Big & Long VS Small & Short - Are big telescopes worth it?

hey there guys how's it going I've often wondered is it actually worth investing into a very large aperture very long focal length telescope like the one that I've just bought the Celestron Edge hd11 when you want to shoot these more traditionally reserved for that type of instrument very small targets such as planetary nebula smaller galaxies or even regions of other larger nebula the kind of thing that really interests me now luckily for me I'm able to make comparisons I've got two peers in my Observatory I'm going to make use of that tonight so let's take a look at what we're actually going to be comparing so as you can see on the screen right here I'm just using a really great website that you should check out yourself astronomy tools and this is their field of view calculator so I've input all the details from the two telescopes that I'm going to be comparing simultaneously tonight uh throughout the course of this one we're shooting M57 in both cases purely in Broadband uh just with the UV IR cut filter so that neither telescope is you know advantaged or disadvantaged do this they're shooting kind of same wavelengths and I'll tell you exactly what we're actually looking at so the blue box the slightly very slightly larger field of view is actually the fullframe camera the player one Zeus IMX 455 paired up with this Celestron EDG HD 11 is native 2800 mm of focal length and F 10 so that's setup number one setup number two the green box is actually a much more moderately sized piece of equipment so it's the ascar 120 Appo paired with the player one Uranus C so that's an IMX 585 based camera and as you can see the field of view that results from both of these two combinations is actually staggeringly similar given the huge differences in focal lengths involved in this and that's you know down to the ties of those two sensors basically um now in terms of actual sampling ratios on these The Edge HD is sampling the sky much more finely I'm shooting in both cases at bin one on these two uh so the blue box The Edge hd11 is sampling at 0.28 AR seconds per pixel whereas much more reasonably the green box is sampling at 0.7 AR seconds per pixel now the common knowledge and approach always used to be and I think it's still Fair ADV now but it probably is due a little bit of revision now I've got access to these AI powered tools used to be one R second per pixel is what you should aim for I really firmly believe you should aim for a little bit below that these days though especially if you are using something like blur exterminator otherwise I'd say it probably still holds completely true now if we just switch over a uh a moment and we take a look at the Imaging plan tonight so uh just as you can see I'm using Nina to minute long exposures I could have gone shorter for this of course this is a very bright Target but nothing if you look at the histogram is being clipped and if we just view the readouts too I think the very brightest regions of this are this uh intersection right here between the hydrogen Alpha and the oxygen in the middle and I'm seeing mean values up to 4700 nearly 4,800 or so at it's absolute brightest so even though it looks bright on the screen that's simply because it's just screen stretched and nothing's actually getting baked on this you know what I mean it's it's all well preserved and it should stack up really well and look nice so we'll see how it goes and uh on to the next bit hey there guys well we're more than a few days on now uh I actually had to ditch that first session and go ahead and try to make another capture on another night and I'd just like to say thank you to everybody who joined me for that live stream you guys made it a whole lot more fun than it otherwise would have been just watching Subs of M57 roll in so now I'm going to talk you through what exactly we've got lined up for you right now and kind of outline everything so the same parameters for the experiment were of course observed all the data was taken on the same night at the same time so same conditions obviously the rigs are exactly as I described earlier in the video and you probably know that there are three little comparisons going on here rather than the expected two and that's because I decided to put all also a drizzled two times version of the ascar 120 data in order to try and lessen the Gap in sampling ratio between the ascar 120 at 0.7 a per pixel and The Edge hd11 at 0.28 so the right hand side drizzled two times should roughly approximate 0.35 RCS per pixel now there are a few things obviously to observe at this point we can't really compare M57 when it's this bright this is just for a reason so we can look at stars we will be taking a look at overall detail a little bit later on as you can see in a further part of the comparison before we do that uh I also do want to just say obviously this is just a for fun comparison it's overall a bit silly you know what I mean we are comparing hugely different telescopes in terms of size and value and overall usability really um but still I thought it might be fun and I have probably really enjoyed seeing this before I got the telescopes to test myself and I hope that you're going to enjoy it too um Sor all that said I've gone on quite long enough let's get on with this so what we're looking at in this case is just data with have flats and bias uh in one hour in each case I took the absolute best frames handpicked uh in all cases for this so I sifted through above 2 hours worth of data got it down to the best single hour and that's what all looking at for all of these comparisons and as you can see star shapes and sizes in the completely unedited images pretty darn good all things considered uh so even though we had a very average night I think we made the absolute most of it with the technique that we applied uh maybe we could have gone a little bit better with lucky Imaging but then would have lost some signal on the fainter stuff swings and roundabouts you know what I mean so at this point without any deconvolution applied whatsoever you can note that we are just about starting to split this into what looks like a pair of course there and then I'm very slightly getting to brightenings of star centroids there beneath and that is what we would expect to see on this thing as that is indeed a group of actually five stars but the the last two are very hard to split and once we apply AI powered deconvolution in the form of blur exterminator sure enough it is cleanly split into a group of four and you'll notice that it hasn't done that on either of the cases on the right not knocking the ascar 120 I think it's a wonderful telescope but as I've said we really are playing The Edge HD at its own game here you know what I mean this is where its strengths really lie going after these tiny tiny little targets um it' kind of really suck if it didn't excel at this kind of thing given the asking price uh an overall size and lack of usability of the thing now um you will know there's a large difference in terms of perceived noise and it really is just due to that image scale uh indeed because we're viewing the M57 nebula at 2 to one on the left hand side for M57 we're Happ to view it at 4 to one on the middle so of course it looks a lot more noisy if we zoomed up this background noise on the edge hd11 up to 4 to one to match the middle all of a sudden that background noise value looks much more similar it is still a little uh