imakebeer

Thanks Peter - I think when I've searched in the past I saw you've done some imaging with the 130 or 150PDS (or both). This is interesting because I'm certain I'm not getting anywhere near 200px 🤔 I only have Stellarium on my mobile, but its the paid version so I'll check if it does this. OK - in the original setup with the SW Capricorn frac I used an eyepiece + eyepiece projection adapter + DSLR. In the new setup with the 150PDS I'm not (at least I don't think I am, if I've understood the terminology) - the 1.25" adapter goes on the focuser, then the Barlow (5x in last night's case), then the 224C. I think this is prime focus, no? Or have I misunderstood? Should I be doing something different? (I did eyepiece projection with the frac because the image was better. I wonder if this is simply down to the fact that the kit SW 2x Barlow is rubbish? But the magnification with the 25mm eyepiece vs. 2x Barlow seemed about the same to me) Ah, OK, thanks - it makes sense what it's doing now and why it takes longer to process. I'm gonna go back through last night's captures again and double check what image size I got etc, plus have another go with drizzle on vs. off etc etc etc. Also it crossed my mind if there's something I needed to change in Sharpcap as I've only used BYN/BYE up to now, but maybe not. I would add that the 224C kept crashing, but I wonder if it was just protecting itself when I set both the gain and exposure high/long while I was trying to acquire the target and focus etc. I also found all the images from the 224C were very green - not a disaster as I could fix it later in post by tweaking the histogram, but odd that it should happen I thought. I'm interested to also try the ZWO ASI120MCS I have - on paper it should be inferior and better suited to guiding, but in practice who knows!

Interesting - in Sharpcap I had it set to 320 x 240 for Jupiter (and Mars obvs, which is smaller) and it was plenty big enough, even with my 5x Barlow in. I'd say the window (240px high) was about 4-5 Jupiters high if you see what I mean. It was certainly bigger than 2-3 Jupiters high for example. Which puts my Jupiter around maybe 60px across??? Which surprises me a bit. But then I suppose you're using an 8" scope, at f/10 (not sure if you're using a Barlow or not, perhaps not). So should the image from a 6"/150mm f/5 (f/25 with a 5x Barlow, no?) really be that small??? In part it's confusing because, since I'm still new, I suppose I don't really know what to expect. Annoyed I didn't think at the time to go grab the 2x & 3x Barlows from the box (just indoors, no more than 2-3m away!) and see what happened. And of course it's peeing down this evening! 😖

Yeah, the SW150PL (1200mm f/8) was on my original shortlist, and probably much better suited to planetary out of the box. One of the reasons I went for the 150PDS (apart from the dual speed focuser which is awesome BTW!👍👍👍💪💪💪) is I figured I can add a Barlow to increase FL for planets much easier than I can reduce it for deep sky. I know there are more pricey Barlows out there, which one would hope also means proportionately better - the reason I got the Svbony ones is they are affordable and allow me to experiment to get a better idea of what will work. There are a lot of equipment variables to play with too - different combnations of cameras (including an ASI120 I didn't mention!), Barlows and potentially two OTAs. There's a check box in Registax, something like show original image size - when I do that it get's bigger but very blurry and pixellated so difficult to see if wavelet settings are better or worse. There's also a setting in AS3!, near the stacking button,I think it's called drizzle (1.5, 2 and 3x I think). That seems to also output a bigger image but I've yet to make it output something better (not helped by the fact I haven't figured out yet what it actually means!) On the number of frames question, @Cosmic Geoff says no benefit beyond 5000 frames (though I'm not sure how that can be only 20s worth - maybe 20s playback, not 20s to capture???). But @Elp you say take more frames - so more than 10-20k frames then? For Jupiter though I thought you run into problems over 3 mins capturing time due to the speed at which it rotates???

About that - a bit less, but thereabouts. I crop the video in AS3! to 150 x 150, the disc of Jupiter is a bit smaller, probably about 125 I'd say (can check again though to be more precise). Out of interest, how do you find up with those figures? I take it there's a way to calculate these things??? I get that bigger images need a bigger scope. What I can't fathom is why they're barely any different in size of the planet's disc between a 70mm frac and the 150PDS??? Am I incorrect to imagine that different strength Barlows will result in different image sizes, i.e. the physical diameter of the blob of light that hits the sensor in the camera?

