advice on a raspberry pi 4

[AstroNebulee]

Hi, I have an az gti mount using a skywatcher wedge and using in eq mode.  I havent used it in anger in this format yet.  Firstly i am going to try mounting a polar scope as my attached image shows. I'm hoping ive calibrated the polar scope well enough. But I've seen comments on here that you can use a raspberry pi4 and polar allign with that. This seems quite a cheap little thing, £32 for a 2gb version or £58 for a 2gb start up kit. I'd only be using it to pa and then use my dslr to take the images. Now i dont want to be taking laptops out with me as i have to carry everything in one go, scope, mount, tripod and backpack so portability is key..  Is there a link to a video where someone is using a pi4 and mount to pa without the use of a laptop.  I'm a total newbie in this form and want to see how the pi4 works in this instance.  I hope this rambling makes sense and thank you in advance for your help.

Edited June 10, 2021 by AstroNebulee

[StevieDvd]

Try the video referenced in this SGL thread to see how PA in Ekos works

Astroberry is free and uses Ekos (as does Stellarmate but the OS is not free)  so it's just the Pi hardware needed. You'd need a browser to view the Pi (or an app as supplied with Stellarmate), so no laptop but a tablet or mobile and keen eyesight (younger than mine).

Steve

[AstroNebulee]

Thank you Steve, I'll look at that thread, for the life of me I couldn't find it, the raspberry pi4 is quite cheap and using free astroberry and ekos with my tablet is doable, can I use my dslr to do the pa, I'll look in the thread though also, thank you again. Just researching other options if my polar scope doesn't work out. 

[rickwayne]

If your DLSR is connected to the Pi (and supported by INDI), you can run the Polar Alignment Assistant with it. It does require that plate solving be working, but that should go OK pretty much out of the box with Astroberry (I use StellarMate OS, so I'm hedging a little bit there).

I remote into my Pi with a laptop for initial setup, just because it's convenient to have a keyboard. But I've done it plenty of times with just a tablet too. StellarMate OS (US$50) includes an app specifically optimized for running your Ekos system from a mobile device. I've had troubles getting it to connect but many swear by it.

 

[Edited to add] The PAA now works on any part of the sky -- you can align using it even if Polaris and its environs are completely obscured. Haven't tried that yet personally but it's quite the feature. Of course  it helps to have your mount pointing somewhere close to the Celestial Pole.

Edited June 10, 2021 by rickwayne

[AstroNebulee]

Thank you, Rick, I'm just researching the possibility of the next step in my astrophotography journey and whether this is a feasible way to go. Still got plenty more research to do but it's looking good so far with all your helpful advice. My dslr is a Canon 600D, do hopefully supported in indi, thank you agsin much good for thought 

[Avocette]

I started my astrophotography journey a couple of years ago with a DSLR and a Raspberry Pi 4 running KStars/Ekos/Indi although not in the Astroberry package at that time. The DSLR images were large and image downloading took a bit of time, so the iterative PA process was noisy (shutter clicking) and not swift, but I was still very pleased to have the option. My AZ/EQ5 mount doesn’t include a polar scope, and my back didn’t enjoy the contortions I used to go through to polar align my earlier EQ5 Synscan mount. In those days SharpCap Pro didn’t allow PA using a DSLR, but I think the latest SharpCap Pro beta 4.0 may have added DSLRs into the camera list.

These days I use an Astro camera with a smaller sensor, hence faster update and download, and no clunking shutter.

’just noticed that you’ve also got an ASI120MC-S. I have one which works very well for the polar alignment and also for auto guiding in Ekos.

Edited June 10, 2021 by Avocette

[Daf1983]

I use a rpi4 with a canon 600d, and I can say it's definitely supported by indi. I have only used to 3-4 times since getting my new setup, I've managed to plate solve with the 600d, but found using the polar alignment module difficult to use with it. Just to emphasise, this is not a problem with ekos, just it takes time for the dslr image to download and for the image to refresh whilst you're adjusting your polar alignment. I haven't tried it with the guide camera as of yet(a zwo120mm-s), but I'm guessing that would be easier.

