how big a spot can PHD2 track on?

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Joseph Perry

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May 29, 2023, 7:30:47 PM5/29/23
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hi.
i am going to the solar eclipse. i need phd2 to track with a camera
the SUN!!!!!! through baader filter..and nd filters if less light is needed!

how large a blob does phd2 allow tracking.

a finder with say 300mm EFL will cause a sun 1/2 degree image
round size on cmos chip of about  3mm say..

any one try a large blob to track on? MOON or SUN or Planet?
joeastro

Bruce Waddington

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May 30, 2023, 12:03:06 AM5/30/23
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PHD2 guides on small point sources, perhaps up to the size of some comet heads.  It isn't going to work on an extended object like the sun.

Bruce

michael dobres

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May 30, 2023, 2:01:10 AM5/30/23
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You should use firecapture or sharpcap. They both have a planet autoguide tool.

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Leo Shatz

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Sep 6, 2023, 12:09:20 PM9/6/23
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I've tried both firecapture and sharpcap. Both weren't reliable, at least for me. It could be a nice new feature for PHD2 being able to guide on "center of mass" of a bright solar disk. Can someone with knowledge of PHD2 source code comment on that? There aren't any well working solutions except hardware solar guider, which cost $$$ and are hard to find.

Thanks,

Leo

Leo Shatz

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Sep 6, 2023, 12:43:59 PM9/6/23
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In the meantime I've consulted with ChatGPT about best ways of detecting and tracking on the full solar disk. Here is the answer I got.

The challenge with tracking the Sun in an image is its relatively uniform brightness compared to a night sky image. In night sky images, stars can easily be detected as local maxima against a darker background. The full solar disk, however, doesn't have sharp features like stars.

Here's a potential approach to detect and track a not-overexposed solar disk for guiding:

### 1. Image Preprocessing:

**Gaussian Blur**: Apply a Gaussian blur to the image. This will help in reducing noise and make the subsequent steps more effective.

### 2. Solar Disk Detection:

**Hough Circle Transform**: This is a technique used to detect circles in an image. Since the Sun is (approximately) a circle, this method can be very effective.

1. Use edge detection (like Canny edge detection) to find edges in the blurred image.
2. Use the Hough Circle Transform on the edge-detected image to identify circles.
3. From the detected circles, select the circle that most closely matches expected sizes and positions based on previous frames (if available).

### 3. Disk Center and Radius Estimation:

Once the solar disk is detected, compute the center and radius of the detected circle. This will serve as the guiding reference.

### 4. Guiding:

Use the center of the detected solar disk as the guiding "star". The algorithm can then compute offsets based on how this center moves from frame to frame.

### 5. Safety Considerations:

Ensure that the algorithm is robust against false positives. One way to achieve this is by incorporating the following:

1. **Temporal Consistency**: If you're taking frames at a rapid rate, the Sun's position shouldn't change drastically from one frame to the next. You can disregard detections that are wildly different from the previous frame.
2. **Size Consistency**: The Sun's size in the frame shouldn't change unless you're changing your zoom. Disregard circles that are much larger or smaller than expected.

### Tips:
1. Implement adaptive thresholds, allowing the algorithm to adapt to varying lighting conditions and potential atmospheric disturbances.
2. Incorporate user feedback. Allow users to correct detections manually. This can help in scenarios where automatic detection fails.
3. Always maintain safety checks to ensure the algorithm doesn't mistakenly lock onto a sunspot or other feature.

It's worth noting that this approach is based on the assumption that the Sun is the dominant bright object in the frame and is not overexposed, meaning the disk's edge is discernible. For overexposed images or scenarios where the Sun isn't the only bright object, additional checks and techniques might be necessary.



Brian Valente

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Sep 6, 2023, 12:57:40 PM9/6/23
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Hi Leo

Solar and planetary guiding has come up many times in the past. It's not something that has been entertained by PHD developers (Bruce can comment more on this here) but it is open source software and anyone is free to develop or add features


Brian




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Leo Shatz

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Sep 6, 2023, 2:56:14 PM9/6/23
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I will try first to make an environment for building the PHD2 on Windows. I wonder if Visual Studio 2013 is a *must* for building the project.

