Date   

Unguided Imaging with a SCT

Bruce Donzanti
 

I am guiding with an OAG on a C11" EdgeHD @ f/10 with a ZWO ASI6200mm Pro but finding guide stars all night long can sometimes be a challenge.  My primary mirror is locked down and focus is performed with the Optec Secondary Mirror FastFocus System.  So, mirror flop and shifting are non-issues.   Thus, I am curious if folks have successfully modeled and performed unguided imaging on a SCT.


Re: Laptop Specs for Mount, Imaging, and Processing

Peter Bresler
 

My setup is a Startech 7 port USB on the OTA going to the Kingdel control computer by the scope. A router connects it to my monitoring computer in the house. I just got this to process large QHY600 files. Normally I just go out there to turn things on and go back in the house.

https://www.amazon.com/dp/B07CWWYS6Q?psc=1&ref=ppx_yo2ov_dt_b_product_details


Re: Laptop Specs for Mount, Imaging, and Processing

ap@CaptivePhotons.com
 

On Wed, Apr 20, 2022 at 08:50 AM, Richard Benoit wrote:
Thanks for the suggestion Bryan. I had thought about a TV but wasn't sure it would work. Intel docs and Google searches didn't make it clear. I'll continue to research it some more.
The short version is an HD TV with HDMI will usually work.  The longer version is that it depends a bit on the bios of the computer, I've had a Raspberry Pi (different thing of course) that would only boot if the resolution of the TV matched one it had predefined.  But in the vast majority of the cases, a HDMI HD (at least) TV will work.

And if you don't have a simple USB Keyboard and mouse, just buy one of the cheap ones off Amazon and have it lying around in case you need it, it will be maybe $20 for both.  The more basic the better so there's no weird software or drivers or wireless dongles to deal with.

While setting it up connected (because you can't get to the bios/uefi remotely later) be sure to review settings like whether it automatically boots on power-on (some cheap ones don't have that option!), and in rare cases there may be settings to control "wait for boot on error" which can sometimes include "no keyboard detected", leaving it not starting once you unplug (again, rare, those were usually old bios' before people started running headless a lot, but it is worth reviewing all settings while you connect the first time). 

Be aware though that there are three different HDMI connector types - regular, mini and micro.  There is also display port which looks like a HDMI except one side is flat not rounded) and small versions of it.  There are adapters for all of these to convert one to the other, so (for example) if the PC comes with a mini-HDMI and your TV is a regular, you will need an adapter (and it may or may not come with it).  You can also convert HDMI to Display Port or to DVI with just an adapter. 

Linwood


Re: Laptop Specs for Mount, Imaging, and Processing

Richard Benoit
 

Thanks for the suggestion Bryan. I had thought about a TV but wasn't sure it would work. Intel docs and Google searches didn't make it clear. I'll continue to research it some more.

Richard.


Re: Laptop Specs for Mount, Imaging, and Processing

Jeffc
 

Out here on the left coast at the dark sky sites, it tends to get HOT during the day. And COLD at night…. It dips down into the low 40s .. Brrrrrr.

So when I’m at a dark sky site imaging under the Milky Way , it helps to have a separate laptop remote controlling the computer on the mount.

I use MS Remote Desktop. It is available on MacOS (and windows), and also on the iPad and iPhone. Yes I can remote control my imaging computer from my phone… if necessary.

Why?

First off there’s no wires to trip over in the middle of the night.

I use a laptop that sips battery and lasts all night long — most of the time the display is dimmed out.

Best of all, when it gets Cold Cold out there, I can take the laptop and stretch out in the back of the Tesla with Camp Mode turned on. It’s a nice 70F in the Tesla All Night Long.

Yes that’s roughing it, but one needs to get the photons.

I don’t use a NUC, but I’m considering a small scope top computer. Maybe a Beelink.

At the moment I’m using a repurposed Mac Mini (headless of course) running Windows10….

The color match with the AP Eagle is quite impressive, don’t you think?



-jeff


Re: APPM Model when changing camera

S Berrada
 

Hi Marcelo,

Thank you very much for sharing your experience.
You are likely right that changing the camera weight could have an effect.  

