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Old Mar 28, 2013, 7:48 AM   #21
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Originally Posted by darlenerenee View Post
would it tell you guys anything if I uploaded a few. I still have some raw photos that I can downsize and convert to jpeg without any edits...
There's a lot to shooting sports. If you want advice on improving your photos - that's a completely different thread. We don't need 100% crops to determine whether a photo is decent or not - It would be fairly evident at standard sizes. We're not judging critical sharpness of a 1.4 lens here. If you want feedback on your photos, post some in another thread - in Critique or Sports section.

From what you've written, you're trying to shoot sports at shutter speeds too slow - so that's going to be a large part of the problem.
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Old Mar 28, 2013, 11:08 AM   #22
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On the Tamron lenses - they're sharp but the focus motors are slow. If you were trying to use the lens for your sports shooting that may be why you were underwhelmed by the performance.
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There's a lot to shooting sports. If you want advice on improving your photos - that's a completely different thread. We don't need 100% crops to determine whether a photo is decent or not - It would be fairly evident at standard sizes. We're not judging critical sharpness of a 1.4 lens here. If you want feedback on your photos, post some in another thread - in Critique or Sports section.
You're absolutely right, John. We don't need 100% crops to determine whether a photo is decent or not. What we're trying to find out is if darlenerenee's shots aren't sharp because the Tamron lens she's using is slow to focus. For that, I'd like to see a 100% crop. Do you have a better idea of how to determine if her lens is slow to focus?

You introduce some minutiae into the conversation, and when we try to address it, you undercut everything that's gone on before. You come late to the party, then invite all the guests to come with you to the bar down the street.
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Old Mar 28, 2013, 4:35 PM   #23
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TCav - sorry if you got your feathers ruffled by my suggestion. But, let's say she posts 5 photos and their 100% crops of arms as you suggest. Let's also say we somehow discount motion blur introduced by her not using a fast enough shutter speed which she indicated is happening. Now, we've got photos that still don't appear sharp. Is there something that tells you:
A) it was the lens being too slow
B) it was the camera not being accurate in it's predictive focus
C) it was photographer error?

I'm not aware of how to distinguish between the 3 causes (much less adding in motion blur). Again,not sure how 100% crops make that determination easier. By all means, the OP can decide as you suggest that "I'm late to the party" and can ignore my suggestion. It's her thread and she can pursue whatever course she sees fit.
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Old Mar 28, 2013, 7:34 PM   #24
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If the lens didn't focus fast enough, and since in most circumstances, the camera won't take the shot unless focus is locked, I'd look for evidence of the shot being captured after the instant of the action she was trying to capture. That could be photographer error, but if we presume she's been doing this for a while, then I'd be inclined to presume that at least some of that was the camera not being as quick as she would like.

At a distance of 100 feet, a focal length of 200mm, and an aperture of f2.8, the total depth of field is about 8.5 feet, so I don't think predictive focus could have anything to do with it. If the camera had an appropriate subject distance an instant ago, a human subject couldn't have moved outside the DoF.
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Old Mar 28, 2013, 8:43 PM   #25
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At a distance of 100 feet, a focal length of 200mm, and an aperture of f2.8, the total depth of field is about 8.5 feet, so I don't think predictive focus could have anything to do with it. If the camera had an appropriate subject distance an instant ago, a human subject couldn't have moved outside the DoF.
Let's take a reasonable 6 second 40 yard dash. That's 6.6 yards per second - about 25 feet per second. So, it doesn't take long to move the 5 feet necessary - 1/5 a second. Assuming the camera was accurately focused on the subject (and not the background or floor or whatever).

As for a camera in continuous mode not taking a photo without a focus lock - everyone has plenty of OOF shots in a burst that indicate that theory isn't reality.

Again, it's up to the OP. If she believes you can intuit whether fault lies with the camera, the lens or the photographer based on the 100% crops - that's her call. I just don't see, based upon your explanation, how you'l make that determination. And, what good would it do?
The OP doesn't like the sensor performance. This won't help that. She can't use the same lens on a Nikon camera. So, she's got to sell it and buy a new lens. We know from reviews the Tamron lenses don't focus as fast as OEM - or even Sigma lenses. So, let's say your analysis either determines - YES the lens is slow or NO - you attribute poor results to something else. How exactly does that help the OP since it doesn't improve her sensor performance?
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Old Mar 29, 2013, 7:11 AM   #26
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Predictive autofocus is about predicting the distance between the camera and a moving subject. When the subject shifts from left to right within the frame, the distance between the camera and the subject doesn't change, so predictive autofocus doesn't have anything to do.

