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Michael,
I think you just inadvertently answered a strange imaging issue I see occasionally.
Maybe I'm seeing my guiding locked onto a bad pixel when I get a really smeared image.
Could this image have been caused by a bad pixel lock?
I was doing a long run on the Iris Nebula last night. Kinda disappointing...
All I know about PEC you could stick in your eye and not know it was there.
I just run the rudimentary PEC offered in the Gemini 2. But couldn't say if it really makes a difference.
--
SonnyE
(I suggest viewed in full screen)
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Hi Sonny,
If using PHD2, go under the Brain icon, and select either 2x2 or 3x3 median noise reduction. That will eliminate bad single pixels.??
However I don't think it's that....
I think the rotated image is due the mount being very badly off polar alignment.? For long duration deep sky imaging, the polar alignment has to first be close by polar scope, then drift aligned. PHD2 has a good tool for that.? Otherwise you get these rotated images like you show.
Are you using a polar scope up the RA tube?? If so beware: polar scopes have a moveable glass "reticule" that must be carefully centered as you rotate the RA axis. You can easily get the center + symbol off the optical center, or crack the glass reticule by overtightening the tiny setscrews.? I think the Orion Atlas manual you can download explains how to center the reticule...
More later...going to sleep now at 2:30 am...
Best, Michael
Michael,
I think you just inadvertently answered a strange imaging issue I see occasionally.
Maybe I'm seeing my guiding locked onto a bad pixel when I get a really smeared image.
Could this image have been caused by a bad pixel lock?
I was doing a long run on the Iris Nebula last night. Kinda disappointing...
All I know about PEC you could stick in your eye and not know it was there.
I just run the rudimentary PEC offered in the Gemini 2. But couldn't say if it really makes a difference.
--
SonnyE
(I suggest viewed in full screen)
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Are there any MacOS tools like PECprep / PEMPro ?
Thanks,
Callium
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sadly no
the closest option is to do something like run parallels
Are there any MacOS tools like PECprep / PEMPro ?
Thanks,
Callium
-- Brian?
Brian Valente portfolio
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On Fri, Jul 3, 2020 at 02:37 AM, Michael Herman wrote:
More later...going to sleep now at 2:30 am...
Thanks Michael! I finally called it a night at 4 AM. LOL! After the disappointing smeartation, I did venture into PHD 2 and tried out the Drift Alignment Tool. That was easy to use, although I wondered if it was accurate. So last night I used the Drift Alignment Tool first, then built my model. Things worked a lot better! (I think) No Smeartation, anyway. Two victims. No to an RA mounted scope. I tried one of those with my defunct and gone away AVX (POC!) I do have Sharpcap. If I could remember to use it. I basically just run as many 3 West, 3 East, 3 West, 3 East scenario's as needed until the stars are landing as near center as they will. Last night (this morning) I did a PHD 2 Drift Align before running my Model. Centered up my victims, started PHD 2, and shot way. (No Meridian crossings, because I was aimed NNE) So far, the PHD 2 drift align is easiest for me to work with. I'm using an Orion SSAG camera, do run a dark library with it, and it has been the one piece of equipment that has always worked good from day 1. (It's a mono camera BTW) My Jury is still out, but I think my bumbling onto the Drift Alignment Tool has helped. Can't hurt. Thank You! ? -- SonnyE (I suggest viewed in full screen)
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Sonny
I do agree that PA improvements will help
you basically have field rotation.?
There is an easy way to visualize this if you still have your original images. Stack them using maximum instead of average and it will show you the rotation
what's happening is it's tracking correctly, but due to PA misalignment, your image frame is rotating around the center,?
Also FYI the pattern within the image that also shows this (called 'walking noise') can be eliminated by using dithering.?
On Fri, Jul 3, 2020 at 02:37 AM, Michael Herman wrote:
More later...going to sleep now at 2:30 am...
Thanks Michael! I finally called it a night at 4 AM. LOL!
After the disappointing smeartation, I did venture into PHD 2 and tried out the Drift Alignment Tool.
That was easy to use, although I wondered if it was accurate.
So last night I used the Drift Alignment Tool first, then built my model.
Things worked a lot better! (I think) No Smeartation, anyway. Two victims.
No to an RA mounted scope. I tried one of those with my defunct and gone away AVX (POC!)