Assuming that the camera weight is about the same, and the connection also, I am thinking ( but not certain) that changing sensor size and pixel size should not change the model because it is based on movements in arc seconds?

Any further thoughts or experience from any other users would be appreciated

Cheers
Sam 


Re: Laptop Specs for Mount, Imaging, and Processing

Worsel
 

Richard

NUCs typically have an HDMI output.  Do you have a TV (or even a streaming device, e.g. Roku) with HDMI input?  

Bryan


Re: Laptop Specs for Mount, Imaging, and Processing

Richard Benoit
 

I also currently run a laptop with a Pegasus Astro Powerbox Advance on a Mach1 and it certainly simplifies cable management. I initially tried a Lenovo X1 Carbon but had it freeze up at low temperatures. I switched to an Acer Enduro (which has a lower minimum operating temperature) which works fine. I set up out in the open rather than in a permanent building.

I've looked at using a NUC but I ran into a problem setting one up - I only have laptops and no separate monitor. I haven't been able to figure out how to initially connect to a NUC without the monitor. Other than buying a monitor (which I don't really have a place for in the house) does anyone have any suggestions on how to do the initial setup?

Richard


Re: Mount slewing acceleration/deceleration profile

Roland Christen
 

There is one thing that could cause a sudden stop at the end of a slew, and that is a low voltage at the terminals of the CP4. This can be caused by the power cord being too long, or by the power supply not delivering at least 12.5 volts at the CP4 terminals. What happens is that the motors cannot slew fast enough to keep up with the commanded speed and fall behind. At the end of the slew the motors are still behind and are still trying to catch up, even though the commanded rate is slowing down during the ramp down phase. The motors will then stop abruptly when the commanded position is reached. This is by no means a normal situation and needs to be resolved at the power supply.

I have seen this more than once in customer observatory setups where the 12 volt power was located some distance away and a large voltage drop occurred in the 12 volt cable feeding the mount controller.

One thing to try is to increase the voltage to the mount to 16 or 18 volts, which will reduce the current being drawn by the controller and which moves the voltage away from the 12 volt limit where problems can occur.

Roland


-----Original Message-----
From: Roland Christen via groups.io <chris1011@...>
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Sent: Tue, Apr 19, 2022 7:03 pm
Subject: Re: [ap-gto] Mount slewing acceleration/deceleration profile

What color is your light on the CP4 controller? Does it turn yellow when it finishes slewing?

Roland

-----Original Message-----
From: Craig Young <craig.young.m8@...>
To: main@ap-gto.groups.io
Sent: Tue, Apr 19, 2022 7:02 pm
Subject: Re: [ap-gto] Mount slewing acceleration/deceleration profile

I have a conference call with Mike and Dave early tomorrow on another issue which may be related.  I will bring this up at the same time.  Thanks Roland.

Craig

--
Roland Christen
Astro-Physics

--
Roland Christen
Astro-Physics


Re: Mount slewing acceleration/deceleration profile

Roland Christen
 

What color is your light on the CP4 controller? Does it turn yellow when it finishes slewing?

Roland

-----Original Message-----
From: Craig Young <craig.young.m8@...>
To: main@ap-gto.groups.io
Sent: Tue, Apr 19, 2022 7:02 pm
Subject: Re: [ap-gto] Mount slewing acceleration/deceleration profile

I have a conference call with Mike and Dave early tomorrow on another issue which may be related.  I will bring this up at the same time.  Thanks Roland.

Craig

--
Roland Christen
Astro-Physics


Re: Mount slewing acceleration/deceleration profile

Roland Christen
 

The mount has a ramp-up and ramp-down and does NOT stop instantly. This is an error of some kind that we will figure out.

Roland

-----Original Message-----
From: Craig Young <craig.young.m8@...>
To: main@ap-gto.groups.io
Sent: Tue, Apr 19, 2022 6:59 pm
Subject: Re: [ap-gto] Mount slewing acceleration/deceleration profile

This is definitely a configuration item we should have available.  For light payloads it is not that big an issue, but with much heaver payloads it becomes quite significant.  Setting the ramp up and ramp down times is a tradeoff between convenience (faster slewing times) and stress on the gearing system (when accelerating and decelerating).  Recommendations from AP would definitely be helpful in setting these times given the payload and mount.

