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Heart and Soul - QHY247C


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Is everyone over Heart and Soul yet? I always get a late start on targets due to my limited visible patch of sky. I have to wait until objects are high enough above the house to see, at which point, everyone else has already imaged them. I find I'm having difficulty processing images from the QHY247C camera and I don't know if it's an OSC issue, if it's this specific camera or something else in the imaging train like the filter causing it. I'm used to mono imaging and the background of a stacked and color combined imaged being mottled RGB splotches, so it's no surprise to find a colored background. With this camera though I'm finding the background of individual subs and the final stacked image to be extremely noisy and in some cases have what appear to be streaks. Noise reduction processes usually take care of it, but it just doesn't seem right to me. The attached preview is from the dark area between Heart and Soul of the stacked image. And of course the attached Heart and Soul image is the final version with noise reduction applied and fully processed.

QHY247C
IDAS NBX filter
WO Redcat
iOptron CEM40EC, unguided
91x180s lights, 20x darks, flats and flat darks
Processed in Pixinsight with final touchups in Photoshop

Preview01.jpg

IC1805_270min_PI_PS_FB.jpg

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13 minutes ago, Buzzard75 said:

Is everyone over Heart and Soul yet? I always get a late start on targets due to my limited visible patch of sky. I have to wait until objects are high enough above the house to see, at which point, everyone else has already imaged them. I find I'm having difficulty processing images from the QHY247C camera and I don't know if it's an OSC issue, if it's this specific camera or something else in the imaging train like the filter causing it. I'm used to mono imaging and the background of a stacked and color combined imaged being mottled RGB splotches, so it's no surprise to find a colored background. With this camera though I'm finding the background of individual subs and the final stacked image to be extremely noisy and in some cases have what appear to be streaks. Noise reduction processes usually take care of it, but it just doesn't seem right to me. The attached preview is from the dark area between Heart and Soul of the stacked image. And of course the attached Heart and Soul image is the final version with noise reduction applied and fully processed.

QHY247C
IDAS NBX filter
WO Redcat
iOptron CEM40EC, unguided
91x180s lights, 20x darks, flats and flat darks
Processed in Pixinsight with final touchups in Photoshop

 

Thats walking noise, you really need to dither a CMOS chip, even more so if its OSC. Also i think you are asking too much if you dont expect the darkest area on the image to show some noise above the signal.

Adam

Edited by Adam J
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26 minutes ago, Adam J said:

Thats walking noise, you really need to dither a CMOS chip, even more so if its OSC. Also i think you are asking too much if you dont expect the darkest area on the image to show some noise above the signal.

Adam

I wouldn't expect no noise at all. I was just saying it seemed noisier than I'm used to. Then again, I'm used to mono. It's a new camera for me so I'm still learning how best to utilize it.

As for walking noise, I've heard of it, but not seen it on this mount or in any of my other image runs before, so I'm not sure what would have cause the drift or why it hasn't shown up before now. I'm also shooting unguided with the Redcat so I don't even know how you would dither besides adjusting the mount manually. My understanding is most capture software relies on PHD2 or some type of guiding software to move the mount for dithering.

Thanks for the insight though. I'll keep it in mind for next time and thoroughly check my mount leveling, PA and balancing.

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7 hours ago, Buzzard75 said:

Heart and Soul image is the final version with noise reduction applied and fully processed.

That's a nicely framed image and despite your concerns about noise there is a lot of detail in the nebula.

I use a CEM25-EC unguided for all of my imaging, so no dithering because I use the ASIair to control the whole process. I use an ASI1600MM mono and a Canon 70D or M6 MkII and todate I have been lucky I guess and seen no evidence of 'walking noise'. Like you I use 180s exposures with ASI16000 on all filters with darks, dark-flats and flats but all pre-processed in APP and the post-processed in PI. Exposure times with the dslr are much shorter as I live in a Bortle 5/6 region so I don't go beyond 120s.

I do go to great lengths to level the mount and perform a PA using a PoleMaster each time I setup. I've tried guiding with the CEM25 a few times but always been disappointed with the result - maybe it's the ASIair derivative of PHD that's giving me the problem.

Hope you get it sorted.

Adrian

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6 hours ago, Allinthehead said:

Adam is correct, dithering really is a must. What capture software are you using? I know Sgpro allows dithering without guiding.

APT. I read somewhere that APT allows dithering without guiding, but I haven't found the setting yet and there were no details on the post. I'll keep looking.

EDIT: found it! Now I just need to figure out how to use it.

Edited by Buzzard75
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