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With point spread function extracted from non saturated stars in the central part of the image. I hope this answers your question.

@powerlord, I took the liberty of downloading the fits file you shared and processed two versions in PixInsight. The difference is that in one versioin I used BlurXTerminator, and in the other I used conventional deconvolution. No other sharpening processes were used, only stretching and colour saturation. I also refrained from using any masks in PixInsight to selectively do any processing. So no star reduction beyond what the deconvolution steps did. In conventional deconvolution it's very easy to over do it and introduce artefacts, I tried to avoid that as much as possible, while still having noticable sharpening. It is obvious that BXT allows much stronger deconvolution than PixInsight's deconvolution process. It can sharpen the image much closer to the noise floor, and decreases stars much more. I used BXT with a strength of 0.70, and custom PSF size. This image (saved as jpeg at highest quality) lacks the H-alpha, so not as smoking as your original.

I imaged the galaxy two years ago, but only collected 5 hours of data, and without Ha filter. If only we still had astro darkness up here, I would revisit this target. Maybe next year.

Very nice. That's a bit of a surprise. Your image shows hints of small Ha regions. Adding Ha could really give this image another dimension.

Very nice. If you rotate the image 90 degrees clockwise, you'll see why it's called the monkey head nebula.

When I look at the deconvolved image presented in this thread, and its comparison to Hubble data, I don't see invented detail. The structures in the deconvolved image are similar to those in the Hubble image. But I think that the deconvolutuon has been pushed too far, introducing artefacts that would most likely also have been introduced by classic deconvolution. As Russel Croman states it so well on his web site, any deconvolution involves guessing. When you see piles of sand on a beach, you can only guess what the sand castle that stood there a few hours earlier may have looked like. And with some detective work, one might even attempt a recreation of it. But such a recreation can only work up to a certain point. The equivalent in astro images should never be pushed beyond that point, or artefacts will be introduced. As a matter of fact, in the original PixInsight deconvolution process, much work went into adjusting parameters so that artefacts were not introduced, while at the same time as much detail as possible was restored. What I see in this excellent image of the Cigar galaxy, when enlarged, is just some of the artefacts that can be the result of any deconvolution. Some tutorials describe such artefacts as "wiggly worms", or "connected structures", and they are an indication that the deconvolution strength ought to be dialled back. In my opinion, that is the case here. If I were to process an image like this, I would do several trials with increasing (or decreasing) deconvolution strengths, and opt for the one with visually the best detail, without showing signs of "wiggly worms".

Sorry. Can't resist. Should I grab my coat? https://youtu.be/aJQmVZSAqlc

Same here. But that should not keep us from trying. You have an excellent image here, which only could have come out better if you'd set up your gear on a high mountain top. Best of luck when you enter it in the competition.

Olly, the days of the Spanish Inquisition ended when the CloneStamp tool was implemented in PixInsight. 😉

Excellent image! On my Galaxy Tab, v 1 looks "punchier". So, please don't enter it in the competition section. Btw, R1 = 0.4×R + 0.6×Ha and R2 = 0.4×R1 + 0.6×Ha. Doesn't that just mean that R2 = 0.16×R + 0.84×Ha, so 84% Ha and 16% red? In other words, will you get the same result with just one pixelmath expression?

Yesterday astro darkness officially ended here in the North, and won't return until mid August. So this is my final entry in this competition, M63 in Canes Venatici Imaged with the SkyWatcher 190MN and ZWO ASI294MM Optolong RGB filters and Baader 7nm H-alpha filter Total exposure time 14 hours, imaged over four nights 19 - 22 April Processed in PixInsight

Adam Block has a whole series of videos on WBPP on his YouTube channel, including on how to combine data from multiple sessions.

@CCD-Freak does the sensor have amp glow?

The recommendation originally comes from astrophotographer Tony Hallas. DSLR cameras have, what he calls "color mottle", large scale colour noise. To efficiently get rid of it, you dither with larger steps. This talk may be a bit dated, but it is still one of the best introductions

Yes, because darks don't always work with uncooled dslrs. In an ideal world, darks should exectly match in terms of temperature, iso/gain and exposure time, in order to remove the digital signature of the camera. For CCD cameras it was generally allowed to scale flats, adjusting the exposure time difference. But cmos sensors, including those in dslrs, don't always allow this. That's why it may be better to refrain from using darks if you can't get them to match the exposures they are to correct (flats and lights). The workflow then becomes: Integrate bias frames to create a master bias Calibrate flats with the master bias and integrate to create a master flat. Calibrate lights with master bias and master flat Use cosmetic correction if you see hot or cold pixels DeBayer lights Register lights Integrate lights to create a master light If you use this workflow and dither at least 12-15 pixels between exposures, you will end up with a clean master image.

Very nice result. My first dso astro camera was an ASI174MM with cooling. Sadly, this model is now discontinued by ZWO, and only the non-cooled and mini versions are still available. These models are marketed as solar camera and guide camera. The ASI174 has, just as the camera you are using, for todays standards a small sensor and large pixels (5.86 um). The large pixels gave the camera a large full well depth, but unfortunately also a high read noise, and it had strong amp glow. Nonetheless, it was in my opinion a great dso camera for galaxies, and very much underrated. I believe that @tomato uses the ASI178 camera for dso imaging with his Esprit refractor. This is also one of the older generations of ZWO astro cameras. This camera also has a small sensor and very small pixels. It was also offered in cooled and uncooled versions. Just as the ASI174, the cooled version is no longer available, and the uncooled version is marketed as a planetary camera. Paired with the right optics, these cameras can perform very well as galaxy hunters, providing a suitable crop factor and small files.

