The Lazy Astronomer

Very nice for such a short integration time. Really like the teal colouring you've got there. The lighter part of the frame is a gradient caused by light pollution and/or moonlight. These gradients generally only become visible upon stretching the image. All the main astro processing softwares have tools to remove gradients, and there are plugins for photoshop as well. Not aware of anything for GIMP though, unfortunately.

Very nice and very ambitious! I particularly like the bubble nebula - amazed it came out that well in just 1 hour.

Dedicated camera all the way! I believe you're correct about the DSLR's video mode, but hey, as you've already got both cameras, why not put the theory to the test, and let the images do the talking?

Flats should remove the dark dust spots from the lights, so either the dust spots are not present on the lights (or the dust has moved slightly between taking the lights and flats), or the calibration process has not worked correctly.

There are no stupid questions! Phd2 sends corrections to improve the mount's tracking.

Excellent first Jupiter! Mine was a horrible, noisy, blurry mess - super impressed with it at the time, but frankly am embarrassed by it looking back now. That wouldn't be the case with yours though! If you've caught the AP bug, kiss goodbye to all of your spare money!!

I also have the 290mm (not mini though), and agree it's a great little camera for lunar and planetary imaging. I would say the most important factors for a planetary cam are high qe, low read noise and high fps. Other factors are of little or no relevance. General advice is to aim for a focal ratio around 5 - 7x the pixel size of the camera, so with the 290mm, you'd be looking for somewhere between f15 and f20 (e.g. 1.5x or 2x barlow on your SCT). To throw an additional option out there, the 462mc is often touted as one of the best planetary cameras available, due to it's very low read noise and high sensitivity in infrared (which is much less affected by poor seeing).

Autodev is probably one of the most difficult things to master in Startools - I struggle endlessly with it trying different roi's and fiddling with the parameters. Sometimes it seems a bit too keen to show the very faintest nebulosity, to the detriment of the overall image, but ultimately it does give a better stretch than film dev. Have you read the unofficial manual? Some useful tips and tricks in there.

I've also seen that precise focus is not required for a guide scope, as such l never bother refocusing my guide scope and pay no particular attention to the fwhm reported by phd2. Typical guiding rms is around 0.6ish" with an eq6r pro, and stars are tight and round on 5min narrowband subs so I'm happy with it.

I have to admit one thing I hadn't factored in on your other thread was the spot diagram of the RASA - that's my mistake, sorry.

Actually, by binning you are potentially losing resolution, depending on the quality of your seeing on the night. The sampling rate of your setup at bin 1 is ~1.9"/px. On nights of average to good seeing, this would be a proper sampling rate. Using bin 2 on those nights will get you a higher SNR for a given integration time, but at the cost of resolution. Another thing to consider is that with a couple of exceptions (e.g. cameras which use the IMX492 sensor), binning in CMOS cameras is done after each pixel has been read out. This means there is practically no difference between binning at capture and binning in post. It would therefore be more advantageous for you to capture at bin 1 and consider binning during processing - you can use the measured FWHM of stars in your stacked image to determine if your conditions on the night mean binning is required. And, while a longer exposure will capture more photons, once you've reached the point where your sky background has swamped the camera read noise, using longer exposures follows a law of diminishing returns. The optimal exposure length for your setup, at bin 1 and gain 100, and assuming a fairly typical bortle 5 sky, is somewhere in the region of a few seconds, not minutes.

Lets start with some questions for you first and this will enable more specific advice. What is your area of interest: Planets? Moon? Deep sky objects? If DSOs, are you more interested in large nebulae or smaller nebulae/galaxies? If the answer is all of the above, be aware no one telescope and camera combination will do all of these things well. Do you have a telescope and mount already, if so, what are they? Do you have any other "normal" cameras (e.g. DSLR)? If you have to (or want to) buy new equipment, do you have an idea of the sort of budget you've got? Whereabouts in the world are you located? (I'm assuming UK for now as this is primarily a UK based forum) and how's your light pollution? And finally, do you have somewhere to image from home (e.g. a garden) and if so, what's the view of your sky like? Can you see polaris from it? If you can't image from home, how far and by what method would you have to travel to a suitable location? P.s. @bottletopburly has just given you probably the best advice you'll ever get on astrophotography 😅

Congratulations to the winners and many thanks to FLO and IKI for giving us all something to do throughout the extremely clouded out summer nights!

Agree completely - I recently replaced my circa 10 year old desktop to beef it up for image processing and was looking to use some of the old components for a dedicated remote scope side PC, but a lack of any usb3 ports meant I'd be sacrificing performance. In the end I discovered the old SSD fit in hard drive slot of the old laptop I had been using (which did have a usb3 port) and jobs a good'un 👍

The only thing I would say, is while you can use a lower spec laptop for capture, it is wise to ensure it uses an SSD if you're interested in planetary and lunar imaging. It made a huge difference to me - the best framerate l could get with my old laptop's HDD was ~25fps, with the SSD I now use, I can easily get 200+fps.

