Auto focus

[Rodd]

I want to try auto focus but am not sure what I need  for my particular set-up/style.  I use Maxim DL, I have an Ascom compatible focus driver and the stepper motors installed on both my scopes.

Currently, I program a sequence in 1 filter at a time.  After a couple of subs are downloaded, I check FWHM/eccentricity values and manually refocus using a B-Mask when FWHM values maintain an upward trend for more than 2 subs.  I usually slew to a bright star near my target.  My focus is pretty good most nights.  But I would like to try autofocus.  I want to be able to program the autofocus to run its routine at a specified time (like after every 20 minute sub, or after 2-3 10 minute subs).  But I don't want to have to slew to a focus star and slew back to continue imaging--then I will have framing/alignment issues (I manually frame my images as well.  Takes only a few minutes, but is necessary as my GOTO accuracy is not spot on as my PA is not spot on because I have a temp setup).  This way--I can program a 4-5 hour sequence and not have to keep running to the scope to check focus every 20 minutes.

Is there a software I can get that will focus on the imaging FOV without slewing to a star, can be programmed to run at a specified time, and that is compatible with Maxim DL?

 

Thanks

Rodd

[Starflyer]

Three words; Sequence Generator Pro.

It's not compatible with Maxim but will replace it, and for much less money. I've used Maxim in the past and wouldn't go back to it now. Amazingly accurate auto focus that uses the star field you're already imaging, timed or based on temperature change.  Seamless plate solving for getting you centred within pixels night after night and superb PHD2 integration.

I know it doesn't answer the question you asked, but having done it both ways I'd go with SGP every time.

 

Cheers,

Ian

[Rodd]

56 minutes ago, Starflyer said:

Three words; Sequence Generator Pro.

It's not compatible with Maxim but will replace it, and for much less money. I've used Maxim in the past and wouldn't go back to it now. Amazingly accurate auto focus that uses the star field you're already imaging, timed or based on temperature change.  Seamless plate solving for getting you centred within pixels night after night and superb PHD2 integration.

I know it doesn't answer the question you asked, but having done it both ways I'd go with SGP every time.

 

Cheers,

Ian

No--I run a dual chip camera and PHD2 requires a plug in that necessitates a delay in the guide commands.  I won't quit Maxim and go to SGP just for auto focus.  Not when I can get CCD autopilot and do the same thing.  I am through with jumping ships.  I jumped to Maxim and am happy with it.

[sloz1664]

Hi Rodd,

MaximDL has it's own autofocus routine although the majority of MaximDL users tend to use FocusMax. There is a cost now for this excellent software but you may be able to search for the free version 3 software. It may still be available.

 

Steve 

[Martin-Devon]

I use Maxim and am very happy with it - for focusing I also use Focusmax - as mentioned above you can still get access to the free version 3 of Focusmax if you google for it. Focusmax can initially be a bit tricky to set up, but once you are there it works extremely well.

[Rodd]

3 hours ago, Martin-Devon said:

I use Maxim and am very happy with it - for focusing I also use Focusmax - as mentioned above you can still get access to the free version 3 of Focusmax if you google for it. Focusmax can initially be a bit tricky to set up, but once you are there it works extremely well.

Do you have to slew to a star to focus and slew back to the target to image--or can you focus on the target FOV?  Also--can you program it to initiate automatically?  or do you have to manually initiate the focus routine.

[Martin-Devon]

For LRGB there's always a star of sufficient magnitude in the frame to get focus with Focusmax. For narrowband you'll need a magnitude 3-4 star for focus, these are often in the frame, but if not I just manually or automate a slew to the nearest star that has this. Focusmax incorporates a feature called 'AcquireStar' which will also find the nearest star for a set magnitude. I control my imaging runs with CCD Commander (which works via Maxim) and routinely run fully automated sessions which includes repeated re-focusing at set intervals during the run. Focusmax will not run by itself in automated mode, you can control it manually and it's easy to run like this, but if you want to get into automation for Focusmax you'll need to incorporate CCD Commander or ACP. Sequence Generator Pro (SGP) is not compatible with Focusmax, nor Maxim, but has it's own focusing system. I've tried both and personally I prefer Focusmax, but other folk may prefer SGP. In addition I much prefer guiding using the system in Maxim rather than PHD, which is the only option for SGP.  I'm somewhat surprised more people don't use CCD Commander for automation - it's very easy & intuitive and there are some excellent tutorials on YouTube by Dean Salman on how to set it up and run it.

