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Old Jan 1, 2010, 6:04 AM   #1
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Default A330 not focusing properly

Hi there,
I just got an A330 and noticed very quickly that focusing is a little hit and miss. Sometimes it focuses perfectly, sometimes it doesn't.

If I take a picture of a building for example the camera will 'lock on' but when i look at the picture it will nearly always be very slightly off focus. If i switch to manual and advance the focus ever so slightly and take it again the picture will by crystal clear.

Same with depth of field. I'll autofocus on something 2 meters away but when i look at the picture I find it actually focused a bit beyond that.

Is this a bit of a sony thing? Kit lense issue or do I have a slighty faulty camera?

Any help would be GREATLY appreciated!
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Old Jan 1, 2010, 6:24 AM   #2
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You see front focus (focusing in front of your intended subject), or back focus (focusing behind your intended subject) on a regular basis from a variety of camera models from virtually all manufacturers. When that happens, it's usually an alignment issue (AF sensor assembly, etc.). They can adjust that kind of thing using specialized test equipment.

Most of the time, it's something the user is doing wrong, though. For example, letting the camera select the focus point, versus selecting it yourself (and most cameras are going to default where the camera is selecting the focus point).

Keep in mind you've got 9 Autofocus points in the sensor, and because the focus plane is not flat (it curves slightly inward as you go towards the edge of the frame with most lenses, especially at wider zoom settings), if you're using an outside focus point, the focus in the middle of the frame will be further away (resulting in backfocus for the portion of your subject in the center of the frame if you're close enough to your subject).

So, for starters, you want to make you and not the camera are selecting the focus point being used. Just press the Fn button and look at the AF Area selection menu choice. It defaults to wide (where the camera decides the focus point to use). I'd try it using Spot (Center focus point), or Local (where you select from the 9 focus points) and see if you still see the same problem using the Center Focus point.

Here is an image showing the 3 different choices under AF Area, and how they differ (it defaults to wide, which can cause issues, depending on your subject type and distance if the camera decides to focus using something other than the focus point closest to your intended subject, or chooses an outside point):



If you still see an issue, here's a page showing you how to check it using a tripod and a chart you can download and print.

http://focustestchart.com/chart.html

If it's off, I'd send it back to Sony and let them calibrate it (and I'd send both the camera and lens in case it's a lens issue instead).
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Old Jan 1, 2010, 6:28 AM   #3
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P.S.

You posted this in our Sony forum under our Point and Shoot camera section. We have a separate Sony Alpha dSLR / Konica Minolta dSLR Forum set up for dSLR models like your A330. So, I'll move this thread to the correct forum now.

BTW, Welcome to the Forums.
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Old Jan 8, 2010, 4:29 PM   #4
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Just to update I fixed this problem by returning it to the shop and exchanging it for a Nikon
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Old Jan 8, 2010, 4:47 PM   #5
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Well... That's one way to go about it. But, whether or not you fixed anything would depend on what the problem was. ;-)

If you start seeing similar symptoms with your new Nikon, I'd make sure to set the camera so that you're selecting the focus point. A common issue with someone seeing focus issues with a dSLR is letting the camera where to decide to focus (and most cameras are going to default that way, so it may pick a closer focus area versus your intended subject if it sees enough contrast in different area of the frame under a different focus point, as a camera is not always going to use the center focus point unless you tell it to).

You do see body and lens issues from time to time. But, usually, it's a settings issue if you're using a camera's defaults.
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Old Jan 8, 2010, 6:51 PM   #6
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Thanks for all your help,
I know every numpty consumer says this about stuff but this really was NOT user error. There was a backfocusing issue with it. I opted for a nikon becasue the sony seemed very clumsy at focusing even when it was working...
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Old Jan 8, 2010, 7:18 PM   #7
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You may have gotten a defective lens or camera then. It happens.
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