Guiding Graph: Page 3 - ZWO User Forum

Guiding Graph

Byrdsfan1948

Hi Chen Well DUH!!!!!!! I guess sometimes the obvious answer was just too obvious for me to observe. "Just turn off auto refresh!"........... I believe I should be able to give that a try next PA!!! :-)))

Actually you also touched very nicely on a few other details here. I do for the most part ignore the circle graphics and for the most part focus on the numbers....... However as you also point out, the adjustments are made horizontally and vertically. But due to the OTA orientation during the PA process the resulting changes in the X and Y directions become a trigonometric function of that orientation angle along the pointing axis of the OTA......
Your other comment is one I never considered and that is that the direction to adjust the AZ bolts as shown by the green arrows depends of which side of the mount your standing on when making those adjustments.
Very helpful comments Chen !!

I have found that the best way to zero in when making the final fine AZ adjustments is to do as you suggest. Once I get close I essentially gently tighten both bolts and then ever so slightly loosen up one side while just slightly, and I mean slightly, turning the other. That greatly limits the travel, while at the same time leaving the bolts somewhat tight. Once I am within the acceptable area I then equally snug down both adjusting bolts, and then slightly pre load one bolt depending in the direction needed for the final adjustment and then slightly loosen up the other side. In essence that eliminates a good deal of the problem of movement when tightening. However the bolts used have threads that are simply way too course for any real precision adjustments. So bottom line is anything better than 0.30 arc seconds is more luck than skill, and certainly not reliably repeatable.

The Alt Adjustment is more problematic because only one adjusting bolt is involved. There is where I probably introduce the biggest component of any PA inaccuracy. I do snug down the clamping bolts but leave them loose enough to allow some final adjustment. But when I do then finally tighten them that does introduce some final movement and inaccuracy.
It is a bit disappointing that a $2000 mount that has some very decent precision designed into it's drive system uses a crude and very sloppy, poorly designed system ( if one could call this a system ) for PA adjustments. But compared to the guiding problem this is small potatoes.

I suppose all is not lost however. When I purchased this mount I knew very little about what to look for in a really quality mount. All in all I am very satisfied with it and even with the draw backs we are discussing here it can still track very accurately with my set up for my current purposes..... What I have now I can see serving me very well for a very long time.

However my wife and I do own a second home in Jackson Hole Wyoming within the borders of Grand Teton National Park. As you might image the skies there are very dark. I can easily see this entire set up making a one way the trip out West latter this year, and that giving me the opportunity for a serious upgrade here....... Hopefully by then I will know a lot more about the really important details !!! :-) Al

w7ay

Byrdsfan1948 However my wife and I do own a second home in Jackson Hole Wyoming within the borders of Grand Teton National Park. As you might image the skies there are very dark.

If, at your age, you can still carry heavy loads, you owe yourself a 10 Micron mount. Once you see and use one, you will know that the Chinese mounts are pure trash. (With an ME's eye, too :-). The waiting list is long, so you might receive one when we can finally travel again :-).

If you have a friend who has a RainbowAstro, you should see the machining (mount body machine milled out of a solid block of aluminum. Heck, each mount is first anodized and then laser etched with its serial number. It is not an especially expensive mount either (at least by California engineers' standards :-).

I have a small stature and could not handle weight. For years, I had been depending on the Takahashi EM-11, the smallest of the Takahashi mounts (not counting the lightweight stuff like the Teegul that are not meant for astroimaging).

I would need a lot of help from Archimedes (Mr. "give me a fulcrum and I will move the mass of the earth") to handle even the smallest 10 Micron mount :-).

As I got older, even the EM-11 became too heavy for me, so I moved to the RainbowAstro, which is not only much lighter, does not require a counterweight (more weights..., it can handle a bigger payload than the EM-11 to boot). I have two of them in case I want to set up two OTA simultaneously, and also with one as a spare since I cannot see taking the EM-11 out to use again in case the one and only RainbowAstro fails. But the tracking precision is nowhere close to a premium US mount.

