Is Active Optics worth it in 2024? 

I investigated this a few years ago and decided adaptive/active optics are not worth it for us amateurs. The active optic systems available could only adjust for first order tilt. The pro grade adaptive optics systems can compensate for higher order distortions (think Fourier transforms being used to analyse the signal and bend the mirror.) Even the best adaptive optic systems can only clean up a relatively small area of the sky (arc seconds ), great for looking at very small very far away things The rest of the image gets more blurry because the telescope as a whole is chasing the seeing at the point of interest.

I was what the guy running my remote observatory called, “the bleeding edge” when I added an SBIG AO to my Planewave CDK17 and 6303 CCD. He and his team spent weeks in near daily contact with SBIG just to get the damned thing to work. Once it did I was able to produce some great images but I’m not sure the AO really added much at the end of the day. Since then (2014 ish ) I have gone back to backyard imaging and would never consider adding an AO system to my current rig. Way way too fussy for very little gain.

When you said "my question for active optics users is", my audio cut out, which I assumed was trolling for about 10 seconds, then the joke went on too long and I realized my earbud batteries died.

I’ve used the Starlight Xpress AO for a couple of years, and it does work. It’s not, as you say Adaptive Optics, it’s just a tip-tilt corrector using a transmission glass plate driven by a servo. At the time, I was using an AVX mount, which is a bit dodgy, so the improvement was dramatic. Now with the CGX-L, it still helps. And it’s not just mount accuracy we are talking about, it helps rain in movement caused by wind catching the dew shield (using an EdgeHD8). I agree that it can’t correct the complex pattern of distortion across the whole field of view; only the true AO can tackle that. But just the two use cases of fine-tuning mount tracking (I find 0.5s works well via PHD2) and wrestling wind disturbance are well worth it.

