a newbie senior Jupiter attempt

[roger jerome]

Hi folks......I am still trying to get my old head around learning imaging.  I was out this morning with my Celestron 9.25 SCT usingn a 2x Barlow and a ZWO ASI 120 MC camera.   I am grateful for members kindly offering their experience and tips.  I was capturing for 2 minutes...50 percent histogram and anywhere from about 35fps to 52fps on different captures.  I think where I was going the wrong way before was I was capturing too bright images and blew out most of the data (?) I have been reading tutorials etc. and am understanding more about exposure, gain, and fps.   I used Autostakkert and Registax 6....though I still have difficulty understanding the wavelet settings....just thought I would send this image....it is a bit of progress for me....though lacking...

Thanks for looking and any suggestions

[Clarkey]

I am NOT a planetary imager, but from my limited experience I would say ignore the histogram and keep the exposures very short to reduce the effects of the seeing - I think for Jupiter something like 5 milli sceonds. You can increase the gain to compensate for the short exposure.

Other than this I will let one of the planetary imaging experts to give you some guidance.

[sorrimen]

Looking good! C9.25 is a fantastic scope to be imaging the solar system with. You’ve clearly been doing some research because most of what you’ve said is right on track. The only thing holding you back is that FPS! I imagine what’s lacking is a combination of exposure and ROI.

The first is easily changed; set your gain to around 80% to start with, and lower your exposure to around 2ms or really just the brightness at which you can see some surface detail to focus on. Checking the histogram is useful for this, but not crucial as anywhere around 50-80% will do just fine.

Make sure your fps is set to ‘Unlimited’ or ‘Uncapped’ or equivalent. Now you’ll want to find ROI or region of interest. Shrink this down until the planet just fits in the box, with a little wiggle room for any tracking errors. Doing this should get you both 1) much higher fps 2) much smaller file sizes for quicker processing  

Great start and good luck moving forward!

Edited September 1, 2022 by sorrimen

[sorrimen]

Oh to briefly add to the above, there should be an output file type somewhere. This will say something like RAW8, RAW16 or RGB24. You want to select RAW8. 

The output format should also be either .avi or .ser. Note that all of this may be default to you anyway!

[astrolulu]

Roger, your picture is processed so strongly that it is impossible to say anything about the original. If you shared a raw image right after stacking, it would be easier to say anything.

[roger jerome]

4 hours ago, astrolulu said:

Roger, your picture is processed so strongly that it is impossible to say anything about the original. If you shared a raw image right after stacking, it would be easier to say anything.

Thank you ....this one is a stack from the same evening.  best 25 percent of 6000 frames.

38 fps

exp 11.878 ms

gain 80

raw 8

6000 frames

157 seconds captured

[Bibabutzemann]

 

Hi,

What was the altitude of Jupiter? What is your focusing procedure? 

Maybe you could show a single frame of one of your top 25%

 

CS Patrick

[roger jerome]

5 hours ago, Bibabutzemann said:

 

Hi,

What was the altitude of Jupiter? What is your focusing procedure? 

Maybe you could show a single frame of one of your top 25%

 

CS Patrick

Thank you.  I think it was about 40 degrees.  I was using a Crayford style focusser.  I do have a motorized one but was not set up at the time.  Here is a frame...

[Elp]

It looks a bit dim, did you try increasing the exposure time in ms? If you also try imaging without the Barlow it will also brighten up but the former should work. The stack however as it is looks alright, a bit out of focus which takes practice and patience.

[Cosmic Geoff]

It would help if you told us which capture program you are using.

I have dug up some of my results for 2018. Here is the actual log for one of the images: (below) Nowadays I would expect to find some more colour. Getting a sharp but realistic-looking image is something of an art.

You will note that the exposure is only 3 ms.  The capture area is 480x480 pixels. Nowadays with a better mount I usually use 320x240px.

The gain is set at 100. Whether I was happy with 100 or there was no way of altering it, I don't recall.  The size of the .ser file was 228MB (probably 3000 frames).  The .ser file was processed in Registax 6. (Lately I have begun using Autostakkert + Registax). 

[ZWO ASI120MC]
Debayer Preview=On
Pan=400
Tilt=240
Output Format=SER file (*.ser)
Binning=1
Capture Area=480x480
Colour Space=RAW8
Temperature=17.7
Discard Split Frames=Off
High Speed Mode=Off
Turbo USB=80(Auto)
Flip=None
Frame Rate Limit=Maximum
Gain=100
Exposure=0.003079
Timestamp Frames=Off
White Bal (B)=100
White Bal (R)=56
Brightness=8
Auto Exp Max Gain=50
Auto Exp Max Exp M S=30000
Auto Exp Target Brightness=100
Mono Bin=Off
Apply Flat=None
Subtract Dark=None
#Black Point
Display Black Point=0
#MidTone Point
Display MidTone Point=0.5
#White Point
Display White Point=1
TimeStamp=2018-06-24T23:11:01.0156882Z
SharpCapVersion=3.1.5049.0

And here is the corresponding image:  

 

Edited September 7, 2022 by Cosmic Geoff

[jacko61]

I've not imaged Jupiter much but one thing I have been told is that because Jupityer moves a quarter of a degree every minute, longer than one minute videos will start to show rotational artifacts and  will lose contrast as a result.

Graeme

[astrolulu]

Hello Roger, I have tried to edit your photo and you can see immediately that its resolution is definitely too low for the instrument you are using. For comparison, I enclose a photo of Jupiter which I took with the old Japanese 60/910 mm refractor (!):

Meanwhile, the best version of your photo that I was able to get looks like this:

It's hard for me to say what is the reason. I have found that SCTs from 8 inches upwards become very sensitive to seeing and the height of the object above the horizon - maybe this is the source of the problems?

For comparison, a photo taken this year with an ordinary, cheap C8-N newt. Your C9.25 should give a much better picture:

[roger jerome]

Thank you all for your generous suggestions.  I appreciate very much your sharing with me examples of how Jupiter should look when imaging and also the settings data. The weather has not been cooperating lately but hopefully soon I can do some more imaging with these inputs in mind

Cheers

Riger

[Bibabutzemann]

20 hours ago, roger jerome said:

Thank you.  I think it was about 40 degrees.  I was using a Crayford style focusser.  I do have a motorized one but was not set up at the time.  Here is a frame...

This looks almost the same as your stacked image. I think your final image should come out better, even with such frames. 

But this single frame is too blurry for a c9.25 anyway.

The pixel size of your asi 120mc should be good enough for decent Jupiter images. Dont know if the seeing was really that bad or if its not properly focused. To rule that out i would use a Bathinov mask and focus on a star, before slewing to the planet.