Newbie needs basic help with ASIStudio

Scubayorp

Hi folks,
I'm very unfamiliar with astrophotography and electronics, so please be gentle.
I have a new ZWO ASI 120 MC-S and running ASIStudio from my MacBook Pro with Catalina 10.15.7.
I'm an astronomy outreach professional and NOT interested in astrophotography per se, but rather want to use the ASI camera to capture live sky views that I will project onto a cinema screen for an audience who will be listening to me talk about the targets as I remotely move my scope across the sky.
My main problem is understanding the basics of how to simply get an image to appear in the software! I don't even know if I should use Planetary Imaging, Deep Sky Imaging, Live Stacking or Deep Sky Stacking?
Can someone please walk me through the process?
Thank you

johnpd

Scubayorp
What you are asking for is a tall order. Unfortunately the documentation that ZWO has (if any) for their hardware and software leaves a lot to be desired. ZWO seems to think everyone has an engineering degree and can easily figure everything out. The only documentation I can find is a brief view of each program located below. It may not be comprehensive but is the best I could find.

https://astronomy-imaging-camera.com/tutorials/a-user-guide-to-asistudio-software-and-the-zwo-asi183mc-camera.html

I have done a lot of public outreach and use the ASIAIR Pro mounted on my scope to handle everything. The ASIAIR is controlled by my iPad. The only part of ASIStudio that I use is FITS Viewer and Deep Sky Stacking. There are some similar processes between the ASIAIR and ASIStudio however. These are the programs available in ASI Studio:
1) ASICap: for planetary imaging.
2) ASIImg: for Deep Sky Imaging.
3) ASILive: for live image stacking (this is what you would mostly use).
4) ASIFitsViewer: for viewing saved images that are in .FITS format.
5) ASIDeepStack: for stacking multiple images taken with ASIIMG or ASILive (if you saved individual images for offline stacking).

QUESTIONS and FURTHER INFO

What telescope and mount are you using? I assume you know how to get them properly aligned and focused before you want to do any viewing. If you never used a camera like this before, getting your camera initially focused can be a little trying. It would be better to try this in the daytime on an object as far away as possible.
Both the ASIAIR and ASI Studio have a "Live Stacking" option. This is what I use most often in public outreach to display some of the finer celestial deep sky objects. This is what you should be concentrating on.
-a. Depending on the brightness of the object will determine how long of an exposure you want to take. Very bright objects such as globular clusters may only need about 10 seconds per image. Each image you take will be stacked live on the screen. You probably would not want to go beyond 30 seconds per image. If you are using an Alt-Az mount, you will notice something called "field rotation" where the border of the image will begin to slowly rotate to the right. You would be limited as to how long you could stack these images as that will become noticeable.
-b. The above documentation mentions a histogram, but gives no picture of it or how to use it so I have no idea what it will show. Below is a blank screen I got when I started ASILive. Since I use an ASIAIR instead of a computer to do imaging, I have no drivers loaded so I have no way of going beyond the blank screen. But I can see some similarities between this and what the ASIAIR shows.

The histogram is a great way of adjusting the image to make it more viewable. On this screen it is located on the lower right. It is very small but there is a "+" button which will make it bigger. I am not sure how much. You do want to make it bigger. If it is anything like what the ASIAIR has, then this is the procedure I follow for adjusting the image.
--1) Wait until at least 3 images are stacked before attempting to adjust the image.
--2) If you are familiar with histograms, there is a "black" point on the left and a "white" point on the right. Move the black point to the right until the indicator line is close to where the high point of the graph is. Then move the white point left until the image becomes brighter.
--3) If your camera has a lot of noise or has amp glow, you will need to take dark frames first that will have the identical exposure, gain, and temperature as your light frames.

If you want to image planets, you would use ASICap. I do not know how this works, but that tutorial gives you some idea.

Good luck and you are providing a great service to the public.

JohnD

Danshep

Scubayorp I use the ASICap portion of ASI Studio. I set up my telescope and have a ZWO 174mm for photographing the solar surface. It is easy to connect the camera to my MacBook Pro and run the software. Then you can either photograph single shots (multiple shots) or video. Of course, you do not have to actually photograph, but can just look at the screen. But if you don’t photograph, then your viewing would have be at the exact time you are presenting.

Got-zwo-asi

Did no one reply to your request?
I would have a similar question - as I just bought a ZWO 385 camera and just installed ASI Studio.
If no one is bothering to answer your question - they probably won't bother to answer mine.