For your scenario of photographing a 60 yard dash, the chances are that the photographer would not be in a position where the runners would be running directly toward the camera. It's much more likely that the camera would be looking at the runners going across the frame, so the subject distance would not have changed at all. Plus, Track and Field events generally occur outdoors, so a photographer would probably be using a smaller aperture, resulting in greater depth of field, reducing the need for predictive autofocus even further.

She wants to shoot indoor basketball, so in low light she'd use the maximum aperture of f/2.8 in order to get the fastest shutter speed (to avoid motion blur due to subject movement) with the lowest ISO (to avoid image noise.) If anything, she'll be following the ball, so predictive autofocus won't be of any use since the ball will be too small in the frame for it to notice. As the ball is passed from player to player, so will her attention, and thus her intended subject and probably the subject distance. Predictive autofocus won't have anything to do because the subject will keep changing. What matters (from the perspective of focus problems) is how fast the lens can change the focus distance as she shifts from one player to another.

As for her not being pleased with the sensor performance, I agree, but she also mentioned the possibility of solving that problem by going with a newer Sony body so she could avoid having to sell all her current gear. I also mentioned that, even if she did shift from Sony to Nikon, the Tamron 70-200/2.8 was still an inexpensive way to get what she wanted. If that lens doesn't focus fast enough on a Sony A700, chances are it won't focus fast enough on a Nikon body either. So let's investigate the possibility that it's a real source of her problem instead of just throwing money at it.
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Old Mar 29, 2013, 12:01 PM   #27
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ok. I hope I got this 100% crop right and managed to get it the right size for this forum.

and absolutely we will work on my skills in another thread in the proper place.

now remember "oh, man, you just need to find yourself another hobby" is NOT a proper response. at 100% these look awful the second one I cropped kind of oblong to include the ball because it looks like my dof played a part. I was focusing on her..

well here goes..
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Old Mar 29, 2013, 5:04 PM   #28
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darlenerenee- I wonder if you could include the full image that these crops were taken from, so as to get an idea as to the size of the crop.
At first glance,looks like good old fashioned high iso image noise is a big part of your problem...
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Old Mar 29, 2013, 8:08 PM   #29
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The first one is a 462x390 crop from what I presume is a 4272x2848 original. If this was the subject that you were trying to focus on, you missed, but not by much. The image is noisy, but it seems that the focus is off too.

The focal length is 75mm, and the crop is about 10% of the total image, so I'd say the subject distance is about 20 feet. The DoF would be a little over a foot either side of the focus distance. it seems to me that the edge of her shoulder (lower right) is more out of focus than the edge of her forehead (upper right) so the focus distance is a little farther than the subject distance. But there's enough detail (ear, eyelashes of her right eye) to make me thing that noise is a bigger problem than focus error.

The second one is a 561x360 crop from what I also presume is a 4272x2848 original. The focus is better. The focal length is 180mm an my guess is that the subject distance is about 32 feet. The DoF would be about 6 inches either side of the focus distance. Considering the detail in the texture of the basketball, her eye, and the stray hairs from the side of her head, I'd say the AF system nailed this one. The noise is still a problem, though.

I think noise is a much bigger problem than any issue you might have with focus.

While it's true that the A77 has only marginally better noise than your A700, I'm certain that the increased resolution will provide a noticeable improvement. I think you should rent an A77 to see how it performs in similar situations.

But a sure fire way to improve your results would be to go with a Nikon D5200 or D7100, but that would mean starting over with your collection of lenses.
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Old Mar 30, 2013, 3:29 PM   #30
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yes the originals were 4272 x 2848.

your advice seems very sound. I looked through some other pictures using different lens to possibly post some, but they seemed the same. where the athletes were stopped, it was better. if they were moving, when the pictures were viewed at 100%, they looked much like the ones I posted. noise was an issue on all.

so I will give some serious thought to renting the a77. unless I just decide to go ahead with the Nikon and be done with it.

thank you!!
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