[Rodd]

27 minutes ago, Martin-Devon said:

For LRGB there's always a star of sufficient magnitude in the frame to get focus with Focusmax. For narrowband you'll need a magnitude 3-4 star for focus, these are often in the frame, but if not I just manually or automate a slew to the nearest star that has this. Focusmax incorporates a feature called 'AcquireStar' which will also find the nearest star for a set magnitude. I control my imaging runs with CCD Commander (which works via Maxim) and routinely run fully automated sessions which includes repeated re-focusing at set intervals during the run. Focusmax will not run by itself in automated mode, you can control it manually and it's easy to run like this, but if you want to get into automation for Focusmax you'll need to incorporate CCD Commander or ACP. Sequence Generator Pro (SGP) is not compatible with Focusmax, nor Maxim, but has it's own focusing system. I've tried both and personally I prefer Focusmax, but other folk may prefer SGP. In addition I much prefer guiding using the system in Maxim rather than PHD, which is the only option for SGP.  I'm somewhat surprised more people don't use CCD Commander for automation - it's very easy & intuitive and there are some excellent tutorials on YouTube by Dean Salman on how to set it up and run it.

Thanks--good news regarding Maxim--I like it too.  Guiding is great.  I was under the impression that CCD Autoppilot will allow me to automate my focus routine.  Autopilot is only $149 (or something like that), while CCD commander is allot more I think.  I had a convo with Tim Pucket of Cyanogen (Maxim), and he said that Maxim "was" focus Max.  It used to be but then broke off to be a stand alone--he forgot this I guess because I writes his own code for everything he said.  Would I really need to obtain focus max--or will the focus routine in Maxim do the same things?  The reason I am interested in this is because right now I use a B-mask and am very careful and get pretty good focus--but I have to be at the scope and initiate the slew, then put on the mask--focus, take it off, slew back (frame!) then image.  Therefor, my 10 image sequence is really only a 2 image sequence.  I do not want to have to be at the scope to initiate focus--even if it means getting better (a little better) focus--because then I can't really program a sequence.  I want to program a 10-15 image sequence, program it to refocus after every 20 minute sub and not have to interfere--but i don't want to spend $700 to do it.   Can't I just get CCD Autopilot?

[Martin-Devon]

Rodd, the CCD Commander package is $99 see:
http://www.ccdcommander.com/

I've tried using the in-built focusing programme in Maxim, but not had much joy, but then again have also not spend a lot of time trying to optimize it either. However, Steve Richards (aga Steppenwolf on SGL and top class imager) does use the Maxim focus system very successfully - check out his recent posts. If you want to automate though, you'll still need something extra on top of Maxim. The slew to a focus star, then slew back to the imaging frame, is all taken care of effortlessly in the automation packages with plate-solve software and takes seconds not minutes to do this and is extremely accurate and reliable. 

CCD Autopilot is old software now, but by all means check it out. CCD Commander offers a free 45 day trial period, is easier to use, so you could also see how you get on with this. 

 

[Rodd]

6 minutes ago, Martin-Devon said:

Rodd, the CCD Commander package is $99 see:
http://www.ccdcommander.com/

I've tried using the in-built focusing programme in Maxim, but not had much joy, but then again have also not spend a lot of time trying to optimize it either. However, Steve Richards (aga Steppenwolf on SGL and top class imager) does use the Maxim focus system very successfully - check out his recent posts. If you want to automate though, you'll still need something extra on top of Maxim. The slew to a focus star, then slew back to the imaging frame, is all taken care of effortlessly in the automation packages with plate-solve software and takes seconds not minutes to do this and is extremely accurate and reliable. 

CCD Autopilot is old software now, but by all means check it out. CCD Commander offers a free 45 day trial period, is easier to use, so you could also see how you get on with this. 