Thanks for the input @Cosmic Geoff 👍 Forgetting about image quality for a moment (seeing, CA, focus etc), do you have any thoughts about image size? With your setup for example, do you get the same in Autostakkert where the actual disc of Jupiter is only 150 pixels across or so? I'd have thought magnifying the image would spread it out over many more pixels on the sensor (at the cost of brightness), but maybe I've misunderstood. Otherwise what are the tricks other folks use to get larger images? (Or am I imagining it and they don't???)

Plenty there to get me started and keep me out of mischief for a little while - thanks 👍 Thanks, and also thanks for the tip about the lens cap 👍 I've photographed M31, 42 and 45 a bit (and 33) but will return for some visual only. M45 was one of the first things we looked at when we got the frac - I still remember being amazed how the fuzzy patch you can only just see unaided resolved into this dense cluster of stars! 😁

Sorry, this is a long one, but please bear with me, i'd really appreciate some guidance. There are two questions here: First, please help me up my planetary imaging game. What is it you guys are doing that I'm not to get (what appear to me to be) large hi-res images of Jupiter & Mars? Second, am I expecting too much from a 5x Barlow? I did my first serious planetary images in October 2022, starting with a SW Capricorn 900mm/70mm frac on a wobbly EQ1 mount. I used a Nikon D5500 or Canon 450D with an Svbony eyepiece protection adapter and 25mm eyepiece. I used BYN/BYE plus PIPP, AS3! and Registax. Considering the basic equipment I was pleased with the images I achieved, e.g. Now I've upgraded though I'm struggling to make any further improvement: SW 150PDS - not the weapon of choice for planetary maybe, but should still be an improvement I think. HEQ5 - tracking at last, and not wobbly like the EQ1! But I found I couldn't obtain focus on the PDS with the previous camera setup, i.e. Canon 450D, eyepiece projection adapter and 25mm eyepiece (not enough inward focus travel), but I could with a 2x Barlow. Instead I tried with the kit SW 1.25" 2x Barlow - I could focus but i think maybe this Barlow isn't great optically, it seems to have lots of CA. I noted that the images were pretty much the same size in terms of pixels across the diameter of the planet as previously with the 25mm eyepiece. I tried again with a different camera - this time an Altair GPCAM3 224C USB3, combined with the same 2x Barlow, but didn't notice any great leap forward in images quality. I wondered if the trick is to magnify the image more, i.e. spread the image out over more pixels on the sensor to resove more detail? Looking at the "Which Barlow?" section of "Planetary Imaging Tutorials" he recommends (I think based on longer discussions on Cloudy Nights) you want a focal ratio about 5 (or 6 or 7) x pixel size in microns, therefore..... So with the GPCAM3 (3.75um) I want a FR around 18.75-26.25. The 150PDS is f/5 so a 4x or 5x Barlow seems about right - I went ahead and got an Svbony 5x Barlow (along with a 2x and 3x). I tried again last night with the 150PDS, Svbony 5x Barlow, GPCAM3 and Sharpcap. I did 3 x 3mins on Jupiter between about 30-70% histogram, and similar again on Mars (about 10-20k frames). When I processes the resulting AVIs in AS3! I was surprised to find the images weren't much bigger than I'd done previously, and the quality was no better than I've achieved before with much more modest equipment. Cropping out the black space of the imported AVI in AS3! both Jupiter and Mars are still well under 150 x 150 pixels. So am I expecting too much from a 5x Barlow? Should I not expect it to give me an image roughly twice the size of a 2x Barlow (albeit dimmer perhaps)? (Test vids on some trees a few hundred metres away at least confirmed it gives this kind of gain at short range at least!) Am I missing something about the image capturing/post-processing? I'd swear others are posting bigger / hi-res / more pixel images. How do you get this extra level of detail? Surely not everyone is using a 500mm+ light bucket to image planets? Is it the equipment, be it the scope, mount, camera, Barlows etc? Is it capture, i.e. do I need many more frames? Am I driving the software wrongly, Sharpcap, AS3!, Registax? Is there something more I need to do in GIMP for example? Thanks if you've read this far - I'd really appreciate some guidance. Cheers! 👍🔭🙏

