So yesterday I finally got a chance to go out and do some imaging, though session was interrupted by clouds and was really breezy (guiding was all over the place), but hey .. not complaining got some more experience, getting better with Polar alignment and set up of the rig etc

So here is the issue, Target for the night was M81, nice above horizon but not too high-up near zenith.

  • Polar aligned, ASIAIR pro found and centred the object correctly.
  • Started Guide looping, found star (HFD was between 3.9 - 4.27 indicating hot pixel wasn't selected by default or myself), guide camera exposure set to 1s
  • RA Calibration failed, it said something on lines of no movement of star or star didn't move.
  • Tried a number of times same problem.
  • I change target to M33, started calibration and calibration was completed successfully and started guiding. No issues..other than clouds and breezy conditions affecting guiding.

=====================
Now this is not the first time this has happened, back in Oct I tried the same... same target (M81) and calibration failed in RA, I thought I has picked a Hot pixel as guide star.

back then I changed target to M33 and calibration was successful and guiding commenced.

Now I don't know if it is the mount, or balancing of the mount (I tend to balance slightly biased towards camera side in Dec).

i.e. something off with balancing which means it has issue a target (M81) which is above horizon but not too high
but is OK with M33 which is high above and close to zenith (some what close) and some how results in ease of calibration.

There is an issue with the ZWO ASI174MM USB 3.0 camera where I can't set exposure > 1s, it freezes guide looping and in preview I get "Exposure Failure".

I've attached the PHD log, if anyone experienced could shed some light that would be great.

ps: guiding was affected by the breezy conditions but on occasions when wind died down guiding was @ ~ 1.53"

phd2-guidelog-2020-11-18-194452.txt
468kB

Thanks in advance,

Nihal.

    @asiair@zwo#41611

    if you mean ASICAP and ASIimg, yes guide camera works fine using ASICAP and ASIImg on laptop. I can set exposure to 120s or greater and take images successfully with ASI174MM USB 3

    it is only on ASIAIR pro I cannot increase the exposure of ASI174MM to anything higher than 1s

    I think this is a bug, and I’m not the only one who has reported this on the forum.

    anymore suggestions?

      @asiair@zwo#41613

      Thanks,

      calibration is set at 1500ms, I’ll increase in steps of 500ms.

      how go I increase star guiding rate?

      • w7ay replied to this.

        keramos how go I increase star guiding rate?

        Hi Nihal,

        Guide rates (0.25x, 0.5x, 0.75x, 0.9x) are in the Telescope Setup window.

        If the guide star didn't move with 0.5x, it is not likely to move with 0.9x either, unless there is some major bug.

        After sucessfully calibrating on M33, did you try going back to M81 to see if you can guide? IMHO, it will.

        FWIW, M81 is a bit too far north to see much movement in the RA direction for calibrating (the longitude circles all bunches up). The suggested PHD2 procedure is to move close to the celestial equator (where RA movement produces large star movement) to calibrate and then slew to your object.

        Chen

            w7ay

            Guide rates (0.25x, 0.5x, 0.75x, 0.9x) are in the Telescope Setup window.

            Ahh Ok I see what Star guide rate means, Thanks. The first time I tried M81, guide rate was set to 0.9x so in practise I have tried both 0.5x and 0.9x and both failed to calibrate.

            After successfully calibrating on M33, did you try going back to M81 to see if you can guide? IMHO, it will.

            Tbh I didn't, in hind side I should have. On the next clear night I was planning to take SW EQ5 mount (connecting via EQMOD to ASIAIR pro) to test it out on M81 to rule out the mount.

            FWIW, M81 is a bit too far north to see much movement in the RA direction for calibrating (the longitude circles all bunches up). The suggested PHD2 procedure is to move close to the celestial equator (where RA movement produces large star movement) to calibrate and then slew to your object.

            So would I calibrate on M33 and guide for a short while then stop, slew to M81 calibrate and see if I can calibrate and guide?

            I'm going to ask a rather dumb question on Balancing the mount.
            Are we suppose to balance the mount with the all cables attached to the cameras and guide scope etc?

            Last but not least, I can't increase the exposure on ASI174MM to anything greater than 1s. I think that in a way inhibits the guide star movement detection as they (the stars) seem rather dim.

            • w7ay replied to this.

                keramos So would I calibrate on M33 and guide for a short while then stop, slew to M81 calibrate and see if I can calibrate and guide?

                Yes, if it succeeds at M33's declination, then the guide calibration should also work at M81. If M33 and M33 are on different sides of the Prime Meridian (I suspect it might be, but depends on the time), you need to also turn on the "Flip" button (in the Info subwindow of the guide window).

                keramos question on Balancing the mount.
                Are we suppose to balance the mount with the all cables attached to the cameras and guide scope etc?