I do have Sharpcap. If I could remember to use it.
I basically just run as many 3 West, 3 East, 3 West, 3 East scenario's as needed until the stars are landing as near center as they will.
Last night (this morning) I did a PHD 2 Drift Align before running my Model. Centered up my victims, started PHD 2, and shot way. (No Meridian crossings, because I was aimed NNE)
So far, the PHD 2 drift align is easiest for me to work with.
I'm using an Orion SSAG camera, do run a dark library with it, and it has been the one piece of equipment that has always worked good from day 1. (It's a mono camera BTW)
My Jury is still out, but I think my bumbling onto the Drift Alignment Tool has helped. Can't hurt.
Thank You!
?
--
SonnyE
(I suggest viewed in full screen)
-- Brian?
Brian Valente portfolio
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Hi Sonny,
I have an Orion SSAG camera too.? ? Now I'm using some newer design ASI cameras, and I realize how inferior the Orion SSAG is (today... in its heyday it was fine!).?? The SSAG has some hot pixels and a lot of noise, making it hard to find weaker guide stars.
I don't want to spend your money, but consider upgrading your SSAG to maybe a ZWO USB3.0 ASI camera.? There are many to?choose from. ? ? The ASI120MM is mono, very high sensitivity and low noise.? I? have them in USB2.0, but recently I tried a large chip ASI178MM that I planned for planetary work. ? ? That 178MM is USB3, and really low noise and sensitive. ? ? I find the USB3.0 cameras to be far more reliable than?the USB2.0 versions.... stronger cable connector at the camera, and faster speed leads to less "dropouts".
Anyway, I'm glad you are enjoying the Drift tool in PHD2.?? Another amateur, in Missouri, Bob Runyan, showed me that Drift tool a few years ago, and it was really a good discovery. However, if I don't do the rough polar alignment with a polar scope (or your better new alternative) then I find Drift alignment is impossible... you have to be pretty close else you cannot find the Drift improvement.
Have fun and continued progress and success.
Michael
On Fri, Jul 3, 2020 at 10:24 AM Brian Valente < bvalente@...> wrote: Sonny
I do agree that PA improvements will help
you basically have field rotation.?
There is an easy way to visualize this if you still have your original images. Stack them using maximum instead of average and it will show you the rotation
what's happening is it's tracking correctly, but due to PA misalignment, your image frame is rotating around the center,?
Also FYI the pattern within the image that also shows this (called 'walking noise') can be eliminated by using dithering.?
On Fri, Jul 3, 2020 at 02:37 AM, Michael Herman wrote:
More later...going to sleep now at 2:30 am...
Thanks Michael! I finally called it a night at 4 AM. LOL!
After the disappointing smeartation, I did venture into PHD 2 and tried out the Drift Alignment Tool.
That was easy to use, although I wondered if it was accurate.
So last night I used the Drift Alignment Tool first, then built my model.
Things worked a lot better! (I think) No Smeartation, anyway. Two victims.
No to an RA mounted scope. I tried one of those with my defunct and gone away AVX (POC!)
I do have Sharpcap. If I could remember to use it.
I basically just run as many 3 West, 3 East, 3 West, 3 East scenario's as needed until the stars are landing as near center as they will.
Last night (this morning) I did a PHD 2 Drift Align before running my Model. Centered up my victims, started PHD 2, and shot way. (No Meridian crossings, because I was aimed NNE)
So far, the PHD 2 drift align is easiest for me to work with.
I'm using an Orion SSAG camera, do run a dark library with it, and it has been the one piece of equipment that has always worked good from day 1. (It's a mono camera BTW)
My Jury is still out, but I think my bumbling onto the Drift Alignment Tool has helped. Can't hurt.
Thank You!
?
--
SonnyE
(I suggest viewed in full screen)
--
Brian?
Brian Valente portfolio
|
On Fri, Jul 3, 2020 at 10:43 AM, Michael Herman wrote:
Have fun and continued progress and success.
?