My 2 cents. There are three aspects of the problem. One is to correct for the optical defects of the telescope. But this is mostly useful for very large, thin optics. When the telescope points low, or to the zenith, the mirror flexes differently and therefore the active pistons behind the primary mirror are activated so that the mirror shape stays correct. This is active optics. It can also correct for example for the layer of eventually hotter air just above the mirror. Flexure of a slab of glass is proportional to the radius of the mirror to the 4th power, divided by the square of the thickness (in cm). So usually amateur mirrors are very stable, do not flex enough to warrant an active optics system. The VLT UT mirror has 410cm radius and 17cm thickness. This gives a R4/e2 of 97777197, and a 20cm mirror (10cm radius) would have to be 0.3mm thin to be as "flexible" as the VLT mirror. 20cm mirrors are typically at least one inch thick, so they don't flex. Big large mirrors need active optics. The Palomar telescope (i.e. 1930 technology) is 254cm radius, but 80cm thick, so its R4/e2 is 650361, so much more rigid than the VLT mirrors. And you can get a good surface provided a mirror cell with many support points. Then there is adaptive optics. And indeed, one can compensate for the real time atmospheric turbulence and recover the theoritical resolution of the mirror (as if it were in space). So there is a wavefront analyzer, and a flexible mirror (and a powerful computer in between) and in real time, the mirror is deformed in order to "counter act" the atmospheric turbulence. This turbulence has a "typical size" which is called the Fried parameter. And it's related to the "seeing", i.e. the Fried parameter is (grossly speaking) the diameter of the optics which would allow you to see the Airy disk of a star. If the "seeing" is 2 arc seconds this correspond to a Fried parameter of 6cm (i.e. the resolution of a 6cm telescope is 2 arc seconds, since the resolution of a telescope is 12/D in cm). What is done is that the wavefront is analyzed in term of the Zernike polynomials (please look on wikipedia for the definition), and it's kind of (really kind of) like a Fourier transform of the wavefront, meaning that you "decompose" the wavefront in a series of polynomials, the first of which is piston, then tilt in X and in Y, then defocus, then astigmatism etc.. See wikipedia, middle of the page). Again for a small telescope, if you correct for tilt in X and Y, you are doing most of the job, since the Fried parameter is about the size of the mirror. If the seeing is 1 arc second, the typical cells are 12cm wide, and if you observe a very out of focus image you will see flying shadows above the mirror. On a large telescope, an out of focus image is covered by a leopard type image (black and white spots) moving very fast, and therefore on a large mirror you need to correct in real time for as many Zernike parameters as you can. And the correction is only valid for a very small angle in the sky (which depends among other of the wavelength, large in the infrared, smaller in blue light) but typically a few arc seconds. Said otherwise if you look at a widely separated double star, say 10 arc seconds apart, you will see that they are not affected by the turbulence in the same way, so with adaptative optics, you can only correct a very small field. And since there is rarely a useable/bright enough guide star in the field, this is why they use powerful sodium lasers (about 70 watts) in order to created an artificial guide star in the field. One can increase the useable field of view using several lasers, again, look for multiconjugate adaptative optics on google. The noirlab page is very good. There are several videos on youtube showing the result of adaptive optics, where you see a dancing blob because of the turbulence, and when they switch the system on, the star becomes stable, and very sharp, and you see the airy ring around the star. The amateur so called "active optics" are just fast guiding systems, clearly not active optics, but I guess it sells better saying "active optics" (makes like a pro system). The original SBIG AO system was designed by Benoit Schillings in California (he is belgian) and it contained a flat mirror, mounted on a yoke system allowing to move in RA and Dec. Useful only if it's very fast, and therefore if there is a lot of light and therefore only useable if there was a magnitude 5 star or so in your field. It didn't allow you to recover the theoritical image of the telescope, it just improved guiding. Large telescope also use fast guiding. The secondary mirror of the VLT telescopes are very light weight (made of berylium, in fact the secondary mirror is almost as expensive as the main mirror) but on the VLT, you can fast guide on a magnitude 16 star, and there are always magnitude 16 or brighter star in the field. It also compensate for the eventual vibrations of the telescope structure because of the wind. One experiment which is easy to do is to photograph a bright star, first with ten seconds exposure, measure the position and fwhm of the star (its size in arc seconds), then expose 2 seconds, then one, then 0.1, then 0.01. With long exposure times, the star diameter is quite large, but stable. As the exposure time is decreased you see the star size become very small but with an erratic motion. Adaptive optics are indeed something which is done at a very high frequency, I have already been very long here, look for "lucky imaging" which is yet another technique in order to improve the resolution of images. It's in fact exactly what amateurs do when the do planetary images. First a video, then a selection of the best images, then the magic of Autostakkert. It can also be done in deep sky object imaging, except you have to process tons of Gb of images. Get well, it's indeed winter coming in the southern hemisphere (first night below freezing yesterday here).

I was an early adapter of SBIG’s unit. After fiddling with it for weeks, I gave up and packed it away, and sold it to an unsuspecting guy a few years later. (He told me it was all user error and he would have it running in no time. He had cash, so I had no problem giving him a “deal”.). At its very best it “may have’ produced ever so slightly better results, and at its worst badly degraded images. By the way, I saw the exact same unit at an amateur telescope swap meet. (it had a small defect in the paint, so I knew it instantly). It was being sold by someone I didn’t know, and he told me that the guy he bought it from just didn’t know how to use it and he was sure I’d get wonderful results if I bought it.

hope you feel better, that little clip at the end was crazy.

Hope you feel better soon! 🤒

Even for professionals, adaptive optics is typically only considered for larger telescopes (D > 2m) since sufficiently many photons need to be captured by a frontwave sensor from an "AO guide"-star to be registered at high enough SNR at >200 Hz for good AO correction. With smaller telescopes the amount of sky available (with bright enough stars) is too small for the investment to be worth it. Also, the isoplanatic patch, the region around the AO guide star that is well corrected by AO, is only about 8 arcsec in ideal turbulence conditions (as illustrated by your moon video), for wider fields multi-conjugated AO with laser guide stars are required, but that is currently out of reach for even most professional observatories.

Good discussion. And hope you feel better - I've been enjoying to rash of new content you've been pumping out this spring!

