Mak 180 owner here. You can eliminate the need for cool down and greatly reduce dew by adding a layer of insulation on the outside of the tube. The distortion from cool down comes from the formation of eddy currents in the tube which are a result of (relatively) rapid cool down. Slowing cool down reduces these dramatically and keeps the meniscus warm enough to inhibit dew.
You forgot the Meade LX65 and LX85 SCTs. Same 200mm ACF optics of the LX200 that are lighter at 5kg and cost less. They have no mirror lock and have the lighter vixen dovetail. I own the LX85. Great telescope so far.
Finally, a "best telescopes for planets" list that actually compares the best telescopes for planets, but not a bunch of $100 to $300 entry-level telescopes.
The Maksutov-Cassegrain has a smaller aperture, but makes up for it by having only 26% secondary mirror obstruction. This basically gives you the same aperture surface area as the other Cassegrains and makes it FEEL like an 8”.
Good discussion and you arrived at my conclusion for a planetary telescope, the classic Cassegrain. You might also want to include the Ritchey-Chrétien Cassegrain but that gets more expensive.
Awesome video as always mate, I'm always watching your content as my first go-to for help/guidance with my purchases! Thanks for making these videos, truly the best on the internet at these types of videos, thanks again.
My Sky-Watcher Skymax 102 is a dew magnet. It's a splendid little Mak; however, it hates the Amsterdam humidity. I made my own dew shield for it. I had an old 10mm thick foam camping mattress. I measured and with a craft knife, cut a strip 20cm x 45cm to wrap around the tube. A 1/3 of it covers the length of the tube. The rest extends in front of the tube, like a lens hood. It's held together with velcro strips. The little Mak is now Amsterdam proofed. I've had the scope out for hours and hours and I've experienced no dew on the corrector plate. it's a really cheap and effective solution, to a really annoying problem. The mattresses, can be bought at military surplus shops, (legerdump) for next to nothing. Sewing shops have self adhesive velcro. I did help sticking the velcro to the foam, with some contact cement. I've enough foam leftover, to make many more dew shields for additional telescopes too.
You're absolutely right. I've made separate videos about mounts like this one: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-8SNDKN_GtRA.html. Perhaps I should also make a video to discuss whole astrophotography setups (mount, telescope and camera). Cheers.
Very well presented video. I think the main issue with central obstructions in the disruption of the light wavefront due to diffraction, rather than simply shading the primary.
Very insightful video! Thank you very much! I think one thing you have left outside of your considerations for this comparison is contrast. I've read that SC telescopes excell in that regard which is probably where they beat the classic cassegrain. It would be really interesting to do a side by side comparison between a classic cassegrain and an SC with otherwise similar specs.
Hi Lennert, I made this video one year ago. AFter that, I bought a CC but couldn't get it collimated. After a couple of frustrating nights, I decided to go for the Edge HD 8". It came collimated out of the box, and produces nice, high contrast images of the night sky. You can find my latest review on that scope here, perhaps useful: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-nYlQv11o6DE.html
Most SCTs actually have poorer contrast compared to Maks or even Newtonians. They excel in their compactness which allows to build small instruments with large aperture, and their short cooling time comparted to Maks.
Very infomative video! Personally I prefer aperture over focal length since you can buy a 2x or 3x (or even 5x) barlow lens but you cant increase the aperture of a telescope
In my short experience, you need both for planetary clarity. Without slowing it down, even with a 3X Barlow (no one uses 5x after 1 or 2 tries - let's be honest) you lose clarity. Of course, you could use a sensor and then slow it digitally, but I am speaking of optics. My home made steam punk looking 8" 750mm with a 7mm 1.25" eyepiece sees Saturn (and 4 moons) as well as Jupiter (and 3 moons) and even Mars (3x Barlow + 7mm) however, it's SO FAST that I can't resolve any detail. I can see witch head Nebula very clear, and can resolve clouds with my eye in Orion Nebula with a 40mm PlossL. However, my eBay-mirror, refurbished Mead 110 x 900mm with a Celestron 12.5x and 3x Barlow can resolve the rings of Saturn VERY easily. I have tried using a restrictor to slow down the scope and adding a long "dew shield" but nothing seems to slow down the 207mm. @Wido's AstroForum has a video about it.
A late comment here but, one of the benefits of the SCT and Macsutov are is correction of aberrations that the classic Cassegrain generates. So image quality I think should be a criteria. Certainly there’s a threshold, I believe the edge of frame is worse in the classic Cassegrain, but it’s worth a consideration.