Nice tip, thanks, I'll try it 👍 The PDS only comes with the 28mm 2", but there's also a 1.25" adapter... And I have the 25 & 10mm eyepieces that came with the frac, plus 2x, 3x & 5x Barlows... So the 10mm + 2x Barlow will get me to 150x which ought to do it as long as the optics are sharp enough - and at least the HEQ5 should be rather more steady than the wobbly EQ1 to do that magnification justice!

A little update... I managed to get out for a couple of hours last night. My primary goal was actually to try some new stuff for imaging Jupiter and Mars, but while I was out I made a point of putting away the laptop and cameras and doing a bit of visual... I started on the moon - not the wisest idea in hindsight but it's a lot sharper through the 150PDS then the frac... Then I moved on to M31 - not helping myself having just looked at the moon, but it was right there. Still a faint smudge but clear enough along with 32 & Nu Andromeda. Possibly not ideal conditions with the moon and Jupiter going down in the west, but... My eyes were just starting to adjust again when my neighbour turned on his landing light which shines down into my garden like a flipping searchlight! 😖😂 I decided to call it a night at that point but it's a start 👍🔭😊

Just in the subject of filters, are these very much a must have? Are they really gonna take things to the next level? At the moment I just have eyepieces: The 28mm 2" that came with the 150PDS Plus the 1.25" SW ones that came with the 'frac - 25mm & 10mm, plus 2x Barlow Having tried imaging it (with limited success so far), frankly I'm amazed you could even remotely see this visually at all! That said, as I mentioned before I've only done precursory visual with the 150PDS so far so really must try - M31 was just a faint easily missed smudge from my B5 location through the 900mm/70mm frac so will be interesting to compare with the 150PDS.

Thanks all for your replies so far, this is all helpful stuff 👍 Regarding variable and double stars: what kind of timescale are we talking to see some variation? (I realise it will vary a lot from star to star, precise type etc but give me an idea) Jupiter for example, you can see the rotation in hours or even minutes. For stars are we talking hours, days, weeks, months or what? I'm aware these objects existed but never knowingly looked at them. Seems as good a starting point as any in terms of seeing something I've not seen before.

I think you've encapsulated it right there. I like imaging - it appeals to my analytical nature, understanding what I did right, what I need to improve next time etc, gradually honing technique... But then to come indoors and just leave the gear to do its thing? Spending time indoors with the family is important - but it still niggles that you're inside watching some garbage on TV when you could be enjoying something much more spectacular outside. FWIW I do encourage them to come out and see if it's not too late, with a little success here and there 👍 It's almost like I need a second purely visual scope while the imaging one is doing its thing... Oh dear, this is how it starts isn't! 😂

Yeah that fact hadn't escaped me when I started imaging M31 recently - the way I think of it is slightly different though... Those photons that we're seeing now - well they left M31 roughly about the time the first humans appeared on earth... Something to pause and think about... Yep, this is important. I've certainly found I enjoy the peace and quiet being in the cool evening air. Not so much the streetlights though! I agree - I knew Jupiter had moons for example, but so what. But then it's a different thing altogether to actually see them for yourself, right there in your eyepiece. Or to realise there's a whole other galaxy, right there, floating just above my garden a mere 2 million light years away!

