Nice work Nick.
you've done a great job with this
Just wanted to say a huge thanks to everyone that offered help & suggestions over the last couple of weeks. I am really dialed in now.
Had a great session last night, all automated with NINA (focus, slewing, syncing w/plate solving and guiding).
Guided with zero issues for 4 hours at 0.62" RMS, dipping into the high 0.4s sometimes but hovering right in the 0.5s mostly.
I do have some occasional spikes to +/- 2" but they dont seem critical. One big spike at -6" - no idea what happened there so I will just watch out for it
The only issue I have now is I feel my focus is leading to bloated stars as my FWHMs are all in the 6-8 arc/sec range but this is not the mount. My HFR in NINA when auto-focusing is 3.5-3.6 which leads to that number.?
Going to get a Bahtinov mask for the refractor just to check the result of autofocus. There is quite a narrow window of focus surprisingly, and maybe my NINA settings are causing me to miss it
I'm really happy with the images - 10 min subs with eccentricity in the 0.5s even with the sensor tilt
-- Brian?
Brian Valente portfolio
|
Just wanted to say a huge thanks to everyone that offered help & suggestions over the last couple of weeks. I am really dialed in now.
Had a great session last night, all automated with NINA (focus, slewing, syncing w/plate solving and guiding).
Guided with zero issues for 4 hours at 0.62" RMS, dipping into the high 0.4s sometimes but hovering right in the 0.5s mostly.
I do have some occasional spikes to +/- 2" but they dont seem critical. One big spike at -6" - no idea what happened there so I will just watch out for it
The only issue I have now is I feel my focus is leading to bloated stars as my FWHMs are all in the 6-8 arc/sec range but this is not the mount. My HFR in NINA when auto-focusing is 3.5-3.6 which leads to that number.?
Going to get a Bahtinov mask for the refractor just to check the result of autofocus. There is quite a narrow window of focus surprisingly, and maybe my NINA settings are causing me to miss it
I'm really happy with the images - 10 min subs with eccentricity in the 0.5s even with the sensor tilt
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Michael
Herman¡¯s Power Supply is the best choice..
?
Derek
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Re: New G11 Question Concerning Stiction
Question..
Doesn¡¯t the Wavy Washer require a machined groove that not all mounts
have??
?
Not
positive, but I don¡¯t believe my mount will accept one..
?
Derek
?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of alan137
Sent: Friday, July 02, 2021 11:04
PM
To: [email protected]
Subject: Re: [Losmandy_users_io]
New G11 Question Concerning Stiction
?
There is no drawback to using the wavy washer.
Nobody who got the washer wishes they hadn't and would rather do the alt=0
trick.
The Losmandy mounts are already front-heavy, and I don't want the thing to tip
over while trying to balance the scope.
Someday, when you man up and get a BIG scope, you will enjoy not having to
crank it to zero for every little change in setup.
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I used the?PST-YD100??from here?
From a LipoFE battery and it has been working great so far
Configurable output voltages and not easy to "knock" the switch to an unwanted level
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On Fri, Jul 2, 2021 at 08:39 PM, Vishal Billa wrote:
Thanks to everyone who replied for your input. I am moving fowward with the G11G with the goal of future proofing my setup for the forseeable future. I have the opportunity to pick up an unused G11G with the FHD, AKS, CKS, TKS, RAEXT, 2x 21lb counterweights, and 1x 9lb counterweight. This is pretty much every accessory available but is there anything else I should get in preperation for this mount? I've seen mixed reviews on the tripod feet for imaging, but are they important for visual? I also planned on powering this mount with the same pocket powerbox I used for my last mount, however the total output for the powerbox is 12V @ 10A and if I'm also powering a cooled astro cam, focuser, and dew heater, I'm not sure if the powerbox can handle the mount's power requirements or if I should be using a seperate power supply for the mount.?
-Vishal
If the powerbox is really rated to output 12v@10A continuously and the output is regulated sure it will work fine. The only question is for how long.? The catch is regulated output and the how long is asked because a 12V output regulated will kill a normal battery's life span pretty quickly without some sort of battery management. An automatic cut off or even a battery voltage display or amp meter to calculate usage to let you know when to shut it off to prevent battery damage would be good.? Lead acid batteries can only be used down to about 12.1 volts or 50% without killing them quickly.? ? -- Chip Louie Chief Daydreamer Imagination Hardware?
? ?Astropheric Weather Forecast - South Pasadena, CA?
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Re: Firecapture autoguide with Gemini 1 ?
Micheal
What a detailed generous response. Thank you
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Vishal,
There have been some reports with the G11G that the higher 15V power supplies work better than 12V. The same probably applies to the GM811G. With my G11G, I use the Losmandy supplied 15V 4.3 Amp AC/DC converter:?
