ZWO ASI 290 MMC: Noisy picture, can't see anything

[Archonom]

Hello there,

I am a newbie in the field of observing the sky. After having some success viewing interesting objects through my scope, I thought I make my dream come true and buy a decent camera for astrophotography (I know, for most of you guys, this is how a typical beginner's horror story starts :P).

I was still in the process of researching and learning, when suddenly I had the chance to buy a used ZWO ASI 290 MMC (color, cooled) camera. Although I did not complete my research and did not know for 100% what I should prepare before buying anything, I thougt I'd be fine by buying this cam for planets and some brighter deep sky objects.

Now the camera is located on my desk and should be fine, so it should not be broken or something like that.

 

Well, since I am still new in this field I was being very naive: I thought I'd simply install all required drives and software on Windows 10 (I also tried on Linux, btw) and then would be able to connect the cam to my PC and view an image through the cam (like, let's say, some stuff in my room), just for testing purposes.

But, after connecting it via USB 3 to three different PCs/notebooks, I always saw only very bright images with strange colors.

Then, reading the ZWO ASI quick starter guide, I learned that without a lense, I would not be able to see anything. Unfortunately, this cam did not come with any fisheye lense or something like that.

So I attached a 2x barlow lense directly to the cam, and then I started seeing lots of dots (noisy picture). I then researched further and read that one should first attach a 1,25 piece to the cam and then wind the barlow lense on top of it (so the setup is: cam -> 1,25 inch piece -> 2x barlow lense).

After doing this, I started seeing very blurry and noisy images (like the one in the attachment of this post).

At first I thought the cam is broken or something like that, but I waved the cam around and also waved my hand on front of the camera, and I started seeing different colors, shades etc. I also think that I can see pixels of the screen of my main PC, so I guess that the cam itself is still fine.

 

But at the moment, I do now know what I am doing wrong.

My first goal is to test the cam by pointing it into an object in my appartment and then being able to see stuff, like  cup, a bottle, my PC etc. I think you get the picture.

My second goal would be to wait until tonight and then put the cam on my telescope and hope to see some stars for the beginning.

 

But I guess that I am doing something horribly wrong and I feel a bit ashamed that I can't succeed even seeing anything.

 

So, it would be great if someone could point me into the right direction and tell me what I should try next. Please feel free to ask me anything if it helps finding a solution.

Things I tried so far:

• Changing the spacing between 1,25 piece and barlow lense
• Used auto focus help in some recording software
• Darkened the room in the hope that the cam can only show stuff when lights are low
• Tried with and without a 1,25 piece and with and without a barlow lense
• Researched the web for folks having a similar issue

 

[PeterCPC]

It is obviously working. Can't you mount it on a telescope? Once on a telescope you should be able to bring it into focus ok. Daytime would be the best to check it out as you can see what you are doing better.

Peter

[wimvb]

Definitely working ok. To get any kind of image, you need a light focusing (positive, convex) lens. A Barlow is no good for this. By having the camera open indoors, you will only gather a lot of dust on the window. Just mount the camera on a scope and try to focus on a distant object (through a window if you want to stay indoors).

[Archonom]

Oh my... thank you very much for the hint!

I mounted it on my scope yesterday (when it was dark) but couldn't see anything.

I just mounted it at daylight, but again, was not able to see anything. All I got was a noisy picture (again).

Then I attached the 2 inch to 1,25 inch adapter to the drawtube, put the 1,25'' piece on the cam and attached it on top of the adapter. After playing a bit, I ended up having a clear picture of a distant house roof.

 

Perfect! I don't know why I didn't think of this myself first. Thanks again, guys!

 

If I may, I have a follow-up question:

What would be the typical way of observing planets and bright deep sky objects with this setup?

Would I put a barlow lense in front of the cam or would I just leave this setup as it is?

[wimvb]

1 hour ago, Archonom said:

If I may, I have a follow-up question:

What would be the typical way of observing planets and bright deep sky objects with this setup?

Would I put a barlow lense in front of the cam or would I just leave this setup as it is?

