ZWO ASIAIR PLUS

[Johnny Carter]

Ok, Emma and I jumped in and bought a 150 MAK GOTO, we did a lot is research and love the scope, and knew it would be better suited for planetary views. So now we are waiting for August to be able to see Saturn and others. In the meantime we have been looking at refractors for a way to look at and possibly photograph DSOs. This starts with a good solid equatorial mount, and we have been looking at the IOPTRON CEM 26 and 28. One of the problems Emma and I both have is we don’t get around too well, and we have seen the horror stories of polar alignment, so again we try to research, and see the the IOPTRON mounts have IPOLAR that lets us align without having to be contortionists. I talked to OPT support, very nice people, and asked about hooking this up to a laptop to visually see what the scope does. Angel suggested a ZWO ASIAIR PLUS, so we are researching that. I have found some mentions here, and now I am curious, can the ASIAIR actually be used for the alignment process, or do you still need to use IPOLAR? Any thoughts appreciated. And btw, this is not something we are doing overnight, We know it is expensive, and we plan to get probably get a mount one month, a refractor the next, then start on peripherals down the road, we are looking at maybe $1000 to $1500 per incident. I value the experience I find here, so I am asking questions. If you know of other combos any ideas are welcome.

[turboscrew]

Ok, Emma and I jumped in and bought a 150 MAK GOTO, we did a lot is research and love the scope, and knew it would be better suited for planetary views. So now we are waiting for August to be able to see Saturn and others. In the meantime we have been looking at refractors for a way to look at and possibly photograph DSOs. This starts with a good solid equatorial mount, and we have been looking at the IOPTRON CEM 26 and 28. One of the problems Emma and I both have is we don’t get around too well, and we have seen the horror stories of polar alignment, so again we try to research, and see the the IOPTRON mounts have IPOLAR that lets us align without having to be contortionists. I talked to OPT support, very nice people, and asked about hooking this up to a laptop to visually see what the scope does. Angel suggested a ZWO ASIAIR PLUS, so we are researching that. I have found some mentions here, and now I am curious, can the ASIAIR actually be used for the alignment process, or do you still need to use IPOLAR? Any thoughts appreciated. And btw, this is not something we are doing overnight, We know it is expensive, and we plan to get probably get a mount one month, a refractor the next, then start on peripherals down the road, we are looking at maybe $1000 to $1500 per incident. I value the experience I find here, so I am asking questions. If you know of other combos any ideas are welcome.

I'm not sure, but I think @SkyHiker has some experience about ways to do polar alignment by plate solving, and without blowing the budget.

[TCampbell]

ASIair can do polar alignment. It does this via Plate-Solving. It uses the camera to capture an image of the sky and plate-solves to determine the coordinates. It rotates the mount in right-ascension, then takes another image and plate-solves that. It does this one last time (so 3 images in all). Having done this, it now knows the center of the RA axis ... and how far away it is from the true polar axis and has you correct the mount.

ZWO added a new polar alignment mode ... it now has two of them. The new mode lets you use a piece of sky that isn't near the celestial pole. They call this the "all sky" polar alignment. This is meant for users who have an obstruction blocking their view of the celestial pole.

You can watch a video of how the original polar alignment process works here:
You can see the new "all sky" method here:

Just a note about the ZWO ASIair. This device mostly supports ZWO brand equipment. They do support most any mount (since ZWO do not make mounts). Originally they ONLY supported ZWO cameras. They now support some 3rd party DSLR cameras by Canon or Nikon. Other accessories such as guide cameras, filter wheels, focusers, etc. only support ZWO brand gear. The biggest issue is usually cameras.

In addition to the mount, scope, and ASIair, you'll also need a primary imaging camera, and a guide-camera. The guide camera is usually installed on a guide-scope either piggy-backed on your main scope or using a side-by-side saddle. In large long focal-length scopes, an off-axis guide adapter is often used (guide-camera shares the main optical tube used by the main imaging camera because the adapter has a tiny little "pick-off" mirror on the edge of the frame designed to bounce some light into the guide camera. While the main camera is taking a long exposure (e.g. it could be 5 minutes) the guide-camera is taking an exposure maybe every 3-4 seconds. This allows it to correct the pointing accuracy of the mount while imaging to avoid stars drifting and getting elongated stars. Guide scopes and guide-cameras are not very expensive and need not be top-end equipment.

One last thing ... and it's a big one. The ASIair is based on a Raspberry Pi computer. It's a tiny computer about the size of a deck of playing cards. Unfortunately they are having the same supply-chain problems as everyone else. As such, the wait time to get one of these is lengthy. Check with your retailer to see if they have any guesses as to how long you might be waiting.

[SkyHiker]

All sky polar alignment, that's great news! I just checked indilib.org and indeed it was added there. I presume that ASIAir uses INDI on the server side. Indeed this is now also available in Ekos and Astroberry that runs on a Raspberry Pi 3 or 4. Ekos has no proprietary hardware restrictions such as cameras, of course. See also https://www.indilib.org/forum/general/8 ... tures.html . An alternative system package is Stellarmate, which is all INDI and Ekos, see https://www.stellarmate.com/ .

[TCampbell]

The ASIair does indeed use INDI (indilib.org). I've looked at the contents of the ASIair SD-card and see the INDI-server and the INDI drivers (I even see INDI drivers for equipment that ZWO doesn't support -- for example the driver for the Celestron SCT focuser is installed even though there is no menu to let users access it using the ASIair client software.)

While I do own an ASIair, I mostly use the StellarMate these days -- also based on INDI -- because I have no restrictions on what devices I can use. INDI has a pretty rich set of support drivers.

StellarMate (by Ikarus Technologies) is by Jasem Mutlaq. Jasem seems to be the main contributor to INDI ... I see a ton of drivers that were built by him. He's been to work with. I reached out to him for help on the focus driver for my telescope and he was really great in supporting me.

[Johnny Carter]

Thanx for the info all. A lot to learn, but some things are becoming clearer.

[AstroBee]

Two suggestions from me. Take them with a grain of salt.

1. If you think you can handle the additional weight during setup, look at the iOptron CEM40 if you can afford it. Don't forget about the used market over on that "other" site.
Remember, a mounts listed weight capacity is generally for visual work. If you are going to image, cut that amount down to around 50-60%. So if you go with a smaller mount like the CEM 28 you are talking about an imaging payload of around 15-16lbs total. The CEM40 gets you a more respectable 20-24lb payload. You have to decide if the weight is an issue. 10lbs vs 17lbs for the mounts alone.

2. This may not be a huge issue since ZWO is quickly becoming the elephant in the hobby camera field but I would recommend going with a NUC PC instead of the ASI Air. Personally, I don't like being locked into a particular hardware brand. It's my understanding, and someone please correct me if I'm wrong, but the ASI Air will only work with ZWO branded cameras. This means your main imaging camera and guide camera both need to be ZWO. I just so happen to have both ZWO cameras but with the Air, you are locked into their brand. I'm a huge fan of NINA, it's almost as easy a program to use as the Air but has more flexibility. It does have a bit more of a learning curve so if you are not into setting up PC software, then maybe the AIR is your way to go.
With the AIR though, the polar alignment routine is NOT going to recognize or use the iPolar camera on the iOptron mounts. It will use your main imaging camera to do the polar routine.

[Johnny Carter]

Thanx for that info, I was going with the 28 simply because of price and weight, but I will look into it a bit more. Emma and I need to watch our budget but at the same time we don’t want to get something that would disappoint and turn us away. I am not positive that we will ever get into Astro photography, but nature photography is a favorite past time for both of us, and the temptation is there, so we are trying to plan for it. Again, thanx all, this is a great site.

[TCampbell]

It's my understanding, and someone please correct me if I'm wrong, but the ASI Air will only work with ZWO branded cameras. This means your main imaging camera and guide camera both need to be ZWO.

Almost ... they do support controlling Canon and Nikon DSLRs (not all models supported, they have a list). But for dedicated astronomy imaging cameras and guide cameras, they only support ZWO cameras. So you could image with, say, a Canon DSLR, but the guide camera would have to be a ZWO camera. You wouldn't be able to use something by QHYCCD or FLI, etc. etc.

Even though I no longer use my ASIair, I have to admit that if you want things to be easy and very portable to the field ... it is a very nice system. I switched to StellarMate after getting a PlaneWave CDK scope. It has an integrated dew heater system and an integrated electric focuser ... and ASIair doesn't support the focuser even though INDI *does* support the focuser. So I just needed to switch to a different platform that lets me use *any* INDI device -- and StellarMate does that.

[SkyHiker]

It's my understanding, and someone please correct me if I'm wrong, but the ASI Air will only work with ZWO branded cameras. This means your main imaging camera and guide camera both need to be ZWO.

Almost ... they do support controlling Canon and Nikon DSLRs (not all models supported, they have a list). But for dedicated astronomy imaging cameras and guide cameras, they only support ZWO cameras. So you could image with, say, a Canon DSLR, but the guide camera would have to be a ZWO camera. You wouldn't be able to use something by QHYCCD or FLI, etc. etc.

Even though I no longer use my ASIair, I have to admit that if you want things to be easy and very portable to the field ... it is a very nice system. I switched to StellarMate after getting a PlaneWave CDK scope. It has an integrated dew heater system and an integrated electric focuser ... and ASIair doesn't support the focuser even though INDI *does* support the focuser. So I just needed to switch to a different platform that lets me use *any* INDI device -- and StellarMate does that.

So does a plain Raspberry Pi 4b with Astroberry installed - no support limitations. With the supply chain problems it's nice to see Stellarmate advertised at a reasonable price. Looking at the Stellarmate specs on OPT it looks like it is a Pi 4b. The nice thing is that it's a selfcontained solution so you don't need to figure out how to make it talk to other tools. You may have to add power especially for the camera cooler. This can be done through a powered USB hub, for instance.

[TCampbell]

So does a plain Raspberry Pi 4b with Astroberry installed - no support limitations. With the supply chain problems it's nice to see Stellarmate advertised at a reasonable price. Looking at the Stellarmate specs on OPT it looks like it is a Pi 4b. The nice thing is that it's a selfcontained solution so you don't need to figure out how to make it talk to other tools. You may have to add power especially for the camera cooler. This can be done through a powered USB hub, for instance.

If you already happen to own a Raspberry Pi (or can get your hands on one ... but that's quite the trick these days with supply shortages of them) you can buy "StellarMate OS" ... that's all the software without the hardware. That's what I did because I happen to have a few Raspberry Pi's already.

These days the preferred device would be the Raspberry Pi 4 Model B (aka "Pi 4B" available in either 2GB, 4GB, or 8GB RAM sizes ... but even the 2GB is more than enough). It will also run on a Pi 3B+ which only has 1GB RAM and even that is more than enough. Linux (Raspberry Pi OS) doesn't have a lot of overhead so it doesn't need a lot of RAM.