Brian Valente

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Sep 6, 2023, 3:43:56 PM9/6/23
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Are you trying to guide on the full disk? I haven't done solar with sharpcap, but for planetary full disk version 4.0 has worked great for me

Bryan

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Sep 7, 2023, 8:31:45 PM9/7/23
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Joe

In my experience, if your PA is good, then you don't need guiding.  The brightness of the Sun will allow you to capture several hundred frames  in a short enough time that there is little drift.  Any of the better alignment qpps (Registax, Stakkert!, etc) will stack these well.  I have even done this with al alt-az mount with only a small amount of field rotation due to short times.

Bryan

bw_m...@earthlink.net

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Sep 8, 2023, 11:32:38 AM9/8/23
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Thanks Bryan.  This is why we haven’t wanted to pursue this kind of feature in the past.  The only use case I’ve heard of for it is long-running (e.g. all-day), unattended tracking of the sun.  Putting this in PHD2 would be awkward at best because so many of the features and the UI are oriented to guiding on point-source objects at night.  I think it would make more sense for someone to create another app to solve the problem, assuming they don’t want to buy one of the self-contained hardware solutions and don’t have a mount that can track sufficiently well at the solar rate.

 

Bruce

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Joseph Perry

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Sep 8, 2023, 12:25:43 PM9/8/23
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hi

will phd2 track out of focus bright star?  like sirus or canope or betelguse???
some one try that.

if you want to track the sun..with any scope go here.


the hinode sg solar autogudier works with any mount and st4 guiding..

or go by the solar tracker by sky-watcher.. you dont need a big scope to
see the sun.

Sky-Watcher SolarQuest Mount: Picture 1 thumbnail this works great

or you can try to get the 

hi.. i got this also.. it does not work well.. wont  move solar or sideral rate like it says.
[and you have to North Pole align any way.

Leo Shatz

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Sep 8, 2023, 2:10:03 PM9/8/23
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The feature would be useful for capturing a sequence of SER files during prolonged time where no amount of accurate polar alignment will be able to keep the image centered - which is especially useful for small sensors of planetary cameras. The only logic required for modification in PHD2 is center detection of the planetary disk and related checks of star profiles/mass/etc. I assume it could be easily handled with the help of few control variables. I have already started modifying the source code and will eventually post updates about my progress.

Best,

Leo

Leo Shatz

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Sep 8, 2023, 2:12:04 PM9/8/23
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The hinode sg solar guider costs few hundred $ and it seems to be hard to find.

Leo Shatz

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Sep 16, 2023, 7:53:58 AM9/16/23
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I have a first alpha version of PHD2 with new guiding on a full planetary or solar disk. In the following weeks (or months) I will try to test it in the real world using a small guidescope and a mono guiding camera coupled with a solar ERF filter and a pair of ND filters.
Attached is the screenshot running in the simulator mode. In the future I'm planning to adapt the star profile code (though it's losing its original meaning showing the STAR profile) and also Target window code for this new mode. Btw, it seems that publically released code of the Star profile window has a problem with graphics scaling. The new method can be sensitive to clouds, so I don't expect it to perform well in cloudy conditions.

Cheers,

Leo
solar_guiding_sim_screenshot.jpg

Brian Valente

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Sep 16, 2023, 2:24:38 PM9/16/23
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Thanks Leo

Looks very interesting! how do you think your modification will perform tracking non-round targets (such as eclipse sequence)?

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Leo Shatz

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Sep 16, 2023, 3:29:17 PM9/16/23
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Brian, thank you for interest in my modifications. I decided to modify PHD2 source code after unsuccessful attempts to do guiding on the full solar disk using other software packages. The method I'm currently using is based on Hough Circle Transform detection and I'm learning that it may have issues with detecting incomplete circular structure during an eclipse. Doing what you've asked for will need additional development and logic that are beyond my current scope of effort.

