Understanding Auto-Focus in N.I.N.A.!
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- เผยแพร่เมื่อ 13 มิ.ย. 2024
- Auto-focusing is one of the most critical functions in N.I.N.A. In this video, I look at the logic used in NINA to determine best focus, and how it is affected by things like focuser backlash.
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Just tried N.I.N.A for the first time mainly because of autofocus. Your video is EXTREMLY helpful! Autofocus worked perfectly the first try! Also, your video on the N.I.N.A. Advanced Sequencer cleared my way through the smoke and it makes perfect sense now. Thanks for the great help!
Thanks for that explanation it confirmed what was going on with my auto focus run .I worked hard to eliminate my backlash and now getting a MUCH better curve. BTW im using trends with hyperbolic and NINA calculates 23 steps of backlash now instead 100+ before. Great Job More Videos Please
Great post! I have been making my way through all of your past posts.
Wow, thank you! Binge watching can be tiring though, take some breaks ;)
you did a fantastic Job with these videos .... please cuiv .. come back ... :)
I am just considering getting an autofocuser and found this very useful and clear. Thanks Cuiv I hope you're doing ok 👍
Thank you Cuiv , many greetings from Greece
I have been fighting a lack of quality automated focus for some time with both NINA, SGP, and APT. All three of these apps use a similar approach, and none were working well for me. After watching your explanation of how NINA auto focus works, I understand the details of the process and how each configuration value is used. NOW I can update my settings (which were way off) and give it a go tonight. Keep these videos coming ... you do excellent work!
Excellent to hear that this is being useful, and thank you for the feedback! I'll go into the actual configuration details in a later video.
@@CuivTheLazyGeek Cuiv ... I have the Celestron Focus Motor on an 8" SCT. This motor takes 1,000 steps to make a full turn of the focuser shaft. I currently have NINA configured with 40 steps and an initial move of 5. Those 200 steps take me out a quarter turn to start the auto-focus process. But I am still not getting a proper V curve. Do you think I should I go father to start? Maybe 5 X 80?
Richard Sauerbrun Hi Richard. I’m about to order this week a Celestron Focus Motor to install on my SCT 9.25. How is overall your experience with this focuser working with NINA? Did your problems get finally solved? Any hint to consider? Thanks!
Outstanding explanation. Thanks for making this video. And thanks for helping me feel better about the ridiculous price I paid for my FeatherTouch autofocuser!
Oh FeatherTouch focusers, like Moonlite, are such a work of art! Never regret getting one! And thanks for the feedback! :-)
Thanks for this video. Very helpful
Cuiv, you are the best!
great!!!!!!! thanks as usual .....
Very informative. Thank you.
As an aside, your English is way better than my French (non-existent!). There's a phrase that you use in a lot of your videos: "this is how it looks like". The correct way to saw this is, "this is what it looks like" or "this is how it looks". Either one of those works.
Please don't be offended, I really do love your videos and your enthusiasm for the hobby! :)
You're right! Thanks for pointing this out - it's a fossilized mistake I make. I am aware of it but I just can't seem to stop myself from saying it...
@@CuivTheLazyGeek old habits die hard. 🙂
In your nina you have the option to figure out your autofocuser's backlash. Why don't I have that option in nina? The button is missing for me.
Thank you Cuiv! I am understand little More. I Will go threw your other vídeos about autofocuse 😀
I hope they help you understand even more!
super explanation :)
Superb!
Thank you!
Cuiv, these are excellent videos! What's the deal with "max increment"? Is this a calculated value? Mine says 999999. Is this a problem?
Max Increment is a value provided by the ASCOM driver of the focuser. It is the maximum number of steps that the focuser can move in one go. If it's 999999 for your focuser, it basically means no limit, and is not an issue!
Well done video Cuiv - I learned a great deal. One question, when I run the autofocus after it gets done with the routine it says it goes back to the original focuser setting. Shouldn't it go to the optimal setting or am I missing something? Your about 12 hrs ahead in Japan so you are most likely setting up so happy imaging. - Cheers
It will only go back to the original focuser setting if it determines that the process has failed - e.g. you ended up with a worse HFR than what you started with. When that happens, it's typically because of uncompensated (or overcompensated) backlash.
Super explained thanks.