 

Wow!!! CCD commander is only $99!  I did not know this.  This is my best option.  Thanks for helping.  of course--I have to take time away from  imaging to get everything working.  This has been my main stumbling block with installing and/or using many things (Maxim's auto focus, Max point, Pempro  etc).  I am somewhat daft when it comes to learning curves.  Maxim and Pixinsight nearly killed me.  It will be sparkling clear out, and I will just not be able to forgo imaging to learn something new.

[russellhq]

If you had the time and determination, I'm sure you could write a script that would be called after every capture in DL to run FocusMax. I've been dabbling with this for a bit but don't have anything yet that would help. The focusmax help file has a very good section on scripting.

[Rodd]

9 minutes ago, russellhq said:

If you had the time and determination, I'm sure you could write a script that would be called after every capture in DL to run FocusMax. I've been dabbling with this for a bit but don't have anything yet that would help. The focusmax help file has a very good section on scripting.

Russell--talk about tipping the apple cart!  I want to simplify, not complicate.  Drivers, scripts, blah blah blah.  Its all I can do to make sure my rig actually works when I turn it on!!!  Seriously.  I've been doing pretty good lately--consistently working, that is, when some setting in my ASCOM driver doesn't get changed somehow--maybe by Windows updates--not sure.  At those times, it takes me a couple of hours to convince my mount that Vega is NOT in China.  Learning how to use autofocus will require me to lose at least 4 hours (or more) of imaging time (I'm a slow learner).  I can never bring myself to do this because imaging time is so rare these days due to crappy weather.  Maybe if I lived in the desert and could image every night I would not hesitate.  The same is true for Pempro, Maxpoint, etc.  I have them all--never used any of them.  But Scripts?  

Rodd

[Gina]

Maxim is expensive Windows software - I'm going for totally free Linux software

[Davey-T]

Maxim DL 6.XX introduced a scripting thingy which I've used for batch processing images, don't know how far it's capabilities stretch though.

Just getting to grips with Maxim / FocusMax 

Dave

[russellhq]

15 minutes ago, Davey-T said:

Maxim DL 6.XX introduced a scripting thingy which I've used for batch processing images, don'y know how far it's capabilities stretch though.

Just getting to grips with Maxim / FocusMax 

Dave

There's a script option in version 5 as part of the camera control. If you look under the autosave option in the camera contol window, you can select a script to run after every exposure. It shouldn't be much of a task to run focusmax after each each exposure.

[Rodd]

15 minutes ago, russellhq said:

There's a script option in version 5 as part of the camera control. If you look under the autosave option in the camera contol window, you can select a script to run after every exposure. It shouldn't be much of a task to run focusmax after each each exposure.

The problem is learning focus Max--though maxim has its own focus routine as well (which is better)   To learn how to effectively autofocus--which for me means being able to program an initiation command, as I do not want to have to manually initiate autofocus, will take time.  I manually focus now and one of the big pluses as far as I am concerned is having the software initiate the autofocus and return to imaging without me having to initiate.   I also want it to focus on the FOV and not have to slew--because then I will have framing issues I am sure. At present when I focus I slew to a star nearby then slew back and have to spend 5-10 minutes returning the scope to the precise same FOV.  And around and around we go.  I am pretty diligent when it comes to focus-using a B-mask I get pretty close.  The other night I hot 2.1 FWHM--which for my skies can't be far from perfect.  So its not necessarily better focus I am after--though autofocus will no doubt be more consistently good, but rather the ability to not have to manually initiate it.  If I knew what I know now when i bought my equipment, I would have set up an on axis guide system, which provides for continual, real time focus, so no more stopping imaging to focus.  Unfortunately the system is expensive and heavy, and it would mean retooling both my scopes--and the C11 edge is right at the mounts limit as far as weight (AP Mach 1).  

[russellhq]

The Autofocus routine in MaxIm DL looks like it can be scripted as well. If you are already familiar with MaxIm's autofocus routine, you should be able to run it automatically after each exposure.

