Jupiter Transit of Europa - help with blue channel

[tooth_dr]

Hi guys.

Despite feeling that I have good equipment and decent seeing, I am frustrated that I cant seem to get a good image of Jupiter.

I was processing a video I took this morning, and discovered that the blue channel is terrible looking and the green is a little better, but it almost looks like they aren't stacked properly.

Any pointers would be really appreciated.

 

1 - Red channel

2 - Green channel

3 - Blue channel

4 - Combined using red as L (!)

 

 

 

[U Cyg]

I don't know anything about RGB imaging, but maybe you could run the blue channel through AS3, or VirtualDub, frame by frame and discard any bad frames, then restack to see if it looks better.  The combined image looks good, with plenty of detail.

Angie

[tooth_dr]

18 minutes ago, U Cyg said:

I don't know anything about RGB imaging, but maybe you could run the blue channel through AS3, or VirtualDub, frame by frame and discard any bad frames, then restack to see if it looks better.  The combined image looks good, with plenty of detail.

Angie

Thanks Angie.  I should have said that I took this with a colour camera, Skyris 618C, so I dont know how to separate the channels to process them individually.

[Grant]

Blue is always the worst channel as it gets scattered the most. Using an ADC will help bring the colours back together especially with Jupiter being reasonably low at the moment but you will need exceptionally good seeing with Jupiter as high as possible to get the blue channel tighter.

You can try splitting your stacked image into each channel and then applying wavelet processing individually to each one before recombining - the splitting and combining of channels can be done for free using GIMP. This might allow you to improve the blue.

I'm not 100% sure, but you might be able to use something like PIPP to separate the channels prior to stacking and then apply different aggressiveness to the quality cut-offs to improve the stacking of each channel.

 

[tooth_dr]

24 minutes ago, Grant said:

Blue is always the worst channel as it gets scattered the most. Using an ADC will help bring the colours back together especially with Jupiter being reasonably low at the moment but you will need exceptionally good seeing with Jupiter as high as possible to get the blue channel tighter.

You can try splitting your stacked image into each channel and then applying wavelet processing individually to each one before recombining - the splitting and combining of channels can be done for free using GIMP. This might allow you to improve the blue.

I'm not 100% sure, but you might be able to use something like PIPP to separate the channels prior to stacking and then apply different aggressiveness to the quality cut-offs to improve the stacking of each channel.

 

Hi Grant I'll look into PIPP, this was also just suggested by another SGL member.

What is ADC?

[Grant]

1 minute ago, tooth_dr said:

Hi Grant I'll look into PIPP, this was also just suggested by another SGL member.

What is ADC?

Atmospheric dispersion corrector = ADC - I've been using the ZWO one: https://www.firstlightoptics.com/zwo-accessories/zwo-125-atmospheric-dispersion-corrector-adc.html

It does a really good job of re-aligning the colour channels back together again, correcting for atmospheric dispersion. The ZWO one is really good value for money, they used to be a lot more expensive.

[Stub Mandrel]

I had exactly teh same and it was caused by atmospheric dispersion.

I know have an ADC and all is well.

 

[MarsG76]

Yeah, blue is always the worst. How long are your recordings per channel? Looks like a little rotation RGB movement.

[geoflewis]

2 hours ago, tooth_dr said:

 

Hi guys.

Despite feeling that I have good equipment and decent seeing, I am frustrated that I cant seem to get a good image of Jupiter.

I was processing a video I took this morning, and discovered that the blue channel is terrible looking and the green is a little better, but it almost looks like they aren't stacked properly.

Any pointers would be really appreciated.

 

1 - Red channel

2 - Green channel

3 - Blue channel

4 - Combined using red as L (!)

 

Hi tooth_dr, first I think that your final image is pretty good. Applying the red as a luminance was a good decision; I was going to suggest that, but noted that you already did that.

As others have stated the blue channel is always a challenge from the UK, especially with the Jupiter, Saturn and Mars currently all at very low altitudes, where atmospheric dispersion is at it’s greatest.

I highly recommend using an ADC, indeed with a colour camera I would argue it’s an essential piece of kit for planetary imaging. I still use mine with my ZWO mono CMOS camera and R-G-B filters, as being broadband filters there is still some dispersion within each band, especially the blue channel. That said you can still get a reasonable alignment by splitting the channels and manually moving them around so that they better align. PS, GIMP and most, if not all, astro processing software will let you do that.

Good luck, Geof

[Grant]

It's worth mentioning AutoStakkert! has an RGB align function which can help during stacking:

http://www.astrokraai.nl/software/latest.php

[tooth_dr]

7 hours ago, MarsG76 said:

Yeah, blue is always the worst. How long are your recordings per channel? Looks like a little rotation RGB movement.

I’m using the same camera as you 618C! I think that recording was 3000 frames, 50s, cropped to 240x260 ROI.  

[MarsG76]

5 hours ago, tooth_dr said:

I’m using the same camera as you 618C! I think that recording was 3000 frames, 50s, cropped to 240x260 ROI.  

Oh, for some reason I misunderstood that you used a mono camera through RGB filters... my bad...

[MarsG76]

16 hours ago, tooth_dr said:

Thanks Angie.  I should have said that I took this with a colour camera, Skyris 618C, so I dont know how to separate the channels to process them individually.

I use photoshop to separate the RGB channels. Gimp will do it too...

I too adjust the RGB channels to sit in the right spot, negating the fringing. Usually I just need to move the red up/down and/or left/reign only 1 or 2 pix last for red and the opposite direction for blue, also only 1 or 2 pixels. 

I line up the red and blue onto the green channel.

This does improve the image, color and detail wise.

[tooth_dr]

It’s not so much the aligning, that doesn’t help, it’s how to separate the channels BEFORE stacking 

[geoflewis]

23 minutes ago, tooth_dr said:

It’s not so much the aligning, that doesn’t help, it’s how to separate the channels BEFORE stacking 

Sorry, I have no idea how to do that, or if it is even possible....

[newbie alert]

Hi Adam as suggested I think a ADC will help you enormously..your data looks great it' just the blue that's scattered..

[tooth_dr]

10 minutes ago, newbie alert said:

Hi Adam as suggested I think a ADC will help you enormously..your data looks great it' just the blue that's scattered..

I think I’ll get one ordered! Good advice on the thread thanks everyone 

[U Cyg]

If you wish to split your file before stacking, I think someone already mentioned PIPP. If you put your avi/ser into PIPP then go to the Output Options tab and select Split RGB Channels (bottom left), it will output three separate files, r g & b. You can then stack and process each file separately, and combine into a colour image in PS/GIMP or whatever!  

Hope this helps, and that I am not misundertanding what you are trying to do!  I'm always a bit slow on the uptake!?

Plus one for the ADC!

Angie

[tooth_dr]

2 minutes ago, U Cyg said:

If you wish to split your file before stacking, I think someone already mentioned PIPP. If you put your avi/ser into PIPP then go to the Output Options tab and select Split RGB Channels (bottom left), it will output three separate files, r g & b. You can then stack and process each file separately, and combine into a colour image in PS/GIMP or whatever!  

Hope this helps, and that I am not misundertanding what you are trying to do!  I'm always a bit slow on the uptake!?

Plus one for the ADC!

Angie

It’s my explanation Angie! It often makes more sense in my head. Thanks again for all your help.