Drift Alignment To Help With Unguided Images
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Tony Benjamin <tonybenjamin@...>
I have an AP 1100GTO AE. I have done a 280 pt pointing model. Even with that I can't get even a 2 min sub without star elongation.
So, I'm going to recheck my polar alignment to make sure thats dialed in. But what about drift alignment? How do you go about it? Is there any good sources on this for AP mounts and PEMPro - or other software? Aside from the above - is there something else I need to do to get at least a 5 min unguided sub?
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Hi Tony AP produced a document on DEC and RA Drift Alignment This is the document I saved off from them. I think it's also available on their website
On Sat, Aug 29, 2020 at 9:13 AM Tony Benjamin <tonybenjamin@...> wrote: I have an AP 1100GTO AE. I have done a 280 pt pointing model. Even with that I can't get even a 2 min sub without star elongation. --
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PHD2 has a good drift alignment tool. PHD2 is free.
SharpCap has a great polar alignment tool. I use this tool every session to dial in my polar alignment. The cost for the “pro” version which has the tool was about $12. You could use that before you do anything else just to get a good idea of your actual polar alignment. It is my understanding from posts by Roland and Ray that polar alignment is not that critical when creating models and that APCC/APPM takes polar alignment induced drift into account when calculating the model. Perhaps Ray or Roland could remind us of what is considered good enough. -- Dean Jacobsen http://astrophoto.net/wp/ Image Gallery - http://astrophoto.net/wp/image-gallery/ Astrobin - https://www.astrobin.com/users/deanjacobsen/
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Ray Gralak
Hi Tony,
toggle quoted messageShow quoted text
Can you provide more details about your setup? That is what kind of telescope, camera, image scale, etc.? -Ray Gralak Author of APCC (Astro-Physics Command Center): https://www.astro-physics.com/apcc-pro Author of PEMPro V3: https://www.ccdware.com Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver
-----Original Message-----
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Roland Christen
Before you go down a bunch of blind alleys, check your RA and Dec drift rates using a guider program like PHD2 or MaximDL. Bring up a guider graph of the two axes, set the exposures to 2 - 3 seconds and turn off the guide corrections to the mount so that you see only the axis drift rates. Do that first before you do anything else, so that you get a fundamental set of drift curves.
If you get straight line drift trends in both axes, then you should be able to model and get a good tracking rate for at least 10 minutes.
If your RA line is not straight, but wanders back and forth (showing periodic error), then you have probably inadvertently turned your encoders off, so they are not really correcting the mount's tracking rate.
Rolando
P.S. never turn off the encoders on an encoder mount.
-----Original Message-----
From: Tony Benjamin <tonybenjamin@...> To: main@ap-gto.groups.io Sent: Sat, Aug 29, 2020 11:13 am Subject: [ap-gto] Drift Alignment To Help With Unguided Images I have an AP 1100GTO AE. I have done a 280 pt pointing model. Even with that I can't get even a 2 min sub without star elongation.
So, I'm going to recheck my polar alignment to make sure thats dialed in. But what about drift alignment? How do you go about it? Is there any good sources on this for AP mounts and PEMPro - or other software? Aside from the above - is there something else I need to do to get at least a 5 min unguided sub?
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Roland Christen
Most likely is that the encoders are turned off.
Next possibility is that there may be some telescope flexing or mirror shifting that cannot be modeled because it's not repeatable enough.
Third possibility is that he may have a very old version of APCC Pro - maybe needs to download the latest version.
Rolando
-----Original Message-----
From: Dean Jacobsen <deanjacobsen@...> To: main@ap-gto.groups.io Sent: Sat, Aug 29, 2020 11:59 am Subject: Re: [ap-gto] Drift Alignment To Help With Unguided Images PHD2 has a good drift alignment tool. PHD2 is free.
SharpCap has a great polar alignment tool. I use this tool every session to dial in my polar alignment. The cost for the “pro” version which has the tool was about $12. You could use that before you do anything else just to get a good idea of your actual polar alignment. It is my understanding from posts by Roland and Ray that polar alignment is not that critical when creating models and that APCC/APPM takes polar alignment induced drift into account when calculating the model. Perhaps Ray or Roland could remind us of what is considered good enough. -- Dean Jacobsen http://astrophoto.net/wp/ Image Gallery - http://astrophoto.net/wp/image-gallery/ Astrobin - https://www.astrobin.com/users/deanjacobsen/
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Tony Benjamin <tonybenjamin@...>
Hi,
Thanks all for the input. The scope I am currently using is a C11 Edge (the mirror is "locked down" - but who knows??). Image scale is .44 with the ML16200. Hopefully will upgrade to a Planewave 12.5 in the near future and kiss possible mirror shift goodbye :) Pretty sure the encoders were on - but will double check tonight. I also have tracking and pointing corrections on in APPM. The only message I've noted of late is that my CP4 firmware needs to be updated? Tony
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Roland Christen
"Pretty sure" will only be confirmed if you do what i suggested - do a guider graph for 10 - 12 minutes with guide pulses turned off. See what your guide graph looks like, maybe even post a screen shot so we have something to work with.
