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  @astro-burak11 сағат бұрын

  Awesome 🤩

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  @the_space_koala8 сағат бұрын

  Thank you! Cheers!

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  @Jcorban0814 сағат бұрын

  Excellent processing work! The ion tail is quite wonky - it’s at a different angle than the dust tail. Love the music too!

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  @the_space_koala8 сағат бұрын

  Thank you! The angle between the 2 tails is *almost* aesthetically ideal 😁😁

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  @TheAceTroubleshooter22 сағат бұрын

  Rollback your APKs folks :)

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  @woody5109Күн бұрын

  Breath taking ☺️

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  @FlobwertКүн бұрын

  Amazing

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  @serkanboydagКүн бұрын

  Thank you for this video.

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  @the_space_koala8 сағат бұрын

  Glad it was helpful!

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  @RudraEditHub666Күн бұрын

  Interstellar music😌🎵

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  @the_space_koalaКүн бұрын

  It’s a go-to with Astro content 😁

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  @RudraEditHub666Күн бұрын

  @@the_space_koala yess.. Interstellar is great sci-fi movie

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  @LuisRivas-ir6ul3 күн бұрын

  Respectfully.... Would you marry me? :)

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  @steadifreddy21874 күн бұрын

  this thumbnail :D you could also hotglue it to a board but these insane cable ties will do just fine i guess

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  @the_space_koala2 күн бұрын

  Eheheh you gotta screen shot the best moment! 😁 I guess the hot glue would’ve worked better

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  @running2standstill6854 күн бұрын

  Thanks for clarifying this. I am a visual observer and i like my Newt for DSOs as its brighter but i use my Mak for planetary observation as its more high def. My Newt as it has spherical mirror maybe bright but not as hidef at higher magnification as the Mak for planets.

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  @_stardust625 күн бұрын

  I'm a visual observer now...I use only slow telescopes (f/10-f/15) ...because all my eyepieces work beautifully in the slow system, no flock of seagulls at the edge. Nice video

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  @the_space_koala5 күн бұрын

  All visual astronomers will agree it makes no sense to push the optics to a “fast” focal ratio!

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  @giovannipaglioli23026 күн бұрын

  Hi and thank You for this remarkable effort! A well done video indeed. It is a very long time I'm trying to explain that "fast" in the digital era is a very uncorrect term to use... Whan we talk about a telescope otpic that was defined "fast" in the old emulsion era, we are now talking about a wide field telescope. In the past we need to fight the non linearity of the emulsion and the Swartzchild effect (also known as reciprocity failure) but today with linear acquisition devices such as CCDs and CMOS this is no more true. As to help Your nice explanation of the "f-ratyio myth" I would like to say something more. As You stated we are trying to collect as much photons as possible coming from the object of interest. Despite the system of acquisition I would like to point out exactly that: the energy coming from a subject is very dependant from the considered angle of the sky we are trying to measure. Every object as it's own energy emitted on a given angle and no f-ratio could chenge that! So, even considering a "perfect" system, we are totally dependant form the photometry! The photometry is the exact measurement of the flux of photons per second on a considered angle. This means that there is a maximum number of photons You can collect per second on a sigle pixel that define an angle (also called spatial resolution even if it is also correct to call it spatial sampling or angular sampling). For every object at a given wavelenght is already known how much photons You can collect... Really doesn't matter how "fast" you fill Your pixel since the ratio between the unwanted and desired signal is increasing proportionally. You fill Your well (pixel or angle of the sky) faster with signal (but is still a fixed flux that comes in in a poisson way and nothing can change that), AND unwanted noise (which is mostly sky-noise). the ratio between the two does not change at all. The only way to improve the signal considering a fixed angle of the sky is to collect more photons in the same exposure time and, as You explained, the only way is to increase the collecting area (bigger diameter)! Hope this could help to better underestand why f-ratio on linear acquisition devices doesn't matter much if not at all. there are few exceptions to that but they are related to the digital system, not the physics that always rules. Try not to consider the system but what's the reality outside that is, in fact, what You are trying to measure or capture and You will better underestand what You're doing... Thanks a lot and keep on this way! I appreciate it very much!

