Help processing Saturn (in RegiStax)

I can't promise anything but I can give it a go.

andrea tasselli:
I can't promise anything but I can give it a go.

I'd really appreciate it! I'm not expecting miracles. And I don't expect you to devote any real time to it. I'd just like to see what someone experienced can do with it versus what I can with it. That way, I can narrow down whether I'm mostly limited by the data or by own abilities. I'm not quite sure which one is the "proper" one to use. So, here are links to both.

https://drive.google.com/file/d/1cVBtQN2lkywCvzqVLAWnZBKrW_ZbeV4L/view?usp=drive_link
https://drive.google.com/file/d/1Z9UdX_M30N9KzkTVJJfagMycjZVdJ5E1/view?usp=drive_link

Thank you! It's definitely better than what I was able to do. And it's better than the already sharpened version. I think maybe it's just the lack of features that keeps it from having that "Wow" factor. I have very, very little experience with planetary. And most of that was with bad collimation and no idea what I was doing. But I have seen in my "Youtube research" many blurry videos miraculously turn into seemingly APOD worthy photos. So, I assumed there was some behind the scenes magic I wasn't privy to. Strangely, I've had decent luck using a 3x barlow on Saturn and Jupiter. But my moon shoots have been nothing short of disgusting. After last night's collimation, the moon looked better than it ever has on my screen. But the trees it was setting behind wouldn't allow me time to start a capture. So, I had to resort to Saturn instead. If the clouds cooperate, I may try again with the moon tonight and see what happens.

I just realized I left the last post on the wrong thread and can't seem to find a way to delete it. So, I guess it's stuck here.

Hi Jaymz, 

I think you are collecting good data, though Niall's question above is pertinent - depending  on your equipment (eg camera pixel size, focal length of telescope), you may be under or oversampling. As a rule of thumb, aim for a focal ratio in your imaging train of about 5-7 times the pixel size in microns.  Use a Barlow lens to get close to this range.

Re Autostakkert, the sharpening function it provides is not intended as an intermediate step in processing your final image. Rather, it is intended to give you a quick indication of the best videos among many, when you have taken a lot of videos in a session. We always work from the unsharpened tiff file, not the Autostakkert sharpened one. I myself leave that option turned off.

Also, check that you are using the appropriate stacking mode for a planet vs a lunar surface before commencing the stacking.  It is an option you select at top left of the stacking menu.

In Registax, there is an auto colour balance function that works quite well for Jupiter, and less well for Saturn.   You might want to try it for Saturn but then reduce whatever it does to the red and the blue channels a bit. It should at least help to reduce the greenish tinge.

When sharpening in Registax, keep the histogram tab open so you can check that you are not clipping the right hand side of the histogram as you sharpen.  Work just with layers 1-3 to simplify matters. You can experiment with other layers later but this is a good starting point.

Best wishes

Mark

I think you are collecting good data

I'll go ahead and touch briefly on the other topics and then we'll come back to the above selected quote. As you'll see, it's going to be extremely relevant. 

Regarding the acquisition, that's the only part I'm confident that I'm fairly well versed on. I understand the techniques and how to go about it. The parts I'm not confident with are the quality of the optics (which I'll get to) and the processing phase. 

On that note, I appreciate all the tips. I will definitely attempt to put them to use when I finally manage to get better data. 

Which leads us to the data quality. As it turns out, I have severe issues. I meant to post the 3 images above in another thread trying to figure out why the Saturn image was so much better than the lunar images (which has been an ongoing issue I haven't been able to understand). What I've gathered is that with Saturn being centered and taking up so few pixels, the issues have limited chance to present themselves. With the lunar images taking up the entirety of the sensor, they become much apparent.

Finally, the issue: I've struggled with collimation for some time. A lot of that turned out to be a bad corrector plate. Long story short, I've corrected that and finally got collimation down. Well enough to accurately collimate a 14" EdgeHD or a RASA? Probably not. An 8" Newt? I think so. Anyway, the collimation is the best I've ever had. Yet my lunar shots are blurry while planets are (seemingly) ok. The problem, which I only discovered last night, is that I'm collimating with my ASI2600MC (as it's the one that stays on the scope 99% of the time) and then switching the imaging train. My DSO train is camera>small extender>OAG>CC>small extender to fit into the tube. While it may seem like a lot, it's all pretty small aside from the camera. My planetary imaging train is camera>barlow>1.25" adapter>ridiculously large extender. At a glance, it doesn't seem like much. But the barlow is rather heavy. Somehow, the tiny 1.25" adapter is the heaviest part of the train (I think it's a chunk off of Thor's hammer). To compound this, the extender needed to reach focus is a whopping 3 1/2 inches long! To be fair, part of that is inside the tube. But the weight's still there. And it still extends the camera pretty far out there. 

