70-200 F4 IS

[ultima16888]

Hi, I'm not sure if my copy ismediocreor what, but pictures I took tends to be not so sharp as what I hard from the forums, but ever since I got this lens I wished that I had gotten F2.8 instead for the faster shutter speed (as I suspect my hands are really shaky that's causing the blur) It was sent back to canon for repair and I got it back and nothing changed. could it be the camera? it's all mysterious to me.This is the 2nd copy that I had. I'm not sure if it helps but I got it from Sammy's camera instead of usual B&H. From what I know this lens is suppose to shoot well down to 1/15 but even at 1/60 the image is still blurry, I've tried to tripod the lens, and same thing, am I expecting too much from a none macro lens(to have the same macro sharpness)?

[Gerafix]

The minimum focus distance with the 70-200 f4 is 1.2m with an apparent magnification of 1:4.8, hardly something to use for macrophotography. Even with a 2x extender you're going to be using f8 wide open and that's getting close to diffraction artifacts for some DSLR's.

[Tony Printezis]

I have taken very sharp pictures with my 70-200 f4 IS down to 1/15 - 1/10. At those shutter speed, I usually shoot 4-5 back-to-back and I usually get 1 or 2 that are good ones.


Tony

[ultima16888]

Tony, I guess, maybe that'll helps, i'll try.. taking continuous.


not trying to take macro shots, just talking about the sharpness of macro lens.


I just tried setting up my lens/camera on tripod and shot a page of text in 2m distance, and the text seems to be soft when blown up to 100% i checked the ISO crop of bryan's test shot, they look nothing like the ISO crop.

[crystalshadow]

I've got one of these lenses and it's sharpness is great. Can you post an example picture with the metadata intact? That might give us a clue what we're talking about.

[Don Burkett]

I had the some sick feeling when I first got my 70-200 f/4. Now I love it.


The learning curve I went through


1) Watch the minimum focus distance.


2) It really performs much better in good light vs marginal light


3) Turn the IS off for tripod shots. Especially for slow shutter speed shots.


I have a sample of the affect of IS on a tripod posted here:


http://www.pbase.com/dbrasco/image/91204039

[peety3]

My classic response to these comments regarding IS lenses: what's blurry in your picture?


If it's the whole picture, you're likely beyond the limits of handholdability, for one reason or another.


If it's your subject, your shutter speeds are too low, and you likely need wider aperture and/or more ISO.


By the common rules of thumb, the non-IS 70-200/4 should require 1/70th to 1/200th of a second on a FF body, 1/90th to 1/260th on a 1D, or 1/112th to 1/320th on other Canon bodies. With a four-stop IS system, those numbers become 16/70ths to 16/200ths, 16/90ths to 16/260ths, and 16/112ths to 16/320ths (2 to the 4th power is 16) respectively. On crop bodies, that'd be 1/7th to 1/20th of a second, depending on zoom. That assumes a steady hand on a steady base.


I'd start by taking your kit outside and shooting solid objects at f/4 (wide open) with shutter speeds of at least 1/500th. How are the pictures then?

[ultima16888]

thank you Don Burkett, good samples u have, yes same learning curve, mfd, and lighting issue, I guess I imagine Bryan did his ISO test in doors.


Peety, thank you for those numbers, and yes i keep my pictures within the limit that I'm aware of, not sure why the images still comes up soft, i'll post some test images as soon as I can.

[ultima16888]

these are about i'd say 10-12 point really legible type, not tiny types. 100% crop of a lightbulb order form(just happen to be there). 200mm f4 1/3, on very steady manfrotto tripod and head, shot with IS off and 10 auto timed capture I can't think of anything else that'll make it more stable than curtain lock, but that's not even practical in real shooting situations. Am I asking too much of the lens or I have a bad copy?


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[Don Burkett]

• Mirror lock up is important at 1/3 second.
• I'm assuming autofocus, try manual focus to see if it improves.
• It's going to be a little soft at f/4 especially if you're not aligned perfectly to your target. try f/8 or f/11
• What are your other settings ISO, RAW, JPG, Contrast, Sharpness, White balance, etc.
• What was your distance from the sensor to the target
• Need Data []