From: "Milton Aupperle" <milton@outcastsoft.com>

Date: February 9, 2008 11:48:36 AM MST

To: Astro_IIDC@yahoogroups.com

Subject: Re: Focusing

Dear Joe;

Astro IIDC does not support any auto focus hardware (i.e. RoboFocus,

FCUSB, FCUSB2, Optec, JMI etc.) currently.

Most people just focus visually on screen, which is pretty easy to do

under good seeing and at reasonable frame rates. As Alan F. said,

achieving focus under poor seeing is just difficult, no matter what

you do.

Compared to DSLR, you'll have a lot easier time achieving focus with

an IIDC camera, because the frame rates are usually a lot higher and

more responsive. Also you can re-size the video window to zoom in on

features too. Usually I zoom in by 200% for small targets.

The sharpness indicator for Astro IIDC 3 works reasonably well for

lunar and solar imaging, but isn't much use for stellar or small

planetary objects. In Astro IIDC 4, we have added in live FWHM/HFD

numeric and visual indicator display for star objects, which will help

you achieve critical focus.

Most of the focussing aid software available is geared towards

achieving and maintaining sharp focus on a single star. So it

generally is of no use for Solar imaging and of little use for Lunar /

Planetary imaging.

Hope that helps..

Milton Aupperle

--- In Astro_IIDC@yahoogroups.com, "Joe Breault" <joebreault@...> wrote:

I am new to the group, and have just ordered a ¼" chip imagining source

color cam without IR cutoff (firewire) to connect up to my macbook

using the

Astro IIDC software I just downloaded. So I am trying to get

oriented not

having used anything but a DSLR in the past and focused for that using

mechanical focusing aids (http://www.stellar-international.com/).

How does accurate focusing occur with these cameras and Astro IIDC?

Do you

mechanically focus your scope based on the image on the screen in the

software? Or based on other indicators in the software? If by image that

sounds like a challenge for solar imaging when the sun will be

washing out

good screen viewing even with covers. Is there a feedback loop from the

software to control a motorized focuser for telescopes?

Sorry I do not know anything about this yet, just a newbie trying to

understand how this works.

Joe

WB2MXJ.com