Is this acceptable for an L lens?

[willg]

got my 70-200 lens today and its great, but i have just heard horror stories about focusing problems and i don't think i have any but just tell me what you guys think..the first pic is straight out of the camera and the second is with some usm applied

http://uploads.jzl.us/files/100percentnousm.jpg
http://uploads.jzl.us/files/100percentusm.jpg

[willg]

those are 100% crops by the way

[tim]

It's pretty hard to tell with such a strange thing to take photos of, but it looks ok to me. Perhaps take a photo of something with sharp edges, like a page of text or something.

[willg]

thats a good idea..and how sharp should it be? should usm not be effective at all or am i asking too much

[robertwgross]

A sharp lens is only one component of getting a sharp image. There are several camera settings and user errors that can screw it up.

I use a standard focus target, which is crisp black and white, printed on 13x19 inch glossy paper. I can place that at any suitable distance and use any lens for a test.

---Bob Gross---

[willg]

what do you think about this....
shot at 200mm 100% crop
http://uploads.jzl.us/files/100percentnousm2.jpg

here is the full frame (sized down)
http://uploads.jzl.us/files/IMG_4779 (Medium).JPG

[ed2day]

Make sure you are doing it in BRIGHT lighting to minimize focus errors. You really have to control conditions--tripod etc., esp. at 200 mm. I'd just go take some pictures outside. Normally this lens is so sharp it doesn't leave you with any question.

[willg]

i just went to the zoo and some of them came out great but some were just obviously out of focus...this is probably my problem

[Jesper]

what do you think about this....To do tests like this properly, you have to really do it carefully, so make sure that you eliminate any factors other than the lens which can cause softness. That means: do it in bright light (outside on a sunny day), shoot from a good, sturdy tripod - not handheld and use mirror lock-up.

Also, sharpening in Photoshop will always make your photos look sharper, even if shot with the sharpest L lens.

[ed2day]

Keep in mind that shooting at 200mm, which you probably doing at the zoo, any shot less than longer than 1/500th sec (assuming 1.6 crop factor) should be suspect for camera movement. And that's if you have a steady hand. For critical comparisons at any speed I'd use a tripod. Discount that possibility before you look at focus.