AstroGS

So, I want to create a list of targets for the period between April - August for my imaging rig that is set in Granada/ Spain. Restricted by the short focal length (300mm @ f4.9): WO Redact 61 + ASI2600MM + LRGBSHO filters but, benefited by the quality of the dark skies (SQM 21.5+/ Bottle 1/2) and the fact that I can image from 26 degrees upwards. Happy to do projects that require multiple nights on one target & I love SHO projects 😉 Currently working on the Leo Triplet on LRGB - I probably have close to 20 hrs on it already and recently processed M81/82 as well. So, any ideas or suggestions will be highly appreciated - thanks in advance.

Did not see it time for yesterday. OIII would have been my choice too but, it requires a good few hours (5+ I would say) @300 sec or even 600 sec exposures to really get some good signal. On the other hand my iteration of this image has no OIII at all and instead it is mainly Ha and SII, with RGB for stars.

A new version - now that I found about stretching, I am playing around with almost all my images and trying to see if I can get more detail out of them. Used for the first time also PI's new Gradient Correction module. Thoughts?

I had the chance to do a simple (by-the-eye) comparison of a few subs, from when I was using Asiair, with "excellent" guiding of 0.3-0.4" vs the "best guiding" I got so far through PHD2 and I can confirm that the 600 sec subs with PHD2 seem to be perfect with round stars end2end, while the ones through Asiair seem to not have the consistent look. I know that this is not a scientific experiment but, I'm really happy with the results when guiding via NINA.

AM5 now sits at a permanent observatory in Spain, carrying a WO Redcat61 with a mono setup, managing the imaging sessions via NINA and PHD2. I can say that it continues to impress me and having great guiding performance. I was concerned if this mount would be able to hold PA for a long period of time but, my concerns were unwarranted Here is an imaging session of the cone nebula, while shooting with a Ha filter @ 600 sec.

@ollypenrice your latest advice on learning how to stretch an image has been an absolute revelation to me and has changed the way i process images. I genuinely spent probably over 6 hrs trying to stretch the images only, starting all over again and again, until i got the level of detail as best as i could. All the other processing tasks (combined) took less time to complete! Thank you 🙂 I have started using PS in combination with Pixinsight now and it makes so much more sense.

@david_taurus83 I just started using NINA/PHD2 and the results are pretty consistent as well. For a reason I feel that it performs better now (round stars end-to-end) than previously although the figures say the opposite! Here are some recent screenshots from PHD2. Also, I am using shorter exp times (1 sec) vs the 2 secs that I had with the ASIAir Plus. However, I would say that on an average is around 0.7-1 consistently and ham getting round stars to edge even at 600sec exposures.

It was with a metal grinder - it took forever but, job was done at the end.

Redcat61, 2600MM, Antlia Filters on an AM5

With average moon luminosity of 80%-90% and with the south part of the sky almost fully covered, I had to choose a target as opposite as possible and decided to go for M81 & M82 on LRGB + Ha. This was the 1st proper time that I tried to shoot a galaxy via LRGB and I thought why not, let's add Ha as, it is quite trendy nowadays. How difficult would it be? Well, it was pretty challenging and I spend a good half a day just trying to stretch the images - 5 in total! And then it was the addition of the Ha; well that was a challenge on its own. But, on the other hand I was happy to see some IFN and this was a first for me. RGB: 55 x 120 sec each Lum: 105 x 300sec Ha: 79 x 300 sec Processed with PI and Photoshop (!). It feels over-stretched but, happy for now - any feedback will be appreciated 🙂

@Adam J if it was the sensor cover glass, wouldnt there be an issue with all filters - including the SII and OIII?

@Adam J @Stuart1971 I thought so too. We changed the orientation of the filter to eliminate this possibility and the results were more or less the same. Another thought was that Pertzval design OTAs might be more susceptible to such effects - especially on OIII @ 2.8nm. But, since the SII & Ha Antlia filters are excellent, I consider the OIII to be defective and will be returned.