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  @the_space_koala6 күн бұрын

  @@giovannipaglioli2302 thank you so much! Indeed this is a very hard point to get across, even if the video is super long with a million examples, based on many comments here and on other sites I have the feeling the message didn’t go through to many people.

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  @giovannipaglioli23022 күн бұрын

  @@the_space_koala keep going! It is something related to traditional photography mabye and, since it is a very diffuse and "known" topic, it is difficult to transfer to people... At the end is only a matter of considering thinks in a different way: we are in the realm of digital and we are no more "taking pictures", we are "making measurements" instead! If You try to look at things in this way mabye it could be easier for anyone to get to the real point. It is sometimes quite counterintuitive but. once acquired, it seems obvious. Thank You!

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  @Kiwi_NZ6106 күн бұрын

  Bro is not gonna catch it too fast for her.

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  @Michael.Chapman9 күн бұрын

  I grew up using film (light sensitive chemical coatings deposited on a thin backing). Focal ratio seems less important to actually capturing an image in 2024, perhaps due to the rise of modern sensors, software and personal computers.

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  @the_space_koala8 күн бұрын

  It’s not that much different on film IMO - you still have “pixels” - the little silver grains - even if nobody thinks about them that way. If you have a higher ISO film your pixel size goes up. In my opinion everything in this video is still valid when you put it into this context.

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  @Michael.Chapman8 күн бұрын

  @@the_space_koala You are a more competent optical scientist than I-which is why I enjoyed viewing your presentation. However, we really did have to off-axis guide, using kludgy cold cameras, attached to precisely collimated scopes, on perfectly balanced and polar-aligned mounts, literally for hours on end, employing dodgy low-res film media of high compromise, pushed to near its limits-and it all could be ruined at any moment by unpredictable weather (no radar or weather satellites for us). Film needed expert chemical pushing during perfect development. Surely for us, if we used a telecompressor to achieve a faster F-ratio we weren’t wrong? I still believe this generation has it easy-which is great! Superb, high-sensitivity electronic digital images produced inexpensively in the backyard by today’s amateur astronomers are just mind-blowing :-)

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  @johnnydanger87019 күн бұрын

  Astro Physics Stafford 150, TECs, any non-Chinese made APO with better glass that actually correct chromatic aberration.

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  @woody51099 күн бұрын

  Not just another pretty face, your very knowledgeable, impressive.

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  @the_space_koala9 күн бұрын

  Thank you for saying that

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  @dmpase10 күн бұрын

  I have another related question for you. I've been trying to use the information in this video to figure out what the maximum field of view of the telescope might be. In other words, what is the maximum sensor size that can be productively used? It would seem to be a function of the focal length and the diameter of the aperture, similar to the pair of triangles you showed for the FoV of the sensor/telescope pair. As I try to work it out, though, it appears you only get full light at the center of the field and as you move off center you get gradually less light until your view is pointing in the direction of the edge of the aperture. (Is this the origin of vignetting?) It seems that somewhere in here is a way to calculate absolute maximum FoV, and how to calculate maximum useful FoV. Any thoughts on this you can add to help me out here?

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  @the_space_koala10 күн бұрын

  This is not so simple as a single formula because you don’t just have to consider the illuminated circle but also the fully corrected field of view. You may have a large circle but if the stars look horrible it’s not very useful. Both of these will depend on the corrector/flattener etc used in addition to the focal ratio. Your best bet is to check for the “fully illuminated circle” and “corrected circle” on the manufacturers website and that would be your sensor diagonal. Also take the corrected circle with a grain of salt as they tend to be a little optimistic 😊

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  @tubedude5411 күн бұрын

  For me the 'advantage' of a large diameter short focal length telescope is not ending up with a scope twice as long and having to have an extremely expensive mount and enclosure to house it in. An 18" scope with a 5 and a half foot tube is way better than it having an 11 foot tube and needing a motorized lift platform to use it!

