Here're a couple of sample images taken with the EOS 50D and RAW(DNG)-converted via Lightroom.
Click on a thumbnail to view the original file (opens in a separate window). Please note that the originals are FULL SIZE samples (=several megabytes) thus requiring a significant amount of bandwidth so please take care of the limited resources here.
Make
Canon
Model
Canon EOS 50D
ISO Speed
400
Focal Length
160.0mm
Exposure Data:
f/5.6 @ 1/1000s
Size
4752x3168
Make
Canon
Model
Canon EOS 50D
ISO Speed
400
Focal Length
200.0mm
Exposure Data:
f/7.1 @ 1/1000s
Size
3168x4752
Make
Canon
Model
Canon EOS 50D
ISO Speed
400
Focal Length
50.0mm
Exposure Data:
f/9.0 @ 1/1000s
Size
4752x3168
Make
Canon
Model
Canon EOS 50D
ISO Speed
400
Focal Length
200.0mm
Exposure Data:
f/5.6 @ 1/800s
Size
3168x4752
Make
Canon
Model
Canon EOS 50D
ISO Speed
400
Focal Length
200.0mm
Exposure Data:
f/5.6 @ 1/2500s
Size
3168x4752
Make
Canon
Model
Canon EOS 50D
ISO Speed
400
Focal Length
40.0mm
Exposure Data:
f/8.0 @ 1/640s
Size
4752x3168
Make
Canon
Model
Canon EOS 50D
ISO Speed
400
Focal Length
28.0mm
Exposure Data:
f/8.0 @ 1/800s
Size
4752x3168
Make
Canon
Model
Canon EOS 50D
ISO Speed
400
Focal Length
50.0mm
Exposure Data:
f/8.0 @ 1/2000s
Size
4752x3168
Make
Canon
Model
Canon EOS 50D
ISO Speed
400
Focal Length
200.0mm
Exposure Data:
f/5.6 @ 1/4000s
Size
3168x4752
Make
Canon
Model
Canon EOS 50D
ISO Speed
400
Focal Length
18.0mm
Exposure Data:
f/8.0 @ 1/1000s
Size
4752x3168
Make
Canon
Model
Canon EOS 50D
ISO Speed
400
Focal Length
50.0mm
Exposure Data:
f/5.0 @ 1/800s
Size
3168x4752
Make
Canon
Model
Canon EOS 50D
ISO Speed
100
Focal Length
18.0mm
Exposure Data:
f/9.0 @ 1/250s
Size
3168x4752
Verdict
Canon had a somewhat weird timing regarding the release of their EF-S 18-200mm f/3.5-5.6 IS. It is extremely difficult to design such a lens to start with and more so under low-cost requirements. Combine these side conditions with the rather extreme quality requirements of a high resolution APS-C DSLR a la EOS 50D (@ 15mp) and this sounds like trouble. The Canon lens has a couple of weak spots. At 18mm the border resolution is soft and heavy vignetting, extreme barrel distortion and CA problems don't help either. The situation improves significantly at 24mm and 50mm before deteriorating again towards the long end of the range. The situation would have been a bit different a couple of years ago when the sensor requirements were lower but combined with the EOS 50D the lens is somewhat outdated straight from the start. Better look elsewhere unless you still intend to use an older generation DSLR for a while.