The color split at 14:24 looks like atmospheric dispersion because the split in all of the corners and the center is in the same direction - blue at the top and red at the bottom.
It may be, but I associate atmospheric dispersion problems to be more common at low altitude. I picked the Elephant Trunk because it was high in the sky in December when I was shooting it (50-70 degrees up).
@@NebulaPhotos Hah, I thought I knew the answer :) The other possibility is that this is an artifact of stacking - if you run Star Alignment on individual color channels of the stack, you might be able to fix this completely because the aberrations appear to be in the same direction and of similar magnitude.
@@NebulaPhotos It looks very like AD to me. You maybe know that an optimal (theoretical 100% Strehl) teleskope is downgraded to an roundabout 90% Strehl "anything" just by that 20-40 dregrees from zenith. Therefore the old rule says "the wise astronomer observes around the zenith" ;-). Or buy an ADC. A usable ADC should have at least 2 prism-pairs, the cheaper ones are hardly to use and inefektive on lower altitudes. A well made ADC with two hq-prisms pairs will work good down to about 50 degrees, okay a bit lower but still ten times better than none. Sadly that I just know two companies who offer such in the amateuer range. Large pro-telescopes usemore pairs or triplet designs (its cool, google for that) to be able to correct even lower. Its a riddle why so few know about that and prefer to give up more and more money for "better" telescopes, oculars, software and so, all things that can solve the physical problem of dispersion, instead of buying an ADC. Including me. For all the money that I waste on the way my current setup I have could buy tho aperture steps up on my nice oil-filled triplet Refraktor. Expansive learning. And an ADC is sooooooo! cool. It feels just like an focuser for the colour. Try it a venus on daylight, Without its a wobbling bright glob, tune in the ADC and snap, the colour is off and there is a shape. Hard to describe, easy to see. It is also a excellent tool to seperate double stars. My list of astrostuff I have had to buy much much earlier: An encoder driven mount instead of annoying autoguiding, an ADC and an simple polar alignment wich is, thanks good at least this, common nowadays. Each of them saves me now ton's of nerves, time and errors. Thank you
OK, right up front it's beautiful and I'd love to have one. My big argument against it though is exactly what you pointed out at around 4 minutes - if I am going for ~1m focal length at f/5.6 - f/7, I could get an entire quality imaging system for $5k by going for a reflector. There is a reason why refractors aren't this big - they're just too expensive to make.
Thank you for your excellent review. Based on this I just bought Askar AP0 120. I have been following your channel for while and I appreciate all your work. One think I would like to point out is the traces of chromatic aberration that you showed in the 2 parallel examples. When you are comparing the views from the flattener and reducer the reducer sample exhibits more chromatic aberration because you are basically you are shortening the focal length this actually changes the calculated compensation on the telescope and produces more chromatic aberration. This event will happen to any telescope that uses lens elements because different wave length of light will bend slightly differently and the focus point will be slightly ahead or behind based on wave length. When you shorten the focal length with the reducer you are causing the light to bend on a steeper angle and this will increase the effect of the chromatic aberration making it more visible. So in collusion if you would like to achieve the maximum optical performance with the minimum chromatic aberration you need to choose a sensor that does not require reducer in order to prevent the additional chromatic aberration. Also the higher the pixel density on the sensor the more defects it will pick up from the surface finished of the optical elements . Again matching the sensor to the optical tube even at pixel density will ultimately improve the overall performance and produce better looking images.
I have just got a Bresser AR152L (6", in old money) refractor. So far this is how my viewing goes: Step-1, Take out mount/tripod. Step-2 Take out telescope . Step-3, Take out bag of lenses. Step-4 Try to mount the bugger. Step-5. Sit down for a bit. Step-6. Starts raining. Step-7 Repeat steps 1 to 4 in reverse.
the 140 is borderline for affordability for me - but the 185 is defiantly out pricewise). the 103 with all accessories is slightly less than the V with all accessories. the 120 is around $350 more than the 103 and the 140 is$700 more than the 120 (all accessories included).
That vignetting you are getting is from the very narrow tubes of the camera. There is now way you would get those sharp stars with those vignetting figures if the vignetting would come from the optics, that is why the obvious problem is the camera opening and also the length of the tube of that opening which is about the diagonal of the sensor. You should have at least 5mm clearance on each sensor corner, but it should be larger due to the tube length, that is about 2 inches. So for this large sensor, a 65mm opening would work well, or the diameter of the correctors back end lens. From what I'm seeing, you have both 68 and 54mm threads for those flatteners, which is good, because you can have vignetting free fields on full frame and possibly medium format given the very good field sharpness.
I found that "chromatic aberration" isn't purely due to optics. You can also consider atmospheric dispersion to be the cause of the aberration you see in your highly saturated comparisons. The only way to correct for atmospheric dispersion is shooting at high altitudes, using an ADC (which may be only applicable to planetary), or using LRGB filters. Anyways, great video!
Looks like a great instrument Nico! As some others have suggested, the colour split when pixel peeping is probably atmospheric dispersion. The extremely thin blue line just discernable on the left limb of the moon video is a sign of (very well corrected) chromatic aberration.
Great review Nico. Too much scope for my mount (and pocketbook) but Askar has really been coming out with quality, economical products lately. Tempting! Dr B from Manitoba, Canada 🇨🇦
I have been hoping for the reviews of the new Askar large aperture telescopes. Thanks for getting one - I am looking at the 120APO (the 140 is borderline and the 185APO is outside my budget) I wish that they were a little more honest about the ED Glass - or more foreword about what type of glass that they use. I also wish that the case for these had a cutout for the flattener and reducer and a space for a cutout for an astro-cam (using the default size for ZWO diameter would be nice).
