ZWO ASI120MC for Planetary Imaging

Discussions of using SharpCap for Planetary Imaging
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RLSARMA
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ZWO ASI120MC for Planetary Imaging

Post by RLSARMA » Thu Jun 22, 2017 6:36 am

After about 4 months of waiting, the Sky God favored me for a while and I got a clear - very clear sky for about an hour or so. Taking the advantage of the clear sky, I put my new ZWO ASI120MC for the first time into my C9.25 SCT on the AVX mount to shoot both Jupiter and Saturn. Sadly enough, I was unable to see any images of my target objects through the camera despite these were distinctly visible through the eyepiece. Having failed in my first shooting attempt using ASI120MC and Sharpcap combination, I didn't waste my time as I saw some clouds started rolling in and I shot the Jupiter with my old EOS 60D and BackyardEOS combination.

Appreciate if somebody helps me as to how to use the ASI as I am a first time user of ZWO camera and Sharpcap.

Thanks in advance.

Rajib
Digboi, Assam, India (Lat: 27 deg N, Long: 95 deg E)

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turfpit
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Re: ZWO ASI120MC for Planetary Imaging

Post by turfpit » Thu Jun 22, 2017 2:03 pm

Rajib

Here are the steps I used to capture this image of Jupiter
Jupiter.jpg
Jupiter.jpg (57.12 KiB) Viewed 6656 times
using a ZWO ASI120MC with Celestron C8 and 2x Barlow, settings file attached.

The alignment process:
  • Carefully align finder scope and telescope on a land based distant object.
  • Carry out a Solar System align using eyepiece.
  • Slew to planet, centre and focus.
  • Add Barlow (if used).
  • Centre and focus.
  • Replace eyepiece with camera.
  • In Sharpcap, set capture Area to 1280x960 (widest field of view = best chance of hitting the object).
  • Target will be out of focus, so is easier to find.
  • Centre and focus the target.
The capture process:
  • Set Gamma=50, ZWO recommended for planets.
  • Set Gain to 60% (70% if using a Barlow).
  • Turn on histogram and select Logarithmic checkbox.
  • Adjust Exposure until Right hand side of Histogram at 80%.
  • Run capture.
  • Reduce the Capture area to 640x480 and run a capture.
Histogram will look something like this:
ASI120-histogram.png
ASI120-histogram.png (6.91 KiB) Viewed 6656 times
As I have become more confident with this, I add the camera instead of the eyepiece, turn on a reticule from the tool bar and Solar System align. The reticule helps with accuracy to centre the target.

Post processing steps were:
  • PIPP to crop and centre the target.
  • Autostakkert to stack the frames.
  • Registax for wavelets.
For Saturn I use a gain of 90% the rest of the process/settings are the same (see attached).

Dave
Attachments
Saturn2.png
Saturn2.png (66.55 KiB) Viewed 6656 times
2017-06-18-2220_4.CameraSettings.txt
(691 Bytes) Downloaded 488 times

RLSARMA
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Re: ZWO ASI120MC for Planetary Imaging

Post by RLSARMA » Fri Jun 23, 2017 6:29 am

Dear turfpit,

I appreciate for the fantastic guide. I'll take a printout of your suggestion and apply it in the field as soon as I get clear sky. Actually I am used to using Canon DSLR with BackyardEOS for both planetary and DSO astrophotogrpahy (I'm a newbie). Having known that ZWO ASI cameras have high sensitivity and ASI120MC is one of the best cameras for planetary imaging, I purchased it only recently. Also I have not used Sharpcap before.

I thank you for your kind help which I acknowledge gratefully and will always remember your support.

Rajib

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turfpit
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Re: ZWO ASI120MC for Planetary Imaging

Post by turfpit » Fri Jun 23, 2017 7:41 am

Thanks Rajib.

Check out the SharpCap documentation at http://docs.sharpcap.co.uk/2.9/

The ASI120 comes with a 150 degree lens. This enables the camera to be used without a telescope, so it is possible to carry out some testing during the daytime from indoors. Just plug the camera into a PC, attach the lens and run SharpCap.

Dave

RLSARMA
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Re: ZWO ASI120MC for Planetary Imaging

Post by RLSARMA » Fri Jun 23, 2017 10:36 am

Dear Dave,

Thank you so much for your kind help and support. I'll surely do that and will come back to you to say you "Thank You" once I am able to successfully handle my new piece of equipment and also SharpCap. Learning through such help and support from person like you is really wonderful.

Thanks again and look forward to saying you my success story with your guidance.

Rajib

JerryKapc
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Re: ZWO ASI120MC for Planetary Imaging

Post by JerryKapc » Fri Oct 09, 2020 2:30 pm

I have a ZWO ASI120MC-S camera with Celestron Evolution 9.25 and Celestron Focus Motor using SharpCap...I still haven't been able to get an image after numerous attempts the last few night including trying to image moon a few nights...tried Mars last night but no image....my telescope focus on Mars and Moon looked good but when I added camera I get a black screen with no clear image ...I adjusted exposure and gain with different combinations many times and adjusted camera focus but still have a black screen with no clear image...any suggestions?

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admin
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Re: ZWO ASI120MC for Planetary Imaging

Post by admin » Sat Oct 10, 2020 1:41 pm

Hi,

this is what I do when I'm having real trouble getting a camera image with a telescope.

* Point the telescope at the Moon.
* Set the exposure to 1 second and the gain to maximum
* see if you see any light in the image. If you do then great if not then shine a torch into the telescope to check that the image then lights up!

Now that you know that the camera is at least detecting light, which is a good start. The next step is to get the moon into the field-of-view.

* If you already pointing exactly at the moon then the image will probably be horribly overexposed – if it's only slightly eliminated then you are probably pointing seeing the glow near the moon. At this point you can move the telescope around always moving in the direction is where the glow brightness increases to home in on the moon.
* Now you should have the moon in view – far too bright and probably out of focus.
* Turned down the exposure and if necessary the gain until the image is no longer overexposed
* try adjusting the focuser now through the whole range of positions – if the image goes dark as you are adjusting then you are moving in the right direction (this means that your initial image was bright because you were looking slightly off the edge of the moon but was so far out of focus at the light spread out to reach the camera sensor – you may need to readjust the pointing of the telescope to find the moon again if this happens).
* If you are using a reflector or refractor and you can't find focus then you may need to add move extension tubes to move the focus range either further back or further in to the telescope. Normally you shouldn't need to do this with an SCT because the focus range is so wide.

If all else fails, remove the camera and hold a piece of paper behind the telescope – as you move it forward and back you should be able to find a position where you see a focused image of the moon on the piece of paper. That's the distance that the camera sensor would need to be at to get a focused image – you can either adjust the focus to try to move the focus position nearer to where the camera sensor sits when the camera is in place or just how far back the camera is to get it closer to the position that you found the focused image.

Hope this helps, Robin

danjhorw
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Re: ZWO ASI120MC for Planetary Imaging

Post by danjhorw » Sat Oct 10, 2020 2:50 pm

Rajib

I have the ASI120MC USB 2.0 and find that it is incompatible with my laptop USB 3.0
Are you having any issues with this, or are you using a 2.0 PC plug in?

Thanks, Dan H

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