the far side of the building, waited for this swimmer to get to that end of the pool and the photo turned out great. The ideal lens would have been the 70 - 200mm 2.8 but if your shooting with a 4.0 - 5.6 general purpose lens you have to be in better light for action shots. Ialso shoot at ISO 3200 and run the photo through a noise program.

Once you understand the peramiters of your general purpose lens, grab light where you can, it does not to bad.

camerageak wrote:
IS is very useful at any focal length, depending on what you shoot. For example, I shoota lot of landscape stuff, which requires greater DOF (small aperture),low ISO for greater image quality, and low light for shooting at dawn and dusk. Ideally, one would use a tripod in these situations. But of course tripods aren't always convenient, or even possible.

And when I travel or go on a long hike, the IS on my 17-85IS allows me to take wide angle landscape shots during the golden hour, with greater DOF 9requiring slower shutter speeds), and higher image qualty (lower ISO), without needing tolug aroundmy tripod.

Now you understand why IS is useful at any focal length...

Chris

www.imagineimagery.com

janetr wrote:
Check this link out: http://www.fredmiranda.com/forum/topic2/143791

An experienced photographer thrilled with the Sigma 18-125 (in low-light)!

This is a pic of a night time street drag taken with the Tamron 28-75 2.8.

It was almost dark, only the dim lights of the fairgrounds illuminated the raceway.

And I was standing on the wall right next to the cars.

The cars approximate speed as they went buy was 60-80 mph.