Michael
Hi Michael, Thank You for the reply. I certainly hear you about the Orion (lack off) Quality issue. My Orion G3 was a POS out of the box, then things got worse. It's so dead now it can't be used at all, but the freakin fan runs. Please correct me if I'm wrong, but the soul purpose of a guide camera is to find a single star, lock onto that star, then the guiding (PHD2) sends the guiding pulses to the mount to guide on that single star. (In a nutshell) Since I'm a dolt about getting things right, I was wondering about that Smeartation I was seeing. (My word. I made it up. Makes as much sense as "Sticktion", a WW2 terminology) I almost always just use the Auto in PHD to pick a star for guiding. The latest version has a nifty picker button that gets the guiding on right away. Love that improvement. Makes my life much simpler and quicker to get to imaging. I do like the USB3 attributes, and hunkier connectors. But my USB cable (for one thing) is a USB 2 configuration. So no need for a USB3 camera, because it's going to get knocked back to USB2 anyway. Of course, no need to let a $9 cable spoil the party. If I can find a 15' USB3 cable, I'll buy it just to have my USB3 Star Tech hub connected to my Baby Dell at it's USB3 port. Can't hurt to give it as much speed from the hub at the telescope, to the computer. Even if my cameras are USB2. Oh! This mud is thick! ? -- SonnyE (I suggest viewed in full screen)
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Hi Sonny
UI really think what you are seeing is field rotation due to polar misalignment - it's not about the quality of the guiding, although i suspect your guiding is reasonably good
as your target moves across the sky, it is tracked, but the polar misalignment causes your framing to rotate. when you image for extended perior?of time, that can be quite a lot.?
I mentioned this before, but there's an easy way to visualize this if you re-stack your images with Maximum integration mode instead of average.
?
On Fri, Jul 3, 2020 at 10:43 AM, Michael Herman wrote:
Have fun and continued progress and success.
?
Michael
Hi Michael, Thank You for the reply.
I certainly hear you about the Orion (lack off) Quality issue. My Orion G3 was a POS out of the box, then things got worse. It's so dead now it can't be used at all, but the freakin fan runs.
Please correct me if I'm wrong, but the soul purpose of a guide camera is to find a single star, lock onto that star, then the guiding (PHD2) sends the guiding pulses to the mount to guide on that single star. (In a nutshell)
Since I'm a dolt about getting things right, I was wondering about that Smeartation I was seeing. (My word. I made it up. Makes as much sense as "Sticktion", a WW2 terminology)
I almost always just use the Auto in PHD to pick a star for guiding. The latest version has a nifty picker button that gets the guiding on right away. Love that improvement. Makes my life much simpler and quicker to get to imaging.
I do like the USB3 attributes, and hunkier connectors. But my USB cable (for one thing) is a USB 2 configuration. So no need for a USB3 camera, because it's going to get knocked back to USB2 anyway. Of course, no need to let a $9 cable spoil the party. If I can find a 15' USB3 cable, I'll buy it just to have my USB3 Star Tech hub connected to my Baby Dell at it's USB3 port. Can't hurt to give it as much speed from the hub at the telescope, to the computer. Even if my cameras are USB2.
Oh! This mud is thick!
?
--
SonnyE
(I suggest viewed in full screen)
-- Brian?
Brian Valente portfolio
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Hello All?
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I wanted to refresh this thread instead of starting a new one for a somewhat related question of my own.?
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I am a recent entrant into AP and have a Losmandy GM8 and CG11, both with 492 digital drives...so strictly push to. (I want to keep it that way for a while before upgrading to OnStep).?
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My question is around the procedure for generating a PEC profile using the 492 Digital drive. I went through the manual but that references a visual setup.?
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I want to do the same thing, but with my autoguider setup using the ST4 ports on the camera and the 492 digital drive unit. My autoguider setup is a 120mm scope attached to a Asi 120mm-s camera. I guess I need to find a way for PhD2 to talk to the 492 digital drive when the PEC setting is engaged. Is that something as simple as running an autoguiding session whilst PEC mode is engaged on the controller ??
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Just to be clear, I am specifically talking about applying a PEC profile to my mount and not about how to autoguide with my setup: I know how to do the latter.?
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Many thanks!?
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Avi?
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Hi Avi,
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it¡¯s been a while since I last used my digital drive so procedures are a bit fuzzy in my memory but, here¡¯s what I¡¯d suggest.
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The 492 drive has an internal feature to save and use a PEC curve. What it does is basically save to its internal memory the corrections applied by the user (or guide camera) while in the recording phase, and then applying those corrections automatically.
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I would start the guiding first with your guide scope/camera. Once the guiding has stabilized I¡¯d turn the recording on and let it rip for however long it needs. After the recording it will start to correct on its own.