Hi there! Thank you very much for your review, probably the first about the big 185 mm😮 May I ask you: Have you detected some spherical aberration during the Star Test looking at bright stars of different colors? Thank you very much, regards from Italy.
It's kinda funny that just one year ago you posted a video asking if there's such a thing as too big regarding telescopes and in that video you were talking about the Askar 130. Now you are really in the big leagues!
Thanks for the review. Thinking about getting back into this hobby after about a 2 year absence. I have a second home/vacation rental near one of the few Bortle Class 1 zones (Greenbank, WV) so I was considering upgrading from a 100mm refractor and had been planning on going to 130 or 150 as those would likely be the max for my current mount (HEQ5) but this has me considering a mount upgrade as well.. LOL-ish
Those corner stars look great. Honestly I'm impressed with what I'm seeing from this APO line. The whole line seems to perform well to the corners despite being the "budget" line. I wonder if a phq version is in the near future :)
Hi Nico, wow thats one monster refractor of a telescope, great video ! Will you make the test data available ? Would be nice to see it, without youtube compression. Appreciate your work, keep it up !
Mr. Carver, good review on this scope! It's hard to believe you can get such color free optics this large for under 5k. I'm glad you used the SW mount. It's good to know it can handle such a large scope. Are you going to keep the scope?
for sure, I'm glad he used the EQ6-R pro as well - that's a very affordable mount if you are talking about a 20kg load! It's way more accessible than the ones that are designed for piers
Excellent, thorough review, Nico. On an unrelated note, seeing your observatory in the background with all the snow, did you think to install heating wires under your exposed rails to keep the snow and ice clear?
Haven't done that yet, because I haven't done any electrical work yet. So for this winter, I'll just be blowing/brushing the snow out of the rails. Hopefully for next winter, I will have the electrical done and can install the heating wires
Excellent review! I really appreciate your enjoyable and in-depth review. For the money it looks to be a nice refractor. Looking forward to some visual reviews of this telescope down the road.
Hello Nico, very nice review - loved it. Here's the thing: I've been mulling in my head for rational justifications to buy anything other than very fast optics; I own a RASA8 and the advantages of f/2 imaging are obvous. I mean, who would want anything other than f/2?? Indeed, why on Earth buy a 5000$ f/7 OTA, when you can have a 2000$ f/2 system that cuts integration times by more than a factor 12 ?? After a few months of letting that float in the back of my head, one day I found the answer. In one word : definition. Of course. An 8" RASA at 400-mm focal length doesn't quite cut it compared to a ~1400-mm 7" APO refractor. I can see a not insignificant difference when comparing your Elephant Trunk Image to mine taken with my RASA 8. A 1400 mm f/2 system would have to be a prohibitive a 28" aperture. So now, yes I think that a higher definition with beautiful details such as the one you've shown us is worth waiting 12x longer to obtain it. It's all a matter of compromise. Thanks for helping me sorting this out! Say... have you compared an EdgeHD 8" with the Askar 185 ??
Different systems for different targets. A f/2 system is a wide field scope, and f/7 or 8 or 10 is a narrow field scope. If you want to image a small galaxy a f/2 system won't do it.
Agreed, there are pros and cons to each. With Edge stars are worse then on apo refractors, filter choise is much limited and you can't have filter wheel on rasa. On the other hand if you are living under darkish skies you find that more than 10 hour integration (on F7 scope) is not really necessary and with higher focal length you can get much more details impossible with shorter focal length. My favorite photos lately has been from a guy on astrobin with 1000mm F7.5 takahashi apo using medium format cameras. With such setup you can get wide field shot but also so much details with single stack that you can zoom and zoom and find new details or galaxies you never thought were there.
@@blufferblue1599 1000-1500 mm FL is a sweet spot for all sorts of targets. Extremes like f2 or f10 are for specific targets, that's why many people use more than one telescope. There is no do it all setup, but there is some middle ground. Luckily the middle range of the FL is where you find many newtonians, so you won't have to break the bank for a Tak
So preordering this in germany would cost 7000 € which is roughly $ 7600. Why do we have to pay almost 3 grand extra (the UK should be even worse off)? Just think about the camera equipment you could get for that price difference alone...
Because my preferred Bordeaux costs me $26 CND, and it’s 2 euros in France. Get the picture? Not to mention the Sangiovese which is X10 here compared to that great Bellavista restaurant in Impruneta, IT. The 185APO is $6500 CDN (4500 E) locally. I get your point. Is there a US-China trade agreement we’re missing?
@@rcjoub I also get your point but to me that's no reasonable justification. You can't tell me that the logistics of shipping and selling that thing overseas cost 3k.
1:01 my opinion is no, especially if you have a dedicated spot and a large mount you might as well just have a 10 or 12 inch reflector astrograph , shorter exposures and more data in theory.
There is something very beautiful about the moon video, it really takes you there. Looks like a great scope for a very reasonable price. Oh, and that number plate 👍👍
Obviously, as in all telescope choice, focal length and image scale depends on local seeing. That 's why i've got my TEC 160FL with AP QUADTCC x 0.72. I'm also very happy with my Askar 107PHQ.
I love my FRA400. Very sharp and round stars. It works well with my ZWO 2600MC. Clear skies to you, but it's been raining here in NorCal since Christmas... :-(
Please tell me the visual Strehl ratio of the Asker 185 APO. By the way, Takahashi's large aperture refracting telescopes TOA-130N and 150B are completely aberration-free. And the imaging performance of the TSA-120 is close to them.