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  @the_space_koala10 күн бұрын

  You’re right! Though I’m pretty sure it would still have to be an expensive mount if you can put an 18” mirror on it 😁

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  @tubedude5410 күн бұрын

  @@the_space_koala Exactly! The mount would probably cost 10X what the optics would!

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  @bulversteher11 күн бұрын

  Thank you for the explanation! Subscribed and looking forward to the Drizzling video! I seriously wonder though - are you the blonde twin of @AnastasiInTech ?

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  @the_space_koala10 күн бұрын

  Thank you very much! I didn’t know her channel - thank you it’s interesting ☺️

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  @bulversteher10 күн бұрын

  @@the_space_koala if you do a sideye in you next video, we can gain certainty 😉

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  @tostativerdk11 күн бұрын

  I really enjoy the depth you go into in your videos and don’t mind at all that they take 30 min :) Keep ‘em coming!

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  @the_space_koala11 күн бұрын

  Thank you I’m glad you think so

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  @dmpase12 күн бұрын

  OK, a question here. It seems the one detail you didn't go into is the brightness per pixel, but that's probably covered in another video. I'm not sure how to approach this, but I have heard that for bright, planetary objects you want small pixels, but for deep space objects (DSOs) you want large pixels. The reasoning is that larger pixels work as larger buckets to capture the fainter light, while brighter objects can get by adequately with smaller buckets. But if two sensors have the same area, the sensor with the larger pixels will have lower resolution, yes? This also touches on image noise, that I don't fully understand but which appears to be different for CCD and CMOS cameras. So it seems we need a video like your "Are Fast Telescopes Really Better?" presentation, but this time for cameras. Do you already have one of those? Is that something you might want to do? Thanks!

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  @the_space_koala11 күн бұрын

  Everything you wrote is correct. There is two videos in the pipeline that are related to these topics (one on SNR and one on drizzling). In the “fast telescopes” video I suggested 2x2 drizzling to use the same sensor and get higher resolution but you would get exactly the same result if the pixels were 1/4 the size (1/2 the size on each side)

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  @dmpase12 күн бұрын

  Once again you have made simple a topic that others make unnecessarily complicated. Thank you!

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  @the_space_koala11 күн бұрын

  Thanks for saying that I’m happy you think so

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  @astro-burak12 күн бұрын

  Great video 🌸✨

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  @arthurcychan13 күн бұрын

  👍👍👍

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  @pietroa637513 күн бұрын

  Knowing Switzerland, it will be completely covered during the night 😅

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  @the_space_koala11 күн бұрын

  Ehehe if it’s not cloudy the wind will come 😁

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  @pietroa637511 күн бұрын

  @@the_space_koala anyhow, there will be a stargazing party end of August at the gantrisch park (canton bern). For sure no rain, no wind, no clouds, and no moon...

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  @the_space_koala10 күн бұрын

  @@pietroa6375 to be honest that sounds too good to be true 😁

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  @woody510913 күн бұрын

  Brilliant, unscripted, wow.

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  @the_space_koala11 күн бұрын

  Thank you for saying that

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  @dmpase13 күн бұрын

  I would give this presentation *five* stars!

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  @the_space_koala13 күн бұрын

  @@dmpase haha thank you!😊

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  @Mike32179514 күн бұрын

  I did a test with and with out darks and I don't see no difference

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  @the_space_koala14 күн бұрын

  Which sensor?

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  @Mike32179512 күн бұрын

  @@the_space_koala idk it was my nikon dslr

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  @HighDepth3D14 күн бұрын

  That explains a lot. Always wondered. Thank you so much!

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  @the_space_koala14 күн бұрын

  It’s impossible to remember their full names 😬

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  @volvotl2214 күн бұрын

  With my 183mc pro to fully remove the amp glow (that can creep back in stretching), I rotate the camera 180 degrees half way through the session. If I take light flats (I don't), how would this work as I am changing the imaging train mid session?