Rolando
-----Original Message-----
From: Tony Benjamin <tonybenjamin@...> To: main@ap-gto.groups.io Sent: Sat, Aug 29, 2020 12:55 pm Subject: Re: [ap-gto] Drift Alignment To Help With Unguided Images Hi,
Thanks all for the input. The scope I am currently using is a C11 Edge (the mirror is "locked down" - but who knows??). Image scale is .44 with the ML16200. Hopefully will upgrade to a Planewave 12.5 in the near future and kiss possible mirror shift goodbye :) Pretty sure the encoders were on - but will double check tonight. I also have tracking and pointing corrections on in APPM. The only message I've noted of late is that my CP4 firmware needs to be updated? Tony
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Tony Benjamin <tonybenjamin@...>
Will do, tonight hopefully.
It says I need to contact AP to get the CP4 firmware updated? Might this play into my issue?
Tony
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of uncarollo2 <chris1011@...> via groups.io
"Pretty sure" will only be confirmed if you do what i suggested - do a guider graph for 10 - 12 minutes with guide pulses turned off. See what your guide graph looks like, maybe even post a screen shot so we have something to work with.
Rolando
-----Original Message----- Hi,
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Roland Christen
No, we have not changed the way the CP4 controllers interface with APCC Pro. However, there is a new version of APCC Pro that might be what you want to update.
If you are using a C14 for unguided, you may run into mirror shift issues that cannot be solved with modeling. I think trying to do unguided imaging with such a scope might be stretching things. First you have very long focal length, next you have an optical/mechanical system that is prone to differential flexure, and then you have possible mirror shifting, even if it's locked down. Reason for the shift is not because it tilts due to gravity, rather that the entire mirror slides sideways due to the clearance between the mirror's central hole and the shaft that it rides on. The mirror is quite heavy and slides around sideways because it is not glued down to the metal shaft that it sits on.
Rolando
-----Original Message-----
From: Tony Benjamin <tonybenjamin@...> To: main@ap-gto.groups.io Sent: Sat, Aug 29, 2020 1:09 pm Subject: Re: [ap-gto] Drift Alignment To Help With Unguided Images Will do, tonight hopefully.
It says I need to contact AP to get the CP4 firmware updated? Might this play into my issue?
Tony
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of uncarollo2 <chris1011@...> via groups.io
Sent: August 29, 2020 11:08 AM To: main@ap-gto.groups.io Subject: Re: [ap-gto] Drift Alignment To Help With Unguided Images "Pretty sure" will only be confirmed if you do what i suggested - do a guider graph for 10 - 12 minutes with guide pulses turned off. See what your guide graph looks like, maybe even post a screen shot so we have something to work with.
Rolando
-----Original Message-----
From: Tony Benjamin <tonybenjamin@...> To: main@ap-gto.groups.io Sent: Sat, Aug 29, 2020 12:55 pm Subject: Re: [ap-gto] Drift Alignment To Help With Unguided Images Hi,
Thanks all for the input. The scope I am currently using is a C11 Edge (the mirror is "locked down" - but who knows??). Image scale is .44 with the ML16200. Hopefully will upgrade to a Planewave 12.5 in the near future and kiss possible mirror shift goodbye :) Pretty sure the encoders were on - but will double check tonight. I also have tracking and pointing corrections on in APPM. The only message I've noted of late is that my CP4 firmware needs to be updated? Tony
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Tony Benjamin <tonybenjamin@...>
Noted.
I want spend the time fiddling with this…will get that Planewave 12.5” J
Heres what my warning looks like for upgrading the CP4 firmware:
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of uncarollo2 <chris1011@...> via groups.io
No, we have not changed the way the CP4 controllers interface with APCC Pro. However, there is a new version of APCC Pro that might be what you want to update.