5k is many greens, but heck if it isn't very good value! Always enjoy your great videos, and I must say, it's because a part of your dear persona comes through. I could listen for hours (and I have xD). Must be a show to accompany in loco for one of those sessions. good things and clear skies :)
Rewatching this video, that flare effect is most likely from the notches on the lock rings in the flattner and reducer. Might need to change them to the hole style to avoid the light skewing and causing those flares.
I still can't get over the results people can get from their own backyards. Less than 20 years ago you would need the Hubble to take such photos. Then last year there was the introduction of the scope I'm most interested in, but can't afford on a retirement check, the ZWO SeeStar S50. I live in SW Utah, dark skies in my backyard and really dark skies a 30 minute drive away.
Seems like Askar did a good job with this and I'd be surprised to see much better results than that from one of the more expensive refractors. What's your educated guess to what more you can get with a more expensive refractor?
@@NebulaPhotos Fair enough. Sharper images is always nice, if you have the skies for it! But the chromatic abberations where pretty darn minescule on this one 😁
Thanks for the video, it looks like a nice scope. Since I would have to buy a mount and probably a tripod/portable pier as well I will probably not be adding this one to my collection any time soon but it is nice to know it is out there.
I'm loving the observatory building series and I guess I already now know the end product. GREAT TO SEE IT'S ALL COME TOGETHER, CAN'T WAIT TO SEE HOW YOU GOT THERE.
Love this review, Nico! I've been wondering about this scope's performance because it is less than half the price of similarly-sized refractors. Seems like it lives up to the hype.
The Skywatcher people are going to love those eccentricity numbers!! I find them amazing and never thought you would get that with that scope on that mount; just on its length alone!! Excellent video….. as always.
Excellent review. The TEC180FL has been on my want list for years, but this Askar 185 is nearly a quarter of the price and seems like a superb value based on your imaging results. I do think it is best in an observatory as opposed to a portable scope. I am curious how it does as a visual scope on planets.
I'd love to see a shootout between a large newt and a giant refractor like this. Both a similar focal length, image scale. In the end it's all about image quality. Would a 12" f4 newt or this refractor be better?
Each system will have pros and cons. People often turn to refractors because they are easy to work with, and usually have higher build quality, 0 maintenance, and this translates into a better image. Mirrored scopes have a much wider range of build quality. Just look at the price of a Chinese Newt and a ASA Newt! Unfortunately ASA doesn't make small newtonians anymore, they only offer a huge 400 mm aperture one at 47000 Euros. So if you compare and expensive APO and an expensive Newt, the results would probably be the same. If you compare a top APO with a Chinese newt probably the APO would do better, as the saying goes, you get what you pay for. Lastly I'm not just throwing ideas, since I use a top 8 inch apo, and I know what they are capable of.
Hii sir pls reply iam new to astrophotography i dont have star tracker i live in bortle 6 zone i want to photograph orion nebula can i take 30 minutes of exposure everyday for 6 days to collect 3 hours of data on same camera settings and then stack it is it possible can i try this to collect more data
I really want to see a comparison between these large aperture refractor and a reflector at similar focal length (like a 10 inch F4 or 8 inch F5 reflector), as the reflector is much cheaper. I just checked my reflector performance and found that the median FWHM and eccentricity is not a lot worse than this refractor (like 10% worse). At a higher focal length the astro seeing is an issue and the refractor may not keep its advantage on optical performance
Those results are stunning, and the cool factor of a 7" refractor is high. But let's keep perspective. Equal results can be achieved with an 8" sct at a much lower cost, and dramatically easier to handle package.
@@zorg1396in terms of equivalent light-gathering surface at a 28% linear obstruction, you are at 192mm aperture. In terms of resolution you still have a 200mm scope with a reduced Strehl ratio. In terms of corrections, there are residual field curvature and chromatic aberrations in any scope of any optical making and have to be tested just as Nico did here.
As someone that owns both a large-ish SCT (C9.25) and a 6" Apo, I don't agree. The refractor has noticeably better contrast for example. There is a lot of scattering going on inside an SCT.
This is one thing I’m trying to wrap my head around…. How equivalent would a 8” edge hd and a 8” refractor in terms of exposure time if both are at f7? I would think that the 25% surface area of the sct central obstruction would reduce the light gathering ability, making it more equivalent to something at a higher f ratio that has no central obstruction. So, if we are taking the f7 of an sct at face value, how much faster would an f7 refractor be? 25%? I feel like there’s an aspect to this I’m missing…
The chromatic aberration IS atmospheric distortion as this is defined by a vertical shift in colour. While it can be corrected with an ADC it cannot be corrected with filters as some have said. This is because in addition to image shift, the scale also changes. Dispersion can be present above 60 degree. Chromatic aberration manifests as a halo as light is focused in one wavelength but not focused at another. As the defocused wavelength is larger, its colour surrounds the focused wavelength. Fundementally as a supplier of premium optics I cannot be anything other than very skeptical of this telescope. The time needed to manufacture glass elements of this size and optimise a cell to allow for thermal emissivity takes time and skill. The cost of the optics just don't add up. I am hearing lots about very poor star test results. This review sample may not be representative of a production scope.
Thank you for the full explanation on the chromatic abberations. I wasn't aware that atmospheric dispersion could be that strong so high above the horizon. Lesson learned! Cheers, Nico
great work , as always. this is a beast of a scope, and it looks very promising at that price. it would be nice to make a visual orientated review using single eyepieces and binoviewers. i know it's not your area of expertise, but since there arent any reviews online yet , it would be nice. also your observatory looks great! clear skies!