It's the opposite: Classical Cassegrains use aberrations better controlling parabolic and hyperbolic mirrors. SCT/MCT use "cost downed" simplest optical surface spherical mirrors causing spherical aberration, with corrective element needed to counter that. Neither does SCT give exactly good wide view: Both Celestron and Meade have models with extra optics to improve off center image quality for photography. But anyway professional wide angle astrophotography often uses Ritchey-Chretien Cassegrain with also primary mirror being hyperbolic.
Thanks for the video. I am also looking for a suitable telescope for planetary imaging. And my favorite here would also be the Cassegrain. One thing: For planets and the moon, it would be a big advantage if the telescope can work in the infrared range that is less affected by seeing conditions. That would be another plus point for the Cassegrain, it has only mirrors and no glass elements that can block infrared. But: Cassegrains suffer from coma! It doesn't matter for planets, but if you want to take a picture of a small deep sky object with the device, the stars don't look nice anymore. The alternative would be a fully corrected telescope like the TS-Optics 8 inch Ritchey-Chrétien Pro. In terms of price, it is almost the same. Disadvantage of this telescope: Collimating is probably quite a challenge. I am curious to see which type of telescope you choose. Many Greetings from Hamburg :-)
A classic cas will have the same collimation disadvantage as an RC as you still need to adjust both the primary and secondary when collimation, and may even need a Collimation Ring / Tilt Adapter to get the focuser inline. (I own an 8" GSO RC and use it for my planatery images).
Hi both, thanks for your insights. Just an update from my side, I spent the last two nights trying to collimate a classical cassegrain, it is very challenging for me. Hope to make some videos on that as well. Clear skies!
@@AstroForumSpace What did you use to collimate? When I did my RC I use a takahashi scope and my guide cam attached to the end so I could view it in sharpcap (you don't need the camera, it just make its easier to see your adjustments). I don't know if this applies to the classic cas but with the RC it helps to remove the baffle from inside the tube so you can see the reflections of the spider on the secondary. This helps with adjusting the primary. If you have small enough hands you can just reach inside the 8" and unscrew it and gently let it rest inside the tube (but don't forget to re-attach it before moving the tube)
The LX200 with the ultra high transmission coatings and hyperbolic secondary mirror (semi-Richtey Chretien) May have the overall best optics of the group.
I went with a 254mm dobsonian. 3200 RMB (around $500): cheaper, bigger aperture and smaller obstruction than the others plus no corrector plate. An extra $250 went on a 5x power mate and I now have a scope that can give me 6350mm focal length which I can use with my Mirrorless camera to get close-up planetary shots. At 1270mm I can see the full moon in frame with ease which isn't the case with any of the 2000mm+ scopes. Drawbacks: portability (1.3m tube), weight (11kg). For the price though, very hard to beat. Planetary cam + 2x Barlow instead of powermate for even cheaper route!
Hey, I see your comment is a year old. I hope you still watch this, lol. Is your scope good for visual as well as being good for imaging? The only way I am gonna be able to drop the money I need to, and NOT have my wife divorce me on the spot, is if I can have a set up for her to look through and see things while I'm imaging on my setup.
@@kevinashley478 Dobsonians are fantastic for visual- hard to find better for the money. Imaging is probably planetary only- you'd need an equatorial mount for deep sky objects. If you get go-to dob, that will cost quite a bit more, and will improve the planetary imaging and visual usage, but still not good for deep sky photography becasue of field rotation.
I just received the Orion 8" newtonian reflector today! I thought maybe Id try a little planetary, but its mainly for deep sky. One thing about it is its very fast at F/3.9, even faster than my spacecat. I may have to look into a 2x barlow and see if I can do a bit of planets also!
Great videos, dude! There's one caveat, you're probably missing about secondary mirror obstruction: you show linear obstruction in the spreadsheet, i.e. obstruction by diameter. If the 33-34% light obstruction would be true, you could cover the whole primary with 3 secondary mirrors, which is obviously not enough :) The light collection power as you could expect is proportional to the area which is in turn proportional to the square of diameter. So the real theoretical obstruction will be for example 0.31*0.31=0.096 or 9.6%. Celestron's official page proves this fact by declaring for their C8: "Secondary Mirror Obstruction by Area 9.77%". So the absolute overall impact is not that great as your spreadsheet says. The relative obstruction loss between the tubes will also be a bit lower, but not that much.
