Hi
Does SGpro allow for multiple cameras running within the same session? I’ve now got two cameras connected to my set up and want to use SGpro for both. I guess I could run two instances of SGpro but how would I then synchronise the cameras to ensure that both are not imaging whilst things like dithering are taking place?
Many thanks for any advice on this.
Currently SGP does not allow for coordinating multiple cameras under the
same SGP instance. The only way to use multiple cameras is to use two
instances of SGP controlling each camera independently. Obviously this
does not allow for things like coordinated dithering etc between the
cameras. However, this feature request is already in the works as many
have expressed interest in it.
For the time being, if you are working with a long focal length scope and a
short focal length scope, if the wide image scale is sufficiently larger
than the narrow image scale you may be able to dither the narrow field
camera and not notice it in the wide field camera images.
Ok many thanks. Look forward to the new feature when its finished…
Yes, this question has been asked (and answered) in maybe 4 or 5 threads so far for maybe a year or more. I am also eagerly awaiting this feature and, in fact, have stuck with 2.4 so far as multi-camera is really the only significant new feature proposed for 2.5 that does much for me that 2.4 does not.
I hope it shows up by the summer when we actually have decent weather. El Nino has pretty much crushed any winter or spring imaging for me.
I know thsi is an old topic but I’m also eagerly awaiting this feature. It has been proposed for 2.5 but never made it into this version. When can e expect this feature?
An update on multiple camera use…
We have a bunch of work done (and hidden) on multi-camera support. True implementation would take a good deal of time. Many people have asked us to release just dithering coordination. While we are not opposed to this in principle, we have to wonder if this is a support black hole. There are a lot of traps when your “slave” instance does something it’s not supposed to… like switch to a new target (there are many pitfalls). Support here is, unfortunately, not as simple as “don’t do that”… we would need to investigate 2 separate sets of logs, correlate them, determine what happened and then (possibly) say “don’t do that”.
Something we need to think about before considering the release of a partial solution.
Two comments:
I think most who want this feature are fairly sophisticated users
Given 1, I’m sure if you released a version on the understanding that it is unsupported for now you would have a enthusiastic bunch of users who would be happy to beta test it and provide feedback.
No need to make it a “support black hole”.
…Keith
That’s another definition of a support black hole. 
The interactions in SGP are already complex and adding another camera module will make it considerably more so. Doing this will add bugs and some will affect everyone, not just the multiple camera people.
Ken and Jared can’t ignore the bug reports, they have to investigate and sort them out. With a major change in the functionality such as this that will be very time consuming.
Chris
Ken, I understand your concerns. Maybe a step by step approach would help lowering the support load. A first step could be a second camera only in “slave” mode of the primairy. e.g same exposure time as the primary and no complex functions. After this you could extend the functions step by step.
Release whatever you can/want and mention NO SUPPORT, period, no grey zone.
I would be happy with 1 master multiple slaves … and all I wan’t need initially is dithering and meridian flip and autofocus of the main unit.
The way I see it,
-master sends pauze command to slaves when it needs to dither or meridian flip or autofocus (you can stop guiding during AF)
Forget about more complex items like autofocus of slaves (people can try to do this and it should work but I understand one can get in deadlock situations if slaves goe beyond traditional point and shoot)
/Yves
Any update on this string? I’m currently running 2 instances and it works but coordinating exposures is the only real issue I’m dealing with.
Hi,
Just wondering if there is any furhter development on this topic. I would like to automate the image acquisition with 2 camera’s and multiple targets. I have version 3 already installed, plate solving/centering/auto meridian flip works fine with one camera.
If I leave dithering out of the game ( not needed in my case ), how could I coordinate the exposures in the two instance of SGP ? My initial idea would be to connect both instances to the mount and to PHD2, allow auto pier flip at meridian for both sessions the same way. Then I start the exposure with a couple of seconds difference manually. I suppose both exposures would wait until guiding starts ( or restored after meridian flip ), this way the exposures would start/stop more or less together.
Any suggestions are welcome !
Clear skies,
Janos
I have used multi instances of SGP for several years to run usually 2, but for a short while, 3 scopes/cameras simultaneously. It has worked amazingly well for me. But I don’t need to dither. More on that later.
Quite frankly, in the general case where you actually want to use a different exposure length on both cameras, I do not think that SGP support of 2 cameras is actually going to help you much over what you can do now – if you ignore the DITHERING issue. The reason for this, assuming different exposure lengths where one is not an exact multiple of the other, is there is always going to be wasted exposure time on the slave camera. This is true even for a perfectly designed and implemented multi-camera support. With SGP support, this would come as wasted time every frame or every few frames of the slave. Doing it now with separate instances of SGP, the waste comes as a trashed frame on meridian flips and possibly on the start of a new target. The exposure length of your slave directly affects how much time you lose. For shorter slave exposure lengths, this lose could easily be much larger for the SGP controlled case.
On dithering: If your FOV is very different on the 2 scopes, using a small dither on the main scope, smallest FOV, may not be noticeable on the slave scope with the much larger FOV. However, I have found that dithering is not necessary if you use the Cosmetic Correction feature of PixInsights’ Batch Preprocessing Script. It does a great job of eliminating hot and cold pixels.
