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Hi there! I have been trying to get my mount set up with my computer for a really long time now. I just got a new EQDIR cable and the PC finally connects to the mount, so I am now able to slew it wherever I want. My equipment:
Software:
Now that the hardware part is correct I still have to get the software to work. I tried to usa a simulated camera to test if everything works correctly. I want to use the PHD2 guiding software and when I tried to start calibrating the mount, i got the error "Calibration failed. Ra didn't move enough". I already looked at several websites and found that I should look at the advanced settings to check that the PC gives a long enough signal [ms]. After I got everything in there correct (i hope), the error message didn't stop showing up. Is this normal when using a simulated camera with your real mount? Last night i tried to connect my mount to my actual camera and i found that it worked. It lost the star a couple of times during calibration until I stopped it again and chose the star manually, because it used a second star the first time which was barely visible. After the mount was calibrated it stared to guide the mount as it should. Now that calibration was solved and it was guiding I got the error message "Star lost. Low HFD". I looked up what this could be and found that I can change the HFD to a smaller value (star detection threshold). This solved this error message but now another one popped up. It said that the Star was now lost because it had changed its size. I also tried to find a solution on the internet but got no good information anywhere. As you can already guess I would like to know why this error occurs and how I can solve it. This are my guide and debug logs (in zip format because debug log is more than 1MB): Log files.zip I am not sure if the zip works as it should. If not please guide me how to upload the files. Any help appreciated! Thanks in advance. Luke |
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| Low HFD usually means either clouds passing by or really poor focus. Have you used an IR filter for the camera? That helps in focusing if the camera is IR capable. Given that you have a 50mm f/3.8 there should be plenty of them stars available. Enable multi-star guiding as well. |
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Did you take a couple of dark frames for the exposure time youre guiding with? This can help removing hot pixels, which sometimes can cause problems, too. In my experience, a decent focus is desirable but not neccessary. However, better focus also gives more signal. Very important is calibrating the guider, and having not too much backlash or inbalance. |
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My suggestion is to use the Profile wizard in PHD2. If you have gone thru that it prompts you to take a “dark library” as @HR_Maurer suggests. You are going to want to do this with your scope pointed within say an hour of the meridian and close to “0” declination which should put you in the southern sky somewhere. Once you do that and get PHD2 guiding for a couple of minutes, I like to then go to the “guiding assistant” and run that for 2 minutes (again follow the prompts) once it goes thru that process then look at possibly changing your settings. If you get thru that process most of the time your guiding will be pretty good with maybe a couple of tweaks here and there depending on how your nights vary. For the most part PHD2 is fool proof. Good Luck! Dale |
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Hi Luke, I don't understand the part where you connected the mount to the camera. The camera is connected to the PC and PHD2. If you're guiding with that guidescope you should have plenty of stars in the field to choose from. Do you see them? That's the basic and most important question. What exposure do you use for guiding? 2-3 should work. First I would make sure that the guide scope is in focus. A classic problem since it will cause the stars to be very dim. When the signal is very weak, it will lose the star. Put sufficient detection around the star (the square where it looks for the star). If your mount moves too much, it will lose the star. CS, Bogdan |
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Hi again, Thanks for the feedback! I haven't had time to test phd2 again in the last few months, but recently I had clear skies again so I was able to test it. @Bogdan Borz I see enough stars in my fov and usually use 2 seconds. Also, the guide scope is really well focused. When I set up my equipment (as in the first post), I didn't have high hopes that something would be different now. But to my surprise, the guiding worked as it should. But only for a few seconds. The calibration went smoothly and seemed to work correctly (every time). But when guiding starts, it loses the star after just a few seconds (as you can see in the attached picture). I don't know why this happens. Also, before I started guiding, I took a long exposure of 30 seconds (iso 3200) and the stars were as round as possible. But after I started guiding and it didn't work as mentioned above, I did the same exposure again but with very poor results. It looks like the mount either didn't track at all or tracked way too fast. But I could hear the mount move (the typical sounds from the stepper motors when it tracks), so I figured that it should track normally, but this isn't the case. In this ZIP folder below you can find the PHD2 guide and debug logs from yesterday and the day before (I tested it twice with the same results). In the next post there are also the two images (before and after - 30 sec / iso 3200) that I mentioned before, as well as a picture of the guide graph, where you can see the malfuncition very clearly (sorry that the picture is a bit blurry) - I have to send them in two posts because otherwise the folder would be too big (> 1 MB). Log files (2).zip Hopefully someone can help me further or show me a solution approach, because unfortunately I no longer know how to get the guiding right. Thanks for your advise! Luke |
