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.
Totally agree - been imaging for over 15 years - so its just getting used to your product vs TSX, MaximDL, BYE, N.I.N.A. CCDStack, PEMPro, CCDSharp, DSS and so many, many more! Hear really good things about SGP by the way! Will be watching how to videos every night till my control PC is rebuilt!
I presume two (or more) Equipment profiles can have imaging runs associated with them - and they can run concurrently?
At least you won’t have to spend time learning how your equipment should behave LOL. SGP is very powerful and it takes time to learn the many different settings etc that you will need to tune to your equipment. I had the advantage of learning SGP while it was still being developed (I’m not a developer, just a happy user and forum moderator).
Joel,
All credit I find it beautifully intuitive. At present I am only using one camera through SGP a ZWO ASI1600MM-0c (and forgot to say cool down camera on connect). I ran all my darks and now testing it again on some 1-2 minute luminance filter shots of NGC 5139 as a continuing sea trial.
One thing that I really do have to sort out - and its an issue I suspect for ZWO not you guys - but love your thoughts. Running two cameras (ZWO ASI071MC-c in APT and the 1600MM-c in SGP I often find 20 - 40 shots into a sequence one of the cameras will stop downloading until I halt the sequence and select disconnect camera, reconnect camera and recommence my sequence. The camera operate from one of two powered USB3/2 port hubs, connected by 3 metre USB3 cable to a USB 3 ports in my astro-lab PC.
I suspect it is the amount of power delivered by USB3 (each camera’s cooler connects to a large lab power supply that can give massive current/at 12V.
Does anyone else see this sort of behaviour here - or have suggestions how to fix it? I have raised this in the Australian Astronomy user group and ZWO Facebook forums - but although many users say yes we have seen this, no developer has provided any suggestions on how to resolve / minimise this.
Many thanks,
Matthew
An intermittent issue like this is probably either USB power related or USB download related. As a test, can you bypass the USB hub and connect the cameras directly to the computer and run a bunch of darks to see if you have download issues?
When I had two QHY CMOS cameras I actually resorted to using USB 2.0 (yes 2.0) cables because anything else and I encountered issues. The downloads were a few seconds longer but it was very reliable.
Hi Joel,
On a 3 metre USB3 cable and on a 5m USB3 cable plus extender either camera fails to be detected by Windows 10. Put it on a Powered hub and they get detected straight away. So I think it is definitely the power on the USB3 cable itself that is critical!
Matthew
Hi Joel,
Narrowed it down to a weird error thanks to APT’s new monitor USB capability; my ASI0120MM-s guide camera when connected on four different USB3 ports keeps disconnecting and reconnecting on two different powered hubs - and this seems to be stuffing up downloads for my main ZWO imaging cameras. When I put the 120MM-s on a USB2 port everything was stable as. I will try a third powered USB3 port tomorrow and see if the problem persists or goes away. Still awaiting ZWO’s feedback on this strange problem scenario - but thanks for your help!
Regards,
Matthew