[Rodd]

23 minutes ago, russellhq said:

The Autofocus routine in MaxIm DL looks like it can be scripted as well. If you are already familiar with MaxIm's autofocus routine, you should be able to run it automatically after each exposure.

I am only familiar with it to say that I know it is there.  Never used it.  I guess I should try.  I have no clue though.  Maybe on a hazy, poor night when imaging is out but stars can still be seen, I will wade into the pool.  But I have been told that I need something like CCD commander on top of Maxim in order to automate the auto focus initiation.  You think that incorrect and that I can do it with a script inside Maxim?

[steppenwolf]

I'm late to this thread but can confirm that I use the built in focus routine in MaxIm DL and have found it to be much more reliable than FocusMax for my fully automated imaging sessions. However, there are two caveats that affect you:-

1. I use CCD Commander to initiate a focus request every 'n' frames

2. I do automatically slew to a 'test' star of my choice and then slew back again to continue imaging

item 1 just makes it all sooo simple and at a very reasonable cost.

Item 2 seems to be an issue for you but really, it shouldn't be because automated plate-solving (care of CCDCommander) will ensure that your framing is perfect every time!

Something to bear in mind here so that you are forewarned - the built in focuser routine in MaxIm requires that you use an 'absolute' encoded focus motor whereas FocusMax will allow the use of a more simple motor drive. Have a look at the MaxIm help files for more detail on this aspect of automated focus.

If you have to use FocusMax because you don't have an absolute encoder then it can be used in the same manner as I use the MaxIm routine by ignoring the 'AcquireStar' feature - and it was this feature that gave me the most angst anyway!!

[Rodd]

2 minutes ago, steppenwolf said:

I'm late to this thread but can confirm that I use the built in focus routine in MaxIm DL and have found it to be much more reliable than FocusMax for my fully automated imaging sessions. However, there are two caveats that affect you:-

1. I use CCD Commander to initiate a focus request every 'n' frames

2. I do automatically slew to a 'test' star of my choice and then slew back again to continue imaging

item 1 just makes it all sooo simple and at a very reasonable cost.

Item 2 seems to be an issue for you but really, it shouldn't be because automated plate-solving (care of CCDCommander) will ensure that your framing is perfect every time!

Something to bear in mind here so that you are forewarned - the built in focuser routine in MaxIm requires that you use an 'absolute' encoded focus motor whereas FocusMax will allow the use of a more simple motor drive. Have a look at the MaxIm help files for more detail on this aspect of automated focus.

If you have to use FocusMax because you don't have an absolute encoder then it can be used in the same manner as I use the MaxIm routine by ignoring the 'AcquireStar' feature - and it was this feature that gave me the most angst anyway!!

I have the Starlight instruments Boss II kit and starlight instruments stepper motors for both the Televue (made specifically for the TV scopes) and the C11 Edge.   Is this what you mean?  If so--I do not have a problem getting CCD commander ($99).  But why is a manual slew necessary--can't it use the FOV?

[Rodd]

6 minutes ago, steppenwolf said:

I'm late to this thread but can confirm that I use the built in focus routine in MaxIm DL and have found it to be much more reliable than FocusMax for my fully automated imaging sessions. However, there are two caveats that affect you:-

1. I use CCD Commander to initiate a focus request every 'n' frames

2. I do automatically slew to a 'test' star of my choice and then slew back again to continue imaging

item 1 just makes it all sooo simple and at a very reasonable cost.

Item 2 seems to be an issue for you but really, it shouldn't be because automated plate-solving (care of CCDCommander) will ensure that your framing is perfect every time!

Something to bear in mind here so that you are forewarned - the built in focuser routine in MaxIm requires that you use an 'absolute' encoded focus motor whereas FocusMax will allow the use of a more simple motor drive. Have a look at the MaxIm help files for more detail on this aspect of automated focus.

If you have to use FocusMax because you don't have an absolute encoder then it can be used in the same manner as I use the MaxIm routine by ignoring the 'AcquireStar' feature - and it was this feature that gave me the most angst anyway!!