Ditto @mikeDnight, those sketches are magnificent in their own right. I have an engineer's eye for detail and can work in a methodical and analytical way to learn how to take and process photographs... But sadly I've never had the artistic flair to be able to create artwork like that 👍👍👍

Question for all you visual-only astronomers: What are y'all looking at through the eyepiece? Please inspire me! In my short newbie astronomy journey I've headed off down the AP route and I feel like I'm missing out sometimes, starting down at a laptop instead of up at the stars. Once the gear (SW150PDS + HEQ5 GoTo, by the way) is set up and taking umpteen photos I sometimes sure back, let my eyes adjust and take it in, maybe with a pair of binos. Pleiades, Orion nebula, Jupiter and its moons, Saturn and its rings... All genuinely impressive through the eyepiece... But then what? In a photo of say M31 you can make out the galaxy(s) of course which are hard/impossible to see visually (and M31 is it of the brighter ones!), and then bajillions of more distant stars all around - and surely you can't possibly see these visually, even with a really big scope? But it seems like what you can see visually, even with a half decent scope, is so much more finite - right? (or wrong?) In my previous 70mm/900mm frac, M31 was just a faint smudge and really missed. So please inspire me! I haven't done much visual with the 150PDS but I'd like to. So how do you keep motivated and fund enough stuff to look at year after year? What do you go looking for? (I'm guessing a GoTo kinda spoils the fun and art of star hopping to actually get your scope pointed in the right place!) Cheers & thanks in advance 👍😁🔭

I only started AP a few months ago (Oct '22). Although I've now got a bigger scope + tracking mount, I'd say you can absolutely achieve quite a lot with your gear, as long as you have a tripod too (even a simple fixed one). As a jumping off point startrails are fun and easy 👍 I have a Nikon D5500 + 18-300mm lens and I started off with this on a fixed tripod and was able to image M31 (Andromeda galaxy - skip to first & penultimate posts) and M45 (Pleiades) - I daresay M42 (Orion nebula) would work too (i.e. brighter objects). I don't think your DSLR or 200mm lens would be radically different. I found I was limited to about 5s exposures before the star trailing became unacceptable. The trick will be to take many light frames (50+, 100+, maybe more, plus darks, flats & bias) and then use software to stack them and post process. Your Nikon might have a built in program to take many exposures (mine does), otherwise you'll need some sort of remote shutter release or computer to control it (e.g. laptop + BackyardNikon). At the moment I've gotten carried away with my new scope & mount (still using the DSLR with it though!), but I think there's a lot to be said for such a light, simple and portable setup as a DSLR + lens + fixed tripod. I haven't tried any Milky Way stuff yet, in any form so can't comment. But my initial astrophotography attempts were actually planets - I used the D5500 again, with my daughter's telescope (SW Capricorn 900mm/70mm refractor) on a manual EQ1 mount, an eyepiece protection adapter and BackyardNikon again. Sounds a lot of stuff maybe but it's really not an extravagant setup! So yeah, I think you can do a lot with what you have, and maybe not too much more. Just be aware as others have said it gets addictive, it's as much about the post processing software afterwards as it the actual picture taking, and be mindful that while one can do a lot we're all still limited by the equipment we have.

Out of interest, where does M33 fit on that scale? Is it much more challenging would you say? M42 was one of my first targets with the 150PDS + HEQ5, I should revisit it, along with M45 too. Funnily enough that's exactly what I had the other night in just 1 image in 90! Dumb question maybe, but by integration time you mean the total time the shutter is open, right? Regardless of whether you do 1 x 3600s exposure or 60 x 60s exposures?

Ooh, clever! I hadn't heard of that. HEQ5 👍

For my Nikkor 18-300mm I don't have any trouble focusing (except when I'm a bonehead and don't double check it is still actually in focus 😖). that said, someone did suggest maybe backing off to 200mm which would allow me to open up the aperture one more stop and so let in more light. So in your case it's possible that by backing off to 160mm you could achieve the same thing, as well as helping with focus and CA.

I'm new to AP so treat my words with caution, but my guess is it's to do with ISO invariance - according to this article (simply the first one that came up in a quick search) some Nikon's are ISO invariant whereas Canon's are not. If nothing else I'm tempted to experiment and see what shooting with my D5500 at ISO 100 or 200 does for me 😁

Thanks @MartinB , it's reassuring to know I'm more or less on the right path with what I'm doing at the moment. I took a few test pics on M33 the other night, 60s at both ISO 400 & 800 but went with 800 in the end. That said I think there's enough "stretch" in the histograms (if that's a phrase?) that ISO 400 wouldn't be too dark so I can give that a whirl next time. I can also compare my D5500 vs. 450D and see if either is particularly better - on paper I suppose it should be the Nikon as it's newer less old and it seems much quicker to send images & video from the camera to the laptop, but who knows. I've been processing the images of M33 from the other night and comparing with my previous efforts - it's certainly heading in the right direction so I'm pleased, but then I see other folks' efforts and I'm just blown away, they're in a totally different league! 😱😬😂 I'm starting to be able to tease out some of the the cloudy wisps of nebulosity on M31, but for M33 I'm still miles off (fainter target I suppose???).