About three months ago I was shocked that this refractor cost € 6.800,- here in Europe, really dirt cheap, about 40% of the cost of premium brand refractors in this class(LZOS, CFF)!! Now I am shocked again since I learned that in the USA it cost $ 4.800,-, about 4400 Euro's! These price differences are one of the reasons I seldom buy new stuff in Europe, only when in big need. Anyway nice review and have fun with the big glass!
it would be interesting to see RGB or one shot colour test.. I think it might show capability of the optics more.. certainly for Narrow band your results look decent enough considering the price point.
All the imaging tests I'm showing from 9:36 to 15:30 are OSC with no filters. The only narrowband results I show are towards the very end from 16:30 on for people interested in that. But I agree OSC is the true test which is why I spend so much more time looking at those results.
@@NebulaPhotos thanks for pointing that out - my phone rang and I thought I paused it looks like I missed a section 12:48 at zoom of 1-2 the stars were actually looking very good.. this is pretty good value for the money if the optics are consistent at this price point. I am thinking most people if they had this would be happy with the results.
It's not just the 5k for the 'scope, it's the upgrade to the EQ8R or Paramount, Losmandy or similar that'll catch you! 😂 What's the size of the native image circle that the scope creates? Are you still connecting the camera with a 48mm extension tube? Needs to be 63mm for the FOV then drop to 48 only at the filter and Camara. No more light drop off that reduces contrast.
4500$? In Italy it's at least 6500€... That said, even for 4500€ I think I'd still pick something like a 12" Newtonian that can cover even a ff sensor with a top end coma corrector. Quality looks nice tho.
Fantastic instrument, for 4800 USD that is a pretty good deal! Nice pictures as well, you are clearly on the more experienced side of astro photography 🤩
That vignetting is because the camera uses 48mm threads, they need to use a wider interface it probably has nothing to do with the scope, but it would probably be less pronounced on a slower scope
Nice review and your channel. Will be doing my astrophotos,( planetary) with a achromat 120mm 1000mm focal length Celestron XL and a Baader semi apo filter and using the ZWO-AS1224MC color camera on a XL 70 equatorial mount. As a note: Just got into this and at the age of 80 so maybe can do some simple processing with the SWO soft ware. Again, Thanks for posting very interesting. At 3,700 ft in North West Arizona
Hi, Nico...did you experience any of the flaring Trevor encountered with his test setup? If not, do you expect it was a consequence of variance in manufacturing or possibly a transient set of events on his imaging session?
I didn't. I think it must be copy variability, as he tried it a couple times and got the same flaring each time. Mine hasn't shown that at all, and I've tried it with various cameras/filters across multiple nights.
That's a monster telescope! And although expensive, I agree that the price is surprising. $5k is still a lot but it's "not bad" compared to some other higher end refractors.
I sure like the ZWO ASI6200 but I don't have an OTA than will cover the entire full frame. I have an 8" Edge HD with a 0.8x reducer and although they say it will work with a full frame camera, it won't. All my images had terrible vignetting that looked like huge light leaks. That camera costs almost as much as the 185 APO. Better have deep pockets as you probably need the EQ8R to round it out. ;o)
The color split at 14:24 looks like atmospheric dispersion because the split in all of the corners and the center is in the same direction - blue at the top and red at the bottom.
It may be, but I associate atmospheric dispersion problems to be more common at low altitude. I picked the Elephant Trunk because it was high in the sky in December when I was shooting it (50-70 degrees up).
@@NebulaPhotos Hah, I thought I knew the answer :) The other possibility is that this is an artifact of stacking - if you run Star Alignment on individual color channels of the stack, you might be able to fix this completely because the aberrations appear to be in the same direction and of similar magnitude.
@@Nabby13 Good idea -thanks!
@@NebulaPhotos It looks very like AD to me. You maybe know that an optimal (theoretical 100% Strehl) teleskope is downgraded to an roundabout 90% Strehl "anything" just by that 20-40 dregrees from zenith. Therefore the old rule says "the wise astronomer observes around the zenith" ;-). Or buy an ADC. A usable ADC should have at least 2 prism-pairs, the cheaper ones are hardly to use and inefektive on lower altitudes. A well made ADC with two hq-prisms pairs will work good down to about 50 degrees, okay a bit lower but still ten times better than none. Sadly that I just know two companies who offer such in the amateuer range. Large pro-telescopes usemore pairs or triplet designs (its cool, google for that) to be able to correct even lower. Its a riddle why so few know about that and prefer to give up more and more money for "better" telescopes, oculars, software and so, all things that can solve the physical problem of dispersion, instead of buying an ADC. Including me. For all the money that I waste on the way my current setup I have could buy tho aperture steps up on my nice oil-filled triplet Refraktor. Expansive learning.
And an ADC is sooooooo! cool. It feels just like an focuser for the colour. Try it a venus on daylight, Without its a wobbling bright glob, tune in the ADC and snap, the colour is off and there is a shape. Hard to describe, easy to see. It is also a excellent tool to seperate double stars.
My list of astrostuff I have had to buy much much earlier: An encoder driven mount instead of annoying autoguiding, an ADC and an simple polar alignment wich is, thanks good at least this, common nowadays. Each of them saves me now ton's of nerves, time and errors.
Thank you
Great video! and analysis. Sharpstar is sending me the 120mm version from this series. Will be fun to do some similar testing.
Excellent review! I just got the little sibling 120 APO a few months ago, loving it!!
I have the Askar 103 and I use it in my Bortel 4 skys at home - I love the images I get from it!
Niko, love your composition. You have a real artistic eye for that. Your new observatory looks really nice, you must be proud of that.
