Green dot on screen, won't let me take picture

[Aneesa]

Hey, all!

So I recently bought a Sony a390 with the standard kit lens. I've noticed, however, in the bottom right corner of the screen, there is a digital green dot that appears when the camera is focused and ready to take a picture. However, sometimes when my camera is really close up the the subject e.g. right next to the picture frame I'm photographing, the green dot will appear and start FLASHING and the lens will not focus, and when I click the shutter, the camera will not take the picture. This happens both in Manual focus and Auto focus.

It's strange, and I'm pretty sure it's not a technical glitch.

I've tried Googling it, but I haven't found anything, nor does the very short User's Manual say anything.

Does anyone know anything about this? Let me know ASAP. Thanks!

 

[Aneesa]

Just an update: The updated manual says that the flashing green circle means "cannot focus. the shutter is locked."
But my camera isn't super-close to the subject, it's a reasonable distance for me to shoot what I intended. Does this mean I have to back up, and then crop the picture later? How frustrating!

 

[Kolia]

Measure the distance exactly, from the sensor mark on the body, to your subject.

Minimum distance should be 25cm.

 

[kassad]

Is the subject under one of the focus points? "close up the the subject e.g. right next to the picture frame" would indicate it's not. What kit lens are you using?

 

[Big Mike]

The green circle is the focus confirmation light. It flashes when it's in the process of trying to focus and it stays lit when you have achieved focus. If it's flashing and not staying lit, it means the camera is unable to focus.

One reason is that it may be too close. Every lens has a minimum focus distance...you will have to check what yours is, and make sure that you are not closer than that.
Another reason could be a lack of contrast. The AF system needs to see contrast in order to work. To test this out, try to focus on a clear blue sky, or try to focus on a plain, white piece of paper...you will likely not be able to (circle will flash). And if it's just too dark, there won't be enough contrast and you won't be able to focus.

A cool tip about the focus confirmation light is that it works with manual focus as well. Try it out.