There probably are some less expensive converters out there but I decided to go with the manufacturer's official unit. TEC cooled cams can pulled 2 or 3 amps, and dew heaters use a few amps too. But with the total load applied you might be dropping below 12V; you would probably need to check with an inline voltmeter/ammeter to be sure.
Regards,
John??
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Re: New G11 Question Concerning Stiction
There is no drawback to using the wavy washer.
Nobody who got the washer wishes they hadn't and would rather do the alt=0 trick.
The Losmandy mounts are already front-heavy, and I don't want the thing to tip over while trying to balance the scope.
Someday, when you man up and get a BIG scope, you will enjoy not having to crank it to zero for every little change in setup.
|
Thanks to everyone who replied for your input. I am moving fowward with the G11G with the goal of future proofing my setup for the forseeable future. I have the opportunity to pick up an unused G11G with the FHD, AKS, CKS, TKS, RAEXT, 2x 21lb counterweights, and 1x 9lb counterweight. This is pretty much every accessory available but is there anything else I should get in preperation for this mount? I've seen mixed reviews on the tripod feet for imaging, but are they important for visual? I also planned on powering this mount with the same pocket powerbox I used for my last mount, however the total output for the powerbox is 12V @ 10A and if I'm also powering a cooled astro cam, focuser, and dew heater, I'm not sure if the powerbox can handle the mount's power requirements or if I should be using a seperate power supply for the mount.?
-Vishal
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Re: G11 and 6¡± f/10 for imaging?
For reference, at 1500 frames per second you could hand hold the scope and get stable images :-)
--
Edward
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Re: "Nudge Mount Out of Safety Limit On Slew"?
FYI the Gemini Telescope.net driver user manual is available via the app itself, under the Help! menu
On Fri, Jul 2, 2021 at 11:05 AM Paul Kanevsky < yh@...> wrote: On Fri, Jul 2, 2021 at 02:01 PM, Chuck Gehrke wrote:
Just curious what this option/command does?
From the driver manual:
Normally if Gemini tracks into a safety limit the mount stops and must be manually backed away from the limit before you can GoTo your next target. Whilst this is a minor inconvenience for someone local to the mount, it is a major problem for automated operations. If this parameter is set it invokes a one second slew, at the currently configured slew rate, away from the safety limit. This feature is used by all ASCOM slew commands, including Alt/Az slews and equatorial slews. It is also used when a park command is issued that requires the mount to move from the current position. The driver waits for the one second slew to complete, and then issues the desired slew/park command, as usual.?
Regards,
? ?-Paul
-- Brian?
Brian Valente portfolio
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Re: "Nudge Mount Out of Safety Limit On Slew"?
On Fri, Jul 2, 2021 at 02:01 PM, Chuck Gehrke wrote:
Just curious what this option/command does?
From the driver manual:
Normally if Gemini tracks into a safety limit the mount stops and must be manually backed away from the limit before you can GoTo your next target. Whilst this is a minor inconvenience for someone local to the mount, it is a major problem for automated operations. If this parameter is set it invokes a one second slew, at the currently configured slew rate, away from the safety limit. This feature is used by all ASCOM slew commands, including Alt/Az slews and equatorial slews. It is also used when a park command is issued that requires the mount to move from the current position. The driver waits for the one second slew to complete, and then issues the desired slew/park command, as usual.?
Regards,
? ?-Paul
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Re: "Nudge Mount Out of Safety Limit On Slew"?
Just curious what this option/command does?
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Re: G11 and 6¡± f/10 for imaging?
Jim,
At 100 frames per second this should not be an issue. I've used a Skywatcher 150mm visually on a Losmandy G11 with classic drivetrain and it had no issues with vibration. Granted this is a 150mm f/8 scope so it is shorter but at over 300x any movement is easy to see with the mark I eyeball.?
--
Chip Louie Chief Daydreamer Imagination Hardware?
? ?Astropheric Weather Forecast - South Pasadena, CA?
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Re: Firecapture autoguide with Gemini 1 ?
Firecapture autoguider works just fine with Gemini-1.? You must of course have a working serial cable, ASCOM, and Gemini.net applet working.?
PHD2 does not care of any orientation of the autoguide camera, but FireCapture does care.
So, here is what you must do:
1. Rotate the planetary video camera so that the mount RA axis moving East West only moves the camera image left-right.? It need not be perfectly lined up but as good as you eyeball it.? ?Just use your hand controller and watch the planet motion ...should be left to right when you press East -West diamond buttons.?
2. In FireCapture, you must go to settings, and turn on the autoguide feature.? This should then have you select the mount, and you'll pick ASCOM and Gemini.net.? that will launch the Gemini.net applet.? You then set that to G (guide mode) [not C for Center mode or S for Slew mode] .