What you call active optics is not active optics. It actually has nothing to do with the optical system but (as you correctly explain) with the guiding. Active optics is used in large telescopes with (compared to former days) nowadays fairly thin mirrors to compensate the shape variation owing to the changing gravity depending on where you point your telescope to. BTW even the Palomar 5m had a kind of (purely mechanical) active optics system, as has the 100m Effelsberg radio dish. The idea of the SBIG system (however you want to call the methology) is to take out the fundamental perturbing mode owing to the atmpsphere in the guide star position (basically that the guide star "jumps" around) - I think this is still an idea worth pursuing, but multi star guiding may be the much more economical solution to a similar problem.

Feel better and keep up the great work. Been digging the music a bunch lately as well.

SBIG use to make an active optics piece as well starlight express...it was ok for back then...but I don't think with the new mounts available you will much of a difference. If I remember correctly it was at its fastest setting was around 7 to 15 hz. Its basically just fast guiding. Your spot on mate. Your better off with a really fast video setup and use lucky imaging.

Oh man, feel better soon, Dylan!

As a visual astronomer active optics could actually quite beneficial for planetary observations. The main issue there is the in/out focus wobble caused by the atmosphere turbulence so you hardly never have a stable sharp image to observe small planetary details. That happens only on a handful of times a year when seeing is exceptional good. Unfortunately we can't do lucky imaging and stacking with our eyes. So here are my thoughts. For planetary we use high focal length and a very narrow field of view, so the distortion of the planet disc is only (or mostly) a focus issue. As we already know the shape of the target (the planetary disc), we could have a focus guide camera, some computer magic (which determines in which direction the image is out of focus) and a really fast micro focuser in the light path, probably some kind of small lens with a piezzo motor. Maybe this could be a kind of AO eyepiece. This way the focus could be corrected in real time (min 30 times per seconds) and the image of your retina would be noticeably sharper for longer times even on bad seeing.

The active optics system I have used uses a 10mm thick BK-7 glass that tilts at up to 10 Hz provides a real benefit for aperture photometry (On a CDK 700). Just for context the focal length is around 4600mm and the RMS tracking is around .2 arcseconds for the current mount model. With active optics the PSF is noticeably less spread out and you can use a smaller aperture to capture the all of the star’s counts. This leads to a significant improvement in the statistics and can let you work with dimmer stars or use shorter exposures. Shorter exposures can be very important when trying to understand the properties of exoplanet atmospheres or factoring in limb darkening, where the transit entry and exit needs to be well captured. The difficulty with the system is finding a sufficiently bright star within the OAG field of view that allows using 1/10s exposures or dimmer, and many objects just don’t have stars available to use. For nebulous or galactic targets, something like blurxterminator gives you the detail that active optics can provide, BUT, there is no guarantee that the counts you get are correct after using it. If you are simply doing imaging I don’t really think its worth it, but if you are doing science such as light curves or star formation rates or asteroid tracking, yes even a 10 Hz system seems to correct for the low frequency seeing and improve SNR.

Really interesting video mate! Hope you're feeling better now 👍

A cheaper alternative to adaptive optics is 'lucky imaging', fast video captures and using software to identify the best images. A 1% selection from video capture with good seeing may rival those from adaptive optics; the only drawback is the longer imaging sessions.

Get better soon! I mean, you could already be better, but I don't know that, so yeah, clear skies and throat!

Hey Dylan !! I have been using it for the last 4 years! The work very well, but 1 - you have to have a large telescope to get enough light for the OAG works fine and 2 - The result work better when you make correction at leas 2 times a second as a max. Ideal 10 times a second. Regards keep up the good work !!

I used the SX AO on a CGE mount with a 2000mm Meade SCT for a year and then used the SX AO on an IOptron CEM70 and Edge 11 for a year. I found it made a good improvement on the images with the CGE, but strangely, when I put it on the CEM70, the results were no better even with better balance and polar alignment. CGE mounts are known for having backlash, so maybe AO can overcome that. I can also say that it takes a fair number of minutes to fiddle with the settings before the AO guides properly. You need to tweak settings after meridian flip as well. I found that in the same amount of time, I could take more subs and get a better overall image. I decided to bench the AO. My sky quality is not particularly good, so to another commenter's point, once you get below 1" rms, you really aren't getting an improvement on your data anyway.

