Jupiter & saturn first serious planetary imaging

[Greggles]

Hi all,

I finally bought a planetary imaging cam the zwo asi462 and gave it a go on thursday night.

Still learning but happy for my first go.

Not exactly sure on what I'm doing regarding post processing so made lots of different edits with the autostakkert sharpened and unsharpened versions. Some times I got better results with unsharpened and sometimes with sharpened haha

As you can see, I seem to have a tendency to over process! Oops.

Any tips welcome! :)

ZWO ASI462
Baader Ir and uv filter
2x barlow
Bintel/gso 10"dobsonian f5
DIY eq platform
Firecapture

Cheers

Greg

[Tulloch]

Really nice images Greg, especially for your first time out, we all overprocess when we start out :)

Based on the size of your Jupiter image (and your aperture and camera), I estimate you are imaging at about f/11.1 (or 3.8x the pixel size of your camera) which is pretty close to optimal.

The sharpening tool in AS!3 is only really meant to be an indicator, there are better programs out there for sharpening (Registax is the default standard, but Astra Image and a newish program called AstroSurface are also used).

Can you give more details of your capture process? Capture time, frame rates, that sort of thing? FireCapture records a logfile for every session, if you want post one of them, that would be helpful too.

Andrew

[Greggles]

Hey Andrew,

Yeah, you are probably spot on. F5 x2 barlow so F10 or there abouts. I have a 3x ED barlow to get me to around f15 which is about optimal but haven''t used it yet.

Unfortunately i've already deleted the .ser and log files as my laptop hit capacity and needed space for next session :( just got the un edited stacks.


I captured in 600x600 around around 3 minutes for both Jupiter and Saturn. Couldn't go longer for Saturrn due to drift and only just learnt about the Autoaline feature which is plan on using next time out. Frame rates were between 90-120 for Jupiter and i cant remember for saturn but was quite a bit lower from memory.

autostakkert - 75% stacks seemed best quality anything lower than 35% had a square artifacts.

Registax wavelets (no idea what i''m doing just guessing) and RGB balance.

final sharpen and curves in Photoshop.


Oh and the Jupiter edit without the BRS was a winjupos image denotation of 3 of the images. Tried with Saturn but couldn't get it working properly.

cheers Greg

[Tulloch]

Thanks Greg, sounds like you need a big 4TB external hard drive (that's what I use to store my video files :)). Even if you delete the videos, the log files are small and worth hanging onto (and possibly still in your trash area).

Sounds like you have the basics covered, you can work out what actual focal length/focal ratio using this equation (from here (http://www.wilmslowastro.com/software/formulae.htm#CCD_Sampling)).

http://www.wilmslowastro.com/software/images/formula28.png

FYI, here is an example of one of my log files for Jupiter, you could use it as a guide if you want.

Try stacking less frames in AS!3 - if you start getting squares then try increasing the AP size. Registax is a real hit and miss affair, just need to play around a bit and see what happens.

I don't use WinJupos for image stacking (for a variety of reasons), I'd concentrate less on that for now...

Andrew

[Greggles]

Thanks Andrew,

Had a chance to get out again and shoot with the 3x Barlow. Got some much better results with Saturn, Attached was actually edited with astrosurface as per your post below. I quite like using it for Saturn, but for Jupiter i couldn't get as good results compared to registax.

Jupiter log:

FireCapture v2.7 01 BETA Settings
------------------------------------
Observer=Unknown
Location=Unknown_City
Scope=Unknown_Scope
Camera=ZWO ASI462MC
Filter=L
Profile=Jupiter
Diameter=45.13"
Magnitude=-2.61
CMI=102.8° CMII=141.7° CMIII=229.3° (during mid of capture)
FocalLength=4000mm (F/17)
Resolution=0.15"
Filename=2020-08-24-1059_1-U-L-Jup.ser
Date=240820
Start=105745.411
Mid=105906.158
End=110026.906
Start(UT)=105745.411
Mid(UT)=105906.158
End(UT)=110026.906
Duration=161.495s
Date_format=ddMMyy
Time_format=HHmmss
LT=UT +10h
Frames captured=14245
File type=SER
Binning=1x1
Bit depth=8bit
Debayer=yes
DebayerAlgorithm=NearestNeighbor
BayerPattern=RG
ROI=1024x768
ROI(Offset)=192x152
FPS (avg.)=88
Shutter=4.578ms
Gain=278 (46%)
AutoExposure=off
AutoGain=off
AutoHisto=75 (off)
Brightness=1
FPS=100 (off)
Gamma=41
HighSpeed=off
SoftwareGain=10 (off)
USBTraffic=100
WBlue=90
WGreenOffset=0 (off)
WRed=50
Histogramm(min)=0
Histogramm(max)=0
Histogramm=0%
Noise(avg.deviation)=n/a
eADU=0.028
AutoAlign=true
PreFilter=none
Limit=none
Sensor temperature=22.3°C

cheers,

Greg

[Tulloch]

