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Old Mar 30, 2004, 11:29 AM   #11
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NHL, nice picture! Any sharpening applied?
You can see the sharpening in the area of high contrast between orange/green... (I don't like the way PBase resize the pictures to their smaller sizes)
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Old Mar 30, 2004, 8:29 PM   #12
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Are you saying the F3.5 picture is also below expectations?
Nope, I'm just comparing the two available photos. I respect what NHL is saying about the DOF and I have experienced this myself with the 100mm F2. However, I can't see, personally, how this can apply to yours because I looked all over that first photo for some hint or semblance of focus anywhere and it just isn't there. It's like the photo was taken through some sort of softening filter in order to affect everything. I don't see any evidence of focus anywhere so I would agree with you that it may indeed be camera calibration that you need. I honestly, from what I've read, doubt that you have a faulty lens because that lens seems to be as good with quality control as it is with sharpness.
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Old Mar 31, 2004, 6:47 PM   #13
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Norm,

Thanks for the input! I don't believe its the camera, since the F3.5 picture is dead on. I had my whole setup calibrated by Canon a few months back, and they adjusted focus for both camera and lenses.

I think I'm going to talk to Canon and see if they are willing to look at the pictures first, then come up with a course of action.

Barthold
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Old Mar 31, 2004, 7:26 PM   #14
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Barthold

Just out of curiosity can you try again with the IS off and see if this makes a difference.
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Old Mar 31, 2004, 9:27 PM   #15
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NHL...

Nifty suggestion, I look forward to seeing the results if Barthold takes you up on that request.

Barthold...

Did you notice any improvement following your little calibration quest?
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Old Apr 1, 2004, 12:01 PM   #16
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NHL, interesting idea. I will try that!

Norm, yes calibration did help a bit. It wasn't terribly far out of whack, but I did have some front-focus issues which were annoying at F2.8.

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Old Apr 1, 2004, 1:17 PM   #17
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Barthold

It just dawned to me last night while reading a professional magazine regarding a new Nikkor lens, actually a true-zoom (the lens hold focus while zooming) AF-S 24-120mm with VR, unlike our EF28-135 IS, which the author said requires 1-2s after the shutter is pressed for the internal lens motor to spin-up before the image stabilizer is at its optimum... It's kind of jerking the viewfinder initially when first turn on.

Were you pressing the shutter immediately or wait for the AF confirmation? A 1/3 of a stop should not make that much of a difference especially for an 'L' lens... really fishy and almost unusable at f/2.8!
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Old Apr 1, 2004, 10:49 PM   #18
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NHL,

I don't remember specifically what I did with this shot. Normally I wait for AF confirmation before taking the shot. However, I have many other shots that are soft at F2.8, more soft at 200mm then 70mm. The IS on the 70-200 is a lot better than the 28-135, it doesn't take long to spin up at all.

But I will re-take the same chimney picture with IS off. Probably the weekend.

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Old Apr 2, 2004, 5:23 AM   #19
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Quote:
Originally Posted by barthold
Normally I wait for AF confirmation before taking the shot. However, I have many other shots that are soft at F2.8, more soft at 200mm then 70mm.
IMO this could be your problem: unless you are on Single Shot AF @ 200mm with the camera shake and the movement amplified, the camera's AF will turn into Servo AF (without the AF indicator lighting up): The focus may be hunting around in Servo AF mode without you knowing or hearing because of USM, and the shallow DOF just show it more than stop-down a little!

... Try a tripod even at 1/4000s just to remove all the unknown.
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Old Apr 5, 2004, 12:50 AM   #20
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NHL, I have the 10D, thus no secret AF switching is happening without my express consent :-)

I re-did the test. I'll post the shots tomorrow (its late now). But with and without IS, with and without tripod the F2.8 shots are about as good as the F3.5 shots. I don't know how to explain it, other than that I need to re-examine my handheld techniques.

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