Canon Lens Question

(deltawake) · (deltawake) **Join Date: Sep 2004** 03-06-2006, 8:12 PM

Thanks all for the previous help with my Digital Rebel Questions. I especially found the Cortese article on the other site to be extremely helpful.

My ongoing concern is this: I have the Canon 100mm USM
lens with macro capability. I am able to get razor sharp ultra close up photos with it. When I try to shoot at 70-80 feet, the images are just not as sharp. I have tried action shots and stills, auto focus and manual focus, varying light conditions. The images just are not as sharp at a distance.
I have other much less expensive Canon lenses with which I am able to get sharper images than I can with the 100mm.
Is this lens just not designed for distances beyond the macro range?

For wakeboarding, I know that most people favor the 70-200 F4, or F2.8. I am going to invest in one of those, but I would like to figure out what's going on with the 100mm.
Sigma has a new 70-200 F2.8. Any opinions. It's a little bit more $$ than the Canon 70-200 F4. It seems like a nice lens and a good value.

(richd) · (richd) **Join Date: Oct 2003** 03-07-2006, 5:19 AM

The 100 macro USM is considered as sharp as any lens Canon makes at infinity distances. Other factors come into play when shooting at those distances that may or may not be contributing to making you think the lens isn't sharp. f stop, focus and handshake (yes even on a 100mm) makes a big difference at that kind of distance. Post a shot that shows what you're seeing and I'll be happy to comment. I own a 100 macro, it's the sharpest lens I own. The 70-200 Canons or sigma will not be sharper unless your 100 is defective.

Here is a full shot from the 100 no processing:

http://www.pbase.com/rd4tile/image/55358102

Here is a crop at 100% (it don't get no sharper!)

http://www.pbase.com/rd4tile/image/55357650

(deltawake) · (deltawake) **Join Date: Sep 2004** 03-07-2006, 7:00 AM

Thanks Rich,
The problem I'm having is more than likely due to my inexperience. I'll try to post some photos later today if I can.
Thanks again.

(richd) · (richd) **Join Date: Oct 2003** 03-07-2006, 7:02 PM

What's interesting is that most people have trouble getting razor sharp macros with this lens (especially handheld) and find it great for normal shooting!

(deltawake) · (deltawake) **Join Date: Sep 2004** 03-07-2006, 10:17 PM

Rich- All of my macro shots are of teeth as I am a dentist. I don't have any way to easily post full size images. As I look back at my fuzzy images, I realize that my error is probably in shutter speed. I had been using the camera on automatic for action shots. When I learned how to check the specific parameters of each shot in iPhoto, I sort of went duh!!! I'm looking forward to getting back out there and shooting lots more. I'll start taking my action shots in shutter priority mode. I'll get better with the 100 before I step up to the 70-200. Thanks for your help!