How very dare you, I've never been so insulted, I've been imaging DSOs 20+ years and consider myself an authority on the subject... Nah, just kidding 🤣 Yeah I'm a newbie, only really been doing it since October, which if you factor in Cloudvember means only a few days of actual practice. So all advice is welcome and very much appreciated 👍 Yep, all the stuff about improving S/N ratio is clear. But it goes as the square root or something doesn't it? That's what @ollypenrice was saying above? So 1000 frames isn't 10 times better than 100, but only 3.16x better noise reduction? The other night 120s wasn't too bad actually, I think polar alignment and backlash might be playing into it. I do actually have a guide scope and camera but haven't fitted them yet, it's on the to-do list. But I think these should help too (as well figuring out how to stop the scope clattering into the tripod on longer runs 😖🤣)

From my newbie perspective, Siril isn't too bad - the tutorials are good and take you click by click through the steps, and stacking with a script is really easy. For me the issues are (1) it's not always obvious what you're doing and more importantly why, and (2) I'm still not clear when to stop in Siril and switch to GIMP 🤔 @wesdon1 (BTW, type an @ symbol followed by the user's name and you can tag them so they get a notification 👍)... Anyway... I posted some of my initial attempts here - you can skip to just the first and penultimate posts... But that gives you some idea of what you can do with Andromeda M31 with just a DSLR and fixed tripod (I also did the Pleiades M45 here). Now I've had more practice with the post processing software I wonder if I could improve them even further now... (I did actually try again the other night but messed focusing 😖) I've difference here is I'm using an 18-300mm lens (maxxed out at 300mm). Not sure if you have this option? Even if not I think there's still a lot to be said for wider field stuff. Keep it up 👍

Thanks @rickwayne , that's helpful I think, as long as I've understood correctly... I was having another crack last night at M33 - now as far as I'm aware my D5500 is ISO invariant... Initially I did 90 x 60s at ISO 800, plus 10 each darks, bias and (this morning) flats. Since it wasn't that late I figured have another go so I tried 45 x 120s at ISO 400 (+ 10 darks, bias & flats again) - this was cut short to about 35 lights as the scope hit one of the tripod legs! 😖 But what you're saying is it kinda doesn't matter which approach I use, and is anything more shorter subs is better, right? (which would suit me because star trailing at present is negligible at 60s but getting noticeable at 120s). So I'm better off just doing lots of 60s lights, right? And just tweak the ISO (with reason at least) to get the histogram in the sweet spot? Is that about right? Cheers 👍

@wesdon1 I can't see your image - my phone doesn't seem to like tifs ☹️ If you save it off as a jpeg and attach it here then it should be viewable in the browser, I think that's what most folks do. Nevertheless, well done for persevering - I'm really new to this, like only a few weeks new (which if you factor in cloudy weather means only a few days off actual experience). Although I've now managed to get a tracking mount and scope, just a few weeks ago I was doing similar to you with a DSLR on a fixed tripod - I agree, you can achieve a lot just with this kit and I looked seriously at just a simple small tracking mount for my DSLR. Two tips I can share from newbie to another: 1. Ok, you seem to have cracked DSS now. But as a beginner I've found Sequator way more accessible. I don't doubt that other tools like DSS and Siril are ultimately better, but as a beginner sometimes you just want to make a bit of progress quickly to make your efforts feel worthwhile as you learn the harder tools. 2. For GIMP processing I can recommend this tutorial on YouTube. I'm sure there's a lot more you can do, bit at the moment these basic steps are serving me well 👍 https://youtu.be/Tl4Ie92MuTs