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-   -   General Snaps - Focusing Problems, Most Vexing :-( (https://forums.steves-digicams.com/canon-eos-dslr-41/general-snaps-focusing-problems-most-vexing-14833/)

Ikker Oct 14, 2003 5:56 PM

General Snaps - Focusing Problems, Most Vexing :-(
 
Hi,

There is probably a Obivious Answer to my Question, But it's driving me up the wall.

I have just got a 300D (Rebel). My previous camera was a Kodak 4800, well pleased with that.

My question, hopefully somebody can help on whether it can be done or not.

The picture I'm trying to take is: General items on a desk all at different distances from the cammera, not huge distance away ( say 750mm to 1000m).

The Kodak would take a picture and everything was generally in focus and sharpish. With the 300d it keeps focusing on a object in the group on the desk and everything around it is out of focus.

Can i stop the 300d doing this, and force it to take more general picture. I think it has something to do with the aperture, mayby.

Any help, guidance, pointing me in the right direction, suggestions greatly appreciated. :-)

Many thanks,

Ikker
PS I'm a complete novice. Still learning :)

Klaus DK Oct 14, 2003 6:34 PM

Hi

It seems to me that it could be two things.

The aperture, which you have chosen with a small F-stop (number) which means that you will get a very small depth of fields (DOF). You could try to increase this.

The focus, which, on your Rebel, has another focussystem that your earlier compact camera, which often a made "bulletproof", which means that you will get sharp shots, but not pinsharp, because the focusing is done from other parameters than your Rebel. Have you check if your Rebel are using some kind of spot-focusing or not ?

NHL Oct 14, 2003 6:52 PM

Klaus is correct the aperture is too big (small f-number) for the available light, plus you'll get less DOF on a dSLR than a smaller CCD Kodak's... You can either reduce the shutter speed if the lighting allows or shoot with the flash (but then you'll have to control the shadows).

For the 300D/Rebel however, turn the control dial to A-DEP (Automatic DEpht-of-Field) and point the two outmost AF points on the furthest and closest objects. The camera will then pick the correct aperture for you so that everything in between will be in focus! :wink:

... You might need a tripod if the shutter is too slow though for the available light. :cry:

eric s Oct 14, 2003 9:42 PM

I know little about the Kodak 4800, but I wanted to mention something which is regularly said. consumer cameras have a much wider depth of field. It has to do with the size of the sensor and the size of the lens opening (someone here explained it to me once, but I don't remember the details any more.)

The 300D has a much larger len opening and sensor, so it's depth of field is smaller. It's a blessing and a curse. When you want a big EOF, you need lots of light (to make up for the smaller aperture), but when you want a smaller DOF, it's easy.

Eric

NHL Oct 14, 2003 11:21 PM

BTW I don't know what lens you have, but usually you can increase the DOF by (1) going wider on the lens, or (2) shooting from further away (or both 1 + 2) for the same aperture! :wink:

Ikker Oct 20, 2003 3:21 PM

Thanks for the Advice
 
Sort of sorted it out :-)

Your advice has helped greatly.

An SLR is a bit diffrent than my Kodak Compact - I love learning curves ;-)

Thanks again,

Ikker


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