Jupiter 2/12/11

[swannies1983 (Dan)]

This is my first imaging session of Jupiter in about three years. This was taken using an 8" Newt, toucam and 2x Televue Barlow. Stack of about 200 frames from 1200. Comments/tips regarding processing most welcome. For example, what's the best way to reduce brightness/contrast of the central region?

[Clayton]

Nice shot Dan In your image the highlights are clipped in the Green and Blue channels. This could have occured at capture time or later in processing? The most important time to get this right is at capture time,and it is very useful if you have a capture program with a histogram display to guide you in this respect. If the clipping occured at the time of capture it could be overcome by dropping the gain a tad or moving to a slightly faster shutter speed. 1200 frames is not a lot to work with. Do you recall the frame rate and capture time?

[swannies1983 (Dan)]

Originally Posted by Clayton

Nice shot Dan In your image the highlights are clipped in the Green and Blue channels. This could have occured at capture time or later in processing? The most important time to get this right is at capture time,and it is very useful if you have a capture program with a histogram display to guide you in this respect. If the clipping occured at the time of capture it could be overcome by dropping the gain a tad or moving to a slightly faster shutter speed. 1200 frames is not a lot to work with. Do you recall the frame rate and capture time?

Thanks Rob. I was using VRecord to capture. I had planned to use K3CCDTools but for some reason, it kept hanging during the recording phase.

My settings were 10fps @ 1/125sec exposure, gain set to about 60%. I recorded 2mins worth of video and followed Mike's tutorial up to processing in Astra Image 2.5MAX. This version is now redundant. Version 3 is available but I can't save images in the trial version. I did a bit of processing in PS such as curves and unsharp mask. Oh, I also didn't split into R G B files.

This is the final image generated by Registax before processing

[Clayton]

Originally Posted by swannies1983

I recorded 2mins worth of video and followed Mike's tutorial up to processing in Astra Image 2.5MAX. This version is now redundant. Version 3 is available but I can't save images in the trial version.

I use V3 but when I am ready to save I zoom in on the subject and do a screen dump into Paint then Save As Jupxxx.bmp I can then open it in Gimp, or CS3 etc

[swannies1983 (Dan)]

Cheeky bugger

So does K3CCDTools offer live views of the histogram for each channel? If not, what recording program does? If it's a processing issue, is it best to split into RGB and process channels individuals to eliminate clipping potential?

[Troy]

Good image.

[Clayton]

Originally Posted by swannies1983

Cheeky bugger

So does K3CCDTools offer live views of the histogram for each channel? If not, what recording program does? If it's a processing issue, is it best to split into RGB and process channels individuals to eliminate clipping potential?

When I used a mate's toucam (as per my signature) I used to use wxAstroCapture http://arnholm.org/astro/software/wxAstroCapture/ to set the exposure (histo about 80%full ) aiming for numbers in the very low 200's as a guide. I wasn't happy with wxAstroCapture as a capture program as I was getting some artifacts outside the planet limb (it may work well for you), so I would shut down wx after I was happy with the exposure, and then open my capture program (QC Focus http://astrosurf.com/astropc/oldvers...programme.html ) , the settings remained unchanged and I would simply capture away
Some people advocate splitting the channels and processing seperately. I have played around doing this a bit, and rarely bother any more. If you control the exposure well then clipping shouldn't be a problem.
I usually do a quick and dirty colour balance simply by stretching the R,G & B channels seperately in CS3 using the highlight slider. Try to leave the stretching until after all your other enhancements as sharpening an image usually results in a further stretching of the histo. Or you might be happier using Registax for your colour balance CS3 also has an auto colour function but normally requires a bit of fading IMHO as at 100% opacity it will tend to clip the highlights.

[swannies1983 (Dan)]

A better effort at processing.

[Shiraz (Ray)]

repro is a big improvement. Regards Ray

[Clayton]

Originally Posted by Shiraz

repro is a big improvement. Regards Ray

Ditto Dan