Messier 106 et al.

[decay]

Hi all,

It has been a long time since my last image post. But recently I managed to set up my rig and spend a few hours on M 106.

m106_2-5.jpg (330.59 KiB) Viewed 5926 times

Guiding was terrible, way more than 1 arcsec RMS. But SV Decon revealed a lot of great detail in the core of M 106 SV Decon is such an awesome tool, I really love it. And I used the HDR and NR modules. But I didn't use the Contrast, Sharp and Super Structure modules. No acutance Shrink module of course would help to tighten the blown up stars, but I was too lazy to mask out all the nice little galaxies that show up in the background.

Finally I decided to create an AstroBin account. I really don't like this 'like' system and I'm not sure if hours of integration time are a reasonable measure for the quality of an astrophotographer. But nonetheless AB is a great place to store and share our images, I think.

https://www.astrobin.com/qreope/

I will post my old images as time allows. Thanks for looking.

As always, comments and constructive criticism are most welcome!

Best regards, Dietmar.

[dx_ron]

Quite nice, Dietmar!

I hope to image this Spring a similar field with the AT130EDT. I'm encouraged by the nice details and rich colors you got from only 3.5 hours. Roughly converting in my head from your f/5 to my f/7 and your B5 to my B6/7, I should be able to get a decent image in maybe 20 hours... It's impressive that you had little enough background graininess as to be able to get by without Contrast. Maybe there are some subtle tricks in Optidev that I haven't learned yet - because Contrast is always an important step in my processing.

Zooming in (OK - pixel-peeping), I see red "flares" always on the upper-right of many stars. I wonder if that is a de-bayering artifact?


Re:Astrobin: I haven't been uploading too many of my images there lately, I should do so a bit more. I made sure to Like your image, though! You got a chuckle out of me - my images tend to attract only a small number of views (<50) and typically 10-ish Likes. I don't worry about it. I've often wondered if part of the game is to Follow a bunch of people in hopes a few of them Follow you back, increasing views and Likes. So I Followed you as the first I have Followed to see if that's true

[AndyBooth]

@dx_ron

Although I review the forums daily, I very rarely post due to the fact I use STools as only a part (but a very important one) of my overall processing routine, which also uses other software for initial stretching, and finishing work, with STools in the middle.
I regularly use Bin,sharpening,HDR,SVdecon, entopy,Superstructure (saturation/brighten/dimsmall), but on non linear loaded files. i then do finishing work in other software.
But here is my m106 using a 130EDT @ F7 to show detail. One shot is the full full fov, and the second a close crop drizzle x2 process integration.
This is only 250mins (100x150s exp) using a Altair Astro 26c camera (2600mc clone), and a Tri RGB filter.
Its noisy due to short data, but goes to show that minimal data also produces results.
I am hoping this gives an idea of scale and detail from a 130EDT F7 setup (mine is an Altair astro branded one).
Other pics with this setup are here.
https://www.facebook.com/profile.php?id=100088635940203

[Mike in Rancho]

Nice to see you getting some time in, Dietmar!

That's a fine M106. Brings back memories of mine. It was a monthly challenge and turned into a purple disaster.

But that led to buying a screen calibrator, so all good in the end.

Yes a number of stars seem to have a mild CA or Pepsi effect, possibly could be helped with RGB channel realignment, or a little extra highlight repair. It is a little more pronounced, perhaps even lumpy, towards the upper right. Probably a CC issue.

Only other extra things I would do here would maybe be some dering (no iteration Shrink) around the three bright colored stars, and since the cores are clipped white, a very mild masked layer blur would cut the harshness a bit.

[dx_ron]

@AndyBooth

Very nice - thanks for posting that! Do you know if the Altair 130EDT uses the same glass as the AstroTech, or the upgraded glass as in the TS version? I suppose, with the triband filter, it would not make much difference for you. Some day I'd like to see someone with that type of filter image the same target for the same total time both with and without it. I assume the filter accentuates the Ha and Oiii, but at the cost of rather a lot of overall signal for a galaxy target.

[AndyBooth]

@dx_ron
The TriRGb filter overall transmission is around 20-25% of my uvir broadband filter, with corresponding increase in exposure times.
At F7 i can swamp read noise (RN^2 x10) in bortle 5/6 boundary with 180s exposures with the Altair 26c at gain 100.
It has three bandpasses, all about 30-35nm. Blue, a red with encompasses ha/hb/sii/nii and a green which passes oii/oiii. It has very good cutoffs, so I can use it even with heavy moon, not as good as narrowband, but good.
The Altair 130EDT scope uses SFPL-53 Synthetic Fluorite ED glass from Japan for the ED lens components, i believe thats the higher quality one compared to the Chinese clone synthetic ED flourite.
Overall I would gauge on galaxies a 10% increase in overall dust lane contrast, but a significant boost in ha visibility, but of course longer exposure compared to uvir.
On nebula the filter is a real boost, almost narrrowband contrast, but with nowhere near the exposure penalty, especially at F7.
I was concerned that on galaxies, I would lose a lot of yellow, but i have not really noticed it.