Chen

Byrdsfan1948

Hello Chen, A quick look at the 10 Micron Mount ruled that out ! No way will I pay more for a mount than a new guitar :-) But seriously it does seem like over kill for my needs........... A quick look at the RainbowAstro ( 135 ) appears to be very interesting....... I have book marked that information and will look it over more closely latter. I assume your opinion is that it is in a different ( improved ) quality class than the more typical ones out there?

Interesting experience last night. It was still cloud covered around sunset so I had written off the night, grabbed a glass of wine, and settled down to watch Jeopardy. During the break before Double Jeopardy I took a quick look outside and found Orion clearly visible. The clouds around that part of the sky had cleared out fairly well. So on a last minute whim, I quickly set up my scope at the corner of my back patio. I have 3 spots marked there to locate my tripod legs to make PA quicker each night. I simply set the legs on those spots. I didn't check for balance, and I didn't even bother doing a PA. I connected the ASIair, and then directed the mount to slew to the Orion Nebula. BINGO!! It came up exactly centered ......... I then quickly connected my Ethernet cable from the ASIair to my home router and was in business in less than 10 minutes. I had enough time to catch the end of Double Jeopardy, and Final Jeopardy.

What was very interesting was that I ended up with about an hour of usable time before the clouds ended the night.   I had no intentions of any meaningful photography.  I simply let the preview view keep reloading as I watched the guiding.     I used both my Tablet as and my Iphone.  In both cases the guiding was far more stable than any recent night. Even with the high clouds that were passing by, the guide star was only lost once, and even then quickly it was then found and guiding restarted.      I did re-calibrate once at my first target but that was it.   I guided on three separate targets.  M-42, Betelgeuse, ( which was doing a good imitation of Mars :-) ) and M-35.   All three targets of course are within the same general area of the sky that was fairly cloud free for the hour.   Because of that I didn't re calibrate when I moved from target to target.  
First of all I am impressed that quickly setting up on those three dots on my patio, with no PA, was good enough for the GO TO function both in the ASiair, as well has my hand controller to work as well as they did.  Both every bit as good as if I had done a good PA.  More importantly was the guiding virtually always under 1.0 total error in very unstable seeing conditions.    Of course we are talking only an hour here but usually by then I am well past the frustration point!

I was at least able to open up those zipped files for the FW upgrade for the guide 120mini guide camera on both my tablet as well as Iphone........... BUT I am unsure in both cases if I was actually successful in installing the upgrade. Other than that the only other thing I can think of, is that by the end of the previous night I had followed one of your suggestions with the Aggressiveness settings. So last night in both cases they were set at 55 as I had left them last session. All in all very interesting but of course hardly conclusive. If I can get a break in the clouds again tonight even if only like last night I'll wash, rinse, and repeat! Al

w7ay

Byrdsfan1948 I assume your opinion is that it is in a different ( improved ) quality class than the more typical ones out there?

The 10 Microns are, but the RainbowAstro RST135 is not.

There is a price premium on the RainbowAstro, not because of precision (although the built quality is top notch) but because of the portability (very light weight and requires no counterweight). In my case, it fits my bill perfectly because I primarily focus on weight vs payload capacity.

The harmonic drive is both a plus and a minus (the same applies to the Hobym). A plus because of the torque available negates the need of any counterweight, and a minus is that a harmonic drive has the highest periodic error in the market, and absolutely requires guiding. Unless portability is important to you, you are better off with a Losmandy G11 (about the same price class, but much better precision) or the 10Micron 1000. Heck, my two RST-135 together cost me as much as a 10Micron 1000GM, and I would have picked the latter if not for the fact that it is so heavy I would need to disassemble it into separate pieces each night.

Chen

w7ay

Byrdsfan1948 I had enough time to catch the end of Double Jeopardy, and Final Jeopardy.

OT: not quite the same without Trebek :-(.

One of the things that I have found is that the best equipment is useless unless you can quickly set it up and tear it down; just like what you did.

My tri-pier and RST-135 (with a dual saddle plate) are permanently outdoors. The ASIAIR, power hub and error mesh router are in a waterproof box that is strapped to the pier. And I have two 12V lines running from the house to the mount (the RST-135 back drives when power is lost, so I have a DC UPS running an independent 12V line to it).