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You may wish to disable DEC corrections in PHD2 as those are ignored by the 492 box but, if there¡¯s some drift in DEC leave them on so as to not loose the star.
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Hope this helps
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Jonathan
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Hi Jonathan?
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This is indeed super helpful.?
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If I get time tonight I will attempt it.?
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I was actually going to use multi star guiding ..I am assuming that is perfectly fine but wanted to confirm since the manual mentions keeping the guide star centered. But I guess that was well before multi star guiding was even available as an option.?
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Once the PEC curve is saved on the controller, is it automatically applied for all tracking sessions going forward ? I assume that is the case until the time I regenerate the PEC profile.?
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Many thanks?
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Avi?
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I don¡¯t think using multi star guiding would be an issue. The drive is only recording the corrections received from PHD2. How PHD2 calculates those corrections would not impact what the mount receives. However, I never tried this so I¡¯m basically just guessing lol. If PHD can use multiple stars while using an ST4 style guider then you should be good to go.
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As for activating PEC, once the recording phase is done the new PEC corrections will automatically start. The manual is not very clear nor do I remember well but, I suspect the PEC curve is stored in memory until you apply a new one. If the PEC light is on when you turn the mount on, then you know it¡¯s working ;). However, if it¡¯s deactivated after a power cycle, then you know it¡¯s mostly just a 4 minutes investment to build a new one and, by the time you realize this, you will already know how to do this :)
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In case you haven¡¯t seen it yet, here¡¯s the .
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Good luck
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Jonathan
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Hi Jonathan,
?
Yeah....PhD2 defaults to multi star guiding...or at least in my version.?
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I attempted calibration last night and made progress (I was fumbling with setting up the calibration run the last time...ultimately figured out that with ST4 guiding using PhD2, I need to setup an Aux mount as "ask for coordinates" and then manually punch in my approx Dec coordinate which was ~8 degrees for me last night).?
?
Then I had to stop for absolutely ridiculous/hilarious reasons: calibration kept failing or returning "poor calibration" messages because the roof of my townhome kept showing up in my FoV..haha. I had setup at the wrong location! And by then I was just too demoralized to relocate my setup, run PA and start over. The pains of not having my own private backyard to shoot from, let alone a dark sky location!?
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I am hoping tonight is the night!?
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I did go through the GM8 manual (right now I am focusing on the GM8...my G11 is in storage).....it doesn't provide a lot of detail around the post PEC steps, but I think it should be obvious. I believe after performing PEC, the red LED is always ON during subsequent sessions unless the PEC profile is erased for some reason or you deliberately turn it off. Either way, I will go through this exercise and report back just in the rare case that someone is actually doing what I am doing. :)?
?
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Avi
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On Mon, Apr 21, 2025 at 08:23 AM, <avishekaiyar@...> wrote:
Hi Jonathan,
?
Yeah....PhD2 defaults to multi star guiding...or at least in my version.?
?
I attempted calibration last night and made progress (I was fumbling with setting up the calibration run the last time...ultimately figured out that with ST4 guiding using PhD2, I need to setup an Aux mount as "ask for coordinates" and then manually punch in my approx Dec coordinate which was ~8 degrees for me last night).?
?
Then I had to stop for absolutely ridiculous/hilarious reasons: calibration kept failing or returning "poor calibration" messages because the roof of my townhome kept showing up in my FoV..haha. I had setup at the wrong location! And by then I was just too demoralized to relocate my setup, run PA and start over. The pains of not having my own private backyard to shoot from, let alone a dark sky location!?
?
I am hoping tonight is the night!?
?
I did go through the GM8 manual (right now I am focusing on the GM8...my G11 is in storage).....it doesn't provide a lot of detail around the post PEC steps, but I think it should be obvious. I believe after performing PEC, the red LED is always ON during subsequent sessions unless the PEC profile is erased for some reason or you deliberately turn it off. Either way, I will go through this exercise and report back just in the rare case that someone is actually doing what I am doing. :)?
?
?
Avi
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Hi Avi,
?
So was last night the night?? If so how did it go??
?
--
Chip Louie Chief Daydreamer Imagination Hardware?
Astrospheric Forecast - South Pasadena, CA?
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Michael Herman
Chip Louie