CMOS Camera for beginner help

[lw2689]

Hi all,

I would like to progress into the world of planetary imaging. The main targets would be the bigger planets, the moon and if possible some bright DSO (M57 being my top achievable DSO on the list with the set up I have). 

Current set up: C6 XLT, Celestron AVX.
Computer: MacBook Pro, however in have recently installed windows using boot camp. 

I have been looking at the ZWO ASI120 and ASI224 both colour as I’m only just starting out and don’t want to get to lost with monochrome. I've read about the 2.0 usb on the 120 playing up so ideally I would look for 3.0 USB. I have looked at the modded webcam option but I’m not that technical, nor have lots of spare time and when you add up the cost I may as well invest. Then if I do progress I can sell it to another beginner like me to upgrade.

I am looking for suggestions, my approx budget is £150-200. 
 

[Cosmic Geoff]

I recommend the ASI224MC.  It's good for planets and small DSOs, or EEVA.

If cash is short, try the ASI120MC-S (3.0 USB) but it's more of an entry level camera.

[endless-sky]

I was undecided between the ZWO ASI 120MM Mini and the ASI 224MC as well. I wanted a camera that would be good for both guiding and planetary imaging. After some research, I decided to get the ASI 224MC. I read all sorts of problematic experiences with the 120MM Mini (others even with the 120MC-S), expecially under Linux/Raspberry (KStars and EKOS suite). Since I use a Raspberry to control my gear, I decided for the better camera. Even the dealer at the store where I ordered it from, without any negative input on my part, immediately suggested the 224MC for a more suitable camera, both for guiding and planetary imaging.

[lw2689]

44 minutes ago, Cosmic Geoff said:

I recommend the ASI224MC.  It's good for planets and small DSOs, or EEVA.

If cash is short, try the ASI120MC-S (3.0 USB) but it's more of an entry level camera.

I see you have the star sense also, I’m looking to buy that also. Is it worth it?

[lw2689]

52 minutes ago, endlessky said:

I was undecided between the ZWO ASI 120MM Mini and the ASI 224MC as well. I wanted a camera that would be good for both guiding and planetary imaging. After some research, I decided to get the ASI 224MC. I read all sorts of problematic experiences with the 120MM Mini (others even with the 120MC-S), expecially under Linux/Raspberry (KStars and EKOS suite). Since I use a Raspberry to control my gear, I decided for the better camera. Even the dealer at the store where I ordered it from, without any negative input on my part, immediately suggested the 224MC for a more suitable camera, both for guiding and planetary imaging.

I definitely am thinking more towards the ASI224. Ive seen the word ‘guiding’ floating around a lot, not 100% sure what that is...yet, but I have a feeling if I decide to progress into more imaging I will soon learn it and this camera can be used to help with it?

Do you need to have a laptop connected all the time to the camera? Sounds like you have a great set up using Raspberry it seems to be quite popular  

[Cosmic Geoff]

1 hour ago, lw2689 said:

I see you have the star sense also, I’m looking to buy that also. Is it worth it?

That's up to you to decide.  It does  save much of the faff of doing a star align, and you can fetch out accessories while the Starsense is doing its thing.  I use it as part of a carry out, quick deploy setup.  Some people have had problems with the SS, others love it.

[endless-sky]

Guiding is more of a necessity when longer exposure times are needed or when you use longer focal lengths (expecially when imaging DSOs, for planetary imaging is not much of a necessity). For example, I have been using a DSLR and a 300mm focal length lens for the past 6 months and the mount alone is good enough to track and give me round stars until 120s of exposure. But I am in the process of acquiring an 80mm f/6 refractor and even when reduced to f/4.8 (384mm focal length) I will definitely need guiding. Basically, you put a second small telescope or finder in parallel with your main imaging setup and you connect a camera (for example the ASI 120MM Mini or the 224MC discussed above) to it. The camera will loop a series of images (usually at 1 - 3s exposure) to a program (for example PHD2) made for the purpose of guiding. The program chooses a star in the field of view of the camera, calibrate the movements of your mount (AR and DEC), and then input corrections in AR and DEC to keep the chosen star centered in the cross-hairs. This way you can get much longer exposures without star trails.

The ASI 224MC can definitely be used for guiding, also.

