It's the little tweaks...
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I thought my PA and balancing were pretty good and felt I had decent guiding, for the most part, averaging around .63" RMS. Except, my lightweight Apertura 75Q. I could never get good guiding with that scope, I just figured the G11, purchased new in July 2023, did better with heavier loads. So, I started going down the rabbit hole.
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I bought the wavy washer for the RA. I turn the latitude down as far as it will go so the RA moves freely and give a slight imbalance to the east. (This is usually the scope side, since my eastern view is only available after about 60 degrees, most of my imaging is to the west, where I can go down to about 35 degrees.) The scope has a small imbalance to the camera side.
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For years I was using the Pole Master and the accompanying software to do my PA. It seemed to be pretty good, but I didn't think I was getting under 2.0" with that software. I started looking around and I was hearing people having good success with that camera and SharpCap, so I decided to give it a try.?
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I ran the PA with the Pole Master software then immediately with SharpCap. SharpCap shows my PA error at 4.3", no way! This has to be wrong I think, so I run through the Pole Master routine again, really tried dialing it in, what does SharpCap say? 3.9".
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I go through the SharpCap alignment and get the PA down to 0.5". check Pole Master and it says I'm off 3.5. That's a big difference but I decided to trust SharpCap.?
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As a result, for the past couple months now, my guiding has been incredible. I'm consistently staying in the range of 0.46" RMS and on some nights in the 0.27" range.?
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My conclusion is, and I always thought good enough was ok, Proper balance and good PA can't be emphasized enough.
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As a note, I'm running L6 and have not upgraded to take advantage of training PEC, I'm using Predictive PEC and don't see why I need to train PEC with the results I'm getting.
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Hi Darryl,
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I don't know if they have changed over time but I've used the same Polemaster camera since they were first released maybe 8 years ago and I have changed laptops and mini computers a few times. Very early on there were driver issues that were resolved over time and the latest stable version 1.3.2.8 is several years old, maybe 3-4 years old? It seems to work fine for me and I even use an ADM prototype universal Polemaster dovetail mount which I clamp to the underside of the scope dovetail in the recommended camera USB port orientation on the left when facing the camera.?
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Using the Polemaster system I was able to routinely achieve a PA error under 30" arc seconds or better. I used my 20 year old G11G that had been updated to current G11G specs, the same maybe 10 year old Stellarvue 50mm f/4 guide scope and SV solid clamshell?with a ZWO ASI120MM mini. This was my standard guide camera / guide scope setup as it matched the QHYCCD QHY5L-II-M specs but the ASI120MM mini was part of a more stable driver ecosystem at ZWO and also compatible with the first gen ASIAIR controller.?
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Ironically since switching to the ZWO ASIAIR ecosystem when Covid was just getting going I never used the Polemaster once the version 2.0 app came out in Beta. Even with my usual driveway spot having no direct line of sight to the NCP most of the year the ASIAIR app gives me very solid polar alignments using the All-Sky polar alignment of the ASIAIR app on the ASIAIR Plus hardware.? The autoguiding is not quite as good as when I can get a direct line of sight PA using the Polemaster, SharpCap or ASIAIR but it is very close.??
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The last time I seriously measured the guiding error of this rig (G11G with piggyback SV50mm f/4 guidescope / ASI120MM mini) was many years ago using PHD2 and it measured well under 0.5" @ 0.48" - 37" RMS on a still air night in the high desert.? Some years later I subsequently upgraded to an ASI290MM mini for the slightly larger sensor diagonal size to get more guide stars in the ZWO OAG-L must mostly for the advantage of the smaller 2.9um pixels. I saw a small but noticeable improvement when guided piggybacked - maybe 10-15% under my regular suburban skies on normal nights sometimes better but that only happens 2 or 3 times a year here. I think this is about as good as it can get given the seeing and I imagine the mount is near its' limits as far as response and settling time to corrections though interestingly some G11G users have reported even lower numbers though I am not sure it has any real impact on the resulting image quality given the advances in image processing software using AI and even a modest GPU.? ?
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I very recently upgraded the piggyback guide camera again to the newer ASI678MM camera for the no amp-glow lower noise and even smaller 2.0um pixels, higher pixel count and even larger diagonal sensor size. Originally I thought I might also use it to image solar system objects in mono but in testing my feeling is the frame rate is too low. So the ASI678MM has become my dedicated piggyback guide scope camera. The ASI290MM mini remains in the ZWO OAG-L for now though I plan to move to the ASI174 to take full advantage of the larger 12mm prism which would give more usable guide stars with the M10" f/6.3 when working @ f/4.?
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Chip Louie Chief Daydreamer Imagination Hardware? Astrospheric - South Pasadena, CA? |
¿ªÔÆÌåÓýProduction ¡ ? From: [email protected] <[email protected]> On Behalf Of Jim Waters
Sent: 04 September 2024 02:48 To: [email protected] Subject: Re: [Gemini-II_io] It's the little tweaks... ? What's the current status of the L6 version?
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Darryl
Chip Louie
David Malanick
David C. Partridge