cleaner on the left hand shot I would say and uh more on that in a moment but hopefully you can see the difference uh right there now when it comes to uh actual real faint stuff so if I just zoom out this view very slightly sorry for the interruptions as I do this you can see on the edge hd11 I do hope this is coming across for you on YouTube I can trace out easily the first of those faint extensions that I can trace it with my mouse pointer comfortably on the ascar 120 it's a little bit lost in the noise on the uh the middle shot so even though we're looking at F10 versus F7 we actually aren't really seeing the uh the expected difference um on this thing when we not certainly seeing not two times faster photographic speed like you'd expect on a camera lens or something like that uh so there's definitely more at play than just F ratio I think the aperture on the left hand shot has really really helped out um as we get a little bit closer and let's say if we just compare again that group of stars down there at a similar level of Zoom if we possibly can um yeah you see I don't think any amount of drizzling and things like that is ever going to recover that amount of resolution and that's fine um I'm I'm sure we can forgive the the little ascar 120 for that I think it it does absolutely wonderfully for a 5 in Appo it's just a little bit outgunned for this kind of thing uh you will knowe however the drizzling has done a really nice job of keeping those star profiles looking really pretty uh at this point obviously this is super duper pixel P I want to point that out uh is ridiculous levels of zoom we're looking at but at this point stars look a little bit like they made out of Lego on the middle image but on the right they're nicely preserved you know what I mean they the clean little Globs of light and on the left obviously they're still very clean um if we move on one more step now by the way to noise exterminator and I just want to say I'm going to put this uh obviously quick one out there support from you guys has been absolutely incredible with those affiliate links a huge huge thank you to every body who's used those uh you really are helping me out so much every single month so I very genuinely thank you for your support through those and if you are on the fence about you know using these tools uh blur exterminator noise exterminator star exterminate that thing download the trials give them a goal um if you're in the you know if you're in the position and you're looking at purchasing tools like that these are the best uh and that is my very honest recommendation to you I think they are unbeatable uh when it comes to the jobs that they're meant to do um I could go on Extreme length about these but like I say I think a picture says a thousand words look at the difference you know between before and after it's all there try out on your own data see what you think for me there was absolutely no going back but there it is uh huge huge difference I would say now if we just take a quick look at this small background Galaxy over here between all three actually not that much in it I think it's more cleanly separated from the background on the edge HD1 image that said I think there's a little bit more overall background glow around it on the F7 image from the ascar 120 but uh I I do prefer the left hand image but that's because I already own all of these Scopes do you know what I mean so I don't really have a horse in the race it doesn't matter to me so much the outcome now um if we move on really quickly I'll close down this part of the comparison we can take a look actually slightly more processed version of things uh once again everything's in the same order so Ed hd11 on the left Uranus C and ascan 120 in the middle and then the same day it drizzled two times on the right uh we're seeing that same sort of thing so the star profiles vastly improved through drizzling and also I think you'll be able to see this even through YouTube's compression there are large differences in terms of about the amount of available detail I think there is plainly more to see on the the rightand image than the middle image um so drizzling if you're trying to do this kind of task with a shorter focal length instrument like this at like 860 let's say absolutely worth your time do drizzle uh in that case now I think it's also fair to say that the Ed hd11 Knocks On's socks off completely I think there is a couple of times more available detail on the nd1 image you know from where I'm sitting it's not really even close um but that's not to say that the ascar has done bad because it hasn't it's just when viewed in context with this image on the left which is really rather sharp um as I've said before it's it's kind of astounded me as the edge HD 11 already uh with what it's able to show with such short Integrations so I think great things probably coming in the future from this thing as long as I can get enough time to actually use it if the skies ever properly clear up but um fine details reals and valleys and little knots in the nebulosity are popping up all over the place on this thing and this isn't even a properly processed image it's just very basic stuff that I've applied to this um I wouldn't stop at this and just say you know hit save I'd certainly take it on further but I wanted to keep things as equal as I possibly could in all three cases and so that's why I've stopped for the comparison here and I hope you guys can see the difference between these three and if we just take a look at that little background Galaxy once again so you know obviously it's much more faintly shown in this comparison there he is on all three the nearby Stars obviously cleanly split right there on the Ed hd11 image cleanly split as well on the drizzled image but the ascar 120 non-d drizzled image looks a little bit like a snowman so once again I think proved positive the you know the the diering and the drizzling well worth it you should always be dithering anyway but the the drizzling especially when trying to capture the absolute most resolution it's a must when you're anywhere near that sort of sampling ratio so uh I think that's an interesting enough comparison one last little look at M57 just while I uh wrap things up and I'd like to say of course and as I always say a huge thank you guys for the amount of support that you have shown uh you're absolutely fantastic and I couldn't be doing this without your help so very genuinely and I mean this thank you so much for all that you do I realized this has gone on way longer than I actually expected it to but I feel like there been an awful lot to say about this thing I'd love to hear what you guys think about it I'll absolutely read every single comment uh let me know let me know what you think and if you enjoyed this do leave the video a thumbs up is it really helps out too um again affiliate links down below if you want to try out these AI powered tools for yourself I give them 10 out of 10 full recommendation they are really good see what you think uh for yourselves if you don't already have them and a huge thanks to those who do and have used those links I'm going to give up talking now I'll leave you at that thanks so much for watching clear skies

Channel: lukomatico

Views: 11,192

Keywords: astrophotography, astronomy, telescope, deep sky astronomy, planetary, pixinsight, blurxterminator, noisexterminator, long vs short exposures

Id: ZdysSs4v2YU

Length: 16min 13sec (973 seconds)

Published: Fri Jun 07 2024