"Pete C." wrote in message
.com...

RogerN wrote:

"Jon Anderson" wrote in message
...
On 7/15/2011 11:58 PM, Gunner Asch wrote:

This is where you really need a F32 lens, or add a pin hole adapter to
your working rig.

Seriously.

Not too many of those around I recon, especially for a modern DSLR.
Such a small aperture calls for long exposures or some really bright
lighting. And I'm locked into that lens for any macro work calling for
a
lot of depth of field (relatively speaking). There's -one- potentially
viable lens on ebay right now. A programmable slide offers the
flexibility
to use any lens I can hang off the front of my bellows.
A lot has changed since the advent of high end DSLR cameras....

It just dawned on me, I -think- I still have a copy of the
step/direction
version of the MaxNC software. Put that on a cheap laptop and I've got
my
control. I also have a Sherline Z axis laying around, and some stepper
motors. Just need a cheap driver and a bit of work... Not as clean and
compact as the StackShot, but a hell of a lot cheaper...


Jon

I haven't used them but I've been interested in the Gecko drives, they
have
enough current capability to be useful for many hobby type CNC
applications.
There are also breakout boards for the parallel port to use with stepper
drives. With that kind of setup you could program your camera moves in
G-code and use M-codes to turn on your output to take the picture. For
software you can use EMC2 for free or there are demo versions of other
software that should let you run it in windows if that's what you want.

If you want cheaper there is a unipolar stepper driver chip, uln5804,
they
work up to something like 1.2A and at the time I bought some they were
$4.95
from spHerbach and Rademansp or something like that.

The breakout board I bought for my parallel port was under $30 IIRC, it
seemed worth it to me to try to avoid damaging the PC with a wiring
mistake.
Some better boards are isolated to protect the PC but the cheaper ones
seem
better than trying to wire straight to the connectors.

RogerN

The various Gecko drives work well, but the OP was looking for a
complete single axis control with GPI/GPO, not a standalone drive that
would need a control added.

I think they usually call those an indexer, the ones I've used are pretty
pricey new but possibly available on eBay. The projects I've done used
indexers in combination with a PLC to position axis at certain programmable
positions. Some used servo's some used steppers.

But another way to get better depth of field is if you can find a
telecentric lens but the field of view is about the size of the lens, also
pricey new.

I guess if you had a remote trigger and a hand crank slide (cross slide
vise) it might be good for experimental.

RogerN