Craig

--
Roland Christen
Astro-Physics


Re: Mount slewing acceleration/deceleration profile

Craig Young
 

I have a conference call with Mike and Dave early tomorrow on another issue which may be related.  I will bring this up at the same time.  Thanks Roland.

Craig


Re: Mount slewing acceleration/deceleration profile

Craig Young
 

This is definitely a configuration item we should have available.  For light payloads it is not that big an issue, but with much heaver payloads it becomes quite significant.  Setting the ramp up and ramp down times is a tradeoff between convenience (faster slewing times) and stress on the gearing system (when accelerating and decelerating).  Recommendations from AP would definitely be helpful in setting these times given the payload and mount.

Craig


Re: Mount slewing acceleration/deceleration profile

Roland Christen
 

Call AP tomorrow, ask for Mike. Tell him what's happening and we'll try to figure out how to do a remote session to find the error.

Our mounts have always had a ramp-up and a ramp-down. Never an instant stop. Something is definitely wrong with the electronics. Is this a new mount, and has this happened right from the start?

Roland

-----Original Message-----
From: Craig Young <craig.young.m8@...>
To: main@ap-gto.groups.io
Sent: Tue, Apr 19, 2022 6:49 pm
Subject: Re: [ap-gto] Mount slewing acceleration/deceleration profile

Yep, definitely stops instantly, which is why the motor box shakes a bit and the OTA oscillates.  If it takes a few seconds to ramp down then I should notice that.
Craig

--
Roland Christen
Astro-Physics


Re: Laptop Specs for Mount, Imaging, and Processing

mjb87@...
 

Agreed. My Pegasus power/USB hubs vastly simplify and shorten the cables attached to rotator, flip-flat, focuser, imaging camera, guide scope, dew heater, etc. I use on on both my Mach2 and 1100GTO setups, and a similar ASI Air hub on my portable RST-135/Stowaway setup. It is especially helpful on the Mach2 given he limited pass-through capabilities compared to the 1100GTO.

Clearly you can replace the hub with a NUC, tough the hub works just fine with me, connected ultimately to my laptop with a 20-foot USB cable (with repeater/booster) and to a separate 10A power supply. (My mounts have their own dedicated power supplies.)


Re: APPM Model when changing camera

Marcelo Figueroa
 

I have used the same model with both an ASI 1600 and an ASI 294 with an Esprit 100 and it works perfect. Of course, the sensor size is almost the same, as well as its weight, so you could say that in this case it is almost the same camera.
 
I guess if the change is significant, there may be some problems.


Re: Mount slewing acceleration/deceleration profile

Craig Young
 

Yep, definitely stops instantly, which is why the motor box shakes a bit and the OTA oscillates.  If it takes a few seconds to ramp down then I should notice that.
Craig


Re: Mount slewing acceleration/deceleration profile

Roland Christen
 

There is a slowdown ramp in the 1600 mount and the motor does not stop instantly, even at 1200x. If it stops instantly, then there is something wrong with the CP4 software, or perhaps you have a problem with the encoder connection. The slowdown ramp of the 1600 occurs over a few seconds, the motor does not stop instantly. We can easily change the up-down ramp via software, but first you have to be certain that you have a problem. Check again to see if the motor stops instantly.

Roland Christen
Astro-Physics Inc.



-----Original Message-----
From: Craig Young <craig.young.m8@...>
To: main@ap-gto.groups.io
Sent: Tue, Apr 19, 2022 5:30 pm
Subject: [ap-gto] Mount slewing acceleration/deceleration profile

I have a Planewave CDK20 on an AP1600GTOAE mount.  The OTA + instruments weigh about 160lbs and the mount is spec'd for 220 lbs, so the payload is well within the capacity of the mount.  But when I slew at 600x from point a to b the motor stops instantly and the OTA rocks in the cradle until settled.  Looking at other mounts with large payloads they use a noticeable acceleration/deceleration slewing profile to prevent this.  I did not see any place in APCC setup to set the ramping profile.  Is this not supported on AP mounts?  For the moment I have changed the slew rate from 600x to 240x (1 deg/sec) which is a bit slow getting around the sky, but it still rocks somewhat when slew is finished.  This has got to be hard on the drive system when this happens.