Thanks for a great presentation! Have a much fun and dark nights!
OK, right up front it's beautiful and I'd love to have one. My big argument against it though is exactly what you pointed out at around 4 minutes - if I am going for ~1m focal length at f/5.6 - f/7, I could get an entire quality imaging system for $5k by going for a reflector. There is a reason why refractors aren't this big - they're just too expensive to make.
8:30 I'm just amazed at the steadiness of the air! Here in the UK we have to wait a long time to get that.
Thanks for another great video. The observatory looks really nice. Will be nice to see your next documentaries for the build.
Ditto! I was like, "What?! The roll-off roof is done?! Where's the video?!" ;) (Great video, Nico!)
Askar is definitely putting out some nice glass. Excellent results from a scope costing a fraction of the competition. Love the license plate, too :)
spot on. I'm so impressed with their recent stuff. I want to sell my Esprit for one their newer scopes.
@@beatsntoons indeed, there's a very good comparison between the Esprit 120 and the Askar 107PHQ in a forum !
This is a wonderful review, Nico! Thanks and keep up the awesome work. Fantastic images!
Thanks Cody!
Thank you for your excellent review. Based on this I just bought Askar AP0 120. I have been following your channel for while and I appreciate all your work. One think I would like to point out is the traces of chromatic aberration that you showed in the 2 parallel examples. When you are comparing the views from the flattener and reducer the reducer sample exhibits more chromatic aberration because you are basically you are shortening the focal length this actually changes the calculated compensation on the telescope and produces more chromatic aberration. This event will happen to any telescope that uses lens elements because different wave length of light will bend slightly differently and the focus point will be slightly ahead or behind based on wave length. When you shorten the focal length with the reducer you are causing the light to bend on a steeper angle and this will increase the effect of the chromatic aberration making it more visible. So in collusion if you would like to achieve the maximum optical performance with the minimum chromatic aberration you need to choose a sensor that does not require reducer in order to prevent the additional chromatic aberration. Also the higher the pixel density on the sensor the more defects it will pick up from the surface finished of the optical elements . Again matching the sensor to the optical tube even at pixel density will ultimately improve the overall performance and produce better looking images.
I'll never be able to do this kind of photography but thanks to your channel i can enjoy it, too!
Now that's a chonky scope. Makes the EQ6 look like an EQ3.
I have just got a Bresser AR152L (6", in old money) refractor.
So far this is how my viewing goes:
Step-1, Take out mount/tripod.
Step-2 Take out telescope .
Step-3, Take out bag of lenses.
Step-4 Try to mount the bugger.
Step-5. Sit down for a bit.
Step-6. Starts raining.
Step-7 Repeat steps 1 to 4 in reverse.
I’ve been looking at that 140… the 185 though, wow what a beast!!!
the 140 is borderline for affordability for me - but the 185 is defiantly out pricewise).
the 103 with all accessories is slightly less than the V with all accessories.
the 120 is around $350 more than the 103 and the 140 is$700 more than the 120 (all accessories included).
Excellent video, as usual. Probably can't beat a 7" apo for crisp high contrast imaging. Looking forward to seeing your new observatory.
Dream scope right there! Thanks for the amazing review!
I saw one of these on Saturday at the European Astrofest in London. Awesome telescope at £4750.
A bargain for that size of aperture.
That vignetting you are getting is from the very narrow tubes of the camera. There is now way you would get those sharp stars with those vignetting figures if the vignetting would come from the optics, that is why the obvious problem is the camera opening and also the length of the tube of that opening which is about the diagonal of the sensor. You should have at least 5mm clearance on each sensor corner, but it should be larger due to the tube length, that is about 2 inches. So for this large sensor, a 65mm opening would work well, or the diameter of the correctors back end lens.
From what I'm seeing, you have both 68 and 54mm threads for those flatteners, which is good, because you can have vignetting free fields on full frame and possibly medium format given the very good field sharpness.
I found that "chromatic aberration" isn't purely due to optics. You can also consider atmospheric dispersion to be the cause of the aberration you see in your highly saturated comparisons. The only way to correct for atmospheric dispersion is shooting at high altitudes, using an ADC (which may be only applicable to planetary), or using LRGB filters. Anyways, great video!
It's mostly down to the optics.
Looks like a great instrument Nico! As some others have suggested, the colour split when pixel peeping is probably atmospheric dispersion. The extremely thin blue line just discernable on the left limb of the moon video is a sign of (very well corrected) chromatic aberration.
Well done some beautiful shots of the moon and deep sky, thanks for sharing.
Great review Nico. Too much scope for my mount (and pocketbook) but Askar has really been coming out with quality, economical products lately. Tempting! Dr B from Manitoba, Canada 🇨🇦
I agree that the color split is atmospheric dispersion. Interesting scope.
Great review. I just got my 140. Can't believe the price is under 2000 USD... With thr FF and FR, the total is 2600. It seems the 140 is good too.
I have been hoping for the reviews of the new Askar large aperture telescopes.
Thanks for getting one - I am looking at the 120APO (the 140 is borderline and the 185APO is outside my budget)
I wish that they were a little more honest about the ED Glass - or more foreword about what type of glass that they use.
I also wish that the case for these had a cutout for the flattener and reducer and a space for a cutout for an astro-cam (using the default size for ZWO diameter would be nice).
I get more CA from my glasses than the images themselves. Very nice!
Hi there! Thank you very much for your review, probably the first about the big 185 mm😮 May I ask you: Have you detected some spherical aberration during the Star Test looking at bright stars of different colors? Thank you very much, regards from Italy.