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  @the_space_koala14 күн бұрын

  If your darks are correct you should be able to calibrate them out perfectly without needing to do this rotation. A reason they may not work is for example if light creeps in while you’re taking darks. I noticed this with my 183MM Pro - light was leaking in somewhere. Now I do darks with the cap on, inside a box, under the bed in a dark room. It sound ridiculous but it works. I don’t see how rotating the camera would be beneficial - it flips by 180° anyway during the meridian flip. If you do decide to rotate the camera you’ll need to take flats in both orientations and calibrate each light with the correct flat.

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  @volvotl2214 күн бұрын

  @@the_space_koala If there is a meridian flip, then yes, rotation is unnecessary (that is how I discovered this trick). The amp glow is so bright on mine there is very little signal under it and artifacts keep creeping back in. I regularly use 300 or 450sec exposures and have at least 35 matching darks. I will follow your advice and increase this to 50+ next session.

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  @AsKyOdA14 күн бұрын

  Thanks for the vid !! Could you one day show your c14 setup, thanks

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  @the_space_koala14 күн бұрын

  Sure thing will do

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  @AsKyOdA14 күн бұрын

  @@the_space_koala thank you, by the way awesome location !!

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  @Charliekils14 күн бұрын

  Why do you sound like you’re about to cry?

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  @the_space_koala14 күн бұрын

  Lmao it’s the excitement I guess

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  @basicalot671214 күн бұрын

  Ya I looked at it with my telescope and saw an asteroid that’s about to hit earth in two days

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  @the_space_koala14 күн бұрын

  lol what

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  @WhooptieDo15 күн бұрын

  wait, you had clear skies in texas? Must have been further north than us!

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  @the_space_koala15 күн бұрын

  this was in Richland Springs. Originally we were about an hour south from there and we took a last minute decision to go up there. The clouds rolled in towards the end though. It was still an unforgettable experience <3

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  @WhooptieDo15 күн бұрын

  @@the_space_koala ah, that would explain it. We had plans for Uvalde, ended up going north to Kerrville but still got clouds.

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  @WhooptieDo15 күн бұрын

  Super dark though with the clouds!

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  @the_space_koala14 күн бұрын

  @WhooptieDo oh no how disappointing

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  @santiagomadruga429815 күн бұрын

  Very clear video. Very well explained with the animations.

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  @the_space_koala15 күн бұрын

  thank you very much, glad you appreciate it

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  @anata512715 күн бұрын

  Don’t cite Celestron. Don’t bring example of RASA. Celestron is mass produced astro-equipment. High quality fast telescopes are always better. If long FL is required, increase size of mirror.

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  @the_space_koala15 күн бұрын

  the RASA is probably the best known and most accessible example of f/2 optics. In any case whether something is mass produced or not has no impact on its theoretical light gathering capability. The video contains reasoning that is generic (the examples mention no specific model of telescope) and can be applied to the cheapest or the highest-end products as well and provides a framework for people to evaluate their options.

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  @thierrymartin837816 күн бұрын

  It seems the lady must have missed optics classes. The only information was that the resoluion power is different between the two types of instrument for the same focal length. However, there is also the fact that the spots do not have the same diameter. the idea of ​​coupling photocytes allows us to take into account the size of the Airy spot. Which would also accelerate the speed. The second point is the tolerance for maintaining focus. We talk about scale factor at this level. But certainly at F2 which spots 4 times larger than the diffraction allows, the resolution has become a detail. What matters is the speed of wide field photography. And yet cameras with small pixels now exist. No one seems to know of correctors that reach the diffraction limit. On the Japanese side, there are still companies thinking about it. The third oversight concerns optical aberrations. These kinds of details make amateurs disappointed with their telescope. Certainly having two distinct instruments allows you to combine the strengths of each for beautiful images. And in fact this seems to be the best advice in this video. With the different brands people get lost and traders are unable to understand and offer their customers products that are not compatible with their instruments because in optics you have to know that it is the piece that decides especially if you want to photograph the deep sky. What criterion imposes the choice of a corrector/reducer. Ss reduction of its focal length, or the characteristics of the baffle in a telescope which is sometimes calculated too accurately for a reducer, see which lets in stray light? The camera has its own characteristics given by the manufacturer, which greatly facilitates its best use. And if we're not mistaken about the camera, it's because we know our instrument. It's exactly like photography: The body and its Cmos become secondary to the lens which is placed in front....Thank you for the video