Craig

--
Roland Christen
Astro-Physics


Mount slewing acceleration/deceleration profile

Craig Young
 

I have a Planewave CDK20 on an AP1600GTOAE mount.  The OTA + instruments weigh about 160lbs and the mount is spec'd for 220 lbs, so the payload is well within the capacity of the mount.  But when I slew at 600x from point a to b the motor stops instantly and the OTA rocks in the cradle until settled.  Looking at other mounts with large payloads they use a noticeable acceleration/deceleration slewing profile to prevent this.  I did not see any place in APCC setup to set the ramping profile.  Is this not supported on AP mounts?  For the moment I have changed the slew rate from 600x to 240x (1 deg/sec) which is a bit slow getting around the sky, but it still rocks somewhat when slew is finished.  This has got to be hard on the drive system when this happens.

Craig


Re: Laptop Specs for Mount, Imaging, and Processing

Wayne Hixson
 

With an arrangement with computer/USB hub/ Power Distribution box on top of the mount, you can use the shortest cables and reduce cable flexure during scope moves. I don’t think I have any cable, power or signal, longer than three feet other than the power cable up to the Eagle and the Ethernet cable back to the GTOCP5. I do run the CP5 power cable from the AP 24-volt adapter, but it is stationary when the scope moves. 


On Apr 19, 2022, at 2:37 PM, Brian Valente <bvalente@...> wrote:


>>> I'm seeing more and more portable imagers attaching them to their smallish imaging systems with a plethora of wires going hither and yon, 

that just sounds like poor cable management

The *idea* is that with the computer on top of the telescope, it has a smaller footprint in the obs, and all of the various astro devices (camera, focuser, rotator, etc.) connect directly to that computer and therefore don't need a cable running off the telescope and to the computer on a nearby table. 

Special-purpose hubs like pegasus astro include power, usb, etc. also help here

On Tue, Apr 19, 2022 at 2:26 PM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:

I personally don’t see much benefit to putting the NUC up with the scope. Most NUCs don’t have quite enough USB ports, and you are exposing your computer to the elements just to use it as a powered USB hub. 
I also have a NUC in the observatory that is wired into our network. It sits next to the 17" astrograph on a table and can be accessed various ways. It's connected to the mount and imaging camera and can handle all sorts of tasks, same as a laptop or desktop. I have a screen and keyboard so I can work the scope either at the mount or inside the main building. What I don't understand it the reason for putting a NUC up on top of the scope. There must be some reason because I'm seeing more and more portable imagers attaching them to their smallish imaging systems with a plethora of wires going hither and yon, that make spider webs look simple by comparison.

Rolando

-----Original Message-----
From: Frank Widmann <fjwidmann@...>
To: main@ap-gto.groups.io
Sent: Tue, Apr 19, 2022 1:34 pm
Subject: Re: [ap-gto] Laptop Specs for Mount, Imaging, and Processing

I use a NUC housed in a waterproof container at the pier. Mine is an industrial quality device that even has real RS232 ports, and I use one to connect to the GTOCP4. All equipment on the mount connects through a RigRunner power distribution unit and a Startech powered USB hub. One power and one USB Cable are routed through the mount, plus one power cable for dew heaters. I can plug any monitor and keyboard/mouse into the NUC and use it as a laptop equivalent but with better controls and displays. However, I normally run the NUC headless and connect using Remote Desktop from my image processing computer in the house. It is also a NUC and has a 27 inch HD monitor connected. It hosts PixInsight and Photoshop. I run the following programs on the NUC every night: APCC and V2 driver, PHD, The Sky X, SGP, NINA, Optec Focus Lynx and AG Optical scope thermal manager. My images are downloaded directly from the NUC at the scope to my Network Attached Storage device and are immediately accessible to my image processing computer. I can also remote desktop into the NUC from my iPad. I personally don’t see much benefit to putting the NUC up with the scope. Most NUCs don’t have quite enough USB ports, and you are exposing your computer to the elements just to use it as a powered USB hub. 

--
Roland Christen
Astro-Physics



--
Brian 



Brian Valente

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