Leo

Leo Shatz

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Nov 22, 2023, 11:25:44 AM11/22/23
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Hi Brian,

I have an update about your question. I've made more progress with the special version of PHD2 with added solar tracking. I've run the test using simulated partial eclipse image - it seems that the algorithm is still able to recognize the solar disk, though it's not  perfect, but seems usable. Attached is the screenshot from the test session. I'd appreciate if someone would be able to test in the real case use. I never submitted by changes to the PHD2 project, but I'd like to share them in the format which would be acceptable by the community.

Cheers,

Leo
solar-eclipse-sim-phd2.png
On Saturday, September 16, 2023 at 9:24:38 PM UTC+3 bval...@gmail.com wrote:

John Nagy

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Nov 22, 2023, 11:49:03 AM11/22/23
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It's funny you posted this today. I'm finished making a lens cap/solar film holder for my guide scope. I designed and 3d printed something and purchased some Baader film. I plan to try solar guiding with my guide scope mounted next to my Ha telescope on my AM5. I wasn't planning to use PHD2 but now maybe I will give it a shot. 

Why do I want to guide on the Sun? Solar tracking speed on the mount works fine for 15-20 minutes but unless your PA is perfect, the Sun still drifts slowly toward the edge of the sensor/frame. I'd like to capture small bursts of frames over a couple hours to make a time lapse of the sun surface and proms. Each session will be only seconds long but the entire group will span a long time and I don't plan to sit by the scope baking in the sun for that long!

John

John Nagy

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Nov 22, 2023, 11:51:49 AM11/22/23
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PS: I'm still on PHD2 2.6.9 dev 4. What version should I use if I attempt the solar guiding? I see Leo is using 2.6.12 above.

Paul Goelz

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Nov 22, 2023, 11:56:14 AM11/22/23
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On 11/22/2023 11:48 AM, John Nagy wrote:
> I designed and 3d printed something and purchased some Baader film. I
> plan to try solar guiding with my guide scope mounted next to my Ha
> telescope on my AM5.
Be careful with 3D printed stuff in the sun.  Regular PLA may start
softening above about 50 degrees C.

I have 3D printed a couple RC airplanes and they definitely need to be
sheltered from full summer sun if they are not flying (ie., with the air
movement keeping them cool).

In full sun I would not trust a PLA solar filter holder.... you might
come out to find it oozing down the side of your scope ;) Definitely
test it first?

Paul

John Nagy

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Nov 22, 2023, 12:04:51 PM11/22/23
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I'm aware. I gave it a very light coating of white paint which should (hopefully) reject most of the heat. Only the top surface will see any sun (if the guiding works as expected/intended). That's only a 50mm guide scope so it gives you some idea of how small the part that actually sees sun will be! Enjoy the pics... I just finished it this morning.
image.png
image.png


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John Nagy

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Nov 22, 2023, 12:08:21 PM11/22/23
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Also, that isn't solar film in there right now. I have some Baader film but wanted to see how the installation would go so I practiced with a piece of old mylar balloon that was still floating in the basement. I'll record some temps with an infrared thermometer when it's in the sun to see how hot the painted white piece gets. Luckily this time of the year it's cool here. Next July/August will be the real challenge for any PLA!

John

Leo Shatz

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Nov 22, 2023, 12:23:36 PM11/22/23
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Hi John,

The version I'm testing is based on my code changes on the top of the latest release v2.6.12 - this version is not publically available. I've asked one of the admins for information about committing source code changes. In the meantime, if you'd like to test my code I can share the phd2.exe executable file via Google drive or similar service. You should first update your version to  v2.6.12. Please let me know if you would be interested. 

The following is the standard disclaimer about the PHD2 software.

*  This source code is distributed under the following "BSD" license
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are met:
 *    Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *    Redistributions in binary form must reproduce the above copyright notice,
 *     this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *    Neither the name of Bret McKee, Dad Dog Development Ltd, nor the names of its
 *     contributors may be used to endorse or promote products derived from
 *     this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *  POSSIBILITY OF SUCH DAMAGE.

