The Ultimate Auto Focus Tutorial: Crisp and Clear Images Made Easy with NINA

[@gr0uch02a]

This is easily the best explanation of AF in NINA that I have seen. It cleared up so many questions I had about the process. Thanks Tony!!

[@franks2725]

Thanks for another great video. I'm slowly working my way through your videos and glad I found this one (I'm setting up my latest rig; a Rok135). Your approach to determining backlash was a lightbulb.

[@Hidden.Light.Photography]

Thank you! This is a great piece of equipment to have and very useful, but setup can be a bit tricky sometimes. I’m very happy this helped :)

[@scorpio1155]

Thank you producing a very imformative video. I've been imaging for years with SGP and would like to give NINA a try. From this video, I learned things about focus that I did not know - Heck, maybe you can teach an old dog new tricks. I've seen that flattened section between the first and second exposures before, but didn't know what it was... THANK YOU! I'm looking forward to checking out some of your other videos.

[@HydrogenAlpha]

Better to use the Backlash Out setting, especially if you have a heavy camera which points down when the telescope points up (not necessarily the case for a Newtonian etc). You want the first large movement to overshoot outwards, and then the subsequent corrections to be inward. That way, when the focusser reaches its position, all of the gears and connections in the focusser train will be pressed up against each other, with gravity holding them there.

[@Hidden.Light.Photography]

I love this and very good point! This is one of those things not many think of and amazing information for the community :)

[@larrychristianson2244]

Always very descriptive and informative.

[@Hidden.Light.Photography]

Thank you! Are you setting up auto focus for the first time?

[@larrychristianson2244]

@@Hidden.Light.Photography Not yet doing AP; considering it. Trying go get a feel for the equipment, tools and challenges involved. I've watched a lot of YT AP videos, and yours are always have the best descriptions and procedures. I do not understand why you don't have a lot more subscribers, your content is far better than most that I see.

[@Hidden.Light.Photography]

Thank you for that! The channel is still in the early stages, but hopefully continues to grow :) Do you have any specific equipment you’re looking at or tossing around?

[@4auswanderer]

Thank you very much for this video. I need a clear sky now to set all up 🙂

[@Hidden.Light.Photography]

I’m glad you enjoyed it! Let me know if you run into any issues and need help.

[@Hidden.Light.Photography]

I’m glad you enjoyed it! Let me know if you run into any issues and need help.

[@W_Parker_Astro]

Thanks for this video, following your guidance has eliminated my autofocus frustrations 👍🏻😃

[@Hidden.Light.Photography]

Perfect, I am very happy to hear! Let me know if I can help you with anything else.

[@dankahraman354]

Excellent tutorial

[@Hidden.Light.Photography]

Thank you! Are you currently using auto focus or looking into it?

[@dankahraman354]

@@Hidden.Light.Photography I have installed 3 ZWO EAFs on 3 of my scopes

[@Hidden.Light.Photography]

Awesome! I know a common complaint with these is the backlash, however, I think they do an amazing job nonetheless. It’s so nice being able to let the scope run and it takes care of the focus on its own.

[@dankahraman354]

@@Hidden.Light.Photography I have R squared equal to 1 in two of my scopes. The C11+Hyperstar had large values to eliminate the backlash. I have ~150 as the step size to steepen the curve so that all the focus points lie on the hyperbolic curve. Here too I have R squared equal to 1. The third scope will have some of the aluminum sanded off the ZWO connector as it is rubbing on the Wega collar. The Wega collar is from Teleskop Service in Germany

[@Hidden.Light.Photography]

That is absolutely perfect R squared, very well done!! I was working on a C11 hyper star and found it also needed very large step and backlash values. Nothing wrong with that as long as it works, right? :)

[@3thomasH]

I just set up my autofocuser and to get the flats on the shaft to line up I needed to move the focuser about 10mm from best focus when I was doing manual focusing. My question is: what settings should I use to get close enough to focus to start an autofocus run? I am using a Pegusus focuser. Tom

[@Hidden.Light.Photography]

That is an amazing question! You are 100% good with what you did :) All you want to make sure of is that there adjustment room on both sides. From there, use the manual focus controls to move the focuser into position to achieve focus. Make sure to finish calibrating and you are good to go :)

[@dankahraman354]

I am getting pinpoint stars even with my slightly optically misaligned f/4 Newtonian. My R^2 was 0.99. Do I have to run Autofocus every time I connect the AF or is this now embedded into the set up? Thank you VERY MUCH!