Because the snow in the next few days is expected to be over a foot, I brought the box back indoors just in case.

The RainbowAstro has no greese to dry out, so the mount is outdoors all the time, under two layers of dry bags when I am not using it.

If I am careful when mounting and dismounting the OTA and guide scope from their dovetail clamps, I have gotten 10-20 arc seconds type polar alignment from night to night. Even when not taking care, I am usually within 1 arc minute (the limit where I don't need to polar realign). But any polar alignment is an exercise that lasts no more than 2 minutes to get less than 10 arc seconds.

Chen

Byrdsfan1948

Chen I have no idea what is going on there with that slider but slide it to the right to read what is written there? As if guiding isn't already a big enough problem to deal with :-) Al

Byrdsfan1948

Hello Chen, I love how this conversation has evolved. It's gotten a bit off topic, from where we started but I look forward to just about anything you have to say. Certainly the enjoyment of reading your comments each morning balances out my frustration of trying, and failing, to get myself an appointment for a Covid vaccine each morning :-)

Jeopardy Is about the only 1/2 hour of network TV worth watching. Alex was of course a 2 nation national treasure. While it is true that none of us is irreplaceable that does not mean that all replacements are equal. At first I was not particularly happy about the "guest host" Ken Jennings idea. But the more I watch I can easily see he is working very hard to incorporate Alex's personality into his delivery. Your 100% correct it's just not the same without Alex but I think Jennings is showing that he really is a worthy replacement. Based on his history obviously a very deserving possible permanent one as well.
Hey speaking of the sorry state of network programming if you have Netflix and in any way enjoy Chess I highly recommend The Queen's Gambit. This is an OUTSTANDING short 7 part mini series that will hook you in the first 15 minutes. My wife does not play chess, yet was hooked in less than 15 :-)

OK back to the general topic. Yes I agree setting up as quickly as possible is critical. In fact it played well into my initial decisions for the equipment I currently own. I wanted something that would not become too much work (including as you mention, too heavy) to set up on those nights like the last few. Last night I had about 2 hours of somewhat "clear sky" so I again took advantage what I was offered. This time however I did do a quick PA. I followed your suggestion to turn off the auto refresh. MY GOD what an improvement! Since I had no intentions of doing any imaging worth post processing I didn't get too fussy. So in just a couple of minutes I was under 45 arc seconds which for my goals last night was plenty good enough. THANKS for that suggestion!!

Bottom line again what limited guiding I was able to do, was quite satisfactory. Last night I actually did set up a short autorun for M-35 where I was taking 30, 60 second subs dithering every other sub. I was very interested to see what if any problems dithering might introduce. My guiding total error settled down to just about 1.0 by the next dither. But more importantly the RA or DEC didn't ever go crazy. As I said last night I was also fighting high clouds that were obviously filtering out a lot of photons !!! I did lose the guide star a few times as a result. So I increased the exp from 3 to 5 seconds. That seemed to gather enough light for the star to be consistently observed by the guide camera. I am certainly that I have NOT yet properly installed that latest FW upgrade for my 120mini yet. I did find some good info on that last night on a Facebook site so I will hopefully properly install that today. So I am now guessing that the sudden guiding improvements have nothing to do with any camera FW upgrade but perhaps due to my current aggressiveness settings, which are 55 for both DEC and RA. Also I think last night maybe taking 5 second guide shots might have helped reduce the chance of shorter exps causing the software to be making adjustments, to the adjustments, if that makes any sense........ Hopefully tonight I can get much more time to work on this as well as hopefully have my guide camera properly updated Al

w7ay

Byrdsfan1948 I followed your suggestion to turn off the auto refresh. MY GOD what an improvement!

I am glad that issue worked out, Al :-). And you are more than welcome. (I checked out BIC's patents and finally figured out who you are, since you mentioned being VP and Italian descent :-) I have 3 dozen US Patents myself.)

