M31 / First light with 2600MC

[AbsolutelyN]

Finally got first image out of the new 2600mc. 4.3 hours on M31 with the RASA 8 - 128x 2 min exposures with 80% moon in bortle 5 at unity gain.  
Higher res on astrobin - https://www.astrobin.com/grod4i/

 

Re-processed to address aggressive noise reduction. Background is a bit lighter to try to pull out what I think is some faint HA in the background. 

Original:

 

Edited November 11, 2020 by AbsolutelyN

[Phillyo]

Absolutely stunning. I love M31 and this is top notch. The level of detail is phenomenal. I took a similar image recently with the 533 on a Samyang, slightly wider than this though. Didn't get this level of detail from it.

[AbsolutelyN]

2 minutes ago, Phillyo said:

Absolutely stunning. I love M31 and this is top notch. The level of detail is phenomenal. I took a similar image recently with the 533 on a Samyang, slightly wider than this though. Didn't get this level of detail from it.

Thanks. I think the detail is simply due to the 8" aperture. The detail here is far more than I got with my Esprit 80 / 1600MM. Just wish the stars were pinpoint across the frame. 

[Phillyo]

15 minutes ago, AbsolutelyN said:

Thanks. I think the detail is simply due to the 8" aperture. The detail here is far more than I got with my Esprit 80 / 1600MM. Just wish the stars were pinpoint across the frame. 

Haha yeah, there's always something that needs tweaking or tinkering. I think we're our own worst critics half the time!!

[DaveS]

That is phenomenal. I've just been scrolling around the full res on Astrobin, and it's gorgeous.

[AbsolutelyN]

40 minutes ago, Phillyo said:

Haha yeah, there's always something that needs tweaking or tinkering. I think we're our own worst critics half the time!!

True but I find you learn quicker if you are a harsh self critic. Saying that I don't think I can fix those stars as APSC is too big for image circle ... so perhaps best not to worry :-)

[AbsolutelyN]

2 minutes ago, DaveS said:

That is phenomenal. I've just been scrolling around the full res on Astrobin, and it's gorgeous.

Thanks Dave. Wasn't expecting much with Moon so bright. Had awful results from these frames for last 5 days but finally figured out the calibration process. 

[Rustang]

Mental! 👍

[ultranova]

Killer camera and scope combo ,

Loving the image,

the only thing I would say, and this is obviously personal preference,

where you have gone quiet deep with your setup, the Galaxy looks a little washed out

as there is so much lum / brightness  , detail and resolution are out standing and the colors

are great. 

well done 

Paul

[AbsolutelyN]

27 minutes ago, ultranova said:

Killer camera and scope combo ,

Loving the image,

the only thing I would say, and this is obviously personal preference,

where you have gone quiet deep with your setup, the Galaxy looks a little washed out

as there is so much lum / brightness  , detail and resolution are out standing and the colors

are great. 

well done 

Paul

Thanks Paul, that's much appreciated. I think I know what you mean. Perhaps more contrast in the arms and darkening the haze around the galaxy may improve it. I'll take a look at that and see what I can do. Sometimes it's best to process an image and then leave it a day and come at it fresh again. Much appreciated. Tristan

Edited November 10, 2020 by AbsolutelyN

[ultranova]

I know what you mean,

But don't drive yourself nuts over it, its easy to catch processing madness lol.

Paul

[PaulE54]

That's really astonishingly good. Looking forward to seeing more from this setup.

Paul E

[ollypenrice]

That's a splendid M31, very obviously. Great use of a fast system, despite the moon. You've also preserved a hell of a lot of detail into the core, which is always tricky. I think you have as much as any image I've seen. It's a great image. Once we regard this image as top notch (which I certainly do) we ask about reservations. I have two: As is often the case with OSC CMOS cameras I think it is red-biased. More blue signal would be nice. The other is that the sharpening does rather shout 'Pixinsight' to me. (Go on, shoot me down and tell me it was all Photoshop! 🤣) No but, seriously, I do feel I'm seeing 'wavelets' more than I'm seeing details in M31. If the image were not of the quality that it is I wouldn't mention either reservation. They are minor.

Olly

Edited November 10, 2020 by ollypenrice
Typo

[vlaiv]

Do you mind me being slightly harsh on your image?