[@Hidden.Light.Photography]

That’s a very good R^2!! I always run auto focus before an imaging run to ensure I’m properly in focus and this is due to temperature change and how the OTA is affected. The last step position of the focuser will be known, but there is always a variance due to temperature :)

[@dankahraman354]

What about setting parameters for an imaging session such as temperature compensation, number of times to run autofocus during either every 30 minutes or after so many subs? This is in the drop down menu under Autofocus in Sequencing

[@Hidden.Light.Photography]

Very good question! I used to run after so much time, however this led to unnecessary auto focus runs. Here’s what I mean and the easiest way to explain/understand it. When you line up your camera sensor the focal plane, you are at focus. There is a zone called the critical focal zone and this is your camera sensor perfectly lined up with the focal plane. Being here is the smallest your stars can be (lowest possible HFR number). As the night goes on, the reason you need to refocus is temperature. As the temperature drops, your OTA shrinks which in turn, pulls the focal plane away from the camera sensor thus the camera sensor leaving the critical focal zone. The same goes for temperature increasing, but the OTA expands. So why not do auto focus after temperature change or number of frames? Frame count won’t affect the critical focal zone. As I mentioned earlier, temperature causes this. Running auto focus after temperature change would be good, but what is the expansion/contraction rate of your OTA with specific temperature changes and how will that affect your HFR? Running with HFR increase is monitoring the HFR of the stars which is a direct reflection of temperature change and doing it this way will ensure your HFR (overall focus quality) doesn’t get too bad by a miscalculation. I hope that makes sense and helps :)

[@dankahraman354]

@@Hidden.Light.Photography The OTA on both scopes is carbon fiber. The C11 (Celestron) is metal....I don't see a temperature probe on my EAF so I will indirectly measure the tube size after say every 30 minutes or 10 subs at 3 minutes each,.,.,,

[@dankahraman354]

@@Hidden.Light.Photography Yes monitoring HFR increase would be the best strategy as stars will get larger regardless of temperature drop or increase.

[@Hidden.Light.Photography]

I’ve been running HFR increase for awhile now and haven’t had any focus issues. Personally, I’ve found this to be the most efficient and keep the auto focus runs to a minimum thus maximizing imaging time. Again, that’s my experience and anyone starting out with autofocus I would recommend HFR as that is directly measuring the stars. Not saying you’re just starting out :)

[@dankahraman354]

@@Hidden.Light.Photography I am a novice to EAF

[@MrMrduke1975]

ok, I have not watched this video yet. We talked back and fourth on another video of yours, and NINA is killing me. So tomorrow night, is going to be clear. At first I was going to just bring my Asiair Plus because I just need some images again lol. I just can't, I have to figure out this NINA thing. The only thing holding me back right now is Autofocus and guiding, but I think I figured them both out. I need to manually focus first, plate solve, TPPA, run Autofocus, and then PHD. I really want to work on Autofocus, because the step size and backlash are what really killing me. Anyway, thanks for the videos!

[@Hidden.Light.Photography]

I know what you mean. We went from tons of clouds to monsoon season so I am going crazy waiting for a good night to get out there lol. Great workflow you just described. Use the focuser controls manually to get in focus. I like to zoom in on a star and get it as small as possible. You’ll get to a point where you’ll learn your equipment enough to know how many steps to move depending on how the stars look :) Follow up with TPPA then calibrate guider and end with autofocus. Follow this video to determine your step size and backlash compensation. Take an image to see your star size and manually enter a step size to see how much the star grows. Only move in one direction so you don’t go into backlash and distort the number. Enter the number you determined for step size to start with and run autofocus to see what your backlash is. Set backlash to overshoot and enter the number you determined on only one side and then dial in your step size from there. You’re more than welcome to get screenshots as you go and send them to me and I can assist :)

[@MrMrduke1975]

@@Hidden.Light.Photography awesome info! I wrote it all down! Thanks again. Only problem I have now is my Pegasus Astro v3 keeps shutting off, even after I changed out cords and did an update

[@Hidden.Light.Photography]

You are very welcome! How are you connecting the V3 in NINA? In other words, I’m running my rotator and flat panel through Unity Platform within NINA.

[@MrMrduke1975]

@@Hidden.Light.Photography yes, that’s what I am doing as well. I tried the focuser with Stellarmate and it’s working perfectly, so must be some setting in NINA

[@Hidden.Light.Photography]

I apologize for the delay on this, I was doing some research. NINA can sometimes be a bit picky with certain drivers. Have you heard of ASCOM Alpaca?

[@DaveUrbanAstro]

Spot on! Where in Arizona are you located?

[@Hidden.Light.Photography]

Thank you! I’m in Queen Creek, Az

[@Real-Tecnica]

I am still a bit lost on the initial starting value of 21675, so my focuser is all the way in and when connected to NINA it's reading 0 . So do you want me to just enter 21675 and begin there?

[@Hidden.Light.Photography]

No worries at all, this can be a challenge sometimes to set up and great question! You are going to want to use the focuser commands in NINA to start racking your focuser out. Every adjustment outward, take an exposure to see where you’re at with focus. I would do little increments such as 50-100 steps at a time until you find focus. Try to keep moving in the same direction so you stay out of backlash. Once your stars are round (doesn’t have to be in perfect focus) it is time to find an idea focuser step size. To accomplish this, move your focuser again using the commands in NINA making sure you are still moving in the same direction as you’ve been. You are looking for your stars to grow. Keep note of how many steps you’re moving your focuser. For example, if you move your focuser 50 steps and the stars show nice growth, then plug 50 into the step size box in the focuser settings screen. Let me know if this helps and also once you reach this point I’m happy to assist with getting backlash compensation set up if you need :)