And 1 more thing (sorry)  why program it to run the focus routine every n frames when you have to do a manual slew?  That means you have to manually begin the refocus--so I don't understand why you need to program it to do it after  say 3 10 minute frames.  If you are not at the scope--it won't do it?

[Rodd]

10 minutes ago, steppenwolf said:

I'm late to this thread but can confirm that I use the built in focus routine in MaxIm DL and have found it to be much more reliable than FocusMax for my fully automated imaging sessions. However, there are two caveats that affect you:-

1. I use CCD Commander to initiate a focus request every 'n' frames

2. I do automatically slew to a 'test' star of my choice and then slew back again to continue imaging

item 1 just makes it all sooo simple and at a very reasonable cost.

Item 2 seems to be an issue for you but really, it shouldn't be because automated plate-solving (care of CCDCommander) will ensure that your framing is perfect every time!

Something to bear in mind here so that you are forewarned - the built in focuser routine in MaxIm requires that you use an 'absolute' encoded focus motor whereas FocusMax will allow the use of a more simple motor drive. Have a look at the MaxIm help files for more detail on this aspect of automated focus.

If you have to use FocusMax because you don't have an absolute encoder then it can be used in the same manner as I use the MaxIm routine by ignoring the 'AcquireStar' feature - and it was this feature that gave me the most angst anyway!!

And one more time....again sorry.  But my goal is to program a 15, 20 minute sub sequence with refocusing after every 2 subs, and then not have to touch the scope until it is done.  I will hover of course, but I want it to do it without me having to do anything but `press  "start".  So far, I can do this--except for focus.

[steppenwolf]

The slew to the 'focus' star is NOT manual, CCDCommander tells it to do it automatically! Once I start an imaging session, I can go to bed - and I do. In fact, my recent NGC7000 image posted a couple of weeks ago was programmed in advance and I wasn't even present at the start.

I am only on an iPhone at the moment so cannot confirm whether your focuser system had absolute encoders or not but your supplier will be able to confirm this.

[Rodd]

3 hours ago, steppenwolf said:

The slew to the 'focus' star is NOT manual, CCDCommander tells it to do it automatically! Once I start an imaging session, I can go to bed - and I do. In fact, my recent NGC7000 image posted a couple of weeks ago was programmed in advance and I wasn't even present at the start.

I am only on an iPhone at the moment so cannot confirm whether your focuser system had absolute encoders or not but your supplier will be able to confirm this.

Thanks abunch Steve.  Read your book by the way.  Wish I had read it earlier.  I think the Boss II kit and associated stepper motors are absolute.  I bought them with autofocus as the primary concern.  I know they are digital.  I guess I should install the motor on the TV like I did on the C11Edge (I have a crayford on that so i can lock the primary down) and give Maxim's focus routine a whirl.  If I can get it to work I can add CCD Commander easily enough.  Even with a manual initiation, if focus is much superior, it will be worth it.  I am manual now so it would not be a greater burden.  But tonight is supposed to be crystal clear for the first time in 2 weeks--not sure I can concentrate when the imaging minutes are slipping by (hours no doubt).   Like polar alignment tweeking in Pempro and Maxpoint--its something I wish I could do in the day time!

 

Thanks---Rodd

[steppenwolf]

I hope the MaxIm focus routine works for you. There are a couple of settings that you need to get right to ensure that all is well but the most important one is the step size (sorry doing this from memory so can't tell you which dialogue box) but don't think it doesn't apply to you ;-). You are aiming for about a 1.5 difference in HFD figures between focus steps as the system creates its 'V' curve. You cannot rely on the figure produced automatically from the ASCOM driver as the system has no knowledge of your actual mechanical focuser arrangement. The help file will tell you how to simply measure this using a ruler to check overall movement for 1,000 or more steps and then how to convert this to micrometers per step.

I would also recommend that you arrange for final focus movement to be IN to take up any backlash. The backlash should also be entered in the system. 

To determine backlash, use the motor to extend the focuser OUT, say, 100 steps then carefully rest you finger on the drive shaft from the motor and move the motor IN, one step at a time, counting each step until you feel the shaft move - works for me! Don't rely on a visual assessment here, touch is far more sensitive and accurate.

Good luck!