3. You must select a point in the planet...or perhaps it aitosejects the center of mass if the whole planet is in the frame.? I don't recall exactly!??
4. You may find that FireCapture gets the E-W horizontal or N-S vertical guide dire tions wrong.? In FC there is in the Settings for Autoguide check iced to reverse the E-W and N-S directions.? You may have to get those checked or unchecked until the autoguiding works.
5. Practice using a star.
Best of luck, Michael
I have a G11 with Gemini 1. Does anyone have any experience using Firecapture to autoguide on planets? Is this possible? Anything else needed?
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Firecapture autoguide with Gemini 1 ?
I have a G11 with Gemini 1. Does anyone have any experience using Firecapture to autoguide on planets? Is this possible? Anything else needed?
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Re: G11 and 6¡± f/10 for imaging?
>>>
That should be adequate for such short exposures. Not great, but adequate.
that was my thought. i'm probably a little more positive because it IS such short exposures it should be fine
On Thu, Jul 1, 2021 at 9:23 PM Joe Bergeron < joe@...> wrote: That should be adequate for such short exposures. Not great, but adequate.
Joe Bergeron
Fellow, International Association of Astronomical Artists
Author, The Endurian Universe novels
Author and illustrator, Cosmic Cat
-- Brian?
Brian Valente portfolio
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Re: G11 and 6¡± f/10 for imaging?
That should be adequate for such short exposures. Not great, but adequate.
Joe Bergeron
Fellow, International Association of Astronomical Artists
Author, The Endurian Universe novels
Author and illustrator, Cosmic Cat
|
Hi Chuck
>>>What if you have a guide lodestar with 8.2 micron pixel size and an image camera with 3.8 micron pixel size? Would that effect or contribute a significant error?
It depends (isn't that like most answers in astronomy) ;)
If you have a specific example you're interested in, you can post the guide and image train image scales (or cameras and telescopes) and we can compare them
you can have a large pixel size on your guide camera but if its guiding well enough and/or the?image scale is close enough, it should be fine. The important measure is the RMS in arcsec/pix relative to the main imaging camera. Guiding on fractional pixel sizes has been around for a while and i think is underappreciated in terms of how effective it is.?
As a general rule of thumb i think image scale of 3:1 of guider image scale to imaging image scale is good. Beyond that the resolution of the guiding setup starts to be limited in terms of how accurate it can be.?
If the guiding RMS is less than 1 pixel for the imaging camera, I would consider that solid guiding.?
Brian
Your reply about image scale got me thinking. What if you have a guide lodestar with 8.2 micron pixel size and an image camera with 3.8 micron pixel size? Would that effect or contribute a significant error?
Chuck
On Thursday, July 1, 2021, 03:53:46 PM PDT, Brian Valente < bvalente@...> wrote:
>>>is this displayed in PHD Log viewer ?
yes, do just be clear i'm talking about the components of the guiding, not the?total guiding rms
If you have a perfect mount with 0 error, you are still limited by other conditions (seeing, wind, vibrations, hardware tilting)
i'm specifically talking about your notion of using PEMPro etc. to reduce the primary periodic error. in other words, what's the value of trying to implement PEC with your current setup
on your 3hr run, your PE for the primary is around 4.3" - FYI you'll notice your drift is much higher, but that's even easier to guide out
this PHD Log Viewer graph shows this:
That number is the calculated unguided PE
you can also choose to just analyze the guide data without backing out corrections:
here you can see your two peaks are both around 0.3" - in other words "residual error" i.e., what can't be guided out given your settings, configuration, hardware, etc.
The primary and 76 sec is prominent, but (here's the important part) they are both fractions of a pixel of your imaging camera.?
can you reduce those values using PEC? sure
will it make a difference? you're talking about error from PE going from maybe 1/3 of a pixel to maybe 1/4 or 1/8 of a pixel? you can decide if that's important to you ?
FYI I would give period length of 76.1s a try on PPEC and see how that goes. maybe drop your exposure time to 1-1.5sec Yeah I think I get what you are saying (not sure how you can tell the "wasn't guided out" error -- where does that come from ?
If I have a 1" guide error then that will also be a 1" error In the imager (since we assume the scopes are moving together - assuming no flex)
Since I am 2.2 a/s in the imager, that would mean 1"/2.2 = 0.45 pixels and for my 0.76 error it would be 0.76/2.2 = 0.34 pixels
Now somehow you managed to come up with the? 1/4" "wasn't guided out" error but my RMS in the log was 0.76" total, so now I am curious about how you backed out the other approx 0.5" - is this displayed in PHD Log viewer ?
-- Brian?
Brian Valente portfolio
-- Brian?
Brian Valente portfolio
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Chip Louie
Edward Plumer
Paul Kanevsky
Chuck Gehrke
Michael Herman