The Lazy Astronomer

I absolutely love it! My favourite image of the year (until your next post 😆)

Bear in mind that AI star removal will very likely create artifacts. These should be largely (or completely) obscured once the stars are put back in - I often quickly add my stars back in (and undo to remove again before doing next thing) at various points throughout the process so I can see how the final, starry, image will look.

The 294MM is a great camera, but fair warning: it can be quite finicky to calibrate properly. Sometimes it's a case of throwing salt over your shoulder before embarking on a flats sequence. 🤣 You seem to have been able to make things work with your existing gear (which is great, and obviously the preferable option for anyone), but if you still fancy yourself a 294MM, I'm considering selling mine within the next few months to fund an upgrade to an IMX571 based model. Drop me a message whenever if you can feel holes burning in your pockets! 😁

I think there's probably a lot of people who have shared the same comet experience, they ain't easy things to deal with, that's for sure! Thanks for your comments, really appreciated - that ion tail still had something to give I feel, but my exposure just wasn't deep enough to really do it justice. Never fully happy 😆

Thanks very much everyone! I really didn't think this was all that good, mainly because I was slightly disappointed with the ion tail based on other excellent images I've seen, but maybe I'm being too harsh on myself! Glad you like it!

Never again!!! (until the next one 😀 - not ashamed to admit that I was as giddy as a child at Christmas when the first sub came though!) I did a bit of read up beforehand, which made capture surprisingly straightforward, but it was sooo difficult to process - this sums up my experience quite well: I still have some artifacts from the star clean up process of the comet aligned image, but this is about as good as I can do right now. Captured on 31/01/2023, 19:53 - 22:33, under an 80% moon. 70 x 30s subs (each) in LRGB. This is an LRGB comet, with RGB stars. Processed in PI. C&C welcome!

Very nice, especially considering it's broadband only - I tried this in RGB only once and it looked rubbish, but you've captured so much of the fainter Ha regions there.

Thanks both. I did use longer exposures, but nowhere near 16x longer, so think I was expecting a bit more noise, but the non-random pattern of the noise confused me. If I'm understanding you correctly vlaiv, then what you've said explains it.

Might be easier to see with boosted STF

Hi all, I was doing a test the other night using gain 0 with the ZWO 294MM. I shot 30 mins each using gain 120 (unity) and gain 0 and quickly stacked today and noticed the noise in the gain 0 stack has a 'blotchiness' to it. I've attached a side-by-side of both stacks below at 100% zoom - any suggestions as to why this may be? Edit: gain 120 is on the left, gain 0 on the right Edit 2: I should also mention both are light frame stacks only, no calibration, and both are displayed with a standard STF

A few questions to clarify your request to hopefully get you the right recommendations: 1. Did you mean processing or capture? 2. If you meant processing, how would you rate your general degree of computer literacy? (Or have you used any sort of image processing tools before?) 3. If you meant capture, what sort of equipment are you working with?

Welcome to the forum. 👋 This is a very common question from beginners, and unfortunately, the best answer is "it depends". The advice you've received above is excellent - you really need to get up close and personal with some different options to figure out what's going to work for you. You also need to think about what you want to use it for, both in terms of what you want to see (e.g. moon, planets, DSOs), and how you want to see it (e.g. visual or photography - if photography, be warned that it is a bottomless money pit 😂). Another very important consideration is where it will be stored vs where it will be used - no point in getting a massive heavy scope if you'll have to carry it down 4 narrow flights of stairs every time you want to take it out, for example.

Oooh what's this I hear about new products? 😁

The FOV would be sufficient to catch it, you won't get the full extent of the tail though as it's quite long - I attempted an image of it the other night with a FOV maybe 1.5x the above and still the tail seemed to go off the edge of the frame.

Very nice - one I'd like to try one day. Question though: what's the cause of the 2 diffraction spikes on some of the brighter stars?

Fancy hinting at the aperture?😁 edit: never mind, just seen WO site: 81mm. Do you know if they have any plans for other sizes?

Cool. So... where are the details then, WO? It really annoys me when companies do this... There was some sort of teaser on the ZWO Facebook page the other day which seems to have amounted to nothing...

P.s. I'm not sure if I've just because I've been looking at it in the orientation above for so long, that it just looks 'different' but can someone please tell me if it looks much better to their eyes when flipped 180?

I am officially sick of looking at this region now, having spent the past 3 months (on and off) processing and reprocessing various different crops of aspects of this image (side note: looking back at the previous cropped sections, I now think they look terrible, but just cannot bring myself to go back and reprocess them again!) I originally framed this to get M52, the bubble, and NGC7538 nicely positioned, but hadn't really appreciated how much other nebulosity was knocking around in the area, had I done a bit more research I think would have tried to find a better composition - a learning for another time. This is about 12hrs in SHO, split equally between the three and processed in PI. I'm looking for tips on how to improve, so please critique! If I was to be critical of myself, I'd say I've probably done my usual of going a bit too far with noise reduction, and I feel like I'm lacking some detail/depth in the nebulosity around the bubble, possibly as a result of the noise reduction and/or something I've done when trying to shift the hue of the Ha from green to yellowy-orange.

Second the above: planetary nebula or galaxies that are normally out of reach for most amateurs to image with a good level of detail.

To add vlaiv's post (with a real world example), I shoot with a 100mm refractor at ~1.7"/px, and based on my recorded fwhm in a stacked image, I achieve, on average, a resolution of 3 - 4" (this is with what I consider to be a typical suburban sky, and typical guiding of around 0.6 - 0.7' rms). This means, generally, I'm oversampling by around a factor of 1.5(ish), which reduces my SNR. But never fear! With CMOS sensors, this cab be recovered by binning in poat processing.

I was recently looking at the Sharpstar 61 too, for wider field imaging, but l have some reservations about its ability to control chromatic aberration. At the minute I'm leaning more towards the WO71GT, but still very undecided...

Phenomenal! Don't normally see this one take centre stage. P.s. never would have noticed the artifact had you not pointed it out

Soooo dusty! Is this straight RGB, or is there some Ha in the California neb? Edit: this image felt strangely familiar - I just realised why:

Well, I was going to post the pixelmath, but I am not allowed without the express written permission of the author of the book.