These cameras all need power supplies of some sort, so I think you need a laptop or at least a powered USB hub. You also need a laptop to download the images, I don't think they have any internal memory. I personally use a Raspberry Pi 4 4GB to control my current equipment: a Sky-Watcher NEQ6 Pro mount and a Nikon D5300. Soon I'll add the ZWO ASI 224MC. There's a very nice pre-built suite, called Astroberry, that you can just install on an SD card, plug in into the Pi and you are basically ready to go. The suite comes with KStars (planetarium software to point the mount to the chosen objects) and EKOS (controller for all sort of devices: camera, guide camera, focuser, GPS, plate-solving, etc.) that also serves as planner for the imaging session.

Edited July 22, 2020 by endlessky

[rnobleeddy]

12 hours ago, endlessky said:

Guiding is more of a necessity when longer exposure times are needed or when you use longer focal lengths (expecially when imaging DSOs, for planetary imaging is not much of a necessity). For example, I have been using a DSLR and a 300mm focal length lens for the past 6 months and the mount alone is good enough to track and give me round stars until 120s of exposure. But I am in the process of acquiring an 80mm f/6 refractor and even when reduced to f/4.8 (384mm focal length) I will definitely need guiding. Basically, you put a second small telescope or finder in parallel with your main imaging setup and you connect a camera (for example the ASI 120MM Mini or the 224MC discussed above) to it. The camera will loop a series of images (usually at 1 - 3s exposure) to a program (for example PHD2) made for the purpose of guiding. The program chooses a star in the field of view of the camera, calibrate the movements of your mount (AR and DEC), and then input corrections in AR and DEC to keep the chosen star centered in the cross-hairs. This way you can get much longer exposures without star trails.

The ASI 224MC can definitely be used for guiding, also.

These cameras all need power supplies of some sort, so I think you need a laptop or at least a powered USB hub. You also need a laptop to download the images, I don't think they have any internal memory. I personally use a Raspberry Pi 4 4GB to control my current equipment: a Sky-Watcher NEQ6 Pro mount and a Nikon D5300. Soon I'll add the ZWO ASI 224MC. There's a very nice pre-built suite, called Astroberry, that you can just install on an SD card, plug in into the Pi and you are basically ready to go. The suite comes with KStars (planetarium software to point the mount to the chosen objects) and EKOS (controller for all sort of devices: camera, guide camera, focuser, GPS, plate-solving, etc.) that also serves as planner for the imaging session.

Whilst I wouldn't argue against using a powered USB hub, I've run into no issues powering a 120 from the usb port of a pi3. It was probably the only device drawing any power though.

[endless-sky]

Well, that's great to know! Right now I am not powering anything through the Pi, as everything has its own power supply (mount and DSLR, which is powered by a dummy battery). The only USB cables that go from the Pi to the mount and to the camera are for data transfer. So, it's good to know that if the only thing needing to draw power was the guide camera, the Pi would be good enough to handle it. Saves me from buying a powered hub, which I really don't have a need for, right now. Thanks for the input!

[lw2689]

22 hours ago, endlessky said:

Guiding is more of a necessity when longer exposure times are needed or when you use longer focal lengths (expecially when imaging DSOs, for planetary imaging is not much of a necessity). For example, I have been using a DSLR and a 300mm focal length lens for the past 6 months and the mount alone is good enough to track and give me round stars until 120s of exposure. But I am in the process of acquiring an 80mm f/6 refractor and even when reduced to f/4.8 (384mm focal length) I will definitely need guiding. Basically, you put a second small telescope or finder in parallel with your main imaging setup and you connect a camera (for example the ASI 120MM Mini or the 224MC discussed above) to it. The camera will loop a series of images (usually at 1 - 3s exposure) to a program (for example PHD2) made for the purpose of guiding. The program chooses a star in the field of view of the camera, calibrate the movements of your mount (AR and DEC), and then input corrections in AR and DEC to keep the chosen star centered in the cross-hairs. This way you can get much longer exposures without star trails.

The ASI 224MC can definitely be used for guiding, also.

These cameras all need power supplies of some sort, so I think you need a laptop or at least a powered USB hub. You also need a laptop to download the images, I don't think they have any internal memory. I personally use a Raspberry Pi 4 4GB to control my current equipment: a Sky-Watcher NEQ6 Pro mount and a Nikon D5300. Soon I'll add the ZWO ASI 224MC. There's a very nice pre-built suite, called Astroberry, that you can just install on an SD card, plug in into the Pi and you are basically ready to go. The suite comes with KStars (planetarium software to point the mount to the chosen objects) and EKOS (controller for all sort of devices: camera, guide camera, focuser, GPS, plate-solving, etc.) that also serves as planner for the imaging session.