The ASIAIR polar alignment initially always required manual plate solve triggers. But ZWO buckle to lazy neophytes, and added the auto refresh function. The problem is what the idiots (both users and implementers) don't realize is that you will need one complete refresh of the plate, after the mount has settled from vibrations, before a subsequent plate solve to be meaningful. Straight out of sampling theory. This usually means something like 3 refresh cycles before the readings even make sense. Most people don't wait 3 cycles after an adjustment. And a single manual adjustment has much more precise timing anyway -- wait N seconds before hitting the refresh button, N depends on how long it takes your mount (and tripod base) to settle. The numbers and green arrows will quite precisely guide you what to do next. The pause before a plate solve is well worth it since you likely will end up with no more than a dozen adjustments of the alt and az bolts, once your muscle memory remembers how much to turn for each arc second of error.

We are talking arc seconds (at least no more than 1 arc minute) type of precision being required. Darn system needs time to damp down (unless you have a 10 Micron <evil grin>).

Chen

P.S. I will give Jennings another chance. Never liked his smirk :-). Trebek's charm has always been his humility. And we know all the information are fed to the host, so it is not important that the host is a walking encyclopedia.

Byrdsfan1948

Hello Chen, Ahh Patents! for a long time we viewed Patents as a double edged sword. A lot of in house engineering innovation was necessary to create the kinds of high speed automation capabilities necessary to produce our products to the extreme quality requirements we demanded. In the final analysis we viewed a lot of that as very valuable trade secrets. In many cases we had to take off the shelve equipment and re engineer it well beyond the capabilities of the original mechanism or sensor. We often had to re imagining how to use something that was designed to do a certain function, to be able to do something very different Think of it like re engineering my Ioptron CEM25ec and in the process give it the abilities of an 10 Micron Mount while outwardly nothing has changed.
So thus comes the Patent conundrum. Since you hold so many yourself I am sure you know exactly what I am speaking about. We did tend to more often patent certain things about our products more than or manufacturing processes. Essentially because reverse engineering a product is pretty straight forward and thus finding ways to circumvent patents easier than figuring out the secrets involved in putting together millions of our product each day with zero defect with nothing to hold in your hand or a patent you could read to find out. But if we could at least write the patents broadly enough and still get that patent issued it was worth doing.
I could tour you through one of our facilities to show you how we accomplished the almost impossible, as well as point out countless amazing trade secrets but then I would have to kill you as a result. Since we wouldn't want to deprive these forums of your amazing expertise I suggest for the sake of science we dismiss the tour idea :-)))))))
BTW I learned this lesson the hard way as a young engineer very early in my career. I was showing a vendor through one of our manufacturing areas and proudly showed off to him how I had designed an addition to his product that gave it a completely new function they never considered....... Shortly after they introduced an entirely new product completely based on my unpatented design. To this day that one hurts!!! But it was a great lesson at an early age.

Anyway, back to the PA issue I believe once again you will be proven correct. By not using the auto refresh during PA both the accuracy as well as time involved to PA will be improved. I suppose another simple improvement ZWO could add would be the ability to set some N number as you mention to refresh to. But they have enough to already work on just getting a few other things right and there already exists a very effective solution :-))

BTW This morning I was able to upload the FW update for my 120mini guide camera but sadly a look out the window right now is not looking at all encouraging for tonight. It was supposed to be partly cloudy. But right now that is not the case. Last forecast still says it will be, so I have my fingers crossed Al

w7ay

Byrdsfan1948 I suppose another simple improvement ZWO could add would be the ability to set some N number as you mention to refresh to.

My guess is that the ASIAIR could keep on taking plates and display a "wait" notification until two successive plates give the same result to say, within 5 arc seconds. Problem is the cheap mounts might take literally minutes to settle to that amount :-).

Too bad you have already applied the firmware update, else I would have requested that you save a PHD2 log before and another PHD2 log after the update, to see if anything changed. In a different thread last week, I had mentioned the jitter and lag of the guide sampling timestamps in PHD2 log.

However, perhaps you can check your USB drive (Udisk on the ASIAIR Samba server) or the microSD disk (Disk on Samba) for old logs and squirrel them away, and note the date and time you had applied to update so there is something to compare in the future.

Chen

RonM

Byrdsfan1948 BTW This morning I was able to upload the FW update for my 120mini guide camera

Sorry to butt in here, I’m considering updating the firmware on my 120mm mini also. Can you tell me if you installed the .img file in the USB3 folder ? The instructions are a little confusing to me.