Hope you feel better soon. I'm sure the airport about 4 km to the south of me would love if I installed a proper adaptive optics system and blasted a laser up into the sodium ions above the stratosphere!

I feel your pain. Get well soon.

Feel better, Dylan!

Wow... dude, I hope you feel better!

Adaptive optics (big observatory version) acts on the secondary/tertiary mirror rather than the primary. Moving around rapidly is typically impractical for the primary because it is typically too large, stiff, and massive. I feel like another comment is required after that string of adjectives, but I'll just let it hang there...

Hoping your son healed up well from the last time I left you a message... From the sounds of things, it's your turn to get better! I make sure my backlash is as good as I can get it, As you mentioned... balance of the gear is next on my list. With all that out of the way. I use a standard install of PHD2 with Predictive PEC turned on along with Multistar. I like 1 second integration exposures. My guide scope is 600mm on top of my C14. The CGX-L will usually give me RMS Errors in the .2 to .6 range. My mount is out in the open so wind usually hurts me and those RMS numbers will sneak up to the .7 to .8 range. What has been helping me the most is short exposures and max gain. At f/11 and the target of say something like M57 or M27. I get very sharp images. I have purchased a few small pixel guide cameras with 1.45 x 1.45, 2.0 x 2.0, and 2.75 x 2.75 micron pixels. These cameras have no amp glow and at max gain show low read noise levels. These cameras will help me get very sharp image of smaller target like small galaxies or planetaries. I'm not a fan of getting much more than a 1000 images but as they saw the more the merrier... The exposure for a target like M57 is in the 6 to 8 second range. I have never gone over 90 seconds even when I'm in Astrophotograpy mode... I have a ton of sats and planes to deal with so I'll usually aguire around 90 minutes of data. This gets wittled down to 60 minutes after rejection. I'm happy with the results which is all that is important... ;-) Get Well Soon!

You got it wrong - most popular active optic is from Starlight Xpress Ltd, which is tilting big fat lens with its own guiding camera in front of the sensor. And NO - you do not need it, because all back focus and other optical elements you need and you get a mess. You are right - it is a high frequency guiding in which you are chasing the seeing... better use lucky imaging ...

Just in passing as the weather for astronomy is lousey. I would have thought that the process of image stacking goes a long way to process out distortions by atmospherics and guiding errors etc giving a real average of your image. In my experience 'stacking' is the real big advance for us DIY astronomers. The two major things by far that influence good images are. 1: A high quality telescope Mirror or Objective. 2: The state of the atmosphere while picture taking . The best optics that money can buy won't cure the atmospheric problem even though it's important for astronomy. A reasonable guiding system is also ideal but it is not going to influence the two most important I mention. I can't see any advantage in even thinking Active optics. Hope you have more luck than me in seeing stars.

There needs to be more of these crowdsourcing videos, everywhere...

Dylan, get well soon! Who else but you will be able to please astronomers with such cool videos?

i only use a small Newtonian but i read in a blog that a refractor does better job at reducing the distortions although i believe it refers to optics and not physical distortions by the atmosphere, i guess, i expect that the only option is observing from higher altitudes. or i think its a good starting point to create a deep learning tool based on the expected image "the moon" for example, but what do i know, SharpCap and FireCapture would have done it if it was a simple approach, i think it's tricky and physically unrealistic I always thought of lifting a remotely controlled Newtonian with a helium balloon very high, ~40km, nasa did that for the microwave background radiation to see the smallest angular scales in the CMB, small wave distortions from inflation. i hope you catch a solution within budget

I used the AO-7 extensively 20+ years ago with my non FL reduced C11. It was extremely useful in that era's context. Back then top mounts barely performed as well as modern middle-range ones. The Paramount ME had just been introduced and purists were lamenting it achieved its respectable performance not through exquisite craftmanship but with the help of nasty computers. In mount PEC was new and simplistic (no fitting on multiple cycles) unless you wanted to pay for expensive add-on software. I had just abandonned my ST4 for a guiding webcam and very quickly after that for a dual sensor SBIG camera. The AO-7 gave me nice round stars at 2800mm with essentially no frame losses which was all I was asking for. Looking back at that 20 yo raw data today it remains acceptable but is definitely not as sharp as the one I get today thanks to improved optics, sky models, and optimized guiding on better mounts. Real current pro AO hardware would, by itself, fill most amateur observatories and have a very, very narrow corrected FOV.

