Focus problem on Canon S3 IS

Sounds like some combination of field curvature and the usual
performance compromises of an large-ratio consumer zoom lens. Try
stopping down to the smallest possible f/stop using the manual
settings. Ultimately though the S3IS is probably not the best choice
of camera for copy work.

Paul Rubin wrote:
Sounds like some combination of field curvature and the usual
performance compromises of an large-ratio consumer zoom lens. Try
stopping down to the smallest possible f/stop using the manual
settings.

TFT will try that but will have to wait for much better lighting ie
daytime.


Ultimately though the S3IS is probably not the best choice
of camera for copy work.

The camera has other uses, the fault just showed up best in the way
described. I was checking other aspects of the camera too, like
pin-cushion distortion (not much at all, so it seems a good lens from
that point of view).

However, now the subject has been raised, what is the best choice for
copy work? The advantage of the S3 is that Canon software (Zoombrowser
EX) makes it easy to control the camera including the zoom from a
computer.

Is there any other camera which better provides that facility? SFAIUI
there are no SLR cameras with motor zoom, which excludes the most
obvious method of getting a really good computer controlled camera.
Plus, Canon seems to be the only manufacturer which offers a remote
capture facility.

"ironer" writes:
Try stopping down to the smallest possible f/stop using the manual
settings.

TFT will try that but will have to wait for much better lighting ie
daytime.

Just use a long exposure if there's not that much light.

However, now the subject has been raised, what is the best choice for
copy work?

EOS 5D with 50/2.8 EF Macro. Well, you asked.

Is there any other camera which better provides that facility? SFAIUI
there are no SLR cameras with motor zoom, which excludes the most
obvious method of getting a really good computer controlled camera.

I don't understand the importance of controlling the zoom from a
computer. Since you have to put the original under the camera, you
should also be able to set the zoom hand. But you should not use a
zoom at all for this. Move the camera up and down on the stand
instead. There are actually motorized copy stands available but it
wouldn't have occurred to me to bother with one. I don't know if any
are computer controlled.

Paul Rubin wrote:
/snip/

I don't understand the importance of controlling the zoom from a
computer.

thnx for the advice: the purpose is to control the camera from a
distance & select shots using the computer directly as the monitor.
That seems to me a far better method of controlling the camera and
assessing a picture than any awkwared squinting through viewfinders.
For instance the camera might be in an inconvenient position. It is not
just for copy work.

You can do all this with many camcorders, but none SFAI am aware, yield
much definition as measured in megapixels.

I'm looking for a camera which will 'do the job' - cost is not an
overwhelming issue. I am just surprised the choice of camera is so
limited.

Hope that explains. Thanks.

"ironer" writes:
I'm looking for a camera which will 'do the job' - cost is not an
overwhelming issue. I am just surprised the choice of camera is so
limited.

You might have better luck with a camera whose zoom range is shorter.
Maybe a G6. I don't know about the computer controlled zoom issue. I
get sort-of-usable results with my A530 but am looking towards some
kind of DSLR setup in the long term.

Really serious professionals use large format scanning backs with five
figure price tags and acquisition times on the order of one minute per
frame.