On Sat, 12 Jun 2010, Philip Pemberton wrote:
> I once saw a digital camera wit ha 2-position
focus control (normal and
> close-up). it dit appear to move the lens on a focussing mount. There was
> no autofocus, or anything like that.
Anything that increases the lens to sensor distance will decrease the
distance between camera and subject. Short focal length lenses need less
movement, and have a wider range of "acceptable" focus.
That's pretty much what these were, only without
the focus switch.
> I wonder if you could use front-of-lence closeup
lenses? The resolution
> of the sensor in such a caerma is not going to be great, so I doubt you'd
> notice any loss of qaulity.
Yes. With on the front of the lens "close-up" of "portra" lenses, it
will
focus on a closer distance. With some loss of lens sharpness.
Probably. The macro mode on most decent digicams
should do it as well.
The "slose-up" lenses will work on the INdecent ones even without a
"macro" (close-focussing) mode.
If you need good quality pictures of paperwork or circuitboards, get
something that will focus close, preferably with a "flat-field" lens (such
as a cheap enlarger lens)