AstroDude42

Maybe this will help you understand. In short:

Planetary Imaging is used to image planets with a telescope (with a very long focal length, i.e. >2000 mm) and camera. Usually it records a video (with short exposure times and relatively small frames) from which you are going to process one sharp image out its individual frames to get rid of atmospheric turbulences. Thus, your camera should be able to record at a higher fps rate.
Deep Sky Imaging will be used to image galaxies, star fields, nebulas, whatsoever with a telescope (from widefield to long focal length) and camera that usually has a higher resolution. It creates images with longer exposure times that can vary from seconds to several minutes. The longer the exposure, the more details you will get in one image. But you can compensate that with "not so long" exposure but more images. That's why there is stacking, which brings out the details of a target when laying all images on top of each other and blending together the pixel values.
Live Stacking can be used to stack those images from Deep Sky Imaging during the active imaging session and produce a higher quality image out of all the images taken. It prevents you from having to post-process all images.
Deep Sky Stacking can be used to post-process the images from a Deep Sky Imaging session after the session ended.

So i guess, in case of the OP, the way to go would be to use Deep Sky Imaging and just mirror the laptop screen to the cinema screen. But (!): in order to see details of nebulas, galaxies, etc. you would need to make long exposures. For demo, it may be sufficient to take one image and not do stacking at all, because it takes a lot of time time. I doubt this is a practical solution during a speech because you would have to wait for the image to be taken, downloaded from the camera, (automatically and minimally) processed and finally displayed by the software. That just takes too long i guess.

Why don't you just use some software like Stellarium or _ Sky Safari_ to project the virtual sky onto the screen? Then you could quickly change the view from target to target and not have to wait for a rather slow equatorial mount to move the telescope.

Hth, Olli

MarkMo

Danshep I am new at this too. I have a orion star blast 6 telescope I am using mm224mc asi camera I can see Jupiter with my eyepiece but when I replace it with the camera I just have a black screen using ASICAP I am not sure what settings to use and what else is wrong I can get good pics of the moon so I am not sure why I cant see Jupiter with camera and a 2x barlow

ASIStudio@ZWO

MarkMo
There may be two reasons for the black screen after you replace the eyepiece with a camera,
1 The Jupiter is not really centered, so after you installed the camera, Jupiter is actually out of the field of view of the camera. Please make sure Jupiter is centered, I recommend you do not use the 2X at first, because when you add the Barlow, the field of view will be smaller, and it will be more difficult for you to find Jupiter. When you do find Jupiter from the camera and center it again, then you can add the Barlow.
2 The exp and gain are not enough, try using a higher gain and longer exp.

w7ay

MarkMo 2x barlow

Keep in mind that a 2x Barlow lens will increase your focal length by 2, and that represents a factor of 4 in exposure value. You will need to increase the camera gain by 6 dB (with ASI cameras, increase the gain by 60 units) or increase the exposure time by a factor of 4 compared to the same Jupiter image before you added the Barlow lens.

If you are familiar with photographic camera terms, that 2x in focal ratio represents 2 "f-stops." It is the usual inverse square law property.

Another thing to consider is the backfocus of the Barlow lens. Depending on the camera distance from the Barlow lens, it may be actually even be acting like an 8x. Which will affect your exposure time even more.

Even telecentric teleextenders like some of the Televue Powermate's magnification factor is dependent on back focus. Some Powermates have a fixed magnification, while other Powermates have magnifications that depends on the back focus -- so even lenses from the same manufacturer will behave differently.

Another factor is that unless the Barlow is parfocal with your camera, you will need to refocus after inserting the Barlow.

I recommend that you try it in the daytime, first without the Barlow. Get the best focus that you can, and note down the drawtube extension. Now insert the Barlow. Refocus and note down the change in the drawtube length. At the same time, check how much the magnification has changed (and you will also have to change the exposure time too). If the magnification is different from 2x, you need to change the spacing between the Barlow lens and the camera. Change that distance to get as close to 2x magnification as possible, since that is the design focal plane of the Barlow.

When you have it all set to 2x magnification, note the change in drawtube distance once more. You will need to apply this same drawtube change at night to get focus with the Barlow inserted.

Most Barlow are meant for eyepiece usage, and the cheap ones don't even have documentation on backfocus. If you get a PowerMate, it will come with a graph showing where to place a camera sensor for a desired magnification, like this:

The "focus position from top surface" axis is basically the back focus distance from their reference point. As seen above, a 5x PowerMate can be used from 5x to over 7.5x. While the 2x Powermate has a constant 2x magnification, no matter where you place the camera.

Chen