To speed up the autofocus, it would be handy if NINA had a "smart" feature. Basically while imaging THAT night, whichever night that may be. The curve it learns from, so it only moves out enough to get the out of focus, and moves into focus. Once it moves enough to where the HFR changes enough say by 1 or 1.5 it goes to the best number vs it continuing. I realize this would be dependent on your setup, but some focusers don't suffer from backlash (like the starlight I use on my tak). I do my autofocus in 125 steps for each point, it nails it every time at the best point (bottom of the curve). I do 125 because I found it gives enough movement to see a difference. I manually focused once in sharpcap, using their tool. Then I went to NINA ran an autofocus, found it landed pretty much where I was in sharpcap (step number). So its pretty darn accurate in NINA, just wish there was a smart feature to speed up focusing.
That would make sense - we already fit a curve (parabolic or hyperbolic) so if NINA were to remember the function it could in theory get to the minimum after measuring a single point. Although it could be mistaken in the direction it takes, so it would still need to double check, and if HFR went up (and there is a potential issue here of getting by mistake where HFR is no longer measurable, or noise is measured instead), go to the other direction. Feel free to suggest it in the NINA Discord, as I haven't done code for NINA in a long time now :-)
Cuiv, I am starting with a DSLR canon. Is there an option to auto focus my telephoto lens within Nina? Thanks!
How did you determine a precise backlash measurement of 93?
It looks like that in NINA the focusing temperature compensation only works with focusers that have an inbedded temperature probe (like the ZWO EAF). I am not using the EAF but another DIY ASCOM focuser (inspired from Julien Lecomte). Does anyone know of a possibility to plug a sort of independant 'ASCOM' temperature sensor that I could use for the same compensation purpose? I am using NINA and happy with refocusing in function of HFR changes, though, so it is more a curiosity question...
I was just looking for something like this, I tried nina AF the other night ( never used autofocusing before) but knew about the V curve. I was surprised as my graph went all over the place in a zigzag fashion, i let it run knowing my original HFR was around 4.4 and it finished on 3.0. so im guessing it stayed on 3.0 when done? but still dont understand why i dont get a curve. thx for the tutorial
That typically comes from a step size that is either too short or too long, or sometimes star detection settings. This could be of help: nighttime-imaging.eu/docs/develop/site/advanced/autofocus/
@@CuivTheLazyGeek thx very much
Could you possibly explain how to setting up NINA with a OAG during imaging when you need to autofocus after filter or temp change? Do you just stop guiding first???
There are options in NINA to stop guiding when autofocusing or filter change!
Don't know if I have to go to a different site for questions?
I have a DC motor Focuser which is recognised in Ascom and operates in APT.
However NINA will not accept it or recognise it?
Is there a way I can use Ascom or change anything.
I,m trying to get the Focus V graph.
Mmmh, it depends on the ASCOM driver - it needs to emulate an absolute position for your DC focuser to work with NINA... Do you get an error message when you connect it or move it? You may want to post on the NINA discord (Discord tab of the NINA website)
And each color will have its own curve. A perfect apochromat would have all the color curves matched.
One question: Im waiting for motorized for my two telescopes. For one one these telescopes I have a reducer. That means I have 3 options for focal view with these telescopes. Is it possible to calibrate this "backlash" for each setup and save this in NINA?
In theory the backlash should be the same, since it's the mechanical steps of the focuser - that being said, you should just use backlash overshoot compensation (which was added later in NINA), so that you can just set a large enough value that will cover all scenarios
@@CuivTheLazyGeek Thank you. Ill check it out. I need to see your videos of how to use NINA first ill guess ;) I actually noticed some profile editing in NINA. Perhaps its possible to setup several setting for each rig.
I thought you were only supposed to set backlash IN OR OUT not both because, they are fighting each other. I saw this in another video. Is that right ?
This is an old video - you have to set both if you use Absolute backlash correction (not recommended) but only one if you use Overshoot backlash correction (recommended). At the time of this video, overshoot backlash correction didn't exist in NINA yet.
12:00 Do not agree. Depends on how finely graduated the gear is. For ZWO EAF 90 is okay.. It's not the end of the world. - For a Pegasus FocusCube2 you can easily have a backlash of 1.000 ! ...but you also have MUCH more overall steps...- Also not the end of the world. - So it all depends. And backlash is NOT something "terrible", it's part of how the focusers are constructed. - As long as you compensate and the relation (!) is okay, it's all good.
My Pegasus autofocuser has 200 steps of back lash (in) and i have to use 125 steps x 4 to get a curve that works.
time for a new one lol
Well, with the overshoot method, I think it can work fairly well! Still, it's amazing how much backlash all those focusers have...!
@@CuivTheLazyGeek yea for 485$ CAD you d think...