From: "Doug" <dwd3m@virginia.edu>

Date: June 1, 2007 8:19:22 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: Any future plans to add focus control?

Actually Milton, I had far more modest goals in mind. I simply am interested in a way of 

controlling focus using a Mac interface - not true  robotic control or smart focus 

estimation.  In essence, my goal is to use the Mac in place of my current focus drive 

control box (i.e., for the TV FocusMate Driver, simple DC motor not stepper) with a 30-60 

fps firewire camera so that I can get near "real time" focus for image capture with Astro 

IIDC.  My interest is solar imaging - I just want to sit inside my house tethered via Mac to 

my scope and control the GM8, my camera, and the focus on my scope.  Astro IIDC lets me 

do the first two and I think the Shoestring Focuser and FCUSB should allow me to do the 

latter.  Now if I can only figure out a way to adjust the tuning ring on my H-alpha filter 

remotely......

--- In Astro_IIDC@yahoogroups.com, Milton Aupperle <milton@...> wrote:

Hi Doug;

We will (have) added Full Width Half Max and Half Flux Diameter as a  

Single Star Sharpness estimator for focus in Version 4 (which runs at  

60 fps on a G4 1.25 gighz LapTop). I don't know if we will add  

support for 3rd party focus motors or not as there has been no  

requests for supporting them. Most of them are expensive to acquire  

(i.e. RoboFocus, JMI Smart Focus, Optec Focuser etc.) and only work  

with specific focusers too. Doing trial and error development with  

remote hardware takes weeks of back and forthing time and I generally  

will not do it anymore excpet if I have the hardware in house.

I'm also somewhat skeptical of how well they work except if you are  

living on top of a mountain or are way south of the Jet Stream.  

Watching the FWHM / HFD numbers jump around when tracking a bright  

star under what I consider "good" conditions makes me think it would  

burn out the focus motor in the course of an observing session :)

HTH..

On 1-Jun-07, at 1:51 PM, Doug wrote: