Is this an alternative to Celestron StarSense?

[Gallandro]

Hi.

I've had a long term interest in astronomy and am just preparing to start getting some gear.
I've spent a while now doing some research, reading and watching videos.

I want to get started in visual observing, but I hope to, get into some astrophotography as well at some stage.
I will definitely always want to be able to do visual, so I can share this with my family, and also I plan to get some decent scope experience for a while doing visual, plus I was thinking in terms of cost, starting out just visual allows me to stage the cost outlay by buying the camera gear later.

I've mostly settled on the gear I'm looking at getting, but wanted to get some advice on one aspect.

I am planning on at the start getting a Celestron SCT with a CGX mount plus the SkyPortal WiFi module.
I was planning on also initially getting the Celestron StarSense.

My plan for later was to get a not-too-expensive ZWO mono camera (at least to start with), EFW, plus a ZWO mini guide camera and an OAG.
To manage all this I was planning on using either an AsiAir or Astroberry setup.

So my question mostly revolves around whether or not the StarSense is effectively a waste in the long run?

It seems to me that the functions the StarSense performs will end up also being able to be done by the cameras with the AsiAir/Astroberry.
So instead of spending the money on the StarSense, can I simply earlier on buy the OAG, guide camera and AsiAir (or Astroberry) and then attach the OAG inline with the star diagonal, and then use the guide camera and AsiAir/Astroberry for alignment and mount control, while still doing visual astronomy (i.e. before I actually buy the "proper" main camera"), and thereby obviating the need for the StarSense altogether?
Or is the idea/setup I've described completely stupid and non-functional in terms of visual observing?
Can I actually use a guide camera via AsiAir/Astroberry for alignment, or does it have to be the main camera (which I wouldn't have in the initial setup I've described)?

Hopefully I've explained myself well enough.

Thanks.

[PeterCPC]

I had a Starsense once but found it inaccurate - I found that I could get better alignment using the mount controls. I think some people do find it useful for purely visual work but for imaging I found it a no no. No doubt you will get conflicting opinion.

[Ricochet]

6 hours ago, Gallandro said:

OAG inline with the star diagonal

Using an OAG for astrophotography requires careful choice of spacers to ensure that the main camera and guide camera are both in focus at the same time. When observing visually, different eyepieces have different focus points and you would be unable to use the telescope focuser to focus the eyepiece without changing the focus of the guide camera. The only option would be to fit a helical focuser to the diagonal and use that to focus the eyepieces instead of the focuser. As far as I am aware, these types of focusers tend to have limited travel and so you would be limited to eyepiece ranges that claim to be parfocal, and would be unable to use items like barlows and binoviewers that can change the focus position significantly. The way to get around this issue would be to use a separate guide scope instead of an OAG, which is basically what Starsense is. If you want to try to save yourself the cost of buying a Starsense unit I would be inclined to try just manually running through the alignment procedure when using the scope visually as you don't need the ultra precise guidance that you do whilst taking long exposure photographs.

[Gallandro]

16 minutes ago, Ricochet said:

Using an OAG for astrophotography requires careful choice of spacers to ensure that the main camera and guide camera are both in focus at the same time. When observing visually, different eyepieces have different focus points and you would be unable to use the telescope focuser to focus the eyepiece without changing the focus of the guide camera. The only option would be to fit a helical focuser to the diagonal and use that to focus the eyepieces instead of the focuser. As far as I am aware, these types of focusers tend to have limited travel and so you would be limited to eyepiece ranges that claim to be parfocal, and would be unable to use items like barlows and binoviewers that can change the focus position significantly. The way to get around this issue would be to use a separate guide scope instead of an OAG, which is basically what Starsense is. If you want to try to save yourself the cost of buying a Starsense unit I would be inclined to try just manually running through the alignment procedure when using the scope visually as you don't need the ultra precise guidance that you do whilst taking long exposure photographs.

Thanks for your help, that makes sense.

 

[Cosmic Geoff]

Let's be clear about what the Starsense (camera +handset) does. It automatically performs a star alignment, saving one the bother of choosing alignment stars, finding one of them in the finder, then the main scope, and performing a 2-star align or autoalign. While the Starsense is doing its thing, you could be moving accessory gear outside.