Edited June 10, 2021 by Daf1983

[AstroNebulee]

9 hours ago, Avocette said:

In those days SharpCap Pro didn’t allow PA using a DSLR, but I think the latest SharpCap Pro beta 4.0 may have added DSLRs into the camera list.

8 hours ago, Daf1983 said:

just it takes time for the dslr image to download and for the image to refresh whilst you're adjusting your polar alignment.

 

Hi

Thank you to both of you, it does sound like the dslr way of PA is possible but a longer drawn out option. I could use my asi120mc-s, but would have to be in the scope and then when PA done swap it over to the dslr as this is how I like to take my images, the trouble then bring balancing the scope again wouldn't it then my PA would probably be off. One other option is to get an attachment for my asi120mc-s to turn it into a method of Polar aligning and fo that with the pi4. If sharpcap allows PA with a dslr now that could be an option. But means taking a laptop out with me, hmmm lots of things to research, thank you again 👍

[AstroMuni]

18 hours ago, AstroNebulee said:

But I've seen comments on here that you can use a raspberry pi4 and polar allign with that. This seems quite a cheap little thing, £32 for a 2gb version or £58 for a 2gb start up kit. I'd only be using it to pa and then use my dslr to take the images. Now i dont want to be taking laptops out with me as i have to carry everything in one go, scope, mount, tripod and backpack so portability is key..

I use the RPi to control my mount but do it via laptop rather than run Ekos off the RPi. There isnt much difference in the way to configure ekos, its just done on the RPi instead of the PC. Wifi connectivity to RPi can become a challenge, so you may need to be close enough to the RPi to use its own hotspot. Other options are installing a wifi extender or running a long ethernet cable from your router to the RPi . I have connected my RPi to the laptop using ~20m of ethernet cable!

I have the RPi4 with 4Gb ram and a 64gb SD card. As you are planning to run off the RPi, buy the largest SD card that you can afford. The files for platesolving are large so will take up quite a bit of space. You will also need the storage for your images.

Here is a good tutorial on setting up the bits https://www.macobservatory.com/blog/2020/6/4/remote-telescope-imaging-on-the-mac-or-pc-using-a-raspberry-pi

Edited June 11, 2021 by AstroMuni

[Stuart1971]

6 minutes ago, AstroMuni said:

I use the RPi to control my mount but do it via laptop rather than run Ekos off the RPi. There isnt much difference in the way to configure ekos, its just done on the RPi instead of the PC. Wifi connectivity to RPi can become a challenge, so you may need to be close enough to the RPi to use its own hotspot. Other options are installing a wifi extender or running a long ethernet cable from your router to the RPi . I have connected my RPi to the laptop using ~20m of ethernet cable!

I have the RPi4 with 4Gb ram and a 32gb SD card. As you are planning to run off the RPi, buy the largest SD card that you can afford. The files for platesolving are large so will take up quite a bit of space. You will also need the storage for your images.

Here is a good tutorial on setting up the bits https://www.macobservatory.com/blog/2020/6/4/remote-telescope-imaging-on-the-mac-or-pc-using-a-raspberry-pi

All good advice…

I run mine from an 120gb SSD which is around 5 times faster, and also run all the software from the RPI, and works very well indeed….just then VNC into it from my indoor PC..

One bit of advice I will share, is that the RPI USB ports are a bit underpowered and if unpowered cameras etc, will be plugged in here then a USB powered hub is in order, also I don’t use the built in WIFI, I have a USB 3.0 wifi dongle, which gives a much better connection over a much greater distance….👍🏼

[KP82]

5 hours ago, AstroNebulee said:

Hi

Thank you to both of you, it does sound like the dslr way of PA is possible but a longer drawn out option. I could use my asi120mc-s, but would have to be in the scope and then when PA done swap it over to the dslr as this is how I like to take my images, the trouble then bring balancing the scope again wouldn't it then my PA would probably be off. One other option is to get an attachment for my asi120mc-s to turn it into a method of Polar aligning and fo that with the pi4. If sharpcap allows PA with a dslr now that could be an option. But means taking a laptop out with me, hmmm lots of things to research, thank you again 👍

Do you guide while imaging? If yes, you could PA with your guidescope and asi120. Use your phone to VNC into astroberry then run the PA assistant in Ekos. No laptop required.

