From: "gaffney.mark" <markgaffney@mac.com>

Date: February 10, 2008 8:40:30 PM MST

To: Astro_IIDC@yahoogroups.com

Subject: Re: Focusing

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

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

My problem is that I`m not using a lap-top near the telescope when focusing and the 

process can be quite a pain ( walking backwards and forwards from scope to computer to 

consult changes in focus). I was looking for anything which would make it easier- short of 

taking the computer outside on a table or something. Even without computer control a 

remote with long cable to a motor outside might be the only solution. I gather the other 

platform for the Lacey controller is called CCDSoft. Mark.