Manual or Auto Focus...

[keller]

I was at a wedding earlier today just messing around taking some photos of family and friends. The camera that was used was a 450D with a EF-S 55-250mm f/4-5.6 IS Lens. I call it the lazy man's lense because i don't have to get up to take the shot. The zoom will reach out and touch someone.


Here is my question.....


I was shooting in manual mode, perhaps with 1 or several subjects that are moving (sitting and turning of the head, hand movements, not a big movement...ect). The camera is in Manual mode and i have autofocus turned on. It seems theshutter speed is around 1/60 - 1/200.


I have noticed when i get ready to take the shot (not sure the correct term) the little red dots appear on the picture when the lense focuses on the subject. If i hit the shutter button the little dot(s) moves and focuses on something else (perhaps a hand, or a drink on the table). Now, i tried to get the camera to make all the dots appear as hoping to focus on everything, but as soon as i hit the shutter button maybe 2 or 3 dots appear and focus on a subject while leaving the other subjects a little blurry.


This link shows a picture in which i am talking about. The girl looks more blurry.


http://img.photobucket.com/albums/v731/nobears/post.jpg


How do i get everyone to be in focus?


I hope all of this made sense.


Thanks....


Keller

[Sinh Nhut Nguyen]

What happened is you let the camera select the focus point for you, in this case the camera generally focuses on the nearest subject.


I always select my focus points, and I use the center focus point about 95%. Use single point, lock focus and recompose.


EDIT:


To get everyone in the picture sharp you need more depth of field and this can be done by closing down the aperture or move farther away from the main subject.

[keller]

So if i do select the center focus point, that would generally mean the subject has to be in the center of the photo at all times?


I guess i was thinking today when i was at the wedding things were moving so fast that i did nothave time to set the focus point before each shot. So i kept it on auto focus...which gave me some blurry images while the person right next to them was a lot clearer.


Also, would a better camera and lense help solve this problem? Just curious.


keller

[Jarhead5811]

It's not a camera/lens problem a $6000.00 camera with a $2000.00 lens would do the same thing. You can use the center to focus, by pressing the shutter half way, then recompose (shift to the Field of view you're looking for) and press the shutter the rest of the way down. Or...select a focus point for the shot in question (this gets pretty easy with some practice).A higher f-stop will yield a deeper depth of field. Again, I can't recommend picking up David Busch's DSLRs for Dummies[/i]enough. It's where I started even though I had someFilm SLRexperience.


(I'm actually going to bed now, G'nite.)

[Sinh Nhut Nguyen]

Also, would a better camera and lense help solve this problem? Just curious

Absolutely NO, if you ask this question I am sure you are eithernew to your camera or haven't used it enough, getting newer equipment only frustrates you more. Master your current camera first.

So if i do select the center focus point, that would generally mean the subject has to be in the center of the photo at all times?

YES, initially your subject has to be in the center of the frame, but there is a technique call "focus and recompose". If the subject is moving too fast, just keep it in the center and crop the image later. If you want to "focus and recompose" on fast moving subject you need to practice the technique.


Good luck.[]

[Jon Ruyle]

Sinh-

getting newer equipment only frustrates you more.

While I agree with the spirit of your post, I must admit that I've never expericnced this particular emotion when getting new equipment []

[Sinh Nhut Nguyen]

Jon, if you've mastered your current camera, upgrading to a newer and better camera is all cool, I'm all for that, after all we only live once and deserve to spend the money we work really hard for right???[]. However don't expect getting a new and better camera will fix operator errors.[]


Keller, just use your camera a lot, learn from the results you get, read the manualand ask question if you don't know. Canon EOS 450D/XSi is a great camera to get started in DSLR. If you got a new and better camera now, you would end up with two cameras that you know very little about. Once you get a hang of the 450D, it's a good time to move up to higher class of camera.

[peety3]

I guess i was thinking today when i was at the wedding things were moving so fast that i did nothave time to set the focus point before each shot.
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I fully, fully agree with others' comments that you should master what you have before looking to upgrade. That said, upgraded cameras offer the ability to choose focus points using a small joystick control that's essentially "always on". It often has to be enabled in menus first, and even then there are some camera-specific things* you want to learn like the back of your hand, but it sure is convenient (and I sure miss it when I grab our Rebel...).


* On my girlfriend's 40D, using joystick focus-point selection seems to disable the factory-default way of choosing focus points, and as a result I don't know how to tell the camera to auto-select focus points. However, with nine focus points, you can pick any point with only one touch of the joystick. On my 1D Mark III, the factory-default way of choosing focus points stays active, so I can jump to auto-select far quicker (though I never use this). However, with 19 selectable focus points, the center point is the only point that's definitely selectable with one push...I can be "thumbing away" to get the point I want sometimes.

[apersson850]

On the 40D, if you enable immediate focus point selection with the joystick, then the button you normally need to press first becomes redundant. So they use that to select the all points active mode.


As I see it, there are two possible methods to focus on something, then recompose.


Either you use One Shot AF and the center point, in which case you aim the center point at the target, half-press the trigger (and keep it there), re-compose your shot to cover what you want it to and then press the trigger completely. Note that if you use this method combined with evaluative metering and automatic exposure, then you'll also lock exposure at the same time as you lock focus.


Or you use Servo AF, move the focusing operation to the AF-ON button (or * on the simpler models) and use the center point. Aim at the interesting part with the center point, press AF-ON until the camera has focused there, let go of the AF-ON button to hold the focus where it is, re-compose and take the picture. In this case you don't lock exposure when half-pressing the trigger, though, even with evaluative metering.


One Shot AF is better in low light than Servo AF, but apart from that, these two methods are equivalent.


Now if you need to track a moving target, and now and then take pictures of it, then you need Servo AF and keeping the active focus point on the subject all the time, while you keep the trigger half-pressed or hold the AF-ON button pressed.


If you want everything covered by the nine focus points in focus, and don't use flash, then you can try the A-DEP setting. It's one of the most bashed modes of them all, but this is actually exactly what it's there for.

[Jarhead5811]

Th red dots are indicating where thecamera is focusing, they will never all light up.Auto select will ussualy pick the nearest object, apears to be the guy's knee in you're shot. You can manually select a focus pointso you decide where it focuses, (Aim for the eyes) which is how I always do it. You might also look into explanations on aperture setting to help understand depth of field.I'd recommend picking up a copy ofDSLRs for Dummies[/i]by David Busch. While I understand the subject he does a much better job of explaining it (according to my Wife I can't explain anything technical)and I need to get back to sleep.


Our sick young'un justgot back tosleep, gotta git while the gittin's good [|-)] zzzzzzzz.


(Please excuse the Southern dialect it comes out when I'm wore slam out.)