Using MetaGuide with SharpCap 4

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zerolatitude
Posts: 156
Joined: Mon Mar 01, 2021 5:24 am

Using MetaGuide with SharpCap 4

#1

Post by zerolatitude »

My lightweight, widefield setup has an iOptron SmartEqPro+ mount, and never could get PHD2 to work well - after much experimentation, the numbers seemed fine, but the stars were consistently elongated. Then tried MetaGuide, which has worked very well for me at upto at least 5 min subs, the maximum I've tried. (see another report at https://www.cloudynights.com/topic/7887 ... p=11356341).

MetaGuide is not as popular as PHD2, so integration with capture apps is limited. I believe it has some integration with SGP, and NINA 1.11. Its still on the to-do list for SC, so using it in SharpCap needs a specific file kindly provided by Frank (developer of MG), plus the SC4 sequencer.

This assumes that MetaGuide is already installed and in use.

1. Download MGSend.exe from the link in the post https://www.smallstarspot.com/viewtopic.php?p=240#p240. According to Frank, it can be placed anywhere; in this case, its at F:\Utilities\MG_Scripts\

2. In SC4, make sure that PHD2 or Lacerta are not selected in Sharpcap global settings.

3. Use the following sequence in the sequencer. for a simple capture This is for subs of 120sec, with a dither every 4 subs, and total integration of 64 min. Edit the parameters to suit.
SEQUENCE
PROMPT FOR TARGET
SET OUTPUT FORMAT TO "FITS files (*.fits)"
STILL MODE
LOOP 8 TIMES
SET EXPOSURE TO 120
SET GAIN TO 102
SET OFFSET TO 15
DISPLAY STRETCH RESET
DISPLAY STRETCH AUTO
CAPTURE 4 FRAMES REQUIREGUIDING False
CAPTURE STOP
SHOW NOTIFICATION "Dithering : Capture stopped" COLOUR Amber DURATION 30
RUN F:\Utilities\MG_Scripts\MGSend.exe WITH PARAMS dither WAIT True
COUNTDOWN FOR 25 SHOWING "Please wait... Settling after Dither"
END LOOP
END SEQUENCE

If to be used in Livestacking, ensure that the guiding setting is off in the Livestacking options.

Then the sequence is, for the same capture parameters as above
SEQUENCE
PROMPT FOR TARGET
SET OUTPUT FORMAT TO "FITS files (*.fits)"
SET EXPOSURE TO 120
SET GAIN TO 102
SET OFFSET TO 15
LIVE MODE
LIVE STACKING START
LIVE STACKING PAUSE
LOOP 8 TIMES
LIVE STACKING RESUME
DELAY 480
LIVE STACKING PAUSE
LIVE STACKING STRETCH RESET
LIVE STACKING AUTOSTRETCH
SHOW NOTIFICATION "Capture paused: Dithering" COLOUR Amber DURATION 30
RUN F:\Utilities\MG_Scripts\MGSend.exe WITH PARAMS dither WAIT True
COUNTDOWN FOR 25 SHOWING "Please Wait...Settling after Dither"
END LOOP
LIVE STACKING STOP
LIVE STACKING SAVE FITSRawStack32Bit
END SEQUENCE

4. Some notes:
a. The dither command as used in MG above has a built in delay of 5 sec after dither. When dithering with SC, my mount takes about 20 sec to settle, so have used a 25 sec delay.
b. In Livestacking, not sure if there is any sequencer command for "livestack <x> frames>", so have used a time limit. The time = sub exposure x subs between dither, which in this case is 120x4 = 480sec. Not ideal, but works, at least for me.

5. Start / calibrate / whatever MG as usual, and once guiding, start the sequencer.
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Re: Using MetaGuide with SharpCap 4

#2

Post by admin »

Hi,

that looks neat, thanks for sharing!

I must admit I have installed Metaguide a couple of times, but have never really managed to work out how to get it working. PHD2 is great because it has a simulation mode that lets you mess around with it without needing a clear sky - I can't see anything similar in metaguide.

cheers,

Robin
zerolatitude
Posts: 156
Joined: Mon Mar 01, 2021 5:24 am

Re: Using MetaGuide with SharpCap 4

#3

Post by zerolatitude »

Happy to share my experience.

