Saturn, Jupiter and Uranus - 14/15 Sept 2023

[geoflewis]

After a hiatus of several months not doing any astro, I've finally got back to some imaging. After much discussion last year with @vlaiv and others, for these images I decided to leave the barlow out, so no extra amplification beyond what the ADC gives.

Here is an IR-RGB image of Saturn with Rhea and Tethys.

Next is an IR image of Jupiter with Io

....and an RGB of Jupiter riding high less than an hour before transit.

and finally, my first look at Uranus in nearly 9 years. On reflection, I should have thrown the IR filter in the mix to see if I could tease out any surface detail.

Thanks for looking.

Edited September 20, 2023 by geoflewis

[Kon]

Great set of images Geof, and fantastic to see you imaging and posting again.

Could you briefly comment on the imaging conclusion? Are you at X5 the camera pixel or something else?

[knobby]

Lovely images, welcome back 👍🏻

[geoflewis]

Thanks Kostas,

Winjupos reported 12.98"/px, so with the 2.9mn pixels of this camera, that gives me approx x4.5 with the ADC in train, which I need for Saturn and also Jupiter when it is at lower elevations. Adding a barlow or PM would put me at x8/x9 which is too much amplification. Last year I took the ADC out for Mars when it was rising high, so added the Baader barlow for about x7 and I may try the same for Jupiter come opposition when I'll mostly image it at +/- 50° elevation. That said, I think the detail coming through without any amplification is already good enough with these small pixels.

Cheers, Geof

[geoflewis]

21 minutes ago, knobby said:

Lovely images, welcome back 👍🏻

Thanks knobby

[Kon]

21 minutes ago, geoflewis said:

Thanks Kostas,

Winjupos reported 12.98"/px, so with the 2.9mn pixels of this camera, that gives me approx x4.5 with the ADC in train, which I need for Saturn and also Jupiter when it is at lower elevations. Adding a barlow or PM would put me at x8/x9 which is too much amplification. Last year I took the ADC out for Mars when it was rising high, so added the Baader barlow for about x7 and I may try the same for Jupiter come opposition when I'll mostly image it at +/- 50° elevation. That said, I think the detail coming through without any amplification is already good enough with these small pixels.

Cheers, Geof

I kind of recollect now. I suppose under excellent seeing you could go higher but these images are looking excellent.

Worth trying Uranus with the IR as it's northern polar hood is starting to face us but you can still get a district banding. Even with my 8" and IR I could capture it.

[geoflewis]

4 minutes ago, Kon said:

Worth trying Uranus with the IR as it's northern polar hood is starting to face us but you can still get a district banding. Even with my 8" and IR I could capture it.

Yes, I'll give it a try. I've not much bother about the 2 outer planets in recent years, in fact I've only imaged them once each back in 2014 with my old 10" Meade, with an even older very slow Imaging Source colour camera. It's about time I gave them a return visit, now that I have better equipment.....🤔

[Space Cowboy]

Good to see you back Geoff! Some good detail there. Have you tried 1.5x drizzle at prime focus?

[JeremyS]

Cracking images Geof 👍🏻

[geoflewis]

1 hour ago, Space Cowboy said:

Good to see you back Geoff! Some good detail there. Have you tried 1.5x drizzle at prime focus?

Thanks Stuart,

I drizzled the Uranus data x3 in AS3! as the image was very pixelated without drizzle, but no, I didn't consider drizzle for Saturn and Jupiter. I'll take a look at doing that, but what do you think it will give me? When I've tried drizzle before all I seem to get is a bigger image.

Cheers, Geof

[geoflewis]

1 hour ago, JeremyS said:

Cracking images Geof 👍🏻

Thanks Jeremy

[geoflewis]

13 hours ago, Space Cowboy said:

Have you tried 1.5x drizzle at prime focus?

Hi Stuart,

Here's a comparison of my original undrizzled and revised 1.5 drizzled, resized as best I could to the original (drizzle vers still a bit bigger).

I can't see any material differences. What do you think?

[Kon]

3 hours ago, geoflewis said:

Hi Stuart,

Here's a comparison of my original undrizzled and revised 1.5 drizzled, resized as best I could to the original (drizzle vers still a bit bigger).

 

I can't see any material differences. What do you think?

I have never made drizzle work for me but I think your drizzled image shows some more details (assuming similar way of processing) at the NEB, SEB and EZ.

[geoflewis]

12 minutes ago, Kon said:

I have never made drizzle work for me but I think your drizzled image shows some more details (assuming similar way of processing) at the NEB, SEB and EZ.

That’s interesting Kostas, as I spent a long time staring at both images under zoom and couldn’t see anything significant. It was actually impossible to apply the same processes, as the larger scale of the drizzled image required completely different wavelet settings in Registax.  Essentially I tried to process to similar noise levels, but it wasn’t easy. I’ve a feeling I pushed a bit further with the drizzled version, but then maybe that’s what drizzling allows. Certainly, at least IMHO, there isn’t enough extra there to bother with it on that data set, so I doubt that I’ll use it again.