It's not actually the image, but rather processing. I think you obliterated the image . Again, I'm sorry to be so harsh, but seriously, I think you went too much with the processing. It looks more like painting than photograph.

Let me show you what I mean.

If I were to show this to someone and ask them, what do you think is in this crop, how many people would respond correctly and say NGC206, or at least - yes, that seems to be some sort of star cluster?

I think that above crop can easily pass as planet surface or similar.

Here it is on another image - same region

If anything, in second image one can clearly see that scattered dots are in fact stars.

[gorann]

Goredeous first light Tristan! I had the same experience in August when I did exactly as you - point my new RASA8 and ASI2600 at M31 (https://www.astrobin.com/kv60c2/). Good object to test first light.

And as you I was also pleased with everything except stars. That system is fantastic but at f/2 any little tilt will mess up stars. I think it is mainly us that process the data that really notice it but it is annoying. I had some night when the stars were ok but it is really a delicate issue. I just got myself a new attachment for the camera that also will allow for filters, and I hope it makes it more reliable against tilt. The Celestron standard attachment does not allow for repeatability in centring the camera as you will have noticed - you can wobble it around at will which is not very satisfactory. Here is what I got and will try if it ever clears here again: https://www.teleskop-express.de/shop/product_info.php/language/en/info/p11535_Artesky-2--Filterhalter-und-T2-Adapter-fuer-Celestron-RASA8-Astrograph.html

 

[AbsolutelyN]

21 minutes ago, ollypenrice said:

That's a splendid M31, very obviously. Great use of a fast system, despite the moon. You've also preserved a hell of a lot of detail into the core, which is always tricky. I think you have as much as any image I've seen. It's a great image. Once we regard this image as top notch (which I certainly do) we ask about reservations. I have two: As is often the case with OSC CMOS cameras I think it is red-biased. More blue signal would be nice. The other is that the sharpening does rather shout 'Pixinsight' to me. (Go on, shoot me down and tell me it was all Photoshop! 🤣) No but, seriously, I do feel I'm seeing 'wavelets' more than I'm seeing details in M31. If the image were not of the quality that it is I wouldn't mention either reservation. They are minor.

Olly

Thanks Olly, that's really appreciated feedback. Sharpening and denoise was indeed Photoshop (not PixInsight) and I did wonder if I'd gone overboard on both sharpening and saturation. It was very hard to bring out the blues which is probably why they've ended up more purple than blue - first ever image I've processed from a OSC camera. As I mentioned earlier I think it's just one of those I probably need to revisit and process again with a fresh eye. I was just so relived to get the calibration sorted after days of issues with banding so probably went overboard in a few areas in my excitement!  

[AbsolutelyN]

7 minutes ago, vlaiv said:

Do you mind me being slightly harsh on your image?

It's not actually the image, but rather processing. I think you obliterated the image . Again, I'm sorry to be so harsh, but seriously, I think you went too much with the processing. It looks more like painting than photograph.

Let me show you what I mean.

If I were to show this to someone and ask them, what do you think is in this crop, how many people would respond correctly and say NGC206, or at least - yes, that seems to be some sort of star cluster?

I think that above crop can easily pass as planet surface or similar.

Here it is on another image - same region

If anything, in second image one can clearly see that scattered dots are in fact stars.

I readily accept your (not so) harsh criticism. That's a really good example and I intend to try to learn and improve.  

[gorann]

Yes, Vlaiv is of course right (as nearly allways). If you have another go at processing the data I think it could end up with something similar to that of Valiv's second image.

[AbsolutelyN]

7 minutes ago, gorann said:

Goredeous first light Tristan! I had the same experience in August when I did exactly as you - point my new RASA8 and ASI2600 at M31 (https://www.astrobin.com/kv60c2/). Good object to test first light.

And as you I was also pleased with everything except stars. That system is fantastic but at f/2 any little tilt will mess up stars. I think it is mainly us that process the data that really notice it but it is annoying. I had some night when the stars were ok but it is really a delicate issue. I just got myself a new attachment for the camera that also will allow for filters, and I hope it makes it more reliable against tilt. The Celestron standard attachment does not allow for repeatability in centring the camera as you will have noticed - you can wobble it around at will which is not very satisfactory. Here is what I got and will try if it ever clears here again: https://www.teleskop-express.de/shop/product_info.php/language/en/info/p11535_Artesky-2--Filterhalter-und-T2-Adapter-fuer-Celestron-RASA8-Astrograph.html

 

I saw the Artesky adapter and was tempted but not planning on using filters. Currently using the Baader 7.5 mm T adapter.  It would be good if Celestron just redesigned the front plate for better / repeatable image quality. As it is every time the camera moves it feels like pot luck on your star quality. It's done better than I thought though. 