DSS can give you a FWHM figure if you load your stacked image into it and analyse (not necessarily sure l particularly trust it to be accurate though - I've seen reports of it always giving a higher figure than PI). As vlaiv said, good guiding is key to good star shapes. Ideally you'd be looking at wanting to get the RMS as reported by phd2 to be about half (or less!) of your image scale. I think we have the same mount (EQ6-R?); l typically see guiding RMS of 0.6 - 0.8", which works well for my imaging scale of 1.7"/px. I've gone up to 5 minute subs (with narrowband filters) with no issue (theoretically no need for me to expose for any longer than that). Your scope's a bit bigger and beefier than mine, but if you see similar RMS, then binning 2x2 should "fix" any star shape issues you experience on longer exposures.

If you're oversampled (like likely you are), then all you need to do is bin the image - either during capture or post processing.

Yes it would - just tell DSS what your desired reference frame is and stack away! Both stacks will then be aligned to your chosen reference frame. Then the fun of blending narrowband into broadband begins! 😁

DarkFrame Optics is a bit of a contentious subject on this forum - you're likely to receive wildly different opinions on them. What l would ask is do you need improved performance: What's your imaging scale? What issues are you experiencing with your current mount that's making you want to upgrade (and then upgrade your upgrade)?

Star reduction is relatively straightforward to do in post, all of the major astro processing softwares have star reduction routines, and there techniques to do it in Photoshop or GIMP as well. Do a search on YouTube, you'll get loads of videos walking you though it.

There's nothing wrong with a bit of over sampling per se (provided your mount can track accurately enough for a given resolution), it just means you'd need more integration time in your images to achieve the same SNR as someone else who sampled 'correctly' (for lack of a better word). Deconvolution may be able to help to recover some of the detail smeared out by the atmosphere in slightly oversampled images too, but as an example, I image at 1.7"/px and to be honest even that is probably oversampling for my sky conditions most of the time. (☹) Most galaxies are tens to hundreds of millions of light years away, so they are pretty small to us. There's two ways to increase your imaging scale: increase the focal length or decrease the pixel size. Both would involve buying new equipment (which is part of the fun of this hobby isn't it? 😁), but either way, l think you'd be better off focusing initially on a better mount or upgrading/tuning your existing one. You'd want to be tracking with an accuracy of approximately half your image scale to attempt to take advantage of any increased resolution. If we accept 1"/px as the limit, then you know you need your mount to be consistently guiding with an RMS of 0.5". Once you can achieve that, then you can look at options for increasing your imaging scale. And now, to throw a spanner in the works, you may want to consider looking into "lucky" DSO imaging, as recently highlighted by astrobiscuit (aka rorymultistorey). This may allow you to image at higher resolutions than traditionally accepted, but would likely need a dedicated astro cam with a high quantum efficiency to be able to capture enough detail in the short exposures used (~5ish seconds).

Heavily caveated by the fact that I have no first hand experience with either, but here's what should theoretically be true: Assuming you're looking at FLOs StellaLyra brand, the RC weighs only about 1.5kg more than the 130pds, so with cameras and accessories you should be easily within your mounts weight limit for imaging - so, no problem there. I've seen conflicting things about how 'easy' to live with RCs are - some say they're basically hassle free and hold collimation really well, others that they can be a little finicky. People with ownership experience will be better placed to advise on this. The next thing to consider is the sampling rate you will achieve. Your camera has 4.3um pixels; with the 130pds, that gives a sampling rate of ~1.4 arc seconds per pixel ("/px). It's generally accepted that the limit is about 1"/px due to the effects of the atmosphere, so 1.4"/px is actually a pretty good sampling rate. With the RC (again, assuming the StellaLyra RC6), you are more that doubling your focal length, which will get you more "magnification" (cue @vlaiv to explain why using the term magnification is not correct when imaging), but it leads to a sampling rate of ~0.65"/px, which puts you below what that 1"/px that the atmosphere is likely to limit you to. What this means is, although your target would appear larger in the frame, you're not really going to be recording any more detail, just spreading that detail out over more pixels. The next downside is that when you 'over-sample' like this, you negatively impact your signal to noise ratio (SNR), by spreading light out over more pixels than is necessary to record the finest detail your sky conditions allow. You could improve the SNR by binning the image in software during processing, but this has the effect of reducing image resolution (to basically the same as if you imaged with your 130pds), so at this point, you might as well save yourself £500 and use that instead! Next issue (a lot of downsides, aren't there?!) is at longer focal length you will much more sensitive to tracking errors. If you're guiding, you'd want to be achieving an RMS of around 0.3" for an image scale of 0.65"/px. Unfortunately, that is likey not possible, or at least not consistently possible, with your class of mount. In summary, there would be minimal (if any improvement) to your images in theory, and it would add an extra layer of complexity/frustration, so personally, I wouldn't go down this route.

Star count is basically the only criteria I use for sub rejection (or at least further inspection of the sub). Really quick and simple to analyse in DSS and sort by number of stars.

What type of file are they saved as? I think NINA's default is FITS, in which case you'll need to download a FITS viewer - plenty of free ones available on the net. Would be quicker to analyse them with your stacker of choice and delete the bad ones though.

That really is something quite special there. I dare say there won't be many people to have captured so much of that dark dust - definitely my favourite image of the year 👍