It's kinda funny that just one year ago you posted a video asking if there's such a thing as too big regarding telescopes and in that video you were talking about the Askar 130. Now you are really in the big leagues!
Thanks for the review. Thinking about getting back into this hobby after about a 2 year absence. I have a second home/vacation rental near one of the few Bortle Class 1 zones (Greenbank, WV) so I was considering upgrading from a 100mm refractor and had been planning on going to 130 or 150 as those would likely be the max for my current mount (HEQ5) but this has me considering a mount upgrade as well.. LOL-ish
Those corner stars look great. Honestly I'm impressed with what I'm seeing from this APO line. The whole line seems to perform well to the corners despite being the "budget" line. I wonder if a phq version is in the near future :)
Hi Nico, wow thats one monster refractor of a telescope, great video ! Will you make the test data available ? Would be nice to see it, without youtube compression. Appreciate your work, keep it up !
Just added the test data to the video description - thanks!
Mr. Carver, good review on this scope! It's hard to believe you can get such color free optics this large for under 5k. I'm glad you used the SW mount. It's good to know it can handle such a large scope. Are you going to keep the scope?
for sure, I'm glad he used the EQ6-R pro as well - that's a very affordable mount if you are talking about a 20kg load! It's way more accessible than the ones that are designed for piers
CEM70 would be better… the EQ6-R is maxed out, if you do it feed it 13.8v not 12.6v
Excellent, thorough review, Nico.
On an unrelated note, seeing your observatory in the background with all the snow, did you think to install heating wires under your exposed rails to keep the snow and ice clear?
Haven't done that yet, because I haven't done any electrical work yet. So for this winter, I'll just be blowing/brushing the snow out of the rails. Hopefully for next winter, I will have the electrical done and can install the heating wires
Excellent review! I really appreciate your enjoyable and in-depth review. For the money it looks to be a nice refractor. Looking forward to some visual reviews of this telescope down the road.
Great review and images Nico! 👌
Espectacular teléscopio amigo
Beautiful image Nikko
I am a big fan of your high quality work. State of the art level.
I hope you can test the scope more for visual use. Many of us are not imagers.
Funny I was just looking at those expensive scope last night. Good review Nico, Thanks.
Hello Nico, very nice review - loved it. Here's the thing: I've been mulling in my head for rational justifications to buy anything other than very fast optics; I own a RASA8 and the advantages of f/2 imaging are obvous. I mean, who would want anything other than f/2?? Indeed, why on Earth buy a 5000$ f/7 OTA, when you can have a 2000$ f/2 system that cuts integration times by more than a factor 12 ?? After a few months of letting that float in the back of my head, one day I found the answer. In one word : definition. Of course. An 8" RASA at 400-mm focal length doesn't quite cut it compared to a ~1400-mm 7" APO refractor. I can see a not insignificant difference when comparing your Elephant Trunk Image to mine taken with my RASA 8. A 1400 mm f/2 system would have to be a prohibitive a 28" aperture. So now, yes I think that a higher definition with beautiful details such as the one you've shown us is worth waiting 12x longer to obtain it. It's all a matter of compromise. Thanks for helping me sorting this out!
Say... have you compared an EdgeHD 8" with the Askar 185 ??
Different systems for different targets. A f/2 system is a wide field scope, and f/7 or 8 or 10 is a narrow field scope. If you want to image a small galaxy a f/2 system won't do it.
Agreed, there are pros and cons to each. With Edge stars are worse then on apo refractors, filter choise is much limited and you can't have filter wheel on rasa. On the other hand if you are living under darkish skies you find that more than 10 hour integration (on F7 scope) is not really necessary and with higher focal length you can get much more details impossible with shorter focal length. My favorite photos lately has been from a guy on astrobin with 1000mm F7.5 takahashi apo using medium format cameras. With such setup you can get wide field shot but also so much details with single stack that you can zoom and zoom and find new details or galaxies you never thought were there.
@@blufferblue1599 1000-1500 mm FL is a sweet spot for all sorts of targets. Extremes like f2 or f10 are for specific targets, that's why many people use more than one telescope. There is no do it all setup, but there is some middle ground. Luckily the middle range of the FL is where you find many newtonians, so you won't have to break the bank for a Tak
Right. Speed at a given resolution depends only on aperture not f-ratio, all else being equal.
So preordering this in germany would cost 7000 € which is roughly $ 7600. Why do we have to pay almost 3 grand extra (the UK should be even worse off)? Just think about the camera equipment you could get for that price difference alone...
Same in Italy, 6500€ is the lowest I can find, insane difference.
Happens a lot with zwo cameras or their mounts, some things are $1000 difference between US and Europe. Way more expensive in Europe.
Because my preferred Bordeaux costs me $26 CND, and it’s 2 euros in France. Get the picture? Not to mention the Sangiovese which is X10 here compared to that great Bellavista restaurant in Impruneta, IT. The 185APO is $6500 CDN (4500 E) locally. I get your point. Is there a US-China trade agreement we’re missing?
@@Prtender I'm aware, yet this still this seems extreme.
@@rcjoub I also get your point but to me that's no reasonable justification. You can't tell me that the logistics of shipping and selling that thing overseas cost 3k.
1:01 my opinion is no, especially if you have a dedicated spot and a large mount you might as well just have a 10 or 12 inch reflector astrograph , shorter exposures and more data in theory.
Good review and congrats on the observatory, but way too many compromises in a 180mm scope for $4800 for me.