No need for a light pollution filter. They will only mess with your colour balance. As @Clarkey wrote, this is a very nice image already. Just add more of the same. Since you are using a dslr camera, you might want to reconsider the use of darks (for lights and flats). Without temperature control, darks sometimes do more harm than good. Pixinsight has a process called cosmetic correction, which helps get rid of hot and cold pixels. You can use it in the wbpp script or "manually".

The hand control of SW mounts has an "all star" polar alignment routine that is better than the polar scope alone (which may not sit straight in its housing). If you use a computer connection (not ST4), you can use PHD for polar alignment. Try to get the misalignment within a few arc minutes. Don't sweat the small stuff. Nebulae seldom have fine detail, so they can look really good at >2 "/p. Galaxies need better sampling, but there's really no point in going finer than 1 "/p or so. As Olly wrote earlier, in practice you won't see much of an improvement in detail if you go beyond the lower limit. But, start by choosing a scope and a camera that you like and will operate with ease. This is more important than fine tuning pixel scale. I have a SkyWatcher Maksutov Newton for all my imaging. It sits permanently on a heavy SkyWatcher mount in an observatory, where it gives great results. A guy I know who lives in northern Sweden, used the same model scope on an EQ6-R in the field (ie he drove to a very dark site and needed to shovel snow before he could set up his gear). He sold the scope after one season, probably because it's too cumbersome to haul around as part of a mobile setup in deep snow. Yes. If you have a reflector, the mirror is probably not fixed in place (it shouldn't be or you will get pinched optics in cold weather). OAG will compensate for mirror movement, a guide scope won't. With an OAG, use a sensitive guide camera (eg the ASI290 mini) or a guide camera with larger sensor (ASI174). But make sure the OAG stalk and prism can cover the sensor of the guide camera. At f/4 you will also need to look into the mechanical quality of the scope, especially the focuser. High grade optics are useless if the focuser can't carry the camera.

That's a very nice start. Your first priority should probably be to make sure that your computer doesn't update when you don't want it to. If you have windows 10 home edition, switch to the pro edition or windows 11. The update allows you to capture more data, which would be your next priority.

The Whale and the Hockey stick, ngc 4631 and ngc 4656. In the background a lot of faint fuzzies Data captured 15th - 18th of april. LHaRGB with a total exposure time of 1026 minutes (17 hours and 6 minutes) Telescope: SW 190MN Camera: ZWO ASI294MM Processed in PixInsight

I started out with the 150 PDS and "upgraded" to a 190MN Maksutov Newton. Focal length wise I went from 750 mm to 1 000 mm, not much of an increase. If you take a look at my Astrobin page, you can see what these scopes achieve in a Northern European climate (link is in my signature). I also went from 1.6 "/pixel with the 150PDS / ASI174 to 0.96 "/pixel with the 190MN / ASI294. Not that I wanted a better pixel scale, it just happened to turn out that way. Any difference in the images is mainly due to me getting better at guiding, focusing, and processing. As Olly said, there's absolutely no point in getting to smaller pixel scales unless you put that scope on a cold mountain top in a desert. The decision between a refractor or a reflector is mainly about three things. 1. Do you mind tinkering with collimation and mirror cleaning now and then? 2. Where do you put the scope? A reflector is always more of a sail in the wind than a refractor, and a smaller mount (heq5) may struggle with that. 3. What is your budget? A newtonian is cheaper than a refractor.

What if you rephrase that question as: what is the best scope for your camera? Scopes come in all shapes and sizes, but pixel size is much more restricted. Most ZWO models seem to have either 3.76 um or 2.4 um pixels. The size is most likely determined by the manufacturing process and the desired sensor characteristics. When I bought my first astrocamera, the ASI174MM-Cool, it was mainly because of its pixel size (5.86 um) and associated large full well depth. When I replaced it for a camera whit a larger sensor, I opted again for a sensor with large pixels (the ASI294MM has 4.63 um pixels). The ASI174MM gave me a pixel scale of 1.2 "/pixel, the ASI294MM gives me 0.96"/pixel. If you want to match a camera to a non-reduced edge 8, you'd need 10 um pixels (or 5 um binned 2×2) to get 1"/pixel. The ASI342MM has 9 um pixels. Close enough. Unfortunately, there doesn't seem to be a cooled version of this camera.

That would be my main concern. The heq5 is supposed to be able to carry 11 kg, but an 8" Newtonian is large, and can act as a sail in the wind. Otoh at f/4 or f/5 you can use much shorter exposures than at f/9. And a long fl telescope, even a lighter one, can be sensitive to wind gusts.

Why an RC, if I may ask? It's a slow scope which will give oversampled images. Oversampling means that light that should fall onto one pixel, is spread over several. Less light per pixel, means longer exposure time to clear the read noise floor. Unless your sky conditions can support the pixel scale, there's not much point in having such a long fl, in my opinion. In comparison, the Stellalyra 8" f/4 newtonian has much more light gathering power, and a more favourable pixel scale, at about the same price.

I have the Epson ET-2850 ink tank, which is up to A4. It generally produces great images, but astro images come out with a colour cast in the background, even if the "colour picker" puts R, G and B at almost the same intensities. It may just be a set up issue.