Edited September 21, 2023 by geoflewis

[Kon]

14 minutes ago, geoflewis said:

That’s interesting Kostas, as I spent a long time staring at both images under zoom and couldn’t see anything significant. It was actually impossible to apply the same processes, as the larger scale of the drizzled image required completely different wavelet settings in Registax.  Essentially I tried to process to similar noise levels, but it wasn’t easy. I’ve a feeling I pushed a bit further with the drizzled version, but then maybe that’s what drizzling allows. Certainly, at least IMHO, there isn’t enough extra there to bother with it on that data set, so I doubt that I’ll use it again.

Yes it's not huge amounts of details but they seem to pop more, maybe the harder pushing is helping, a bit less noisy too.

[Space Cowboy]

15 hours ago, geoflewis said:

Thanks Stuart,

I drizzled the Uranus data x3 in AS3! as the image was very pixelated without drizzle, but no, I didn't consider drizzle for Saturn and Jupiter. I'll take a look at doing that, but what do you think it will give me? When I've tried drizzle before all I seem to get is a bigger image.

Cheers, Geof

Drizzle should give you finer detail if the data is slightly under sampled. Certainly worth a try I reckon.

[geoflewis]

1 hour ago, Space Cowboy said:

Drizzle should give you finer detail if the data is slightly under sampled. Certainly worth a try I reckon.

Thanks Stuart

Ok, I’ll take another look at drizzle with my next set of good data, but at x4.5 px size, I think I’m pretty well sampled…. 🤔

[geoflewis]

@Kon@Space Cowboy

I thought I'd see how far I could push the drizzled version and maybe I did leave something on the table. What do you think?

 

I added a fully worked up version, which is slightly larger and has colour saturation and levels applied

Edited September 21, 2023 by geoflewis
added fully processed version

[JeremyS]

I’d love to see further Uranus images during the apparition, Geof. Few people are following it, yet amateurs are making useful observations 

[geoflewis]

27 minutes ago, JeremyS said:

I’d love to see further Uranus images during the apparition, Geof. Few people are following it, yet amateurs are making useful observations 

Thanks Jeremy,

If the conditions allow I'm going to see what I can get by adding an IR pass filter into the mix. I haven't even tried Uranus or Neptune since 2014, so it's probably about time. I found it very challenging to get Uranus on the camera sensor the other night, as my eyepieces and camera weren't parfocal and my finderscope was a cheap poor quality one. Neither of those factors are a problem for bright Jupiter, Saturn and Mars, but the much fainter ice giants are something else. I've now added an extension tube to my 40mm eyepiece to get that parfocal with the camera through the C14, plus I've mounted my old 62mm Revelation Astro guide scope on the rig, which together with an equally old 9mm illuminated reticule eyepiece that I originally bought for manual drift alignment, should make centering the target on the sensor much easier... 🤞

[Space Cowboy]

9 hours ago, geoflewis said:

Hi Stuart,

Here's a comparison of my original undrizzled and revised 1.5 drizzled, resized as best I could to the original (drizzle vers still a bit bigger).

I can't see any material differences. What do you think?

Sorry Geoff, I did not realize you had already done a drizzle version. Yeah, not much difference but I agree with Kostas the drizzle has a tad more detail in the central bands. As you say they have to be processed differently which maybe is why some people have more success than others with drizzle.

[Space Cowboy]

1 hour ago, geoflewis said:

@Kon@Space Cowboy

I thought I'd see how far I could push the drizzled version and maybe I did leave something on the table. What do you think?

 

I added a fully worked up version, which is slightly larger and has colour saturation and levels applied

For sure theres more pop in the detail Geoff though there is quite a bit of colour noise coming through.

[geoflewis]

29 minutes ago, Space Cowboy said:

For sure theres more pop in the detail Geoff though there is quite a bit of colour noise coming through.

Thanks Stuart,

I’m still learning how to use the colour camera and I’ve probably pushed the processing too hard. I think I need to shoot a lot more data to get equivalent signal that I get with the ASi290MM and RGB filters. The bayer matrix leaves the red and blue very short of signal, so I probably need to integrate x2/x3 as much data or more. 

[Kon]

2 hours ago, geoflewis said:

Thanks Stuart,

I’m still learning how to use the colour camera and I’ve probably pushed the processing too hard. I think I need to shoot a lot more data to get equivalent signal that I get with the ASi290MM and RGB filters. The bayer matrix leaves the red and blue very short of signal, so I probably need to integrate x2/x3 as much data or more. 

I agree with Stuart a bit noisy but more details on the last set . Worth playing with derotation, it had helped my captures this season, as I seem to control the noise better.

[geoflewis]

29 minutes ago, Kon said:

I agree with Stuart a bit noisy but more details on the last set . Worth playing with derotation, it had helped my captures this season, as I seem to control the noise better.

Thanks Kostas,

The image is from a set of 7 x 60s derotated SER videos captured at 8ms. So I had to run those though AS3! again for the x1.5 drizzle version, then apply wavelets to each resulting TIFF before puting them through WinJupos. The final colour and DN adjustments were in PS(CS2) and Affinity Photo.