MG can use the ASCOM mount simulator. For the camera, you can "sort of" simulate during daytime by using a bright spot or light in the room as a "star". It does need a Directshow camera, or in case of ZWO etc, the DS driver to be installed, and the star threshold setting may need to be adjusted. I used a torch on the other end of the room:-)

Yes, PHD has a much easier interface, but at least for me, that unfortunately didn't translate into easier guiding even after experimenting for several weeks. The difference, especially with the low end mounts, made it worth the while for me at least.

The snapshot is 4x300s subs, just stacked, DBE, PCC, autostretch in Siril. Nothing else. This from a $500 mount without belt drive and a PE of +-30-40 as per 10min! Its captured with the above script (though its just 4 subs in a test, so no dither or loop really). Pixel scale is 3.1 as/px, but the mount cant take a much larger scope anyway.

While you are here, can I ask for a sequencer command in Livestack - "Livestack <x> frames and pause/stop"? :-) Setiing a loop on time is always a bit risky.

Thanks
M8_MG_4x300s.jpg
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Re: Using MetaGuide with SharpCap 4

#4

Post by admin »

Hi,

thanks for the additional info on MG. I will have another play when I get some free time to look at it.

Is this the sequencer step you were looking for?
Capture.JPG
Capture.JPG (22.09 KiB) Viewed 6122 times
cheers,

Robin
zerolatitude
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Re: Using MetaGuide with SharpCap 4

#5

Post by zerolatitude »

Yes, but without the <Save as> part.

2 reasons.
1. May not want to save intermediate steps.
2. At least in manual, this resets the LS after the save. I suppose it would do the same in the sequencer?
The pause after x frames is just to carry out a dither or send a notification or whatever. So would prefer the LS to continue without a reset.
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Re: Using MetaGuide with SharpCap 4

#6

Post by admin »

Hi,

the save does not reset, but the reset does save (if you have autosave option turned on). However, the above step *does* close live stacking as it completes, so not perfect for your use case.

How about

Code: Select all

Wait for Live Stacking to stack <Count> more frames
That would allow your sequence to control all the live stacking in detail and make sure the waiting is correct for the next guide point.

cheers,

Robin
zerolatitude
Posts: 156
Joined: Mon Mar 01, 2021 5:24 am

Re: Using MetaGuide with SharpCap 4

#7

Post by zerolatitude »

Is that already existing or is it the proposed one? What happens when the x frames are stacked? Pause or stop?

So the usage would be something like this?
Wait for Live Stacking to stack <Count> more frames
Pause Livestacking
<Do whatever>
Resume Livestacking

If so, would livestacking pause till the next command is executed or would it continue on its own path?

Can I suggest another option?

Livestack <x> frames and then <pause/stop> livetacking. Both parameters would be in the sequence parameters window. The number of frames as a spinner and pause/stop as dropdown. This would make it clear and the usage would be simpler

Livestack <x> frames and <pause/stop>
Do <whatever>
Resume Livestacking

If pause, the same livestack would resume
If stop, the existing livestack would stop and a new one would start with same other parameters.

Thanks
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Re: Using MetaGuide with SharpCap 4

#8

Post by admin »

Hi,

it was a proposed change, and I think you are right - it needs to have a way to pause stacking after that number of frames - in particular it should ensure that live stacking doesn't start another frame.

Overall, I think that the best format might be

Code: Select all

Wait for livestack to stack <count> more frames then pause
i.e. no pause/stop option - it keeps things simple and if you want a stop instead of pause then that could be the next step.

I will look into implementation of this - hopefully a small task.

cheers,

Robin
zerolatitude
Posts: 156
Joined: Mon Mar 01, 2021 5:24 am

Re: Using MetaGuide with SharpCap 4

#9

Post by zerolatitude »

That would be great.

Thanks.
zerolatitude
Posts: 156
Joined: Mon Mar 01, 2021 5:24 am

Re: Using MetaGuide with SharpCap 4

#10

Post by zerolatitude »

Just saw this inatest update.

Thanks
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