Regards,

Leo

John Nagy

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Nov 22, 2023, 12:27:52 PM11/22/23
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Thanks for the information Leo. Let me try and get this up and running with one of the other pieces of software I've read can do the solar disc tracking/guiding and then I'll reach out to you. I'm most familiar with PHD2 having used it for a few years and would love to use it instead of the others.

This would be great for folks planning to capture the solar eclipse next year!
John

Paul Goelz

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Nov 22, 2023, 12:30:05 PM11/22/23
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On 11/22/2023 12:08 PM, John Nagy wrote:
> Also, that isn't solar film in there right now. I have some Baader
> film but wanted to see how the installation would go so I practiced
> with a piece of old mylar balloon that was still floating in the
> basement. I'll record some temps with an infrared thermometer when
> it's in the sun to see how hot the painted white piece gets. Luckily
> this time of the year it's cool here. Next July/August will be the
> real challenge for any PLA!
>
> John
Cool!  Lets hope ;)

Paul

Leo Shatz

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Nov 22, 2023, 12:36:19 PM11/22/23
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Ok, pls give me some time to build the release version (so far I've been running the Debug version) and test it installed on top of publicly available v2.6.12 version. Please follow here for updates ...

Leo

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Leo Shatz

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Nov 22, 2023, 12:41:52 PM11/22/23
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I'm building a Windows version. If you need the Mac version, I won't be able to help you at this time. Please let me know.

John Nagy

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Nov 22, 2023, 1:01:37 PM11/22/23
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No problem, take as much time as you need. I'm using the Windows version.

Thanks,
John

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Leo Shatz

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Nov 22, 2023, 1:05:50 PM11/22/23
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Ok, here is the link for downloading the custom built phd2.exe

First, you should download and install the phd2 latest version v2.6.12 from the PHD2 official website. The phd2 files should be installed on 64-bit windows folder "C:\Program Files (x86)\PHDGuiding2". 
Rename the original phd2.exe file from this folder to phd2-original.exe, download the custom PHD2.exe binary from the link above to some temporary folder and then copy-paste it to the folder where original phd2.exe was stored (C:\Program Files (x86)\PHDGuiding2).
I advise to run anti-virus detection software on my file to make sure it's safe.

When you start the PHD2, the version should read PHD2 Guiding 2.6.12-planet. If you see this label, it means that my special version is running. You should then run the Tools->Planetary dialog, adjust planetary detection parameters (the most important parameter that you should probably touch is "max radius". See description of each parameter in the context sensitive help message displayed next to each one of them. Click Enable button and close the dialogue box. Assuming that you have solar disk in your guider field of view, click anywhere near the solar disk. If PHD2 was able to detect the solar disk, it will encircle the solar disk with a thin green circle and you are all set. If PHD2 complains that it failed to find guiding star, you should run the Tools->Planetary dialogue again and adjust the parameters until PHD2 will detect that solar disk.

If PHD2 is detecting the solar disk, run calibration as usual and then start guiding. I expect that any clouds could disrupt the guiding and cause problems.

Good luck and let me know how it goes.

Leo

Leo Shatz

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Nov 22, 2023, 1:10:18 PM11/22/23
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Just a small correction, PHD2 seems to be 32-bit program, so it's installed in the 32-bit program folder, which is still "C:\Program Files (x86)\PHDGuiding2".

Leo Shatz

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Nov 22, 2023, 1:16:45 PM11/22/23
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This was exactly my reason why I decided to develop solar (planetary) guiding for PHD2 - for making long sequences where perfect polar alignment is not enough.

