On Wed, 15 Jun 2005 19:56:16 +0100, lok
(Tony Hodge) wrote:

Another poster has commented on focussing - I find this very hard wioth
just a simple rack and pinnion focus track (and no 'fine focus' like I'm
used to on microscopes.

Keep it up, I'm sure we'll both improve!

Accurate focussing is quite tricky even for seasoned imagers. What
looks fantastic on the camera's preview screen can often be a
disappointment when blown up on a computer screen. One thing you can
do to gain confidence that your gear can actually do the business -
deliberately defocus a tiny amount - just enough so that you can see
that the moon's actually out of focus. Note the direction you need to
turn the focussing knob to achieve focus and take a series of images
moving the knob towards and through focus by the smallest amount you
can achieve each time. Take a couple (or three) images at the same
setting to hopefully eliminate wobble/wind/etc. effects. When you
review the pictures after the session, look for the sharpest image in
the set. If the sharpest isn't up to much then you may have an optics
issue.

Knowing you can achieve accurate focus with your set-up will help to
increase your confidence enormously.

For stellar images with the 350D try something like DSLRFocus
(www.dslrfocus.com).


--
Pete
http://www.digitalsky.org.uk
Global Projects - http://www.globalobservers.net