Ron

Byrdsfan1948

Certainly not butting in here at all Ron. I saw someplace else recently the same question you are asking here. The response from ZWO was to use the img file. Which is what I did yesterday. I'll see if I can find that response and if I do, I'll try to post it here.

Just wondering what if any issues are you having with your 120mm mini? I'm just wondering if you are having any, if they match mine? I've watched my guide star just disappear, ( in perfect seeing conditions ) the image screen break up, the star being lost etc. An assortment of issues that once they start, often times making guiding totally impossible.
Lastly I want to make clear I am no computer expert so while I'm am fairly certain I did this update correctly I can't say with certainty that I have. I probably won't know until I get a chance to test it, the next even somewhat clear night. Which here in New England does not look like any time soon.

To do the update all I did was to connect my 120mm mini via it's USB cable to my windows computer. I opened the USB3 folder mention and the camera was immediately recognized. When I hit update ( or whatever that button is ) it appeared that the update only took a second or two. I then got a message that it had been successfully installed. BUT as I said until I can test it I won't be 100% sure. Nor of course will I have any idea if it even helps with my above mentioned problems.
I was able this morning quickly able to at point 120mm mini and guide scope out the window at some stars and confirm that it still works after this update. So at least I know at this point I didn't break it :-)) Good Luck!! Al

RonM

Byrdsfan1948

I can’t seem to get consistent guiding on the same target each night. Sometimes it’s the RA axis that’s off (high RMS error) other times it’s the DEC axis. I have yet to get a total RMS below 3.00. Also it was taking a long time to calibrate. I also noticed a line in all my guiding logs that says “Settling Failed “.

I’m not sure the problem is the guide camera and will wait to update the firmware. I spent more $ on my mount to get the EC version to speed up imaging without guiding and I’ve taken 4min exp/ 30 frames with good results, at least to me anyway. I started using guiding to take longer exposures that’s when all this started.

A couple times I did seem to have trouble locking on a star. I’ve since added a red filter on the guiding camera and am not having that problem now. I have pictures of my last 3 guiding graphs and can post them if I can figure out how to do it.

Ron

Byrdsfan1948

"However, perhaps you can check your USB drive (Udisk on the ASIAIR Samba server) or the microSD disk (Disk on Samba) for old logs and squirrel them away, and note the date and time you had applied to update so there is something to compare in the future."

Hello Chen, I would be very happy to try that if you wouldn't mind telling me how???? :-))) You are asking me to do something currently beyond my computer skill levels........... :-)) Al

w7ay

Byrdsfan1948 Hello Chen, I would be very happy to try that if you wouldn't mind telling me how???? :-)))

Do a Google search on how to access a Samba server with your computer.

On macOS and Linux, it is simply a matter of using the network to connect to smb://192.168.1.123 (the actual IP address is what your router has assigned to the ASIAIR). Raspbian (the OS that ASIAIR uses) has a built in Samba file server.

You can use the GUI in macOS by selecting the Go item in the Main Menu of the Finder and choose "Connect to Server...". Then simply type in the address as above (the "smb" identifies the type of server), or let the Go dialog browse for all connected file servers on your home network. The ASIAIR will be one of them.

While you are at it, go to your router and change the ASIAIR DHCP address to a fixed, reserved address. This way, each time you try to access the ASIAIR on your network in the future, it will be available at the same fixed address.

Furthermore, in the ASIAIR network setup window, you can give your ASIAIR a distinct name (in case you have more than one; or you take the ASIAIR out to a remote site that has other people using ASIAIR). My four ASIAIR (two v1, and two current models) each have its own name and fixed address at home. If you don't do that, the ASIAIR will append part of its serial number to the string "ASIAIR_" and use that as the device's name -- which makes it difficult to figure out which is which.

When you open the network volume, you log in as guest. You will see two items, one is "Disk" (the microSD card) and the other is named Udisk (for USB flash card or SSD). Pick the one that you were using in ASIAIR while autoguiding and you should find the PHD2 logs in there (the logs disappeared between ASIAIR v1.5 and v1.5.3, but is back).