If you are using a C14 for unguided, you may run into mirror shift issues that cannot be solved with modeling. I think trying to do unguided imaging with such a scope might be stretching things. First you have very long focal length, next you have an optical/mechanical system that is prone to differential flexure, and then you have possible mirror shifting, even if it's locked down. Reason for the shift is not because it tilts due to gravity, rather that the entire mirror slides sideways due to the clearance between the mirror's central hole and the shaft that it rides on. The mirror is quite heavy and slides around sideways because it is not glued down to the metal shaft that it sits on.
Rolando
-----Original Message----- Will do, tonight hopefully.
It says I need to contact AP to get the CP4 firmware updated? Might this play into my issue?
Tony
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of uncarollo2 <chris1011@...> via groups.io
"Pretty sure" will only be confirmed if you do what i suggested - do a guider graph for 10 - 12 minutes with guide pulses turned off. See what your guide graph looks like, maybe even post a screen shot so we have something to work with.
Rolando
-----Original Message----- Hi,
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Bill Long
You can update the firmware from the AP website.
From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Tony Benjamin <tonybenjamin@...>
Sent: Saturday, August 29, 2020, 11:20 AM To: main@ap-gto.groups.io Subject: Re: [ap-gto] Drift Alignment To Help With Unguided Images Noted.
I want spend the time fiddling with this…will get that Planewave 12.5” J
Heres what my warning looks like for upgrading the CP4 firmware:
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io]
On Behalf Of uncarollo2 <chris1011@...> via groups.io
No, we have not changed the way the CP4 controllers interface with APCC Pro. However, there is a new version of APCC Pro that might be what you want to update.
If you are using a C14 for unguided, you may run into mirror shift issues that cannot be solved with modeling. I think trying to do unguided imaging with such a scope might be stretching things. First you have very long focal length, next you have an optical/mechanical system that is prone to differential flexure, and then you have possible mirror shifting, even if it's locked down. Reason for the shift is not because it tilts due to gravity, rather that the entire mirror slides sideways due to the clearance between the mirror's central hole and the shaft that it rides on. The mirror is quite heavy and slides around sideways because it is not glued down to the metal shaft that it sits on.
Rolando
-----Original Message----- Will do, tonight hopefully.
It says I need to contact AP to get the CP4 firmware updated? Might this play into my issue?
Tony
From:
main@ap-gto.groups.io [mailto:main@ap-gto.groups.io]
On Behalf Of uncarollo2 <chris1011@...> via groups.io
"Pretty sure" will only be confirmed if you do what i suggested - do a guider graph for 10 - 12 minutes with guide pulses turned off. See what your guide graph looks like, maybe even post a screen shot so we have something to work with.
Rolando
-----Original Message----- Hi,
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Ray Gralak
Hi Tony,
It says I need to contact AP to get the CP4 firmware updated?If APCC is showing that message means you are not running the latest mount firmware. You can download it from the link below. You may need the password from the manual that came with your mount. https://www.astro-physics.com/software-updates/ -Ray Gralak Author of APCC (Astro-Physics Command Center): https://www.astro-physics.com/apcc-pro Author of PEMPro V3: https://www.ccdware.com Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver -----Original Message-----
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Ray Gralak
Hi Tony,
toggle quoted messageShow quoted text
From the screenshot, your firmware is definitely out of date. You are running P01-11 and should upgrade to P01-14. That probably is not the problem, but it doesn't hurt to have the latest firmware. As Roland said, using an SCT for unguided imaging at that image scale is going to be challenging because of random shifts in the positioning of the mirror. Those shifts can happen when creating a model that will pollute the model. You can check for this by using APPM to do a 5x verify run using your model. If there is randomness in the setup, the 5x verify results would show that. -Ray Gralak Author of APCC (Astro-Physics Command Center): https://www.astro-physics.com/apcc-pro Author of PEMPro V3: https://www.ccdware.com Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver
-----Original Message-----
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W Hilmo
I image with an 8" EdgeHD 800 and I get about the same performance that Tony does unless I guide with an OAG. The thing about the EdgeHD scopes is that they do not have mirror locks at all. They have mirror clutches that consist of two flexible rods installed on the back of the scope at 120 degrees from the focus knob. This provides some support for the mirror to keep it from tilting (although since the rods are flexible, they can and do bend if the focus knob is turned while they are set). But they do nothing at all to prevent the lateral movement that Roland describes. The end result is that if I go either unguided or with a guide scope, I get elongated stars. They are clearly noticeable on two minute exposures at 0.5 arc seconds per pixel. As such, my EdgeHD requires either an OAG on ONAG any must be guided. And this is on my AP1600 with absolute encoders and a pointing/tracking model built through APPM.