Hope you feel better soon! AO sounds a bit extra for the regular consumer set up, where most of the mount problems can be solved with making sure everything is properly balanced and use PHD2 guiding.

You are right thinking that it may not be worth it today. Those devices sold by Sbig (like the AO8) and Starlight xpress ( SXV-AO-LF) were useful 10-15 years ago when our mounts were not as well built as they are today. Back then, the promise was basically to obtain the performance of a good EQ6 with an EQ5 for exemple. Or even to make a crunchy old EQ6 behave "better". The marketing also suggested that you could fight the seeing a little bit if you you could montior a guide star bright enough to go at 0.1s guiding exposure but that is almost never possible at high focal length. Anyway, today our mounts are better made than back then so it doesn't really make any sense anymore. In your case, with your EQ8-Rh it would be a waste of money I think. It would make more sense to just sell the EQ8 and get a more premium mount.

Excellent discussion! The short answer, in my opinion after 6+ years is NO, it's not worth it. For about five years I used an AO-X unit with an SBIG STXL16200 CCD camera and integrated SBIG filter wheel and OAG. The telescope is a PlaneWave 17" with a focal length of 2915mm. The mount is an A-P 1600. About a year ago I switched to a QHY600 MM CMOS camera and an SBIG StarChaser OAG, since it was said to be compatible with the AO-X in my new setup.. I left my AO-X in the imaging train. Diffraction Limited has yet to properly update their software for the AO-X with the StarChaser OAG, so my AO-X is currently functioning as an expensive spacer. Also, when I made this change I tweaked my A-P 1600 mount's alignment and ran A-P's APPM modeling software. The result is that the images now are as good or really better than those I got with the active AO-X and the SBIG STXL16200. I currently have my guide software "bumping" to correct any errors every 15 seconds, but I could lengthen that considerably. Admittedly, changing the camera as well as the AO-X status makes the experiment less than perfect since the QHY600 is a superior camera, but I fully agree with your comments. The AO-X was just correcting for guiding errors and the APPM modeling software makes these extremely small. When you add in what can be achieved with BlurXterminator or other AI-based deconvolution software, it's even more clear that AO not adding anything.

AO might be better suited for photometry on variable stars to better keep the star circularized on the sensor and thus easier to perform the math to generate a magnitude value as compared to a stable comparison star. Additionally, you're only interested in the single point (spread across a handful of pixels), and not the entire field of view as a whole. It might also help with spectroscopy to avoid smearing the spectrum. But what do I know, I've never done a single run on a variable star for the AAVSO, but my father would to ten or so a night with a mk1 eyeball. And thanks for getting me up off my but and out into the hot Texas heat to image the Sun. X - @AlphaAstronomy I think you might find my aircraft photobombing images strangely attractive.

Hey Dylan. So…if I’m hearing you correctly, what we Really need is an AO module, deformable mirror kind, as the next big thing to hit the market for us amateurs…of course, it has to be affordable🤓 Like you , I’ve always been intrigued with that tech that the Pros use, and always imagined how one could produce a smaller version that could fit right at the secondary mirror spot on the RASA for example. So there you go Celestron engineers: your next project. Get cracking! 😂

Since it's not actually adjusting to match the atmospheric conditions, I can't see how active optics could possibly improve an image if you're already getting sub-arcsecond guiding, which is below the seeing conditions at almost any site. Essentially it's just chasing the seeing. Back in 2009, when I was first getting into the hobby, there was a guy in our local astronomy club who had an SBIG "adaptive optics" (his term for it) system. I was always puzzled about how that could work because it was obvious he wasn't deforming his refractor's lens. He produced beautiful pictures, though, and maybe back then it made a difference. I dunno.