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  @the_space_koala15 күн бұрын

  Thank you for your exhaustive comment! There’s definitely an infinite number of factors to consider and it’s simply impossible to discuss every subject in one video - this was already way too long as is. Hence the disclaimer (mentioned twice) in the video - that we’re focusing on equivalent light collecting capabilities only for this comparison. Pixel sizes and camera sensors are also a whole other topic but I got around that by saying we’re using the same exact sensor for the comparisons. The take home message of this video is to make people understand that fast optics trade off image scale for a wider field of view. This is true for any system in general and it takes a while for people to wrap their heads around this - astrophotographers, that is. A visual astronomer would find everything I said extremely obvious - only the diameter will matter 😁

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  @montanausa32916 күн бұрын

  So many fast scopes sacrifice resolution. I’ll stick to my toa-130 at 7.7 with only a flattener.

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  @the_space_koala15 күн бұрын

  The best telescope is the one you have and love! ❤️

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  @PopeAstro6 күн бұрын

  I love my 250mm Newt at f/3.5 and 150mm Newt at f/3

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  @The_Tauri16 күн бұрын

  A banger video! Thanks for the explainer, just what I needed.

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  @the_space_koala15 күн бұрын

  Thanks, so glad it’s helpful

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  @CDigata16 күн бұрын

  Did it work well at F2?

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  @the_space_koala16 күн бұрын

  Yes it did. As it’s not narrowband it will work at any f ratio!

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  @ati3x16 күн бұрын

  Good video and explanation. But it is "only" first partof the true. then comes the over and under sampling questions, which is also depending the focal lenght and the pixel size. Then comes the atmospheric/seeing conditions. So the astrophotography is not so simple... Anyway, feliratkoztam a csatornádra! :)

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  @the_space_koala16 күн бұрын

  Yes but it’s a whole different discussion, nothing to do with how “fast” you can take a picture. Köszi 😁

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  @maojiexu743516 күн бұрын

  The key is the image domain. The imaging speed is just a bonus.

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  @komr32317 күн бұрын

  benefit of a fast telescope is the option to complete imaging in short time which is extremely good for: - unstable weather area - limited time for people to have a full time job - easier to process frames taken in the same night.

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  @the_space_koala16 күн бұрын

  I don’t think you watched the video 😁 the point is this benefit holds true only under certain circumstances

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  @komr32316 күн бұрын

  @@the_space_koala watched the whole vid. There are certain benefits as you mentioned for the fast telescope which I totally agree. These benefits can never be replaced by a slow telescope with more zoom power by mosaic or whatsoever, and I just pointed out how important those situations are.

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  @astroindianx17 күн бұрын

  Faster than my Lambo 🔥

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  @the_space_koala16 күн бұрын

  I’m fast AF boi

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  @j.s.340717 күн бұрын

  Really good content here, but I think the binning discussion could be clarified to mention that 2x binning on CCD camera's still incur the Read Noise penalty on the 4 source pixels instead of just the generic term "noise". So in the 2x binning CMOS case the read noise increases by sqrt(4) = 2x for CMOS but stays 1x for CCD. However the absolute noise levels in CCD technology are much higher than CMOS by a factor of 8x and greater.

