9 replies to this topic

[Ed Wallace]

I mainly image dso's, but I also image planets when they are at or close to opposition. I'm not very adept at the planet process. I usually use a color camera for planets for simplicity. I recently used a mono camera to image Jupiter with Io and its shadow. I took RGB videos, 60 seconds each. I stacked in Autostakkert and then sharpened a bit using Registax. I then used Winjupos to derotate and combine the RGB images. The result (attached) has serious misalignment of RGB when looking at Io. I also tried omitting Winjupos: I stacked in Autostakkert, then sharpened a bit with Registax, then opened the RGB images as layers in Gimp. The result had the exact same misalignment. I can manually align the layers such that Io is good, but then there is a red tinge on one side of Jupiter. Also I notice that when I manually align the RGB layers while looking at Io, they are not quite aligned right when looking at Io's shadow. I'm unsure how to correct this, mainly due to my lack of knowledge and experience with planetary imaging.  I took 14 sets of 60 second RGB videos, and am looking forward to seeing what I can produce from them. I would appreciate some pointers from more experienced imagers. 

 

 

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[Tulloch]

This might be atmospheric dispersion, caused by the atmosphere refracting different parts of the spectrum in diferent amounts. This occurs more when the target is at a low elevation, how high was Jupiter when you took this image?

 

More information about the effect and how to correct for it in Sec 6.4 of the FAQ at the top of the page (or linked to below).

https://www.cloudyni...-december-2024/

 

Of course, it could just be misalignment of the mono frames...

 

Andrew

[Mike Phillips]

I see the same thing in my 14" with 30s per channel.  If it bother's me enough I shift them in post processing with PS easily.

 

HTH,

 

Mike P in NC

[Ed Wallace]

This might be atmospheric dispersion, caused by the atmosphere refracting different parts of the spectrum in diferent amounts. This occurs more when the target is at a low elevation, how high was Jupiter when you took this image?

 

More information about the effect and how to correct for it in Sec 6.4 of the FAQ at the top of the page (or linked to below).

https://www.cloudyni...-december-2024/

 

Of course, it could just be misalignment of the mono frames...

 

Andrew

The planet was quite high, so I didn't use my adc. It seems to be misalignment of the mono frames, but different features seem to be misaligned by different amounts. I can manually align the frames so that Io is good, but then Jupiter itself has obvious misalignment, with a red tinge at the left hand edge.

[Ed Wallace]

I see the same thing in my 14" with 30s per channel.  If it bother's me enough I shift them in post processing with PS easily.

 

HTH,

 

Mike P in NC

But if I look at Io and manually align the frames, then Jupiter itself has obvious misalignment. 

[RedLionNJ]

There's a setting (somewhere) in Winupos to encourage it to pay attention to the satellites of Jupiter. I'm not sure if it's on or off by default. You'd need a relatively recent version, but that setting (which, of course, I can't remember) might do the trick for you in this situation.

 

Found it - under Derotation of R/G/B frames. I think it's off by default:

 

[Mike Phillips]

But if I look at Io and manually align the frames, then Jupiter itself has obvious misalignment. 

It's because they move at different rates.  You can composite them in layers in GIMP or Photoshop if you have patience.

 

 

There's a setting (somewhere) in Winupos to encourage it to pay attention to the satellites of Jupiter. I'm not sure if it's on or off by default. You'd need a relatively recent version, but that setting (which, of course, I can't remember) might do the trick for you in this situation.

It's in derotation of images here -  

[Ed Wallace]

It's because they move at different rates.  You can composite them in layers in GIMP or Photoshop if you have patience.

 

 

It's in derotation of images here -  

They move at different rates - that explains it. Sometimes I need someone to point out the obvious! Thanks.

 

I'll try redoing them in winjupos tomorrow.

[Ed Wallace]

There's a setting (somewhere) in Winupos to encourage it to pay attention to the satellites of Jupiter. I'm not sure if it's on or off by default. You'd need a relatively recent version, but that setting (which, of course, I can't remember) might do the trick for you in this situation.

 

Found it - under Derotation of R/G/B frames. I think it's off by default:

 

image_2025-01-11_225325285.png

I'll try redoing them in winjupos tomorrow. Thank you.

[Ed Wallace]

This time I checked the boxes in winjupos to optimize image measurements (R/G/B) and correction of planetary moons. There was improvement in the moon, but it has a red tinge at the lower left, while its shadow has a red tinge at the upper right. 

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Edited by Ed Wallace, 12 January 2025 - 02:13 PM.