I had this ideea of using a 98% transparent LCD film that would go in front of the camera sensor and would respond to corrections from the guider as a micro lens matrix able to correct for half a sine wave of variation. I could go into more detail but there is no way for me to develop it any further and would gladly pass on the flag to better funded folks

I did investigate adding a Starlight Xpress AO unit to my imaging train but decided against it. The advice on Stargazers Lounge was that its best use was when you had two long FL 'scopes in tandem to allow for flex between them, guide on one 'scope, use AO to correct the other. My current main instrument is an OOUK ODK 12 on an ASA DDM85 which uses a double sky model and encoder guiding to get below 0.25" error, I've often seen 0.1" so I think AO would be unlikely to make any improvement.

I wonder if it could be useful on specific scientific work when you are interested in a point souce and want to keep it on the same pixel? Would still require a good mount.

At 2:35 it is done by tilting a "glass block" in front of the CCD chip ( ex. SBIG AO-7 ) or a mirror (ex. SBIG AO-2 ). It helps a lot. But I guess you know that by now.

Just a thought - Why not implementing fine guiding into astronomy camera itself? Small actuators that will move the sensor assembly ud-down and left-right across the focus plain. The movements needed are only couple of pixels across, about 10-20 microns. The rest would be handled by the mount.

I still have the SBIG AO-7 and AO-8, it was only useful for bad mounts like the MEADE I had. Now that I have the Paramount MX and the ZWO AM5, it’s not worth it.

Man I thought Barry White had returned at the end of the video lol, I think with software like blur Xterminator not that I use it as I'm not a proper astronomer helps with bringing out the finer detail so I think its a case of is it really necessary these days. Mounts have improved sure although I'm using a 15 year old plus Celestron CGE pro which is working brilliantly, even better as all the Celestron electronics have been junked in favour of an Onstep kit which works well on the ASCOM platform. Everyone at the moment has gone strainwave crazy at the moment but they all still have errors so apart from portability I don't feel the need to be buying one any time soon.

I wonder if there would be a way to make adaptive optics in a cheaper way and where you can use it on your normal optics? Maybe if someone can invent a 45° adaptive mirror that would be great thanks!

20 years back, I would contribute high cadence photometry of cataclysmic variables to the "Center for Backyard Astrophysics.". My instrument was a LX200 / 12 which I tweaked ** extensively until the unguided periodic error was ~2.5 arcsec p-p.I would normally run the scope at f/6-ish. My camera was a ST-8XE with an AO-7. Provided I could find a 10th mag star in the field, It could perform corrections at about 10 Hz. The photometric runs would last 8-10 hours and the exposures would vary between 30 sec.and 2 minutes. My experience was that the noise floor was significantly improved when the AO-7 was working well. If memory serves, I was able to perform photometry on 16.5 m targets with noise close to 1 millimag. Ignoring the AO-7, I did not use any guiding, The long runs meant that a cloud going through the field caused the guiding to go nuts. Instead, I tweaked the drive rate & alignment so that the scope would drift less than ~3-4 moa over the run. Short version - it was very effective for photometry provided I used the guide chip that was mounted next to the primary chip. ** tweaking - I replaced all the RA bearings with precision rollers, cut bronze worm wheels, polished the worms against the worm wheels for several weeks, pinned the fork arms, replaced the dec bushings with rollers, worked on the RA drive motors. I also installed a motorised Ban Slyke focuser.

I worked on adaptive optics for lasers for many years. The price of a standard commercial wavefront sensor was around £20000 to £30000 (five years ago) depending on the type. An adaptive mirror that is capable of kHz correction rates will be a significant fraction of that cost in addition. A laser guide star system that allows the AO to be used anywhere in the sky (i.e. not just where there's a bright enough star in the field) will cost more. This is why true AO systems are only used by professional astronomers at large telescopes. They are also used mostly for IR imaging because the amplitude of the errors is smaller at that wavelength. As a planetary imager myself, I would say the use of AO or even the simpler tip/tilt correctors are not worth the trouble and cost given the relatively limited scope for improvement they offer. If the seeing is bad enough that the image is moving a lot it is likely to be breaking up as well, and the device won't correct that. The only real solution is to wait for better seeing . . . 😢.

