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The "No EQ" DSO Challenge!


JGM1971

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12 hours ago, JonCarleton said:

I'm getting used to a new camera (ZWO 178MC)...or more like "not getting used to" the camera. 

Thanks for posting Jon, I've very recently purchased the ASI178MC and am interested in the gain setting you used for M42. Did you use the online SharpCap tool to determine the local sky electron rate? The low read noise and high QE of the sensor really does help with Alt-Az imaging.

Every best wish for you imaging with the camera in the future.

Cheers,
Steve

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Steve,

So far, because of my exposure limitations, I have been using about 200 for gain.  I also have had reasonable luck with the automatic settings for gain, although the offset, which is apparently similar to GAMA, I find that the automatics don't work as well sometimes.  I have been using an offset of 100-120.

I have, so far, used the camera with Indi/Ekos, CCDCiel and AstroDMx_Capture.  I prefer AstroDMx_Capture, but often when working with guiding, it is easier to just stay in the mechanical platform, rather than jump back and forth to an imager.  I don't use Windows software (and haven't for a few decades), so all my software programs and hardware platforms are Linux/Unix.

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These two are attempts at longer exposures.  I got guiding working reasonably well (KStars Internal Guider).  The Helix Nebula is about 100-60 second exposures and the Sculptor Galaxy is 30-30 second exposures (gain 200).  These are a bit more challenging than others I have done, as they are dim.  The seeing wasn't ideal that night, which left me a tad focused-challenged.  I also had quite a bit of rotation after stacking, as expected with longer Alt-Az imaging time.  But...I got =something= at least.  Still getting used to the ZWO ASI178MC.

HelixNebula.jpg

SculptorGalaxy.jpg

Edited by JonCarleton
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I have so long not commented here. Nice to see the many new posts! I have already a SkyWatcher mini wifi mount, but still I do often pics/videos without that. I have a Celestron Nexstar 8 SE on Alt-Az mount and I made a short video before yesterday. I had brilliant sky conditions and I just took 300x1 sec exposure at ISO 51.200 with my Sony A7s. I used the C8 with 0.63x reducer to get more light, but the camera was in crop mode, to cut the vignettation. At the maximum (1040p) resolution you can see a satellite too, it comes at 0:17 from the right upside corner. The oroginal video is only 12,5 sec (24 fps), but I changed the speed to 0.5x, so its 12fps now. 

 

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We got a night of clear sky, so I decided to experiment with longer exposures.  Alas, at 30 seconds and a gain of 300 on the ZWO ASI178MC, I was only able to get 6 of 40 images that were reasonable to stack.  Tracking and guiding weren't too bad, but there was enough wind to cause vibration issues on the wood deck on which I perch the scope.  Guiding RMS 0f .27 doesn't seem terrible for a Alt/Az.  The plot stayed well within the 2 arcsecond circle.  You do have to crop out a bit of rotation after a half hour or so.

It was 6 images at 30 seconds each, then.  M77 is a bit of a dim, tough target, but here it is.  Stacking with Siril, stretch and minor touch-up with StarTools and GIMP, though I didn't spend a lot of time on this as I hope to try this target again with some more image time.

M77.jpg

Edited by JonCarleton
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I found that observing on a wooden deck that just breathing was enough to cause vibration.

Sorry was off doing a quizz

That's a new galaxy had to go look it up. For your 6 images it's great you can see it's a galaxy with it's arms. Good luck with getting more of this target.

 

 

Edited by happy-kat
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  • 4 weeks later...
5 hours ago, SpaceDave said:

My attempt at M81 and M82. New to the hobby so I am fairly happy with the result :)

445 x 10sec lights, 50 x darks, 50 x biases, 50 x flats. Taken with a 6SE and Canon 600D. Also used a f6.3 focal reducer. 

C3FD53DE-754A-404B-A82E-8E22B5F64E62.jpeg

Beautiful images with no eq Dave, something for me to aspire to with my Skymax 127 and az gti 

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On 20/01/2021 at 15:39, JonCarleton said:

We had a good night of seeing conditions, so I got some distant targets, Cleopatra's Eye Nebula and Superman Galaxy. Stacked 100 subs @ 20 seconds for each image.

NGC1535.png

NGC7479-SupermanGalaxy.png

Awesome photos.

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My attempt at the Andromeda Galaxy and Whirlpool Galaxy. Think I may need more lights and a shorter focal length for Andromeda!

Both images used 350 x 15 second lights, 50 darks, 50 biases, 50 flats. Taken with a 6SE and Canon 600D. Also used a f6.3 focal reducer. 

Andromeda edited.jpeg

Whirl edited.jpeg

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4 minutes ago, happy-kat said:

Love the way the two images show the extremes of DSO sizing. 

When processing be careful of the back point as too dark can clip an image and lose detail.

Thanks. I'll keep that in mind. I seem to move toward darkening the image too much in order to reduce the noise in the black of space.

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2 hours ago, SpaceDave said:

My attempt at the Andromeda Galaxy and Whirlpool Galaxy. Think I may need more lights and a shorter focal length for Andromeda!

Both images used 350 x 15 second lights, 50 darks, 50 biases, 50 flats. Taken with a 6SE and Canon 600D. Also used a f6.3 focal reducer.

Good work there. I can't help feeling that with about 1½ hours worth of data you ought to be able to get more out of your M31 image, even if taken at f/10, in particular, a bit of colour. What are you using to process your stack with? In my experience as much comes out of processing as it does with data gathering. True, if you don't get good enough data you can never get a good picture, but good processing can make or break a picture.

I've had good success with StarTools. If you can accommodate its workflow, it does seem to get the most out of the data with not a lot of effort.

Ian

Edited by The Admiral
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^ very true I got quite a bit out of my m31 with very little data and using 2" of aperture using DSS and startools.

There might be more in your data that could be extracted, and if there isn't it's fun to try and in this weather any processing is time not wasted.

 

Edited by happy-kat
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1 hour ago, The Admiral said:

Good work there. I can't help feeling that with about 1½ hours worth of data you ought to be able to get more out of your M31 image, even if taken at f/10, in particular, a bit of colour. What are you using to process your stack with? In my experience as much comes out of processing as it does with data gathering. True, if you don't get good enough data you can never get a good picture, but good processing can make or break a picture.

I've had good success with StarTools. If you can accommodate its workflow, it does seem to get the most out of the data with not a lot of effort.

Ian

Thanks for the advices. I used SIRIL to stack the M31. I am new to astrophotography and it's editing, so I could be making quite a few mistakes during the stacking and editing process. I'll have a go at StarTools. Thanks.

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1 hour ago, happy-kat said:

^ very true I got quite a bit out of my m31 with very little data and using 2" of aperture using DSS and startools.

There might be more in your data that could be extracted, and if there isn't it's fun to try and in this weather any processing is time not wasted.

 

Interesting. I'll take a look at those two softwares. Thanks!

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55 minutes ago, SpaceDave said:

Interesting. I'll take a look at those two softwares. Thanks!

I've not used SIRIL but DSS (free) is primarily used for calibration and stacking. It can process images, but I don't think many use it for that.

StarTools just processes, it doesn't calibrate or stack. It is very reasonably priced, and all features can be trialed before purchase, except it doesn't save.

Ian

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4 hours ago, The Admiral said:

I've not used SIRIL but DSS (free) is primarily used for calibration and stacking. It can process images, but I don't think many use it for that.

StarTools just processes, it doesn't calibrate or stack. It is very reasonably priced, and all features can be trialed before purchase, except it doesn't save.

Ian

Great, I've downloaded DDS and have a video tutorial too :)

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