New d40...weird thing happening...

[andrea_javarauckas]

I am very new to the world of DSLRs. I've been doing lots of reading and

practicing, so hopefully I'll be taking some great pictures before long.

Anyway, for now, I've been using the Programmed Mode (and sometimes Auto).

Sometimes, when I press the shutter release half way down (as if to take a

picture), the lens goes back and forth, as if trying to focus, never comes into

focus, and then the shutter won't fully release. I was taking some pictures

indoors last night and when it started happening, I just figured the camera

couldn't find suitable exposure for the shot and therefore, wouldn't let me take

the picture. But I tried again today, in full sunlight, and it still does

it...with no apparent rhyme or reason. Anybody know what's going on? Thanks.

 

Andrea

[alvin_wong]

<p>Andrea, you need to focus on "something" when using an autofocus lens. Preferably, you should focus on the edge of an object or a solid line. Autofocus relies on contrast detection; if you point the camera at a solid block of color (i.e. sky, or a white wall), the system will "hunt" for focus.</P><P>I suggest you read Dante Stella's excellent <a href="http://www.dantestella.com/technical/afblues.html">article</a> for a more detailed explanation.</p>

[ShunCheung]

Try switching off auto focus first and see whether your camera is working fine without AF.

[nick_bumgardner]

Andrea,

 

Alvin is right for the most part and guides you to an excellent article. In addition most af points are more sensitive to vertical lines than horizontal. The center point is also more sensitive than the outlying points. A faster lens will also allow for faster focusing because it allows more light into the camera.

[Michael R Freeman]

<i>"I just figured the camera couldn't find suitable exposure for the shot and therefore, wouldn't let me take the picture."</i><P>

 

Nothing "weird" happening here. That's how it is supposed to work. ;-)<P>

 

The problem was not suitable exposure, rather the camera could not lock focus. In some focus modes, if the camera cannot autofocus (because of insufficient light or contrast) and lock onto the subject, then the shutter will not release (no point in taking an out of focus photo). As Shun indicated, switch to manual focus in those situations, and all will probably be well.

[tom_luongo1]

Try focusing on a large black dot on a piece of paper or a big black cross on a piece of paper. The autofocus system should work easily on those types of targets.

[aldrich]

I have experienced something similar on my D40x. Unlike what you folks are describing, however, Mine claims to be focused. The AF section lights up in red, and if I have confirmation beeps turned on, I hear it, yet it will not take the picture. If I switch from Auto to Manual on the lens, and back to Auto, this always solves the problem. Perhaps a jam-up in the AF? Perhaps the mode I shoot in? I nearly always shoot in A, S, or M.