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Here are the images before and after the malfunction as well as the guide graph (sorry for the bad quality, I had to downscale the images a lot). Images.zip Thanks! Luke |
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The image with the star trails clearly shows that the mount is not tracking at that point. The guiding graph shows, that the DEC axis only corrects in one direction, which it usually should not. Just a stupid question: did you already started your mount to track and did you set the tracking rate to siderial? If the tracking rate is different, the things you explained could be a result. In the image with the guide graph, you can see that the selected guide star is too bright. the histogram of the star has a cut of top and the star is saturated. However, this will have a negative effect on guiding, but it should work in general. I'm using NINA and sometimes after I slew the mount with a faster speed manually and then trying to guide immediately, the selected star "jumps" out of its tracking box. The mount seems to slew at the fast rate for a short while. In this case, I have to manually select siderial tracking again. But I'm not sure, that this is related to your own problem. Anyway, in my experience, PHD2 is quite fool proof. If you did run the a polar alignment routine which a lot of software offers today (even PHD2 has its drift alignment) and you calibrated using the assistant, it should work at least somehow. Usually it should work even very good, because that's what I do all the time. I assume, there is some step in the things you do around your guiding missing. Here's what should work (just to have it mentioned): 1.) Focus guide and main camera (main camera mainly to be able to plate solve) 2.) unpark mount 3.) calibrate PHD2 guiding 3.) slew to the target 4.) make sure, you or your software selected siderial tracking rate and tracking is on 5.) select guide star 6.) start guiding ... Maybe you can list the exact steps you do to find a solution. I barely have to change settings in PHD2 itself. I assume, you set the correct focal length of the guide scope in your profile, as well. There must be a very simple solution to your problem. Everything else would be very surprising. CS Christian |
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Hi Luke base on you issue, here I have few suggestions. First increase the tolerance in tool->setting->guiding, Then increase the SNR. Those can help with losing star issue. CS Jiawei |
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Hi, thanks for all the Feedback! @Christian Großmann I didn't know that there is anything like a "too bright star", so thanks for the hint. Here are the requested steps (I don't think I missed something)
@JIAWEI HU Thanks for the help. I'm going to try these tips. I actually just discovered that there is multi star guiding. So I'm also going to try it to see if this brings any improvement. I hope that there will be clear skies soon so I can see if any of these tips solve my problem. Thanks! Luke |
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Lukas Bauer: If the histogram is "cut" at the top (the star is saturated), PHD2 has hard times to find the center of the star, because in that region all pixels are white. If you select a dimmer star, guiding is more accurat. Your steps look good so far. This should work. The multi star guiding is a big improvement and much more reliable. It is a bit strange that EQMOD stops tracking after some seconds. I never had this issue. It's also strange, that your guiding stops after some seconds, too. This is weird. One could think the problems are related to the same issue. I used APT some years ago and switched to NINA. I haven't used it for a while now. So I have no idea anymore how it works. But maybe it's worth a try to open just GSS and PHD2. Then move to a random star manually, start tracking in GSS and try if PHD2 is guiding properly. If this is working without APT open, then APT may cause the problems. I really don't know. But it's worth a try. This is the only obvious thing that is different to my setup. |
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Lukas Bauer: Hi Luke, Well, it is pretty much clear that the mount is simply not guiding when you connect it to PHD. Pretty weird behaviour. Could you please show us some screen captures from your brain settings in PHD2 (Camera, Guiding and Algorithm)? It is not possible to be able to calibrate and guide with the assistant and then to stop guiding like this. Is the calibration correct? Sometimes the problem is EQMOD that does not communicate well with the mount, try to increase the impulse duration. Bogdan |
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Hi, @Christian Großmann I don't think These issues are related, because sometimes the guiding is bad (non-existend) from the beginning, wheras EQMOD always needs a few seconds before stopping. But I'm going to try and just use the to programms and nothing else. @Bogdan Borz Always good to hear that I have an issue that is impossible.  Although I don't use EQMOD anymore, I am going to try increasing the impulse duration. The calibration should be correct - it works flawlessly every time. Here are the pictures from the brain settings: brain settings.zip Thank you for your help! Luke |