I used to use an F10 12 inch scope on a fork mount (yuck) and used to have all sorts of tracking issues and nearly always had oval stars especially if there was a bit of wind. I used an Active Optics system and it really did make a difference and did a great job countering the shortfalls in the guiding system specifically. It was the first time I got really nice round stars with that particular setup. Once I switched to a really good solid CGX mount , it did not make any difference and was not worth the extra setup complexity it introduced. In hindsight it would be much better to have spent that money on a good mount rather than the adaptive optics.

What you described Dylan sounds like it should be called active tracking or active mount control. I think for many people this would just be an unnecessary expense to solve guiding issues that could have been resolved in the main by fine tuning the mount, guidance software or using an OAG. I know my own guiding still needs some improvement but living in the UK with it's predominantly cloudy skies I don't get a lot of time to play around with the guiding which isn't that bad so long as I don't do over 5min exposures. If I had a long focal length scope it would be different though. I live near a small regional airport which shares its runway with a large aerospace factory. Skyward pointing lasers are a non starter, unless you wish spend the night in the company of the local constabulary instead of imagining. Get well soon.

What we probably want it to correct the incoming wavefront with an active/adaptive optical element (I wasn't really aware of the two terms "active" and "adaptive" ... For me both are quite the same and pushing your mount faster, doesn't make a lot of sense to me). The impact of atmospheric distortion is probably way bigger than the improvements that you can make to your guiding. To correct for atmospheric distortions, we would (ideally) need an element close or in the pupil of the optical system. For your SCT this is the Schmidt-plate. Maybe the primary mirror would also work. But in any case, the element would be huge! There are ways to correct the wavefront in transmission or reflection, but the problem is, you also have to know how the incoming wavefront is distorted. Therefore, these special lasers are used, to generate an artificial star. But you also need a wavefront sensor. All in all, this will cost a fortune. I guess this is why no company will address this technology to the consumer market.

I don't know if AO has good ROI or not for the average amateur astrophotographer however conceptually, moving microns on a small payload (camera) would make more sense than moving a large payload (OTA/Camera/etc) microns for corrections?

If any manufacturers are reading this, please roll out a cheaper adaptive optics system :) It seems like a DLP/DMD chip controlled via FPGA in the optical train would work. I think there is an opportunity here

Why not just decrease your expoure time and try to distortion correction in pixinsight? It will take a ton of storage and processing time but would serve a similar function. You could at least try this to capture the details and use the longer exposures for luminosity.

First I ever heard of this!.

Jolly mate I was distracted by the giant shoelaces around your neck lol. Just messing with you always look forward to new content.

BTW: Sulphur Hexafluoride can really help getting your voice back to normal!

Well, it appears that "active optics" for amateurs is a significantly different process than for the professional telescopes. One method of active optics consists of attaching many actuators to the back of the primary mirror which then push on it or pull on it so as to keep its perfect parabolic or hyperbolic shape no matter what the scopes orientation. And of course this is all done under computer control. This is particularly critical for the way todays thin and lightweight mirrors are being made.

Get well soon.

Be well, Dylan O'Donnell. 🐿

As you mention its usually possible to rid most causes of tracking errors without the use of adaptive optics. Reducing tracking errors can really help. A recent review of the iOptron HAE69C EC (ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Q9MYfrigo_k.html) showed a manufacturer readout of the tested mount to only have about 0.15 arcsec RMS periodic.

You would need piezos to actuate a sensor this small. The relay would have to be very high and you'd need a standalone controller. Not worth it at an amateur level.

Why did you turn your power off? lol - I also kept my laser on my Z73. It's mounted on their so nicely I didn't take it off, even though I don't need it like I did with the Skyguider Pro. Running the GTi now on that build so it's fully automated. Get well soon, mate!

you sounded so sick at the end, clearly not buying enough astrophotography gears. get well soon!

so.... the vessel with the pessel has the pellet with the poison and the flagon with the dragon has the brew that is true??