Here is a good pdf on the testing of these types of filters.
The altair filter is essentially the same as the antila rgb ultra filter.

https://www.researchgate.net/profile/Ja ... dGlvbiJ9fQ

[decay]

Thanks for your like, Ron! So now you have two followers in total, Mike and me. If you want to get likes, just drop me a line.

I've often wondered if part of the game is to Follow a bunch of people in hopes a few of them Follow you back, increasing views and Likes.

That's pretty exactly what I thought, and I guess it's true. But why are they doing this? There are people who have thousands of subscriptions. That's completely useless. Unless it's just to satisfy some kind of narcissism, like we can see on Instagram. OK, coming of age is not so easy, as we all know - but grown up people doing such complex things like astrophotograpy behaving like teenagers?! OK, rant over.

Roughly converting in my head from your f/5 to my f/7 and your B5 to my B6/7, I should be able to get a decent image in maybe 20 hours

I'm really not sure about my B5 and your camera might be more sensitive than mine. So I guess, it's worth a try. Seeing (and guiding) was so bad that all the smaller stars we can see in Andy's image have disappeared for me. You will have better luck, I hope.

It's impressive that you had little enough background graininess as to be able to get by without Contrast. Maybe there are some subtle tricks in Optidev that I haven't learned yet - because Contrast is always an important step in my processing.

I don't think that you're missing something in OptiDev. It's always a problem to find the right brightness/noise level for the background. This is especially a problem when processing small(er) galaxies and less of a problem when processing more or less field filling nebulae or star clusters. So I suppose you are setting the right background level using Contrast module while I did that using OptiDev. It just doesn't matter I guess.

I'm often not satisfied about the look of the background that StarTools produces. Too much noise or brightness level and the SuperStructure and Denoise modules will produce some kind of ugly mottling. More or less, but most times it is visible. I don't think that I'm doing too much wrong, because the images of our friends here often show this as well.

What I did in this case: Pushing back noise level and brightness of the background while using OptiDev. It took several attempts, but I used Guy's STReplay tool which helped a lot. I omitted SuperStructure to avoid mottling. In NR first screen I pushed up Grain Size to 15px (!). On the second screen I reduced Scale Correction in order find a reasonable balance. I'm sure it's not intended to be used in this way but at least it helped to get out what we see.

[decay]

But that led to buying a screen calibrator, so all good in the end.

Yeah, I just thought that as well. My wife will for sure roll her eyes, but image processing on uncalibrated screens is a bit of a game of chance.

Yes a number of stars seem to have a mild CA or Pepsi effect, possibly could be helped with RGB channel realignment, or a little extra highlight repair. It is a little more pronounced, perhaps even lumpy, towards the upper right. Probably a CC issue.

Zooming in (OK - pixel-peeping), I see red "flares" always on the upper-right of many stars. I wonder if that is a de-bayering artifact?

Thank you both for pointing out. I noticed that too, but I thought it might be caused by setting a dud sample when using SV Decon. I will check that. Usually I don't have problems with my CC. Sometimes the focuser shows some tilting But the stars are rubbish in this case anyway.

Best regards, Dietmar.

[decay]

Although I review the forums daily, I very rarely post due to the fact I use STools as only a part (but a very important one) of my overall processing routine, which also uses other software for initial stretching, and finishing work, with STools in the middle.
I regularly use Bin,sharpening,HDR,SVdecon, entopy,Superstructure (saturation/brighten/dimsmall), but on non linear loaded files. i then do finishing work in other software.

That's interesting, Andy. Could you give us some more details? What software do you use beforehand and afterwards? And - most interesting for me - why do you do that? Which aspects of processing in ST do work better for you using other software? Is it related to background issues, as described above?

Best regards, Dietmar.

[dx_ron]

Thanks for your like, Ron! So now you have two followers in total, Mike and me. If you want to get likes, just drop me a line.

I've often wondered if part of the game is to Follow a bunch of people in hopes a few of them Follow you back, increasing views and Likes.

That's pretty exactly what I thought, and I guess it's true. But why are they doing this? There are people who have thousands of subscriptions. That's completely useless. Unless it's just to satisfy some kind of narcissism, like we can see on Instagram. OK, coming of age is not so easy, as we all know - but grown up people doing such complex things like astrophotograpy behaving like teenagers?! OK, rant over.

I'm sure we're all at least a bit narcissistic - matter of degrees, I suppose. Anyway, I'm pretty sure my last thoughts will be neither of "I sure wish I'd gotten a Top Pick nomination" or "At least I got a Top Pick nomination".

Roughly converting in my head from your f/5 to my f/7 and your B5 to my B6/7, I should be able to get a decent image in maybe 20 hours

I'm really not sure about my B5 and your camera might be more sensitive than mine. So I guess, it's worth a try. Seeing (and guiding) was so bad that all the smaller stars we can see in Andy's image have disappeared for me. You will have better luck, I hope.

Hopefully I'll find out. It won't be because I'm afraid of it - I spent my last clear night on something even less appropriate for light-polluted skies - M94. Though I really should have put that time into adding to my Owl/Surfboard data. I suppose M97 & M108 take up a small enough fraction of the frame that they can tolerate some moonlight and aggressive Wipe.