Focusing

[tbaehnck]

Hi all,

 

one question about focusing with sequenz. Are the units for the offset really in mm? And in the autofocus menu also?

I asked beause there is no chance to tell sequenz the stepsize of my hires stepper? So how sequenz will do know how many steps are necessary i.e. 2mm. ?

 

Or are you using all the offests in maxmDL?

 

Thanks and best regards

Thomas

[lukepower]

Thomas,

sequence doesn't know

It's that easy. I dunno if it calculates it using the focuser driver or if it is a remainder of times when Sequence only supported the ASA focusers, though...

[MarkS]

Hi Thomas,

 

I ran into the same problem with the Microtouch/FocusMax set-up on my refractor.

 

I found that it was necessary to trick Sequence into moving the focus by the right distances.

I measured how many steps the Microtouch needed to move 1mm. In my case it moved 72mm for 20,000 steps, ie 0.36mm per 100steps.

I then established that Sequence thinks 100 Microtouch steps is 0.1mm, so that I had to set the coarse and fine AF steps in Sequence to 1/3.6 times the actual value I wanted.

 

Using this as a starting point, I then altered the steps until I got the right HFD shifts for coarse and fine shifts.

 

This has given satisfactory AF performance during Sequence runs.

 

With the focus offsets, I just used what Sequence AF measured, and it worked OK.

 

Hope this helps!

 

Mark

Edited September 14, 2016 by MarkS

[nakbrooks]

Excellent tip to add to the Wiki Mark !

[Corpze]

Hi Thomas,

 

I ran into the same problem with the Microtouch/FocusMax set-up on my refractor.

 

I found that it was necessary to trick Sequence into moving the focus by the right distances.

I measured how many steps the Microtouch needed to move 1mm. In my case it moved 72mm for 20,000 steps, ie 0.36mm per 100steps.

I then established that Sequence thinks 100 Microtouch steps is 0.1mm, so that I had to set the coarse and fine AF steps in Sequence to 1/3.6 times the actual value I wanted.

 

Using this as a starting point, I then altered the steps until I got the right HFD shifts for coarse and fine shifts.

 

This has given satisfactory AF performance during Sequence runs.

 

With the focus offsets, I just used what Sequence AF measured, and it worked OK.

 

Hope this helps!

 

Mark

Hi, I have a similar problem;

My scope is a f3,4 which have a critical focus zone (CFZ) of 27 microns.

My sesto senso / Starlight feather touch combo has a resulotion of 0,0007423mm per step  (should be 0,7 microns right?)

32000 steps is a full rotation of the starlight focuser, which is 23,7536mm

So, in that case, 1mm should be 1347 steps (32000 steps divided with 23,7536mm)

 

What values for Fine and Coarse do i have to have for the auto focus routine to runs optimal?

Is Sequence set to assume 100 steps is 1mm?

Edited October 15, 2019 by Corpze