I think we could put a collection together and send over the singing nurse. “I heard that you were feeling ill. Headache, fever, and a chill. I came to help restore your pluck…” Dylan will feel much better afterwards.

This is a great question but, I had my fingers crossed that you were going to test something new. Any excuse to add technology to my setup.

I know nothing about active optics but found the video interesting Barry White.... um I mean Dylan.

Haha, I've got FA knowledge about adaptive or active optics but I am also crook as a dog and will be having the rest of the week off work. "Every cloud has......." Damo

Get well soon mate. You sound like you’re a cyborg lol

As soon we can readout 8k with 240 fps we can do the rst with AI.

Hope you feel better, but in the meantime take advantage you should play some blues riffs on the guitar.

nfi were u live mate but in vic we got some pritty dam good bortal 1 spots with free camping and you dont even need a scope =p

Wow...sounds like Barry White doing astrophotography in Australia. "Hey LMC, who's your daddy?" Hope you feel better soon Dylan. CS & GB from Black Hills of South Dakota!

Am I the only one who's been watching this channel for like 5 years and just now noticed the buttcrack shot in the intro? lol😂

I've never seen active optics, but there's a guy in the club using adaptive optics with no real result that I can see. This could be technology waiting for a manufacturer to implement it well. Hope you're feeling better soon, Dylan! Eat chicken soup!

Meanwhile, i still cant polar align.

How do we get the algorithm to work?!?! Feels like you’ve been stuck at 48k forever 🤯

No. As processing and data transfer speeds continue to ramp up, while using smaller form factors and less electricity, digitally adaptive optics will probably be the thing. Why physically deform an optic at a 1ms polling rate when you can realtime deform the incoming data with enough processing grunt. Where things like BXT perform point spread function corrections in post, there will probably be a real-time solution that applies correction and normalization for every subframe, perhaps Even eventually at a frequency that can mitigate atmosphere. Still many years away from that reality, but I can see it eventually going there. I wouldn't be surprised if ZWO is looking into eventually packaging something that does real-time deconvolution.

Couldn’t this be done at the software pixel level?

Ironic. I watched this video and the power was cut off at my house too.

I'm really not sure that adaptive optics are going to give you much unless you're already in a very good seeing location, i.e. 3000m up a mountain in the middle of the ocean. You're corrections simply aren't going to be significant enough for the seeing conditions, for the likes of you and I near sea level with 99% of the air still above us aperture is really the best option (IMOHO). Get well soon!

Ahhhh you must of been looking at Corona Australis.

if on someone else's budget, would be awesome to compare & find out.

I didn't even know that active optics were in use by amateurs.

BlurXterminator??? lol😆

Have you tried looking at it but NOT looking at it? 🤔 Active optics in my house is making the kids grab a different eye piece.

The aliens are on their way to punch us in the eye, because they’re sick of us shooting lasers into their eyes.

You did not fully get it how active optics work, I think.

Sorry but my ignorance on the topic would only complicate things!

I see your kid in the background cuts you no slack.

Did you blink twice or not?

at least its not herpes 😂

see a guy on youtube uses it and seemslike it creates little more conrast. That is all I know.

Hmm, maybe test active optics on the ice giant planets of our Solar system? You complained before they aren't fun to observe, because they are just blurry blue spots in your images... Get well soon!

I was impressed by this video of Starlight express active optics when I saw it and i dream one day of having it but not right now. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-i8IPQrED8iY.htmlsi=T4NTfqtbpEIxYBV6 Btw, the secret to feeling better is rest; but I mean real rest. While sick, get very exhasted without sleeping; usally the second night. Then setup a nice rest area for long sleep and take a z-quil....and boom....after 8-10 hour of straight sleeping, you should wake feeling like a King, Champion, an Ultimate Warrior!!!!

I have no experience or educated opinion on active optics. However, did you take advantage and record some lyrics for a dope dubstep track?! (I hope so) 😅 Feel better, Dylan!