Two questions though if I may? 

1. Have you removed the optical window from the RASA? Feels like just an extra piece of glass in the optical train but I'm worried if I remove it it might make focal position different. 

2. If you run a DBE on your flats do you get this banding pattern?

   

[AbsolutelyN]

3 minutes ago, gorann said:

Yes, Vlaiv is of course right (as nearly allways). If you have another go at processing the data I think it could end up with something similar to that of Valiv's second image.

I'll have a go at some point over the next few days. It was a lot of firsts and rushed processing during a lunch break so can probably come up with something better. Suspect the biggest flaw in processing this is using Topaz De-noise. It's really good but often produces that painterly effect so need using very carefully. 
 

[gorann]

7 minutes ago, AbsolutelyN said:

I saw the Artesky adapter and was tempted but not planning on using filters. Currently using the Baader 7.5 mm T adapter.  It would be good if Celestron just redesigned the front plate for better / repeatable image quality. As it is every time the camera moves it feels like pot luck on your star quality. It's done better than I thought though. 

Two questions though if I may? 

1. Have you removed the optical window from the RASA? Feels like just an extra piece of glass in the optical train but I'm worried if I remove it it might make focal position different. 

2. If you run a DBE on your flats do you get this banding pattern?

   

Yes, I removed it since Celestron says you should do it if you use filters and I have also used the RASA with my ASI1600MM and Baader filter drawer. As you say that window has no purpose so better take it off, although it will probably have no major effects on your ASI2600 images.

I have not taken any flats yet (almost sacritlege) - but I have no dust bunnies yet in my system and I fund that those dark corners can be easily fixed in processing or cropped away.

 

[AbsolutelyN]

Just now, gorann said:

Yes, I removed it since Celestron says you should do it if you use filters and I have also used the RASA with my ASI1600MM and Baader filter drawer. As you say that window has no purpose so better take it off, although it will probably have no major effects on your ASI2600 images.

I have not taken any flats yet (almost sacritlege) - but I have no dust bunnies yet in my system and I fund that those dark corners can be easily fixed in processing or cropped away.

 

That's interesting. I was not planning on taking flats either as I've never needed them with the 1600MM on the RASA. However I found I cannot stack the images without flats as I get the same banding pattern shown above when I stack the lights which makes it impossible to use the camera without flats. No sign of the banding in the darks or bias. Contacted ZWO and they just said you need to use flats. Not sure if I have a dud camera or this is inherent to the chip.  Lights without the flats look like this which is just unusable. 

[gorann]

Why do you do DBE on a flat? In any case I found that flats are a mess with OSC so I wait until I really need them. Also with the RASA 8 the ASI2600 really have a bit too big chip, the RASA 8 is not really not supposed to light up more than a 22 mm diagonal, Anything you can get out of the corners are just bonus.

But the colour banding looks odd - I have not seen that but then I have not imaged RGB with the ASI2600 under moon light. It could be a moon light issue.

[AbsolutelyN]

1 minute ago, gorann said:

Why do you do DBE on a flat? In any case I found that flats are a mess with OSC so I wait until I really need them. Also with the RASA 8 the ASI2600 really have a bit too big chip, the RASA 8 is not really not supposed to light up more than a 22 mm diagonal, Anything you can get out of the corners are just bonus.

But the colour banding looks odd - I have not seen that but then I have not imaged RGB with the ASI2600 under moon light. It could be a moon light issue.

I don't do DBE on the flats 🙂 I only did so as I could not figure out where the banding was coming from and did a DBE to see if it was embedded in the flats too - which it is. 

Didn't think of moonlight but it can't be that as the flats have the banding and they were taken in daylight. Perhaps it does not matter as I know I can get rid of it now but it's taken me a week to get a usable image out of the camera, was almost at point of sending it back.  

[gorann]

Well, that banding is odd - have you shown the flat to ZWO?