Digital camera auto focus tips?

[afreshpath_admin]

I am trying to get better quality photos out of my digital point and shoot camera. The auto focus is not the greatest and when I use manual mode to stop down the apature, things get a bit more dicey.<br />
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I want to keep the subject in sharp focus while the foreground and background are pretty much out of focus.<br />
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The camera is just a Kodak Z740. Lots of features for snapshots but no manual focus or exposure bracketing.<br />
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One shot that came close to the depth of field effect I wanted is here<br />
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http//howto.netmorale.com/viewtopic.php?p=338<br />
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It's the first of the three that you see.<br />

 

[jubae24]

you may find this a little weird but i used to use petroleum jelly, i would smear it around the edges of my lens to get the desired effect your looking for until i was able to use photoshop )

 

[antonim]

the appeture range of point and shoots is poor, sounds like you are about to out grown the Kodak,

so if you want exclusion (what people call blurryness) get a DSLR and learn light, exposure and technique.

people seem to thumb this down (jealous or something) go do a night course or day course in photography, I studied for years and still do - seems to work for me

PS the 3rd shot is pleasing

a

 

[DrSam]

It's going to be darn hard to "de-focus" too much using a digital camera while keeping the main subject in sharp focus. The smaller the sensor, the greater depth of field you will have. Generally speaking, the smaller the camera, the smaller the sensor. Your Z740 has the smaller of the two more common sensors out there - 1/2.5". Most of the pictures you take with your camera are quite sharp from near to far distances and there is a reason for that which I will explain.

While we speak in terms of the 35 mm equivalency of digital lenses, don't forget that the digital sensors are usually smaller than a full-format 35 mm frame. Most of the more popular point and shoot cameras have the smaller sensors. It's only about 5 mm wide and 4 mm high. The lens on required to cover that angle of view on your camera is an ACTUAL 6-63 mm zoom lens. At these focal lengths, the background is going to almost always be in pretty sharp focus.

In other words, if you WANT to defocus the background, you are going to have to work pretty hard at it. You would have to zoom to the longer end of the lens and set the aperture open as wide as it will go, if your camera even allows you to control the aperture, and get pretty close to your main subject while having the background a fair distance away.

The bigger the sensor, the easier it will be to achieve pleasing bokeh. This means moving to a dSLR, which all have sensors about 20 times bigger than the typical P&S digicam. If you want to really go for brokeh (very bad pun intended), you can get a Canon 5D and you will get exactly the same effect you are accustomed to in a 35 mm camera, since the sensor is the same size as 35 mm film.

You can see some example of what is rather easily attainable with a DSLR at http//www.flickr.com/photos/samfeinstein/tags/bokeh/ Read the captions, though, because a couple of these are done with point and shoot cameras. Study the set-up to see how I did this. It's only doing exactly as I said in my answer above. If you like this effect, I agree with Anotoni that you are probably ready to move up to an SLR.

Wikipedia does pretty well on the subject of depth of field. See http//en.wikipedia.org/wiki/Depth_of_field

See also http//www.photo.net/learn/optics/dofdigital/

 

[PDA]

First things first, grab your camera's manual. If you have a macro mode, that will be your best bet. Usually though, you will need more light in macro mode with a point and shoot digital. Expect to use a wide aperature and no zoom at a close range.

You can also enhance the effect or creat a faux one by using Adobe Photoshop or Corel Paintshop Pro Photo. To do so, use the selection tool, outline your subject, and then reverse it so that your subject is not what the selection is. Then use the Gausian blur at about 10-20% of the image's pixels.

Lots of practice is needed to make it work, but you always have options.

 

[MasonT]

I agree with Antoni - the third image is great.

I'd just like to add something. I'm just stabbing in the dark here but I'm wondering if you understand how an autofocus works. The AF is usually in the centre of the viewfinder (unless it can be set to the side) and will only focus on virtical lines of contrast. I'm not sure about your camera but it may work with horizontal lines as well.
Anyway, it's usually best to hold the centre of the viewfinder on the focal point while holding the shutter halfway and once it's focussed, move the camera to how you want the subject framed before pressing the shutter all the way. After a few years of trying, my wife still can't focus an image -)