Hi jmacon,
Thanks for your reply ! I would like to keep it simple: same exposure on both cameras, typically 10min. Do you have experience if both cameras can be connected to the same instance of PHD ? That is crucial, because it makes the second instance & camera wait until guiding is calibrated/settled. This is valid for a meridian flip as well I suppose: I think the second instance will detect that PHD is not guiding, so it will restart the current frame. I will loose some minutes on the second camera, but that’s not a problem.
jmacon makes good points. As he mentioned, if you are waiting for one exposure to finish before starting an exposure on the other camera you are wasting a significant amount of imaging time.
If however you just let both cameras run and only one camera/SGP controls the mount etc, then you will have to throw away a few subs from the second camera but you’re not really losing much time in light of the first point above.
Currently it’s not possible for the cameras to be connected to PHD2. The way it would potentially work in the future is that SGP would control everything (both cameras and PHD2 etc).
But I’ve come to the conclusion that running two instances of SGP with one instance controlling PHD2 and throwing out some subs from the other instance works great.
Because I am using a CCD and CMOS camera, I shoot 10min subs with the CCD and 3min subs with the CMOS camera. SGP controls the CCD camera, PHD2 and the mount, while the other instance of SGP just controls the CMOS camera and just keeps snapping pictures. I only lose a few minutes worth of CMOS subs while a meridian flip etc is taking place.
I even dither with my setup. I dither the CCD images ever 2-3 images (so every 30min or so) and again just throw out the one 3min sub that takes place during the dither.
However I would disagree with jmacon that dithering is not necessary, especially for CMOS cameras. Without dithering CMOS cameras tend to have inconsistent background pattern noise, and while PI’s CosmeticCorrection can correct for something it can’t correct for that. That’s why I still dither.
joelshort,
Thanks for you detailed advises, I will go on the path you suggested: one camera to control PHD & mount. Hopefully I can test my setup within 1-2 weeks when weather allows.
Hi folks,
Day one of using SGP - I am getting back into astrophotography after a multi year break. The key thing I want to know is how to I best set up SGP if on my mount I have two side by side scopes, with their own specific focusers and ZWO cameras (a mono + filters 1600MM-c Pro and a colour 71MC-c). I saw this (old) post - apologies but I did search if this has already been resolved and can see it was a work in progress 2-3 years ago and I wondered where it ended up!
Can someone point me to reading or a Youtube demo etc of the best way to do this? I want if possible SGP to control both cameras and focusers (and one of two guide camera OAG and a third one mounted on top of the second for when I can’t find a star in the OAG).
Can SGP do this? Do I set up two separate instances / profiles of gear and bring one up - give it imaging plans then swap to another profile. Any advice (even confirming if SGP has this capability to control two independent cameras and focusers simultaneously) will be greatly appreciated!
Many thanks,
Matthew
Take a look at my post earlier in the thread.
You’ll need to run two instances of SGP. The “master” SGP runs one scope, focuser, camera, mount and autoguiding (PHD2 I assume) including functions like plate solving, meridian flip etc. The other instance is just a “dummy” that only controls the second camera and focuser.
Depending on your setup you will probably need to disable dithering on the master instance, unless your second scope image scale is a lot larger than your first scope image scale.
Thanks Joel - that makes sense -is there documentation you can point me to on how to start multiple instances of SGP that can remember separate configurations.
So can I set up SGP somehow to say SGP configuration 1 instance controls all of scope + SCT focuser (Meade), filterwheel ZWO and Camera ZWO 1600mm-c plus say PHD2 and/or guide camera ZWO 120MM, whilst SGP configuration 2 instance is aware of but doesn’t control mount position or PHD2 guiding - it only controls scope 2 focuser (Moonlight) and camera ZWO OSC 71MM-c?
In the past with BYE controlling two Canon cameras on my scopes I had to set up two separate installs of BYE in different hard drive directories to give them separate configuration files and launch icons. What do I do with SGP to best do what you are suggesting?
Many thanks, Matt
What you need to do is set up “Equipment Profiles” for your different equipment configurations. Basically you create a template that has all your settings for various equipment combinations, then you create “sequences” based on those equipment profiles.
You don’t have to do anything crazy with installs of SGP. You can run as many instances of SGP as you need. Just launch one instance, create a new sequence based on a profile you previously created, then launch another instance and create a sequence based on a different profile you created.
I suggest you spend some time reading through the help file included with SGP (Help menu/Help File). There’s lots of good information in there. I also suggest you look to Youtube and watch some videos on how to use SGP. Here’s some examples: https://www.youtube.com/playlist?list=PLsB_vBMDYE_oble25beg6MUoUpDw13gqm
It sounds like you have a lot to learn, as we all did at first. My advice would be to go slow and learn in incremental stages. I know you want to jump into multi camera imaging, but that might be an exercise in frustration if you aren’t clear on how SGP works with one camera setup. I think you’ll save yourself some stress if you focus on one scope/camera/automated setup first, then when you are comfortable with that you can add the second setup.