Excellent images Greg, especially Saturn, you can make out the Cassini Division right to the front of the rings, and even a hint of the polar hexagon! Jupiter is possibly a bit over-cooked, but there's certainly lots of detail there.

Thanks for posting your logfile, I'll just comment on a few items I noticed that stand out.

FireCapture v2.7 01 BETA Settings
------------------------------------

Duration=161.495s <---- could increase to 180 (300 for Saturn)
Debayer=yes <---- for best performance and higher fps, record the RAW footage (ie not debayered), and debayer in AS!3. Recording the debayered video also makes your video file 3x larger as you are recording 3 colours, not 1
ROI=1024x768 <---- Reduce the ROI size, unless you are interested in capturing the moons, all you are recording is black space and this reduces your capture rate
FPS (avg.)=88
Shutter=4.578ms <---- With this shutter speed, the maximum fps possible is 218, but you are capturing at 88, due to the larger ROI and recording the colour information.
Gain=278 (46%)
Gamma=41 <---- Record with gamma OFF, you can add this later
HighSpeed=off <---- Record with HighSpeed ON
USBTraffic=100 <---- If you start losing frames, try a slightly lower value for better results, I set it to 70
WBlue=90 <---- I believe this should be closer to 86
WRed=50 <---- I believe this should be closer to 69

A lot of the locations for these settings are in this post, but it was for ver 2.6 rather than 2.7, but most things are in a similar spot :)
http://www.iceinspace.com.au/forum/showthread.php?t=185290

Debayering in AS!3 is the best way to take these images - yes, it looks terrible on the screen while recording, blocky and monochrome, but it's the best way to do it.

Reducing the ROI during recording is also highly recommended. Yes, you might have to make slight corrections during capture to keep the planet in the FOV, but the file sizes are smaller and the frame rate can be higher. Firecapture shows you a continuous update on how many frames per second it is recording, both while recording and when observing. Try to match the shutter speed to the fps value indicated, if you set the shutter speed to 5ms, then the fps rate should be 200. Set it to 10ms then you should see 100fps. This way you are not "wasting light" by having to increase the gain to get the histogram level up, but not getting the frame rate to match.

The USBTraffic value is a strange one, ZWO cameras tend to like to hog all the resources, so if you let it have 100% of them then it can overflow the USB buffer and you lose frames. Setting a value too low reduces the fps value. I find a value of 70 is about right for my computer, ymmv.

Do not record with the Gamma value on, it may make the image look better on the screen, but you can make all those corrections afterward on the computer. Record as pure a video stream as possible.

Based on previous result from the ASI462MC, I reckon the Wred and Wblue values should be set at 69 and 86 respectively. This was from another CN post which is shown below.
https://www.cloudynights.com/topic/719778-some-musings-images-on-the-asi462mcs-noise-etc/page-2#entry10376048

With a few little tweaks and a bit more practice, your images will improve even further, and you are already significantly ahead of where you were :)

Hope this helps, Andrew

[miketheobscure]

This, this is the story of my life now :)

Your Saturn especially is great, & for your only second attempt, amazing.

[Greggles]

Thanks Mike

And thank you Andrew,. Wow, what an informative post. Cant wait to get out and image again now.

Will make all changes! Dam debrayering, tried to turn it off for when I was doing IR pass images of moon s d coulsnt figure it out. Every time I thought I didnt it still recorded in colour. Will check out post below to sort it out.

Had to use the beta because other version wouldn't pick up the 462 :(

I started recording at 600×600 but my diy mount is just not accurate enough. Its killing me! Currently looking at other options beside my current DC motor drive.

Again thanks for all you advice and support andrew

[Tulloch]

No worries, try for the smallest ROI you can, but if 100 fps is all you can get (which should be the minimum for Jupiter) , set the shutter speed to 10 ms and reduce your gain accordingly to give you 50% histogram levels.

Here is the option you want for recording in raw always - it's in the Image/Debayer menu at the bottom of the Settings window, it's really useful :).