Otherwise you could balance your setup with the DSLR and then swap for the asi120 just for PA. A slight imbalance during PA isn't a big issue.

Edited June 11, 2021 by KP82

[Stuart1971]

8 minutes ago, KP82 said:

Do you guide while imaging? If yes, you could PA with your guidescope and asi120. Use your phone to VNC into astroberry then run the PA assistant in Ekos. No laptop required.

Otherwise you could balance your setup with the DSLR and then swap for the asi120 just for PA. A slight imbalance during PA isn't a big issue.

This is all possible, but you will need the eyesight of a hawk to PA with EKOS from a phone screen….😮😮 which I certainly don’t have….🤨

[TerryMcK]

All good advice to use Astroberry with the PI4. I would just go for the 4GB version if I were you.

I have several PI4's for my setups and Astroberry/Kstars/EKOS is a fully functional observatory control system, whether just a basic rig or an all singing all dancing rig with dome etc. with everything inbetween. All for free apart from the cost of the PI.

[KP82]

18 minutes ago, Stuart1971 said:

This is all possible, but you will need the eyesight of a hawk to PA with EKOS from a phone screen….😮😮 which I certainly don’t have….🤨

No, you don't need a super sharp eyesight. You can zoom in while doing PA in Ekos. I do that quite often with my home made electronic finder for visual use (made of pi4 + pi hq camera + 9x50 finder + a gpio button + some self written python scripts).

Edited June 11, 2021 by KP82

[AstroMuni]

6 hours ago, AstroNebulee said:

it does sound like the dslr way of PA is possible but a longer drawn out option.

Ekos does PA quite well, so I would do the following...(which is what I do on my scope - the only difference is I use my ASI camera for imaging)

- Use your polarscope to visually polar align.

- Use the DSLR to platesolve and do final alignments using Ekos. Use the PA tool and the Ekos mount model to do multi star alignments.

You should have a very decently aligned scope

 

 

Edited June 11, 2021 by AstroMuni

[BCN_Sean]

If using a Pi4 for this, ignore the SD card completely as the main system drive; buy a decent USB 3 thumb drive, set the Pi so it's going to boot off it and use that instead.  The biggest bottleneck I've found with these things is the time it takes to pull the image down from the camera on to the Pi if it's having to buffer it to the Pi's SD card, also boot times are a lot quicker and the system is a lot more responsive as well.

With testing my setup with it, using a USB drive over the best SD card I have, the image actions are significantly quicker especially if the camera is connected to the USB 3 ports; I've not timed it fully but it's in the order of tens of seconds.

The other thing with it, is using solving using the local astap seems to make a better job than the inbuilt EKOS solver and as the DB is already in place, there's not the need to download the extra database files.

[powerlord]

Have you considered an ASIAIR ?

The pro is 300 quid, but the old model sells second hand for 80-100 quid.

The pro is a pi4 under the covers, the old one a pi3.

yes it ties you in to zwo cameras, etc - but it does work well with loads of DSLRs - your canon included. And no fuss or bother.

I read about lots of folk getting sick of trying to get the clunge of astroberry working and giving up, and decided to go the ASIAIR PRO route, and frankly it's awesome imho.

I bought a nice big samsung tablet, and got it connected to my home wifi, and can now happily sit in my bed at 2am, moving around the sky and setting targets and shooting stuff.

I plan to move to asi1600 at some stage, and filter wheel, focuser and it's compatible with all that too.