From: chris1011@... Sent: 8/29/20 11:18 AM To: "main@ap-gto.groups.io" <main@ap-gto.groups.io> Subject: Re: [ap-gto] Drift Alignment To Help With Unguided Images No, we have not changed the way the CP4 controllers interface with APCC Pro. However, there is a new version of APCC Pro that might be what you want to update. If you are using a C14 for unguided, you may run into mirror shift issues that cannot be solved with modeling. I think trying to do unguided imaging with such a scope might be stretching things. First you have very long focal length, next you have an optical/mechanical system that is prone to differential flexure, and then you have possible mirror shifting, even if it's locked down. Reason for the shift is not because it tilts due to gravity, rather that the entire mirror slides sideways due to the clearance between the mirror's central hole and the shaft that it rides on. The mirror is quite heavy and slides around sideways because it is not glued down to the metal shaft that it sits on. Rolando -----Original Message----- From: Tony Benjamin <tonybenjamin@...> To: main@ap-gto.groups.io Sent: Sat, Aug 29, 2020 1:09 pm Subject: Re: [ap-gto] Drift Alignment To Help With Unguided Images Will do, tonight hopefully. It says I need to contact AP to get the CP4 firmware updated? Might this play into my issue? Tony From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of uncarollo2 <chris1011@...> via groups.io Sent: August 29, 2020 11:08 AM To: main@ap-gto.groups.io Subject: Re: [ap-gto] Drift Alignment To Help With Unguided Images "Pretty sure" will only be confirmed if you do what i suggested - do a guider graph for 10 - 12 minutes with guide pulses turned off. See what your guide graph looks like, maybe even post a screen shot so we have something to work with. Rolando -----Original Message----- From: Tony Benjamin <tonybenjamin@...> To: main@ap-gto.groups.io Sent: Sat, Aug 29, 2020 12:55 pm Subject: Re: [ap-gto] Drift Alignment To Help With Unguided Images Hi, Thanks all for the input. The scope I am currently using is a C11 Edge (the mirror is "locked down" - but who knows??). Image scale is .44 with the ML16200. Hopefully will upgrade to a Planewave 12.5 in the near future and kiss possible mirror shift goodbye :) Pretty sure the encoders were on - but will double check tonight. I also have tracking and pointing corrections on in APPM. The only message I've noted of late is that my CP4 firmware needs to be updated? Tony
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Tony Benjamin <tonybenjamin@...>
Thanks for the input W.Hilmo! Tiny font btw J
I have gone ahead and ordered a Planewave 12.5” and will sell the C11. Drastic measures, but will put an end to mirror flop!! J Looking forward to the cloudy skies!
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of W Hilmo
I image with an 8" EdgeHD 800 and I get about the same performance that Tony does unless I guide with an OAG.
The thing about the EdgeHD scopes is that they do not have mirror locks at all. They have mirror clutches that consist of two flexible rods installed on the back of the scope at 120 degrees from the focus knob. This provides some support for the mirror to keep it from tilting (although since the rods are flexible, they can and do bend if the focus knob is turned while they are set). But they do nothing at all to prevent the lateral movement that Roland describes.
The end result is that if I go either unguided or with a guide scope, I get elongated stars. They are clearly noticeable on two minute exposures at 0.5 arc seconds per pixel. As such, my EdgeHD requires either an OAG on ONAG any must be guided.
And this is on my AP1600 with absolute encoders and a pointing/tracking model built through APPM.
From: chris1011@... No, we have not changed the way the CP4 controllers interface with APCC Pro. However, there is a new version of APCC Pro that might be what you want to update.
If you are using a C14 for unguided, you may run into mirror shift issues that cannot be solved with modeling. I think trying to do unguided imaging with such a scope might be stretching things. First you have very long focal length, next you have an optical/mechanical system that is prone to differential flexure, and then you have possible mirror shifting, even if it's locked down. Reason for the shift is not because it tilts due to gravity, rather that the entire mirror slides sideways due to the clearance between the mirror's central hole and the shaft that it rides on. The mirror is quite heavy and slides around sideways because it is not glued down to the metal shaft that it sits on.
Rolando
-----Original Message----- Will do, tonight hopefully.
It says I need to contact AP to get the CP4 firmware updated? Might this play into my issue?