Starsense works by plate-solving, but it is not a direct equivalent of the plate-solve you can perform yourself with your own camera and software. The results of a Starsense plate-solve cannot be directly accessed.

I have found that the Starsense is of most benefit when attached to a quick-deploy setup like my C8 SE, where the whole assemblage can be caried outside as a single unit, Starsense started and the setup ready for observing within minutes (ignoring cool-down time).  Personally I have not found the Starsense to be as accurate as a good 2-star auto-align. but it is accurate enough to get objects into a low-power eyepiece and it certainly saves some annoying fiddling about and crouching. And the handset has some handy object lists.

If you have a heavy kit that needs to be assembled before use, and which has GPS, the time taken by doing a 2-star align is a small proportion of the total assembly & setup time (typically 20-30 minutes), and it hardly seems worthwhile attaching a £300+ accessory to shave a little off this time.

What kind of imaging are you intending to carry out? Your choice of scope and mount implies that you have in mind either planetary imaging, or deep-space imaging of small objects.  Be advised that while the former should be fine, the latter is by all accounts NOT for beginners.

I have tried unguided images of planetary nebulae with a C8 and the images are no sharper (allowing for the difference in image scale) than those taken through a much cheaper 102mm achro refractor.   You may get more satisfying results if you start your deep-space imaging with a small hgh-quality refractor, or even a camera + telephoto lens.  Have you acquired and read the book "Making Every Photon Count" by Steve Richards? It is repeatedly recommended here as a guide for would-be astro imagers.

[Gallandro]

4 minutes ago, Cosmic Geoff said:

Let's be clear about what the Starsense (camera +handset) does. It automatically performs a star alignment, saving one the bother of choosing alignment stars, finding one of them in the finder, then the main scope, and performing a 2-star align or autoalign. While the Starsense is doing its thing, you could be moving accessory gear outside.

Starsense works by plate-solving, but it is not a direct equivalent of the plate-solve you can perform yourself with your own camera and software. The results of a Starsense plate-solve cannot be directly accessed.

I have found that the Starsense is of most benefit when attached to a quick-deploy setup like my C8 SE, where the whole assemblage can be caried outside as a single unit, Starsense started and the setup ready for observing within minutes (ignoring cool-down time).  Personally I have not found the Starsense to be as accurate as a good 2-star auto-align. but it is accurate enough to get objects into a low-power eyepiece and it certainly saves some annoying fiddling about and crouching. And the handset has some handy object lists.

If you have a heavy kit that needs to be assembled before use, and which has GPS, the time taken by doing a 2-star align is a small proportion of the total assembly & setup time (typically 20-30 minutes), and it hardly seems worthwhile attaching a £300+ accessory to shave a little off this time.

What kind of imaging are you intending to carry out? Your choice of scope and mount implies that you have in mind either planetary imaging, or deep-space imaging of small objects.  Be advised that while the former should be fine, the latter is by all accounts NOT for beginners.

I have tried unguided images of planetary nebulae with a C8 and the images are no sharper (allowing for the difference in image scale) than those taken through a much cheaper 102mm achro refractor.   You may get more satisfying results if you start your deep-space imaging with a small hgh-quality refractor, or even a camera + telephoto lens.  Have you acquired and read the book "Making Every Photon Count" by Steve Richards? It is repeatedly recommended here as a guide for would-be astro imagers.

Thanks Geoff for your comments.

I’ll get a copy of that book.

[KP82]

As said above OAG isn't going to work well in a visual setup. But to answer your original question, yes the functionality of Starsense can easily be replicated with a guide cam, guide scope and astroberry. In fact the homebrew solution can do much better. I've assembled a little device based on my ap experience to do exactly what you want. It's made of the RPi HQ camera, a standard 50mm SW finder, a RPi 4B and astroberry (along with my own python scripts). With this device I can get extremely accurate PA for visual within a few minutes. There is no need for star alignments anymore as plate solving will always place the objects in the eyepiece even at high power, making double star observation a breeze. It can also be used together with SkySafari as a "push-to" guide for manual mounts

Edited November 16, 2021 by KP82