Chen

Byrdsfan1948

Thanks Chen, I give this a try but no guarantees :-) Al

Byrdsfan1948

Hello Chen it's been a few cloudy nights here, until a few hours of clearer skies early last night, and this morning. Hopefully maybe a couple of hours tonight as well before our next storm rolls in.
I didn't want to risk anything after I did the ASI120mm mini FW upgrade so I have not tried your PHD2 log suggestion above here. I wanted to be sure I would not put myself out of business before I tried out that upgrade. Well now I have a few hours of experience after that upgrade to report on.

The bottom line so far is....... Still very unstable and very problematic guiding. So here are a few details. First of all I used my Iphone 12 to do my PA with and got to under 0.30 Arc Secs fairly quickly. What is interesting is that once I hit finished, I got that fireworks display. I never had gotten that before on my Samsung tablet. Not that I am enamored by that display, but I do find it worth mentioning that for whatever reason it does not happen on my Samsung tablet. Also another very minor difference. When finishing the auto centering after slewing to an object, my tablet says "Finished", my IPhone says "Confirmed". Perhaps why the difference makes some sense to you?

As far as the guiding. At first it was a total mess. Actually I was not even able to do a calibration. At times it seemed that the camera just stopped taking pictures and would just do totally black. I had instances of Star Lost as well as what appears to be the mount slewing looking for a star. Sometimes it would re find the star and resume guiding other time not. Eventually things seemed to settled down and I was able to star guiding but I'm unsure if the calibration sequence was every totally completed. Once guiding I started my auto sequence. Since I was just testing, I set up a simple sequence of 40, 60 sec subs on M-13. I dithered every other sub. What I soon learned was the dithering really screwed up the guiding until the point where eventually I had to stop it. The subs looked OK but the total error was all over the place. I'm assuming that the frequent dithering probably resulted in guiding number that are not reflective of the actually guiding tightness. After about 20 subs I paused the Autorun, and stopped the dithering, I resumed the Autorun and for the next 19 subs had guiding results often under 0.65 error. I had also increased my camera gain to 50. During the 20th sub the guiding just stopped again.
I also noticed that when I tried to slew to M-81 my tablet said it was below the horizon. But in fact it was very high in the sky. On the Go To page it did appear to show as to be below the horizon. Which was wrong! I decided to restart my tablet and it showed properly and I was then able to slew to it. Something is very weird there.
With all the issues I'm mentioning here do you think it might be a reasonable idea for me to delete the ASIair APP and then reload it? Or do you think perhaps my ASIair OS might be corrupted? I did make a back up when I got my ASIair new and I do know it was done properly. Should I give those ideas a try? Al

RonM

Byrdsfan1948 I have the same mount as you and this might be a long shot but did you set the guiding to “Allow RA guiding” in the hand controller settings. It’s on page 30 in the instructions.

Byrdsfan1948

Hi Ron, Thanks for the suggestion. To answer your question, YES that is set to "allow RA guiding". Which as the instructions say would allow input corrections from the ASIAir Pro. Also on page 28 the instructions discuss setting the guide rates for RA and DEC. In my case I have them both set to 50% of the sidereal rate. I am using a WO GT71 with a .8 reducer so my effective FL is about 340mm. With that FL I am finding that the Ioptron CEM25ec does an excellent tracking job for me even without auto guiding. However with the ASIair I really need to guide in order to be able to dither. I would think that since I can get some very excellent guiding as I did for a while last night that my problem is not with the mount. What is your experience? Al

w7ay

Byrdsfan1948

Al, if you are constantly losing stars, see if you can attain a better focus. Then set the gain so that the intensity of the star profile in the upper left corner is between 150 and 250. Don’t let it flat top (255) since the centroid will jump around when it goes through various degrees of saturation. If the intensity jumps around by more than a factor of 2, you probably have thin clouds.

However, I suspect that there is somthing fundamentally wrong with ASIAIR. ZWO is barely passed the first step of the alcoholic anonymous seven step scale, so perhaps they will finally be looking for a bug.

In the meantime try the real PHD2, and you will discover that your mount probably autoguides fine.

Chen

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