For my first "proper" image since I setup the telescope in Spain, I chose the Jellyfish Nebula using my Redcat61, 2600MM camera, and Antlia 2.8nm LRGBSHO filters mounted on an AM5. Over 24 hours of data were collected, with the focus on revealing the nebula's full colours in SHO. However, a setback occurred as nearly 7 hours of OIII-filtered data proved unusable due to unexpected halos and star bloating. Despite efforts during the image processing phase, the OIII data remained unusable. Undeterred, I decided to salvage the project by combining the excellent Ha and SII data with RGB stars, using Pixinsight and the Foraxx script, resulting in an image that I am pleased with. Although the outcome diverges from a faithful representation, the artistic approach yielded a dramatic and interesting scene, in my opinion. Ha: 68 x 600 sec SII: 38 x 600 sec RGB: 40 x 120 sec each Calibration files: Flats, Darks and Bias (50 each)

Very impressed - thank you. I will most certainly do so.

@ollypenrice this is how it looks after (my personal best) stretching. I tried through the available Pixinsight tools (that I know of) to remove the halos but, since they are integrated in the nebulosity, I am finding it difficult to remove without leaving a residual shadow.

Thanks Olly - Content Aware Fill is a feature of PS if I'm not mistaken and unfortunately I do not use PS. Probably I will have to put some serious thought on start learning how to use PS. I will be sharing though the star aligned & cropped, xisf OIII stacked image, if anyone wants to play around 🙂 OIII.xisf

It is not a highjack - it is a nice warming conversation of two friends sharing the same love for the cosmos as, it would have happen if we were all together at a star party. My best wishes to Dave.

Followed Stuart's suggestion and I might like the new version better as it reveals more detail but, the 1st one is more "dramatic" I would dare to say - thank you for the suggestion @Stuart1971 Thoughts?

Thank you - I will try to push a bit more the stretch to see if I can get a bit more of the dust.

Well I cannot fault the Antlia filters both the Ha and SII are absolutely fantastic as well as the LRGB - it seems that only the OIII had an issue. Compared to my previous 7nm these are really good.. In case it helps - I am attaching 1 from each for your review 🙂 2024-02-01_23-34-42_Ha_-10.10_600.00s_0010.fits 2024-02-05_00-36-10_OIII_-10.00_600.00s_0007.fits 2024-02-03_23-01-58_SII_-10.00_600.00s_0017.fits

Thank you. When I get back home I will have a look. Great feedback

For my first "proper" image since I setup the telescope in Spain @PixelSkiesAstro I chose the Jellyfish Nebula using my Redcat61, 2600MM camera, and Antlia 2.8nm LRGBSHO filters mounted on an AM5. Over 24 hours of data were collected, with the focus on revealing the nebula's full colours in SHO. However, a setback occurred as nearly 7 hours of OIII-filtered data proved unusable due to unexpected halos and star bloating. Despite efforts during the image processing phase, the OIII data remained unusable. FLO and Antlia are investigating the issue for me. Undeterred, I decided to salvage the project by combining the excellent Ha and SII data with RGB stars, using the Foraxx script, resulting in an image that I am pleased with. Although the outcome diverges from a faithful representation, the artistic approach yielded a dramatic and interesting scene, in my opinion. I welcome any feedback or insights and hope you find joy in the unique rendition of this beautiful nebula. When I sort out the OIII filter issue, I will add the OIII and probably more Ha and SII too. Ha: 68 x 600 sec SII: 38 x 600 sec RGB: 40 x 120 sec each Calibration files: Flats, Darks and Bias (50 each)

Thank you @Ouroboros - yes indeed. I used the GHS. I think I did 3 or 4 samples of it before I was almost happy! Although I am into astrophotography for the lat 3-4 years now, I just start to understand the importance of stretching and how to do it. I am sure at the hands of someone that is more experienced than me, can get more detail by performing a better stretch.

I was playing around with the Ha filter, while testing NINA, the focuser and the tracking and managed to acquire approx. 23 frames of 300 sec. Trying to learn how to improve my stretching techniques in PI. in this image, I performed the stretch in small intervals while trying to keep the faint Ha nebulosity visible.

So, one area to improve is the stretch and that way I can control better contrast and the background?