Tony
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of uncarollo2 <chris1011@...> via groups.io
"Pretty sure" will only be confirmed if you do what i suggested - do a guider graph for 10 - 12 minutes with guide pulses turned off. See what your guide graph looks like, maybe even post a screen shot so we have something to work with.
Rolando
-----Original Message----- Hi,
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Bill Long
Love the CDK scopes (or in my case iDK) they are a joy to use and produce excellent data. Congrats! The 1100 will enjoy it too.
From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Tony Benjamin <tonybenjamin@...>
Sent: Sunday, August 30, 2020 3:51 PM To: main@ap-gto.groups.io <main@ap-gto.groups.io> Subject: Re: [ap-gto] Drift Alignment To Help With Unguided Images Thanks for the input W.Hilmo! Tiny font btw J
I have gone ahead and ordered a Planewave 12.5” and will sell the C11. Drastic measures, but will put an end to mirror flop!! J Looking forward to the cloudy skies!
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io]
On Behalf Of W Hilmo
I image with an 8" EdgeHD 800 and I get about the same performance that Tony does unless I guide with an OAG.
The thing about the EdgeHD scopes is that they do not have mirror locks at all. They have mirror clutches that consist of two flexible rods installed on the back of the scope at 120 degrees from the focus knob. This provides some support for the mirror to keep it from tilting (although since the rods are flexible, they can and do bend if the focus knob is turned while they are set). But they do nothing at all to prevent the lateral movement that Roland describes.
The end result is that if I go either unguided or with a guide scope, I get elongated stars. They are clearly noticeable on two minute exposures at 0.5 arc seconds per pixel. As such, my EdgeHD requires either an OAG on ONAG any must be guided.
And this is on my AP1600 with absolute encoders and a pointing/tracking model built through APPM.
From:
chris1011@... No, we have not changed the way the CP4 controllers interface with APCC Pro. However, there is a new version of APCC Pro that might be what you want to update.
If you are using a C14 for unguided, you may run into mirror shift issues that cannot be solved with modeling. I think trying to do unguided imaging with such a scope might be stretching things. First you have very long focal length, next you have an optical/mechanical system that is prone to differential flexure, and then you have possible mirror shifting, even if it's locked down. Reason for the shift is not because it tilts due to gravity, rather that the entire mirror slides sideways due to the clearance between the mirror's central hole and the shaft that it rides on. The mirror is quite heavy and slides around sideways because it is not glued down to the metal shaft that it sits on.
Rolando
-----Original Message----- Will do, tonight hopefully.
It says I need to contact AP to get the CP4 firmware updated? Might this play into my issue?
Tony
From: main@ap-gto.groups.io
[mailto:main@ap-gto.groups.io]
On Behalf Of uncarollo2 <chris1011@...> via groups.io
"Pretty sure" will only be confirmed if you do what i suggested - do a guider graph for 10 - 12 minutes with guide pulses turned off. See what your guide graph looks like, maybe even post a screen shot so we have something to work with.
Rolando
-----Original Message-----
Hi,
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CurtisC <calypte@...>
> I have gone ahead and ordered a Planewave 12.5” and will sell the C11.
Did you consider the EdgeHD 1100?
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Tony Benjamin <tonybenjamin@...>
Sorry, should have typed the extra. It is a C11 Edge HD that I am replacing J
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of CurtisC via groups.io
> I have gone ahead and ordered a Planewave 12.5” and will sell the C11.
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Hi Tony,
With a C11HD obviously it's a little less simple. I am also in this perspective to be able to use my C11HD on my Mach2 with exposures of more than 1 'and everything depends on the possibility of making a good model.After trial and error, I ended up first improving my MES with Sharpcap, then I noticed in the models made that the orthogonality in DEC was really not good. Either Flip Mirror, or something else like tilt on the camera. As I have a motorized PO FT I have adjusted the MAP as well as possible with the mirror adjustment then blocked without forcing it and also modified the camera fixation. Yesterday evening the 29 point model then the 92 model, despite clouds coming to disturb the resolution of 10 points on the west, indicated better measurements in terms of orthogonality. I then made a test on a star low on the horizon (Near Jupiter) and near the meridian. After 5 'it was still positioned on the center of the crosshair (200%) on the image provided on Sharpcap. Then 6 'exposures on NGC6888 turned out to be quite successful.There are still areas for improvement to get a smoother tracking correction, but I think I can say that there is a possibility of modeling with a C11 and doing poses greater than 3 '. The link with my post on the subject. https://ap-gto.groups.io/g/main/topic/mach2_orthogonality/76392947?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,20,76392947
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