70-200mm f/4 and T1i

My mother has a T1i, is looking to upgrade to a 70D, and just got the 70-200mm f/4. When we were playing with it today, she felt that the images where really soft and out of focus. I agree. Granted, she zoomed all the way in on the photos, but they did seem a bit out of focus in some pictures and sharp in others. I chalked it up to the fact that it was used on a T1i and the body was the limitation, but I am unsure. What do you think? I put it on my camera (don't laugh, it's just a Rebel XS) and we had the same effect. Some were sharp and some weren't really in focus. Will this change if and when she gets a 70D? I need opinions!!

if they were OOF on some images and sharp on others i'd say it's user error. I'd have a hard time chalking it up to the lens if you can get sharp shots out of it some of the time. Not to mention the 70-200 F4 is regarded as one of the sharpest lenses canon makes and it's also a very cheap way to enter the world of L glass. Given what you've said I highly doubt upgrading to the 70D will fix the issues I'd suspect it's something in your mother's technique. Without looking at the pictures though it's hard to be more specific than that.

Agreed that it's hard to determine without seeing some samples. That being said, the first thing I'd suspect is shutter speed, especially since you mentioned your mother was using the lens zoomed all the way in, and this lens does not have IS. I like to account for the crop factor on a APS-C camera, so I'd say you should aim for a shutter speed of 1/320 at a minimum for sharp pictures, more so if your subject is moving fast.

Agree with the shutter speed assessment of your problem. Post some examples, please. I know I can't hold my 70-200 2.8 steady at 1/200 w/o the OS engaged.

Was there nothing in focus, or was the intended focus point out of focus?

I am thinking it was either missed focus (perhaps camera is selecting focus point?) or shutter speed (hand shake or subject motion).

As others have said, samples with settings would help determine what the issue could be.

I work with a 70-200 F/4 in my gigs and it's sharp as a tack.
Work on your stance and technique... shutter speed should be up.

Test is on a tripod and you'll know if it's the camera or user error.

Unless there is something wrong with the specific copy of either the body or the lens, neither is the problem. The 70-200 f/4, if you mean the IS version, is an extremely sharp lens. And there is no reason at all why it should not produce sharp images on a T2i, or any other Rebel, including your XS. (I'm not laughing--that is a capable camera). The T2i has a newer, better sensor than my camera, and I get very sharp images from the 70-200.

The fact that you got the same result with two different bodies suggests that there is nothing wrong with her T2i. So unless you have a defective lens, the problem is technique.

Blubayou wrote in post #16230010
Was there nothing in focus, or was the intended focus point out of focus?

I am thinking it was either missed focus (perhaps camera is selecting focus point?) or shutter speed (hand shake or subject motion).

As others have said, samples with settings would help determine what the issue could be.

No, most of the pictures had something in focus, but it was usually too the left of what was intended to be focused on. I'm sure that a remedy would be to do it manually, but you would think that such a good lens would do a better job in autofocus.

Thank guys! I must clarify, the issue was when we upload the pictures and "zoomed" to 100% on the photo. They seemed sharp, but not as sharp as some. I'm thinking that the problem is not a fast enough shutter speed and/or having to use a higher ISO in order to use such a high shutter speed, degrading the quality of the picture. These older Rebel's doing like a high ISO. I'll post some pictures.

Handheld
Shutter: 1/320
Aperture: f/7.1
ISO 800
180mm

(I'm not positive I uploaded these correctly, I've never uploaded one on the forum before)

Tripod
1/13
f/4
ISO100
200mm

To me those look okay for 100% crops. Are you shooting JPEGs? The first picture is at ISO 800, which I believe for a T1i is getting a bit high, and there is a bit of noise being shown there. The in-camera noise reduction can lead to a loss of detail and make the picture look "less sharp". Also, I think focus is just tough to nail on such a small subject, especially at 180mm!

On the 2nd picture, looks fine to me. The frog's nose (do frogs have noses? snouts?) area looks sharp, can see the pores or whatever...

I'd say do this test - Set the camera on a tripod, ideally outdoors in really good light so you can shoot at ISO 100 and still get a fast shutter speed (I'd say at least 1/500) and f/8. Use live view and zoom in on your subject and use manual focus to fine tune your focus. Then try the shot. If you do that, I'm going to say your pictures will look tack sharp.

But judging by your 2 examples, I don't think there's anything wrong with your equipment...

horton581 wrote in post #16230920
Handheld
Shutter: 1/320
Aperture: f/7.1
ISO 800
180mm

800 ISO really kills IQ on the older rebels. I'd probably open it up to F4 and drop the ISO on that sort of shot.

horton581 wrote in post #16230981
(I'm not positive I uploaded these correctly, I've never uploaded one on the forum before)

Tripod
1/13
f/4
ISO100
200mm

1/13 at 200m?? That's a really decent picture for that slow of a shutter speed at that focal length.

I suggest shooting in better light and/or shoot on a tripod to really see what that lens is capable of.

Also you will have a shallow dof when you are zoomed in to 200mm , much of the image will not be in focus, with my rebel I select the focus point 95 percent of the time..