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Lukas Bauer: Hi Luke, : ). The problem you have is real, what I said that is impossible for the mount to track correctly on its own, for PHD2 to calibrate and be able to move the mount for the correct distance during calibration and then to stop tracking during guiding. It seems that you entered a wrong number for the camera pixel size 24 (probably 2.4) and the search area is 15. If that's the case, it will never work. Try with the correct pixel size and search area 50 let's say, like this it won't lose the star quickly. Still puzzles me how can it calibrate correctly. Bogdan |
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HI, am so sorry, I sent you the data from another profile, where I tried to simulate the camera. In the correct profile I set the search area to 50, but the pixel size was already correct, so this data should work now? Or am I still missing something, that maybe was correct in the wrong profile? Here are the new and correct screenshots: brain settings_correct.zip Thanks! Luke |
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Well, you have 0 gain. That's wrong. Set it at 90%, if not you won't be seeing any stars if the field contains only faint stars. You have no noise reduction. Try any, median for example. You calibration step is not the same as mine for your setting, but I don't know what are your advanced settings (the button next to the step size) in Guiding. I forgot to ask you about your guiding speed (compared to sidearal) how much is it? I use 0.8 for example. My settings give me a step of 1050 ms for a 25 pixel calibration distance. 12 steps. So check the advanced parameters too, but try to modify the camera settings first. Bogdan |
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Hi, Thanks for letting me know about the gain and noise reduction  I never checked the camera settings because I just thought as long as I see a few stars everythings fine. In the advanced settings there are these values: FL: 180mm Camera binning: 1 Calibration steps: 12 Calibration declination: 0 Pixel size: 3.75 Guide speed: 1.01 Calibration distance: 25 This gives me the value of 600 ms. Should I change the guiding speed to 0.8? Luke |
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Try it at 0.8 for example, lower than the sidereal speed (the speed of the sky). If you make corrections faster than the sky movement, it will be hard to reach equilibrium. Second, your declination is not 0. Don't tell me you live at the Equator : ). Put the dec where you image from, if not, it's a false data location for your calibration. Vitis Austria is 48°. So put this in the setting. |
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Ok, thanks! Is there anything else that can be optimised or that's required for phd2 to work? |
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| Let’s try all these modifications. I think it will work. Usually I lower the aggressiveness, but you have to check when is guiding. |
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Ok, thanks! The weatherforecast says there shouldn't be any clouds on Thursday evening all the way until Friday morning so I'm going to try the new settings, hope that everything works and let you know if it works or not as soon as possible.  |
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Hi, after a while, yesterday evening the clouds finally started to go away and I could test the guiding. It is definitely better than before, but I noticed a very strong drift in the Ra axis: guide log Ra-Drift.zip Does this mean, that my tracking rate is too small or too big? Another thing that I noticed, was that the automatic star choice is always extremely bad and results in PHD2 constantly losing the star. Even if I pick the star manually, it is there in one exposure but not in the next one. Therefore PHD2 loses the start again. Sometimes I even see next to no stars with already 3 sec exposure time. I also tried putting the gain at 95 and 100, but nothing really helped. The picture which is linked above was a rare moment, where PHD2 locked on a star and didn't lose it. Therefore I was able to record that error. This is the guide log from yesterday evening (Debug log is too big, so there is only the guide log - should I post the Debug log too?) log files new (3).zip Thanks for the help! Luke |
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Why did use gain 0 in the guiding camera? I didn't see any corrections sent by PHD2 Did you test PHD2 manually move the mount ? > Pick a star > center> under tools in PHD2 choose manual guide> see if the mount response ?? Good luck |
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Hi, as far as I know the gain is currently set to 100. I don't know why PHD2 didn't correct anything, I just though that it just wouldn't show. The mount did respons to the PHD2 signals. Thanks! |
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Lukas Bauer: Hi Lukas, I quickly took a look at your guiding photo, there is a note saying MountGuideEnable = False. Weird. What was your mount again? You should check the parameters in ASCOM too for the mount, see what is enabled (PulseGuiding on?). Does not seem to respond in RA. Did you recalibrate close to the ecliptic? When you change the parameters you have to calibrate, near the South and the Ecliptic. |