After your neighbour's roof top, I would point the scope at the moon. It's bright, and high in the sky. So it's dificult to miss. Then take a few images, and stream a video, just to get acquainted with the setup. I would wait with the barlow until the second imaging night at least. A barlow will move the focal point further out, and make it more difficult to point the scope accurately. Btw, you never mentioned which scope/mount you have. I assume you have some kind of tracking mount (alt-az or equatorial) with motors.

If you haven't already, download a program that will show you the night sky (stellarium, Cartes du Ciel / SkyChart, Kstars, to name a few). This is the easiest way to figure out what's best for viewing at any particular night. Some DSO's you could try (bright ones) are the Orion nebula and stars in Orion's belt (with a bit of luck you can even catch the flame nebula, although the moon may have it otherwise).

The beehive cluster (M44) may be a bit large for your camera, but there are other star clusters that are bright and are easy targets.

For other DSO's it's better to point the scope away from Orion. If your site allows, you can try M51 and M81/82 to the north.

 

Have fun!

 

[Archonom]

Just came back from a short session with my scope and the cam. I managed to see the stars with the capture software on my notebook, which made me quite happy. I also realized that I still have much to learn until I will be able to shoot something, but the first steps are taken. Thanks again!

 

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After your neighbour's roof top, I would point the scope at the moon. It's bright, and high in the sky. So it's dificult to miss. Then take a few images, and stream a video, just to get acquainted with the setup. I would wait with the barlow until the second imaging night at least. A barlow will move the focal point further out, and make it more difficult to point the scope accurately.

This sounds reasonable to me. Will do so!

 

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Btw, you never mentioned which scope/mount you have. I assume you have some kind of tracking mount (alt-az or equatorial) with motors.

After having consulted someone with lots of experience, I ended up with a EQ6-R Pro, GoTo and a 8" inch Newton (200PDS 200mm 1000mm f/5).

As far as I understand it correctly, for astrophotography it is required that the equipment is able to track stars and hold them into the view so they don't "run away" (sorry, not a native speaker, but I guess you know what I mean). The EQ6 and GoTo combination should be able to do so. I tried to achieve something like this during the short session, and it seemed that the mount corrected the scope's alignement all the time. So the same stars were visible during the session; however, the stars still moved a bit, so I guess there is an even more precise way. Is guiding with another cam one of those ways and is it required for astrophotography, even when you have such a mount with GoTo?

 

Quote

If you haven't already, download a program that will show you the night sky (stellarium, Cartes du Ciel / SkyChart, Kstars, to name a few). This is the easiest way to figure out what's best for viewing at any particular night. Some DSO's you could try (bright ones) are the Orion nebula and stars in Orion's belt (with a bit of luck you can even catch the flame nebula, although the moon may have it otherwise).

This is a great hint. I have stellarium on all devices and am already getting familiar with it.

 

[wimvb]

12 hours ago, Archonom said:

After having consulted someone with lots of experience, I ended up with a EQ6-R Pro, GoTo and a 8" inch Newton (200PDS 200mm 1000mm f/5).

That's an excellent combination, but not the easiest to start with. Be prepared for a learning curve.

The eq6 will track stars, by counteracting the earth's daily rotation. How accurately it will do so, depends on how well the mount's rotational axis (right ascension, ra) is lined up with earth's polar axis. This is polar alignment. For observing, just point the mount in the right direction using its polar scope. For astrophotography, use the polar alignment routine in the synscan hand controller. Other methods may be better, but the synscan routine is easier and faster. And my guess is that you don't want to spend your first year in this hobby just setting up and tearing down your gear, but also observe and image the night sky.

Use your camera with a high gain setting, and keep your exposures below one minute. But take lots of them (100+).

And at about this point, I would recommend you invest in three things (in this order)

1. https://www.firstlightoptics.com/bahtinov-focus-masks/starsharp-bahtinov-focus-masks.html

2. https://www.firstlightoptics.com/books/making-every-photon-count-steve-richards.html

3. https://www.firstlightoptics.com/coma-correctors/baader-mpcc.html

The last one may need some adapters and spacer rings, so you need to contact FLO, and explain what you're using.

Good luck, and have fun