Brian Valente

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Nov 22, 2023, 1:46:57 PM11/22/23
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Hi Leo

Looks like you experienced what I was going to recommend anyways: posting enhanced or custom versions for testing and feedback is the way to go. I'll be downloading it as well, and assuming I will ever see the sun again (northwest) i will certainly give it a try

Brian

Leo Shatz

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Nov 22, 2023, 1:59:11 PM11/22/23
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Hi Bryan,

I'm glad to know that you'll give it a try. I'm currently rather limited with my solar setup, but I certainly would like to test my custom version in the field when it will be possible. Please let me know how it goes for you.
Thanks,

Leo

John Nagy

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Nov 22, 2023, 10:00:19 PM11/22/23
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I downloaded and installed the 2.6.12 version. Then I downloaded and replaced the file with Leo's version. I started the software back up and I see the appended "planet" behind the version. I should be good to go tomorrow if the weather is clear. Wish me luck and I'll try to log and report back on everything I see. Should I do that here or somewhere else (direct to Leo and Brian)?

John



bw_m...@earthlink.net

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Nov 22, 2023, 11:01:32 PM11/22/23
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I think it would be better for you guys to communicate with each other off-forum for this project.  It isn’t part of PHD2 at this point and there is likely to be a lot of traffic for this alpha testing.  FWIW, I’ve done the same thing myself, for example with testing of multi-star guiding.

 

Thanks,

Bruce

 

From: open-phd...@googlegroups.com <open-phd...@googlegroups.com> On Behalf Of John Nagy
Sent: Wednesday, November 22, 2023 7:00 PM
To: open-phd...@googlegroups.com
Subject: Re: [open-phd-guiding] Re: how big a spot can PHD2 track on?

 

I downloaded and installed the 2.6.12 version. Then I downloaded and replaced the file with Leo's version. I started the software back up and I see the appended "planet" behind the version. I should be good to go tomorrow if the weather is clear. Wish me luck and I'll try to log and report back on everything I see. Should I do that here or somewhere else (direct to Leo and Brian)?

 

John

 

 

 

On Wed, Nov 22, 2023 at 1:59 PM Leo Shatz <leonid...@gmail.com> wrote:

Hi Bryan,

 

I'm glad to know that you'll give it a try. I'm currently rather limited with my solar setup, but I certainly would like to test my custom version in the field when it will be possible. Please let me know how it goes for you.

Thanks,

 

Leo

 

On Wednesday, November 22, 2023 at 8:46:57 PM UTC+2 bval...@gmail.com wrote:

Hi Leo

 

Looks like you experienced what I was going to recommend anyways: posting enhanced or custom versions for testing and feedback is the way to go. I'll be downloading it as well, and assuming I will ever see the sun again (northwest) i will certainly give it a try

 

Brian

 

On Wed, Nov 22, 2023 at 8:25 AM Leo Shatz <leonid...@gmail.com> wrote:

Hi Brian,

 

I have an update about your question. I've made more progress with the special version of PHD2 with added solar tracking. I've run the test using simulated partial eclipse image - it seems that the algorithm is still able to recognize the solar disk, though it's not  perfect, but seems usable. Attached is the screenshot from the test session. I'd appreciate if someone would be able to test in the real case use. I never submitted by changes to the PHD2 project, but I'd like to share them in the format which would be acceptable by the community.

 

Cheers,

 

Leo

John Nagy

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Nov 23, 2023, 6:44:35 AM11/23/23
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Leo Shatz

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Nov 23, 2023, 9:31:19 AM11/23/23
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In view of the latest requests, I would ask anyone who is interested in this feature and would like to participate in alpha testing of my version, please contact me in private.

Leo

Leo Shatz

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Dec 11, 2023, 4:49:25 AM12/11/23
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Hello everyone,

I've created a private FB group for testing and discussing the new feature, which can be especially useful for imaging the Solar eclipse. Please join me here PHD2 Solar & Lunar Tracking (beta) Forum
The link will expire soon, as FB has limited it for the next 36 hours. If you would wish to join the forum later, please send me a private message.
The Windows version is now available for download and testing after few weeks of preliminary tests, bug fixes and new features - at this GitHub page Download PHD2 (planetary guiding) for Windows platform - beta
A note for developers - I've released the source code of the new feature available on the GitHub as a forked version of the master PHD2 repository and created the new branch v2.6.12-planetary.

Thanks,

Leo

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