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  @the_space_koala16 күн бұрын

  You’re right. My thinking was that someone will be using either a CMOS or a CCD and then think of using that camera on different scopes. Also, it would be worth discussing that the absolute noise (the variability of the signal) is still there either way. I think it’s a whole other discussion but I agree

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  @giovannipaglioli2302Күн бұрын

  Hi! Interesting statement but I would like to consider What You correctly said from a different angle. It is true that, in terms of "absolute" readout noise (nothing more 'cos there are many other type of noise or better to say "errors" related to the CMOS and CCDs) the CMOS sensor is a "winner". The fact to consider other than that is: how big is that unavoidable noise in percentage Vs. the signal acquired on a single shot? The most desirable sensor of the moment is probably the 2600 and all it's incarnations. The pixel size of that sensor is 3.7x3.7 microns of silica. Now look at the physics and what is the "real" maximum charge retainable but that area of silica. In the best scenario it could be no more than 12/16Ke, very distant from what vendors state in they'r specs. Mabye it is possible that the electronics make an inbetween reading of the data in a buffer and retain these numbers for a final sum prior to the readout but this is, in reality, not a "real" full well and the readout noise should be doubled in this case 'cos of the double lecture. Anyway a bigger pixel means a bigger full well just becouse there is more area of silica to retain the charge of the photoelectric effect. If You have a true full well of 50Ke and a readout noise of 5e You hav a 0.02% of uncertanty in Your data (this becouse the readout could be -5e to +5e so a total maximum fluctuation of 10e). If You have a sensor with 3e readout but on a true full well of 10Ke You have a 0.06% of total error that is three times more! Don't read just the "absolute" numbers on graphs and specs in the CMOS world, they could be marketing tricks! If You read the gain at will the 3e readout happens You will see that the full well is "reduced" from the maximum becouse You are going to accept less charge to generate an ADU or, if You will, You are sacrificing precision counting photons on larger and larger blocks for apparent increased sensitivity... Counting with increasing approximation is an error in digital world and it is exactly what we call "noise" since You choose to introduce approximation and so "uncertanty" in what You read and this is exactly noise in digital... Hope is not too technical and gives a different perception on the "lower noise" in CMOS...

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  @JonnyBravo031117 күн бұрын

  I just ran into your channel - this video showed up in my recommended feed. I think you did a very nice job explaining the pros/cons of "fast" glass. As someone who owns an 8" EdgeHD, an 80mm triplet refactor and a 150mm newt (the same one you've got sitting on the shelf behind you), I can very easily relate to the challenges posed. Collimating my EdgeHD is extremely simple. The f/2.8 newt takes considerably more effort. I actually bought one of those Ocal devices to help me dial it in because the typical Cheshire tubes / lasers weren't good enough. Spacing and tilt are also far more difficult to manage on the f/2.8 scope than on the EdgeHD because the critical focus zone is so much smaller. One point I'd like to bring up regarding your comparisons of drizzled vs non-drizzled data. Because, like everything else in astrophotography, there are _always_ compromises. In the case of drizzle, you're trading resolution for noise. In the 2x drizzle, you're spreading the noise of 1 pixel over 4 pixels. If we assume the same conditions you did in your examples, the 2x drizzled image will have about 4x noise than the non-drizzled one. To get relative parity in noise profiles between the two data sets, you'd need to take 4x as many subs (noise halves for every doubling of exposures) and ensure that data is well dithered. Anyway, dithering, drizzling, sampling are likely a topic for another video (or 3 😀).

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  @the_space_koala16 күн бұрын

  Hey congrats on the nice scopes 😁 I 100% agree with your calcs and as far as I can tell this is exactly the information I tried to convey. As it’s extremely difficult to show SNF I showed the drizzled images as being “darker” and said you’ll need to expose 4x as long to get the same amount of light (which is the same as the same level of SNR). Which of the cases was this not clear in? Perhaps I should clarify!

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  @alepsycho17 күн бұрын

  Great video, the exemples were clear and easy to understand.

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  @the_space_koala16 күн бұрын

  Thank you I’m glad you found it easy to follow!

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  @CDigata17 күн бұрын

  I like it Fast - save time but can loose quality good to still use other ratio`s.. emm who you waving at? ;)

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  @the_space_koala16 күн бұрын

  Ehehe it’s a habit - can’t talk with a firm hand 😁