                Yes, it all affects the drive; the amateur German mounts just don't have enough torque to countact gravity. That is why I switched from a Takahashi EM11 mount to a RainbowAstro RST-135. Not only does the latter not need any balancing, it does not need a counterweight. I have been able to construct dual saddle plates without even worrying about the balance issue associated with dual saddles (RA balance changes with different Declination angles).

                keramos I can't increase the exposure on ASI174MM to anything greater than 1s

                I see lots of people reporting that issue. Lack of regression testing from ZWO, as usual.

                What are you using as a guide scope? I use a 55mm objective (250mm focal length) guide scope and have not had problems finding suitable guide stars even with the ASI462 camera and on top of that, I use an IR-pass filter on my guide scope; plus I need to use short 0.5 second guide exposures to keep up with the time derivative of the periodic error of my mount). Have you bumped the gain of your guide camera up already?

                Chen

                        w7ay

                        RainbowAstro RST-135 would be ideal for me, light weight and portable but I’ll have to sell an arm and a leg (may be both)... if you know what I mean but in grand scheme of things it would be worth the investment.... some day!

                        So my main scope is WO Redcat 51 (250mm FL) and guide scope is WO Uniguide scope 30mm (120mm FL).

                        Indeed I have bumped up the gain I think it was around 250 if I remember correctly. I believe I can go up to 400 (which might be pushing it a bit).

                        Given that ASIAIR is locked to ZWO products (dslr being exceptions), it’s a shame that quite a few things not working as expected. One would expect that new features would have bugs but features carried over from previous versions should perform as before not take 10 steps backwards. I think they should open up beta testing to more Users.

                        ASIAIR is a great product, I love it and can see the appeal wouldn’t mind buying more zwo products but they need to improve.

                        Having said that I’m waiting on ASI071MC pro and filter drawers... come on zwo clear the back orders ... fast 😬

                        • w7ay replied to this.

                            keramos I think they should open up beta testing to more Users.

                            Their Beta program is open to anyone who is brave enough.

                            However, having more testers won't help because they don't understand the concept of Beta testing. With Beta tests, the testers get to test and feed back problems. You then fix the problem and let it again be tested. Rinse and repeat until you are happy with the most recent beta, and burn that latest beta as the golden master.

                            What they do instead is change the code between the final Beta and the released software. Often, old bugs creeps back in (lack of regression testing) or some new feauture gets added. It is simply pointless to test anything if code can change between the final beta (that testers can touch) and the golden master (that is not beta tested).

                            What ZWO calls Beta testing is more like what real software companies call a "preview" of new features.

                            Chen

                                w7ay

                                yesterday got a chance to revisit M81, this time calibration was successful and was able to guide.

                                Had to keep dithering off as it wouldn’t settle.

                                Difference from previous attempt(s), gain bumped up to 330 and using EQ5 mount with EQMOD.

                                • w7ay replied to this.

                                    keramos Difference from previous attempt(s), gain bumped up to 330 and using EQ5 mount with EQMOD

                                    Possible problem with your other mount:

                                    a) too much backlash, so it won't start moving (could be balance issue too, you can try to preload the gears),

                                    b) ASIAIR bug in not sending the correct guide rate to the mount,

                                    c) the Calibration pulse is too short; although this parameter should only delpend on guide rate + plate scale of the guide scope.

                                    If M33 takes more than 20 steps to perform autoguide calibration, you may have to increase the Calibration pulse length, so that there is enough RA movement at M81.

                                    But if M33 calibration is consistenly successful and M81 is not, your best bet is to use PHD2's recommendation and go nearer to the celestial equator to calibrate autoguiding. Even if the RA moves at M81, you might be spending a lot of time for it to complete 25 pixels worth of movement. It might be faster to just go closer to equator, finish the calibration in 15 steps and then go back to M81. Just do it on the same side of the Meridian as M81 (simple to just pick M81 in the GOTO panel and change the Declination to closer to the Equator and perform a GOTO).

                                    It is great that it is at least working with the EQ5.

                                    Chen

                                      8 months later

                                      My ASIAIR pro doesn't auto-guide calibrate my iOptron GEM45-EC properly. It goes through the East-West part of the routing fine but the North-South movement (DEC) just sits there doing nothing and I get the dreaded 'clearing backlash' for many attempts. It's confusing because Asair-pro controls the go-to's fine and the (Asiair-pro) 4-way arrow keys slew the mount just fine.
                                      iOptron hasn't been able to solve the issue and I have all the latest firmware packages installed. Basically my expensive GEM-45-EC mount is useless for best imaging if I can't dither and auto-guide. My iOptron CEM60-EC is great with no issues...

                                      I can't tell if it's a problem on the iOptron side or the ZWO side, but It may be the ZWO side. Any help appreciated.

                                      James

                                        guitarmaker According to ZWO this is an INDI issue but they don't want to reveal if they have been talking to the INDI developers or not. There is a workaround though. Before starting guiding, disconnect the mount in the ASIAir app and then immediately connect it again. Then start the guiding calibration.

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