Macro mode on p&s, what is it?

[Robert Roaldi]

I have been curious about what the macro button (e.g., on p&s digicams) does. In the old days of manual focus 50 mm lenses, I sort of understood it. The macro version "moved out" farther; that is, it had a greater range of focus adjustment. I am not sure that this understanding is correct.

But on digicams (I own a G3) there is a buttom one presses to engage macro mode. I am not talking about the picture mode (on the same dial as Av, Tv, M, etc) but the seaparate button on the back of the camera. When you press this, you can suddenly focus closer, or so it appears to behave.

What is the camera actually doing?  Why doesn't the camera operate in "macro" mode all the time?  The manual doesn't really explain anything.

If there is a site that explains this, I'd appreciate the link. Thanks.

[Gary Brown]

Why doesn't the camera operate in "macro" mode all the time?[a href=\"index.php?act=findpost&pid=99652\"][{POST_SNAPBACK}][/a]

Focusing would presumably be slower if you left it in macro mode all the time, since it would have a wider range to hunt over when focusing, but note also that some cameras assume you're focusing close-up if you're in macro mode and say they won't attempt to focus at longer distances.

Note the focusing ranges shown in these extracts from two different camera manuals.

[boondock]

I have been curious about what the macro button (e.g., on p&s digicams) does. In the old days of manual focus 50 mm lenses, I sort of understood it. The macro version "moved out" farther; that is, it had a greater range of focus adjustment. I am not sure that this understanding is correct.

But on digicams (I own a G3) there is a buttom one presses to engage macro mode. I am not talking about the picture mode (on the same dial as Av, Tv, M, etc) but the seaparate button on the back of the camera. When you press this, you can suddenly focus closer, or so it appears to behave.

What is the camera actually doing?  Why doesn't the camera operate in "macro" mode all the time?  The manual doesn't really explain anything.

If there is a site that explains this, I'd appreciate the link. Thanks.
[a href=\"index.php?act=findpost&pid=99652\"][{POST_SNAPBACK}][/a]

Most P/S cameras have an extra lens that drops in behind the main lens and allows close focus.  So when the macro mode is set the camera can not focus on distant subjects.
B