There is something very beautiful about the moon video, it really takes you there. Looks like a great scope for a very reasonable price. Oh, and that number plate 👍👍
Obviously, as in all telescope choice, focal length and image scale depends on local seeing. That 's why i've got my TEC 160FL with AP QUADTCC x 0.72. I'm also very happy with my Askar 107PHQ.
As usual AMAZING ,once again nice review
I love my FRA400. Very sharp and round stars. It works well with my ZWO 2600MC. Clear skies to you, but it's been raining here in NorCal since Christmas... :-(
Great review, very detailed and all the aspects that are important. Well done. Thanks.
Please tell me the visual Strehl ratio of the Asker 185 APO.
By the way, Takahashi's large aperture refracting telescopes TOA-130N and 150B are completely aberration-free. And the imaging performance of the TSA-120 is close to them.
Great repport! Thanks 👏👏
5k is many greens, but heck if it isn't very good value!
Always enjoy your great videos, and I must say, it's because a part of your dear persona comes through.
I could listen for hours (and I have xD). Must be a show to accompany in loco for one of those sessions.
good things and clear skies :)
Rewatching this video, that flare effect is most likely from the notches on the lock rings in the flattner and reducer. Might need to change them to the hole style to avoid the light skewing and causing those flares.
I still can't get over the results people can get from their own backyards. Less than 20 years ago you would need the Hubble to take such photos. Then last year there was the introduction of the scope I'm most interested in, but can't afford on a retirement check, the ZWO SeeStar S50. I live in SW Utah, dark skies in my backyard and really dark skies a 30 minute drive away.
Excellent video Nico! Looking for to seeing more from this scope! Clear skies!
Great Video, Are you using Topaz Photo AI? It was a Game Changer for me. This Telescope is on my next buy list to be mounted on a CEM60EC Mount.
Seems like Askar did a good job with this and I'd be surprised to see much better results than that from one of the more expensive refractors. What's your educated guess to what more you can get with a more expensive refractor?
Sharper stars (a little less fuzz), less chromatic abberation when really pushed. That's my educated guess (don't hold me to it) :)
@@NebulaPhotos Fair enough. Sharper images is always nice, if you have the skies for it! But the chromatic abberations where pretty darn minescule on this one 😁
The matched optics really help.
Thanks for the video, it looks like a nice scope. Since I would have to buy a mount and probably a tripod/portable pier as well I will probably not be adding this one to my collection any time soon but it is nice to know it is out there.
The observatory looks finished which caught me by surprise as you know, we only saw the walls last time.
I'm loving the observatory building series and I guess I already now know the end product. GREAT TO SEE IT'S ALL COME TOGETHER, CAN'T WAIT TO SEE HOW YOU GOT THERE.
Love this review, Nico! I've been wondering about this scope's performance because it is less than half the price of similarly-sized refractors. Seems like it lives up to the hype.
The Skywatcher people are going to love those eccentricity numbers!!
I find them amazing and never thought you would get that with that scope on that mount; just on its length alone!!
Excellent video….. as always.
Please review the willam optics pleadies 111
Great performance from the Askar and good to see your observatory in action.
Great review. Concise and focusing on what we need to know! Thank you!
Excellent review. The TEC180FL has been on my want list for years, but this Askar 185 is nearly a quarter of the price and seems like a superb value based on your imaging results. I do think it is best in an observatory as opposed to a portable scope. I am curious how it does as a visual scope on planets.
Great shots, Nico! Great review! Thanks!
I'd love to see a shootout between a large newt and a giant refractor like this. Both a similar focal length, image scale. In the end it's all about image quality. Would a 12" f4 newt or this refractor be better?
10"f4 newt for .8x reducer.
Each system will have pros and cons. People often turn to refractors because they are easy to work with, and usually have higher build quality, 0 maintenance, and this translates into a better image. Mirrored scopes have a much wider range of build quality. Just look at the price of a Chinese Newt and a ASA Newt! Unfortunately ASA doesn't make small newtonians anymore, they only offer a huge 400 mm aperture one at 47000 Euros. So if you compare and expensive APO and an expensive Newt, the results would probably be the same. If you compare a top APO with a Chinese newt probably the APO would do better, as the saying goes, you get what you pay for.
Lastly I'm not just throwing ideas, since I use a top 8 inch apo, and I know what they are capable of.
Hii sir pls reply iam new to astrophotography i dont have star tracker i live in bortle 6 zone i want to photograph orion nebula can i take 30 minutes of exposure everyday for 6 days to collect 3 hours of data on same camera settings and then stack it is it possible can i try this to collect more data
Good to see a sky watcher mount there! And thanks for your content.
I really want to see a comparison between these large aperture refractor and a reflector at similar focal length (like a 10 inch F4 or 8 inch F5 reflector), as the reflector is much cheaper. I just checked my reflector performance and found that the median FWHM and eccentricity is not a lot worse than this refractor (like 10% worse). At a higher focal length the astro seeing is an issue and the refractor may not keep its advantage on optical performance
Those results are stunning, and the cool factor of a 7" refractor is high. But let's keep perspective. Equal results can be achieved with an 8" sct at a much lower cost, and dramatically easier to handle package.
What is the central obstruction of an 8" SCT? On a C8 I believe it is 28% from diameter, which would lead to a 146mm clear aperture.
The refractor has a faster focal ratio, though, when using the reducer. But you have a point about the portability/size for sure.
@@zorg1396in terms of equivalent light-gathering surface at a 28% linear obstruction, you are at 192mm aperture. In terms of resolution you still have a 200mm scope with a reduced Strehl ratio. In terms of corrections, there are residual field curvature and chromatic aberrations in any scope of any optical making and have to be tested just as Nico did here.