At present my setup is either a 1200d or 6d, asi120mm guide camera and hacked up EQ5 EQSTARPRO mount.

For me, I think ZWO have really nailed it - it's simple to use, powerful, reliable and 'just works'.

[barbulo]

59 minutes ago, powerlord said:

I plan to move to asi1600 at some stage,

I said the same words once in this forum and somebody asked in return: Why the ASI1600 if you have its evolution available (ASI294MM Pro)? I’m still thinking about that. But for the mid/long term. 
Regarding the Astroberry, I’d stick to it and use your ASI120 with a find/guide-scope to PA. 

[rickwayne]

On my Pi 3, I could never get plate solving reliably working. On the 4, it's a few seconds. I never tried using binning with a DSLR, but it's not completely inconceivable that the driver will cause it to shoot a lower-res (read: faster-downloading) image for PA. Or you could just change the resolution on your camera yourself if it lets you do that while USB-ing. Maximum binning (minimum resolution) is absolutely fine for this purpose.  If you have the 120 mounted to a guide scope, that  will work perfectly well for PA, it doesn't have to be perfectly collimated with the mount axis or the imaging camera.

I just tried out Ekos's PAA far, far away from Polaris last night -- I am talking pointing to a random sky patch at about 130°. Since I couldn't manually line up with Polaris to get the mount in the neighborhood to start with, it took several go-rounds, my initial error was over three degrees. But according to PHD, I nailed it within 2 arcminutes.

[powerlord]

1 hour ago, barbulo said:

I said the same words once in this forum and somebody asked in return: Why the ASI1600 if you have its evolution available (ASI294MM Pro)? I’m still thinking about that. But for the mid/long term. 
Regarding the Astroberry, I’d stick to it and use your ASI120 with a find/guide-scope to PA. 

ooo. I dunno there are so many, I was just going with what folk were recommending. and it comes in  package with filiters and filter wheel with a decent discount. I'm a numpty - it's not a choice I've made. is that the general view ? are 1.25in sensors still enough with the slightly larger sensor ?

[AstroNebulee]

9 hours ago, KP82 said:

Do you guide while imaging? If yes, you could PA with your guidescope and asi120.

Hi no I don't guide whilst imaging yet, I just hook up my dslr to the az gti in az mode, I've not managed to have a cvlear night yet to try the sw wedge with my AzGti and polar scope. 

[AstroNebulee]

7 hours ago, powerlord said:

The pro is 300 quid, but the old model sells second hand for 80-100 quid.

This sounds like a good option, £300 is way out of my budget but £80 much better 

[rickwayne]

astronomy.tools has a bunch of very useful calculators, including one for filter sizes for a given sensor size.

The 294 looks like a fair bit more camera for a little more money, though you have to be persnickety about your calibration frames (e.g. don't scale darks, shoot to the exact exposure time of lights, likewise for dark flats if you use those). It has pretty serious amp glow. That's not a deal-killer -- my 183MM Pro does too -- but you do have to pay attention.

[rickwayne]

If £300 is way out, I would seriously consider the Pi/Astroberry route. Heck, it's almost as cheap as an intervalometer. If you want something cheap and turnkey, StellarMate OS:

• £46: Pi 4 4GB and power adapter
• £10: Case for Pi
• £35: StellarMate OS
• £10: MicroSD card

That gives you a Pi 4B, like the ASIAir Pro, that you can control with a phone or tablet app to run an imaging sequence, perform polar alignment, do guiding, or indeed just about any observatory function. Though admittedly it lacks the the shiny red metal case of the ASI product. 

If you're looking at the old model of the ASIAir, you already know my opinion about plate solving on the 3; that's something you will want, at least someday.

[AstroNebulee]

Thank you Rick, that's an impressive bit of research there, thank you very kind of you, it's definitely something for me to go on now, I'll continue watching the YouTube tutorials, and learn mord about it before biting the bullet. But this all looks so feasible for my next step into a more advanced astrophotography role. Thank you again 👍