So I spent the rest of the evening researching Raspberry Pi and wow I think this might just be a game changer!! I had been trying to workout how I was going to lead all the wires into the house so my old laptop won’t die in the cold during winter. Problem solved. Ordered one last night and really looking forward to experimenting and giving Astroberry a go. 

22 hours ago, Cosmic Geoff said:

That's up to you to decide.  It does  save much of the faff of doing a star align, and you can fetch out accessories while the Starsense is doing its thing.  I use it as part of a carry out, quick deploy setup.  Some people have had problems with the SS, others love it.

I can’t decide if I am being a lazy observer or going for convenience to increase observing time. I’ll go with the later.. I think I will invest. Thanks for your help.

 

8 hours ago, rnobleeddy said:

Whilst I wouldn't argue against using a powered USB hub, I've run into no issues powering a 120 from the usb port of a pi3. It was probably the only device drawing any power though.

Really good to know. Looking forward to RPi and using ASi120/224 depending on how sucessful pay day is!

[endless-sky]

Save up on the Starsense and get the ZWO ASI 224MC, instead. The reason I suggest you to do this is because with the Astroberry package, you'll be able to do plate-solving and star alignment will be something that you'll never feel the need to do again. With plate-solving, all you have to do is take a picture of where the telescope is pointing (2-3 seconds is enough, just so that some stars are visible) and the software will calculate exactly where you are pointing at. From there, you can tell it to slew to an object, plate-solve again, and it will keep doing it until the object is within the specified tolerance away from the center of the frame (usually it takes 3-4 iterations).

Save your money, let the software do the work for you!

[lw2689]

43 minutes ago, endlessky said:

Save up on the Starsense and get the ZWO ASI 224MC, instead. The reason I suggest you to do this is because with the Astroberry package, you'll be able to do plate-solving and star alignment will be something that you'll never feel the need to do again. With plate-solving, all you have to do is take a picture of where the telescope is pointing (2-3 seconds is enough, just so that some stars are visible) and the software will calculate exactly where you are pointing at. From there, you can tell it to slew to an object, plate-solve again, and it will keep doing it until the object is within the specified tolerance away from the center of the frame (usually it takes 3-4 iterations).

Save your money, let the software do the work for you!

I’ll be DM’ing you for help you know that right? Haha. Thanks again. My plan was to buy the star sense and a ZWO camera. If I only need that camera then that will work in my favour for sure. Can the camera be put on the main scope to plate solve? I don’t have a guide scope thats all.

[endless-sky]

Feel free to DM me, I don't mind helping if I can. I have gladly helped another guy with Astroberry. Whenever you need, I can point you to those threads, too, they have quite a lot of useful information and inputs from other users.

Regarding plate-solving, yes, you can do it directly with the main scope and the ZWO camera that you will choose. You attach the camera to the telescope, slew the mount to an object, hit plate-solve and the software will do the rest for you. If you do it like this, the Starsense is completely unnecessary.

Of course, it's not completely plug and play. You'll have to input some settings in EKOS for plate-solving to work (the dimensions of the sensor, pixel size and focal length of the telescope). You'll also have to download some map index files, if you want to do plate-solving offline (highly recommended and faster). But once you have done that and see your first plate-solving work, you'll never miss star alignment ever again. In fact, you don't need alignment at all - except for polar alignment, of course.

The way I do it is like this:

- polar align with the polar scope

- slew to a bright star to focus (if the star is not in the field of view, plate-solve so that the mount can center it)

- slew to the target that I want to image, plate-solve until the framing is exactly how I want it (also, I rotate the camera until framing is to my taste, at this point)

- plan the sequence (number of exposures and exposure time)

- enjoy the images as they are captured and shown on screen

You only need two plate-solvings: one for the star that you are going to use for focusing and one for your target. The 3 / 5 star alignment is to get a better sky mapping, if you plan to do visual observation, but that's not really needed if you can go straight to the subject you are interested. If you want to image more than one target in the same session, then you can just slew to the next one and plate-solve again and repeat as necessary.