On Tue, 05 Feb 2013 15:20:56 -0800, Searcher7 wrote:

I haven't gottena all of the particulars worked out yet, but I am
working on designing a camera stand and trying to decide on the best
material to make most of it out of.

I'm not trying to reinvent the wheel, but a special project makes it
necessary to be able to take a series of as many as 180 equally spaced
photos across a 45° swing and be be able to do the same again without
any perceptable deviation.

In other words if I take a picture at 12-1/4° and then continue turning
the camera all the way to the end, when I return the camera to the same
spot I took the photo I will need to be able to stop and lock the camera
so that the photo next photo I take there is *exactly the same as the
previous one I took.

This is not plausible with conventional camera stands. So I'm trying to
decide on the best metal to make the moving parts out of. A metal that
will best retain it's dimensions under changing temperature conditions.

To start. Would cast Iron be a plausible candidate?

Well, if you really mean exact, then it can't be done.

Off by one pixel? Off by ten pixels? What's _really_ acceptable? And,
how much angle does a pixel subtend, on your system?

If I were going to try this, if I were going to make just one, and if I
felt my time was worth anything at all, I'd base things on a rotary
table. You can get them with scary accuracies, if you're willing to
spend money on it.

Then, depending on the accuracy I _really_ needed, I'd decide what I
needed to mount it on.

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com