From: Milton Aupperle <milton@outcastsoft.com>

Date: February 10, 2008 8:08:41 PM MST

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Re: Focusing

Hi Mark;

On 10-Feb-08, at 7:34 PM, gaffney.mark wrote:

Milton, Perhaps you`re right, the camera is in different focus than it is through the 

eyepiece for instance. I`m unsure if that`s the case what these focusers normally use as a 

guide or if the two interfaces( the focuser and the Firewire camera) are matcheable?

They have nothing to do with each other. The focuser motor doesn't even know if a camera is attached let alone what it is.

Would  

Robofocus or FocusMax be normally using the usb camera window in Maxim DL or 

something?I wonder if adjustments can be made using RF or FM for the discrepancy?

Robofocus spins a motor that turns the Rack & Pinion gears that moves the focuser - they have no idea if they are in focus or not. They can be configured to correct for temperature changes if they are calibrated, but it doesn't focus itself.

The camera simply transmits frames of video - it has no idea if there is even a telescope attached let alone whether it's in focus or not.

FocusMax is a software Plugin for MaxiM-DL, so it's really running within MaxiM-DL and is the software that takes images from the camera (captured by Maxim-DL) and then adjusts the motors on "Robofocus" to make it focus on a single star.

If 

it`s impossible to  link the two it`ll save me the expenditure at least. Mark.

Myself, I wouldn't be buying a focuser unless I was doing DSO's and then I'd only use it for temperature compensation. And your under estimating your ability to get sharp focus simply by twisting the knobs, especially for solar, lunar and planetary imaging.

The other thing is that all of the focusers expect you to use a single star. They are basically useless for Solar, Lunar and larger planetary disks in auto focus modes. And moving a large distance off target to a bright star for focus may cause the mirror to "shift", which will completely throw off your sharpness you just did.

HTH..

Milton J. Aupperle