Hello.

A place to share images that you have taken with SharpCap.
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Please upload large images to photo sharing sites (flickr, etc) rather than trying to upload them as forum attachments.

Please share the equipment used and if possible camera settings to help others.
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Neil
Posts: 18
Joined: Tue Feb 14, 2017 8:00 pm
Location: Cardiff, UK.

Hello.

#1

Post by Neil »

Just by way of making my presence known, this is the first live stack I did with Sharpcap.
98stack2.jpg
98stack2.jpg (21.33 KiB) Viewed 3970 times
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admin
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Re: Hello.

#2

Post by admin »

Thanks for sharing Neil :)

what equipment were you using?

cheers,

Robin
Neil
Posts: 18
Joined: Tue Feb 14, 2017 8:00 pm
Location: Cardiff, UK.

Re: Hello.

#3

Post by Neil »

Hi Robin, Comments above re posting images and equipment lists duly noted.

This was using an ASI178MM, through a SW150PDS, 92 frames stacked.

[ZWO ASI178MM]
Pan=0
Tilt=0
Output Format=Fits files (*.fits)
Binning=1
Capture Area=3096x2080
Colour Space=MONO16
Temperature=7.5
Hardware Binning=Off
High Speed Mode=Off
Turbo USB=80
Flip=None
Frame Rate Limit=Maximum
Gain=178
Exposure=19.885148
Timestamp Frames=Off
Brightness=299
Gamma=51
Auto Exp Max Gain=255
Auto Exp Max Exp=30
Auto Exp Max Brightness=106
Apply Flat=None
Subtract Dark=None
Display Brightness=1.01111111111111
Display Contrast=1.66666666666667
Display Gamma=0.873333333333333
TotalExposure(s)=1829.433616
StackedFrames=92
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admin
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Re: Hello.

#4

Post by admin »

Thank you Neil - no intent to criticise you for missing this off - I only thought about the camera settings and hardware being useful after seeing your post :)

cheers,

Robin
Neil
Posts: 18
Joined: Tue Feb 14, 2017 8:00 pm
Location: Cardiff, UK.

Re: Hello.

#5

Post by Neil »

No problem, I took it the way it was intended!
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Re: Hello.

#6

Post by admin »

Hi Neil,

I have seen what I think is your post on Facebook with the glow in the corners of the frame at longer exposures. This is amp glow and it's a common feature of the Sony sensor (174, 178, 290, 224 etc) cameras. Whether it really comes from an amplifier in the way that amp glow on CCD chips did I don't know for sure, but it's signal created by the sensor itself very gradually during exposures.

Different manufacturers have gradually added amp glow suppression hardware to their cameras to minimize this in the latest models (I think QHY were the first with this, but other manufacurers have worked it out too and followed suit). I don't know if these are hardware changes to the camera or driver/firmware changes. Anyway, it might be worth seeing what you can find on the ZWO forums to see if there are any hints there, but otherwise dark subtraction should help.

cheers,

Robin
Neil
Posts: 18
Joined: Tue Feb 14, 2017 8:00 pm
Location: Cardiff, UK.

Re: Hello.

#7

Post by Neil »

Hi Robin,

Thanks for that.

I don't know if you have followed the FB thread fully, but I eventually found that the (what I now know as) amp glow was so prominent because I had set 4x4 Binning. Still being relatively new to this I knew that it would increase the sensitivity at the cost of resolution, but it didn't twig that amp glow would be affected, this was the first time I had encountered amp glow to a significant extent.

What threw me as well was that I remembered trying out the camera with a ten-minute sub a while back, in order to check guiding (the resultant image is posted to the FB thread) and didn't recall any amp glow, but having found the image again, and knowing what I am looking for, I can see evidence of it in the bottom corners (no binning).

Knowing what I know now I am happy with the camera again, I have taken 5 x 300s darks and the glow has virtually disappeared.

I have posted several images to the thread, all this has been enlightening!

Cheers,

Neil.
jimmyscotts
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Location: Upper Coomera, Queensland, Australia
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Re: Hello.

#8

Post by jimmyscotts »

Hello there
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