After getting another blurry moon again the other night after what I thought was the best collimation I've ever had, I slewed back to a star to defocus and was horrified at what I saw. The outer ring was bulgy and the inner ring was shaped like a football. That's when I threw in the towel. In my defense, it was 4am and I had nothing to show for it. I had no idea why this disaster was on my screen and I had no desire to stay outside any longer to figure it out. It wasn't until last night it clicked what happened. At least that's the working theory. I've got to wait a couple more days for these clouds to clear before I can confirm.

Niall MacNeill:
Thanks Jaymz. The Meade LXD75 is a Mount is it not? What is the objective diameter of your scope and its focal ratio please?

Yes, you're right. My apologies. I must have been really tired last night. I've never referred to it as anything but the SN8 (203mm/812mm). For some reason, when you asked, I looked over at the scope and typed exactly what it says on it. In my defense, I've always thought it somewhat odd that they branded all 3 scopes in the line with the name of the mount rather than the scope. Technically, I guess they did it with 6. They were originally branded with "LXD55" before they updated the mount. But to my knowledge, the OTAs are 100% identical other than the single number change printed on the side.

Niall MacNeill:
Thanks for the clarification. Your scope is a challenge for planetary imaging. 203mm is at the bottom end in terms of suitable diameters and the short focal ratio makes it a challenge to get adequate sampling. To sample adequately, for the best of seeing you need a barlow = 6.9 x pixel size (microns)/ focal ratio = 6.9 x 3.8/4 and that is 6.5X. 
Nonetheless you can produce a decent image as you have, but recognise you are undersampled with a 3X barlow....thus the comments about the size of the image. It is too small and therefore there are not enough pixels to resolve fine detail.
As you noted good collimation is essential and Newtonians can be a challenge in that regards. But yes the first thing is to get the scope well collimated.
Once you have all that working for you, start with an exposure of 20ms and see whether you can get the histogram to 80% by adjusting the Gain. If you can't, then at maximum Gain, increase the exposure. However, recognise that once higher than 20ms you are risking not "freezing" the seeing. I would image for 2-3 mins for your size scope. If you can get multiple runs you will be able to use WinJUPOS to derotate and combine to get more data. Each video should be processed with Autostakkert and the resultant images saved as a TIFF. These can be sharpened with RegiStax. You will have to consult the literature on how to do that. The resulting sharpened images can be further processed in WinJUPOS and a further round of sharpening can be done in RegiStax (but lower settings than before), given the extra data. Further denoising and other image processing steps can then be undertaken as you see fit.
Good luck.
Niall

Niall, 

   I appreciate you taking the time to respond. I'm all too aware of the shortcomings of my scope. But as primarily a DSO imager, the 8" f/4 is great. Most of all, I love its versatility. Not many people can image Andromeda and Mars with the same scope. 
   You've provided some good processing tips. I look forward to giving them a shot when I get this scope fixed. As it turns out, it wasn't flexure in the focus tube. It was the secondary mirror not being centered. The reason it became more noticeable with the moon is because, at normal focus, it wasn't as obvious. With the barlow extending the focal plane outwards, the entirety of the secondary became visible and made its misalignment obvious.
   So, now I'm off to try to figure out how to solve yet another problem. This is my second iteration of this scope since the last one had an accident. Having marked the primary mirror holder and the OTA, I was able to freely remove the primary as needed. It wasn't until I was putting it back together today that I realized that THIS scope isn't marked; the other one is! So, now I have a mirror on the floor with no idea how to orientate it. Luckily, there are only 4 options for replacing it. The bad news is that I haven't the slightest clue what I'm looking for if I choose one of the 3 incorrect ways. So, I guess I'm off to start another thread. With any luck, I'll be able to come back fairly soon and update with a much improved Saturn image!