As someone that owns both a large-ish SCT (C9.25) and a 6" Apo, I don't agree. The refractor has noticeably better contrast for example. There is a lot of scattering going on inside an SCT.
This is one thing I’m trying to wrap my head around…. How equivalent would a 8” edge hd and a 8” refractor in terms of exposure time if both are at f7? I would think that the 25% surface area of the sct central obstruction would reduce the light gathering ability, making it more equivalent to something at a higher f ratio that has no central obstruction. So, if we are taking the f7 of an sct at face value, how much faster would an f7 refractor be? 25%? I feel like there’s an aspect to this I’m missing…
Great video! Which would be better or would it be worth the price difference to go with the 185 over a Celestron Edge?
The chromatic aberration IS atmospheric distortion as this is defined by a vertical shift in colour. While it can be corrected with an ADC it cannot be corrected with filters as some have said. This is because in addition to image shift, the scale also changes. Dispersion can be present above 60 degree. Chromatic aberration manifests as a halo as light is focused in one wavelength but not focused at another. As the defocused wavelength is larger, its colour surrounds the focused wavelength. Fundementally as a supplier of premium optics I cannot be anything other than very skeptical of this telescope. The time needed to manufacture glass elements of this size and optimise a cell to allow for thermal emissivity takes time and skill. The cost of the optics just don't add up. I am hearing lots about very poor star test results. This review sample may not be representative of a production scope.
Thank you for the full explanation on the chromatic abberations. I wasn't aware that atmospheric dispersion could be that strong so high above the horizon. Lesson learned! Cheers, Nico
great work , as always. this is a beast of a scope, and it looks very promising at that price. it would be nice to make a visual orientated review using single eyepieces and binoviewers. i know it's not your area of expertise, but since there arent any reviews online yet , it would be nice. also your observatory looks great! clear skies!
YOU GOT ONE!! AWESOME
The video of the Moon was very cool. Thanks for the videos.
Great video mate, thank you
About three months ago I was shocked that this refractor cost € 6.800,- here in Europe, really dirt cheap, about 40% of the cost of premium brand refractors in this class(LZOS, CFF)!! Now I am shocked again since I learned that in the USA it cost $ 4.800,-, about 4400 Euro's! These price differences are one of the reasons I seldom buy new stuff in Europe, only when in big need. Anyway nice review and have fun with the big glass!
Stunning images. How difficult was guiding?
Damn, Nico !! That's massive ! 😂 Can't wait for what you're gonna capture with it !
it would be interesting to see RGB or one shot colour test.. I think it might show capability of the optics more.. certainly for Narrow band your results look decent enough considering the price point.
All the imaging tests I'm showing from 9:36 to 15:30 are OSC with no filters. The only narrowband results I show are towards the very end from 16:30 on for people interested in that. But I agree OSC is the true test which is why I spend so much more time looking at those results.
@@NebulaPhotos thanks for pointing that out - my phone rang and I thought I paused it looks like I missed a section 12:48 at zoom of 1-2 the stars were actually looking very good.. this is pretty good value for the money if the optics are consistent at this price point. I am thinking most people if they had this would be happy with the results.
It's not just the 5k for the 'scope, it's the upgrade to the EQ8R or Paramount, Losmandy or similar that'll catch you! 😂
What's the size of the native image circle that the scope creates?
Are you still connecting the camera with a 48mm extension tube? Needs to be 63mm for the FOV then drop to 48 only at the filter and Camara. No more light drop off that reduces contrast.
4500$? In Italy it's at least 6500€...
That said, even for 4500€ I think I'd still pick something like a 12" Newtonian that can cover even a ff sensor with a top end coma corrector.
Quality looks nice tho.
Excellent. Well done mate 👏
Fantastic instrument, for 4800 USD that is a pretty good deal! Nice pictures as well, you are clearly on the more experienced side of astro photography 🤩
Skywatcher brought me here, lol. This is a great transition from the What’s Up Webcast!
That vignetting is because the camera uses 48mm threads, they need to use a wider interface it probably has nothing to do with the scope, but it would probably be less pronounced on a slower scope
Nice review and your channel. Will be doing my astrophotos,( planetary) with a achromat 120mm 1000mm focal length Celestron XL and a Baader semi apo filter and using the ZWO-AS1224MC color camera on a XL 70 equatorial mount. As a note: Just got into this and at the age of 80 so maybe can do some simple processing with the SWO soft ware. Again, Thanks for posting very interesting. At 3,700 ft in North West Arizona
would love to see some side by side images of other telescopes of the same targets. great work
Totally different to see this from the dark site in NH! ❤🎉
Some wonderful raw Lunar work. Great glass.
Really enjoyed this video 👏 thanks for putting this together 👍🔭
Hi, Nico...did you experience any of the flaring Trevor encountered with his test setup? If not, do you expect it was a consequence of variance in manufacturing or possibly a transient set of events on his imaging session?
I didn't. I think it must be copy variability, as he tried it a couple times and got the same flaring each time. Mine hasn't shown that at all, and I've tried it with various cameras/filters across multiple nights.
@@NebulaPhotos That's very helpful to know. Thanks.
Great review!
Excellent and informative review.
That's a monster telescope! And although expensive, I agree that the price is surprising. $5k is still a lot but it's "not bad" compared to some other higher end refractors.
I sure like the ZWO ASI6200 but I don't have an OTA than will cover the entire full frame. I have an 8" Edge HD with a 0.8x reducer and although they say it will work with a full frame camera, it won't. All my images had terrible vignetting that looked like huge light leaks. That camera costs almost as much as the 185 APO. Better have deep pockets as you probably need the EQ8R to round it out. ;o)