Best Way to Focus using Sharpcap Pro on Planets

[sandconp]

I posted a recent image of Jupiter which did not turn out too bad but everybody tells me that it's looks to be out of focus. Is there a Sharpcap Tool that would help me achieve focus? I did try Fourier Detail Detection and I wasn't sure if I was using it right but it seemed to work. My goal was to get 'green' chart lines on the graph versus yellow or red. Somebody else suggested that I Contrast (Edge) Detection but I haven't tried it. They also suggest to focus on a Star using a Bathtinov Mask then swing over to the planet and I should be very close. I have used the Bathinov Mask tool for Deep Sky Imaging and it seemed to work very well but then I bought a automatic focuser which eliminates the need for me to use a Bathinov Mask for Deep Sky Imaging.

I do not have an automatic Focuser on the scope I use for planets which is a C11 but I do have a Feather Touch Focuser which is very nice and allows me to adjust find focus. I will attach my image here out of AS!3 and processed with Registax and you can see it's blurry and everybody tells me it's a focusing problem but when I look at the video while imaging, it seems to look pretty clear to me but I can't say for sure it 100% focused. My collimation is spot on so that's not the problem. I do live in the northern US where we rarely get good seeing conditions but when I took the image, the seeing factor was a 4 which associates to a 'above' average seeing conditions.

Any help with using Sharpcap to help me achieve good focus using Sharpcap would be much appreciated. I am ok with using the Bathinov Mask to achieve good focus if I have to focus on a star close to the planet.

jupiter.jpg (47.65 KiB) Viewed 832 times

[turfpit]

when I look at the video while imaging, it seems to look pretty clear to me

It is possible that you are in focus but have captured a long video and has resulted in smearing (during processing) due to the fast rotation of the planet. Can you post:

• a screenshot of the captured video being played in SER Player

• capture details, length of capture & fps

If this is the case, then WinJupos could be what is required - capture several shorter videos, then derotate these with WinJupos. Your existing video file (if long) could be split using PIPP to produce several files with appropriate WinJupos naming.

See viewtopic.php?t=2857 for further info.
Also https://www.skyatnightmagazine.com/astr ... ry-images/

Even when I get 'good focus' with planetary, there are still frames which are out of focus due to an unsteady atmosphere. For me, planetary focus is very much an 'averaging' thing.

You will find plenty of info on the web about maximum capture times for planets.

Dave

[sandconp]

Here are the details. I believe that I did a 2 minute capture which equated to 15,372 frames.

[ZWO ASI178MC]
FrameType=Light
Debayer Preview=On
Pan=1228
Tilt=800
Output Format=SER file (*.ser)
Binning=1
Capture Area=640x480
Colour Space=RAW8
Temperature=12.7
Hardware Binning=Off
High Speed Mode=On
Turbo USB=100
Flip=Vert
Frame Rate Limit=Maximum
Gain=222
Exposure=7.8180ms
Timestamp Frames=Off
White Bal (B)=48
White Bal (R)=70
Brightness=0
Auto Exp Max Gain=247
Auto Exp Max Exp M S=30000
Auto Exp Target Brightness=100
Mono Bin=Off
Trail Width=3
Minimum Trail Length=100
Trail Detection Sensitivity=9
Remove Satellite Trails=Off
Background Subtraction=Off
Planet/Disk Stabilization=Off
Banding Threshold=35
Banding Suppression=0
Apply Flat=None
Hot Pixel Sensitivity=5
Subtract Dark=None
NegativeDisplay=0
Display Black Point=0
Display MidTone Point=0.5
Display White Point=1
Notes=
Celestron Telescope Driver=RA=00:09:56,Dec=-00:36:02 (JNOW)
TimeStamp=2022-10-08T04:24:22.7206298Z
SharpCapVersion=4.0.9268.0
StartCapture=2022-10-08T04:24:22.6984897Z
MidCapture=2022-10-08T04:25:22.8544897Z
EndCapture=2022-10-08T04:26:23.0097405Z
Duration=120.311s
FrameCount=15372
ActualFrameRate=127.7686fps
TimeZone=-5.00

nftcFFz9Ca.png (335.74 KiB) Viewed 800 times

[turfpit]

The SER playback looks reasonable as far as focus goes - GRS visible. The 2m capture will be reason for lack of clarity in the final image. Because of the speed of rotation of Jupiter, there will be a difference between the first and last frames which are 2m apart (you could check this). If these 2 frames were stacked, then there would be a slight smearing of the image because of the rotation. Even stacking less frames won't help.

See Q10 & Q11 in https://astronomy-imaging-camera.com/as ... peach.html. 60s captures, repeated 10 times and WinJupos for de-rotation.
Also http://www.damianpeach.com/barbados10rw.htm to compare with and without use of WinJupos.

Jupiter with a C11, 7x60s videos https://www.astrobin.com/rf9aol/.

Don't forget to set WinJupos file naming in SharpCap's settings. The Martin Lewis (Sky At Night) link in my previous post outlines the workflow.

A 1m, f/17 scope up a mountain gives good seeing conditions http://www.damianpeach.com/picdumidi2017.htm.

Dave

[turfpit]

You could use PIPP to split the existing capture into 3 files - say frames 1 - 5000, 5001 - 10000, 10001 - 15000. The 3 files would give you data to practise with and should produce an improved final image.

A WinJupos file name will look something like 2020-06-23-2347_5.ser. This would load directly into WinJupos without the need to manually enter date/time. You would need to rename the PIPP output files to look like the example.

Dave

[sandconp]

I did not know there was a setting for WinJupos File Names using Sharpcap and I did find the settings so I will try it next time. I do have PIPP and I do like your suggestion so I will try that.

I imaged Jupiter for about an hour total with 2 Minute Videos because I wanted to create a Video of Jupiter Rotating using PIPP. Would there be any other reason to take 2 minute segments for an hour to produce a better image? I would think not because of Jupiter's fast rotation right?

[turfpit]

I have never done an animation but I suggest keeping the capture below 60s (to avoid smearing), then wait say 10s then capture and repeat. It will need some experimentation with the delays as regards smoothness. Maybe a 10m session to start with as this could be quite intensive as regards processing.

Dave

[sandconp]

I was also be interested in what tools I should use in Sharpcap Pro Tools to help me get good focus and if it's a good idea to get focus on a star first using a Bathinov Mask then slew over to the planet?