I do not think it is actually the matter. The mater in planetary imaging is that the secondary obstruction impacts how the Airy disk appears: the larger the obstruction, the more energy is dispersed into Airy rings, rather than the central spot. This makes little difference during good conditions, but in bad observing conditions makes the image way more suspicible to seeing.
Planetary viewing is about resolution and in that it's the diameter of obstruction which matters. And in corrector lens using Cassegrains (Schmidt/Maksutov) actual obstruction is bigger than secondary mirror size, because of secondary mirror's being surrounded by "baffle" tube/cone. Also because of usually viewed planets being quite bright, reflecting of light from tube walls (to mirror) should be minimized by either baffles or flocking.
@@tuunaes resolution is about how far the farthest points of the mirror are from each other, or simply diameter. Obstruction harms the light collecting power, not resolution.
@@AstroForumSpace I visited Utrecht several times. I used to live at the Dutch border on the German side and been everywhere on the Dutch soil. Love that place!
I use the N200/1000 for deep space, haven’t take a picture yet. But you have to align the mirrors so many times during the night due to temperature decrease.
I'm no expert but I heard that you should have your telescope out side for about 4 hours before you do your viewing. It's got something to do with having the telescope at the same temperature
@@TIGER-rx8gt hmm okey, i mostly have it set up 2 hours before polar allignment (so around 10 oclock). Sometimes even earlier. And then the mirror alignment at 12, but at 1 oclock or sometimes even earlier the alignment is already wrong.
I took the LX200 as it is much liked among astronomers, but the LX65 (and 85) are also interesting. I wanted some between brand variation. Perhaps a good idea to do within brand comparisons as well. Clear skies.
You're welcome. By the way: I finally decided on an edge hd 8". It's more expensive but gives me excellent views. See other videos on my channel. Clear skies!
... one thing to note with the range of Classic Cassegrains on offer the TS version has quartz 'glass' for both primary and secondary mirrors - so is a bit more expensive (approx 100€) than the Omegon variation at base price without discounts. Having quartz 'glass' offers the least flex as temperature changes - so effectively the 'fastest' cool down period too. The thermal coefficient of the 'pyrex' alternatives is not as good - so cheaper glass = cheaper telescope.
Thank you for adding this info Seafox. At present, I'm having a very hard time with this scope. The primary is out of alignment and this is the first time I'm collimating a classical cassegrain. I might need to buy some tools beyond the chesire piece that I've bought with the scope.Clear skies!
SnaxxNZGaming some people like to have at least some dual purpose when buying a multi hundred dollar telescope. I understand SCTs aren’t the best for deep sky but they are good for a lot of objects out there.
Hi Wido, As always a very nice and informative video! :) I wanted to ask, what would be a better choice between a 127/1200 achromatic refractor and a 127/1900 Maksutov Cassegrain considering both solar system and deep space photography and observation? I had almost made up my mind for a big Newtonian (8" or 10" aperture) but as a first scope I want something which is not too bulky.
The MAK is Nice for planets but too slow for deepsky. The achromat is faster but will show false colours and will still be somewhat slow. Don't know your budget but perhaps a nice widefield ed or apo refractor?
@@AstroForumSpace Thanks for the input! One more question in that regard. Is ED Hexafoc any good compared to ED APO? I see that ED hexafoc is a lot cheaper compared to ED APO. Budget wise I don't want to go beyond 1000 euros but since I am in India I dont get the same options as EU/US and some of the items have huge import taxes.
@@abhimanyusingh2572 Hi, "hexafoc" refers to the focuser, not the glass of the refractor. ED stands for extra dispersion glass, which greatly improves colors. Always check if the refractor is an ED doublet - two glasses - or triplet - three glasses. triplets have the best color calibration but are also heavier and more expensive. APO usually refers to 3 glasses, but always check this. Good luck!
The Ttitle of the video is somewhat misleading. It's not "viewing" but "photographing" planets. The best views of planets are achieved with refractors. Best views through an eyepiece of Jupiter and Saturn I ever experienced was with a Zeiss 150mm f/17 refractor (achromat if you can believe that) in the stady airs of Southern California. Yes the view through only 6" was better that any Newtonian and Cassegrain of much larger size. We also compared it with the "rejected" scope, the Evostar 6" refractor ... superb telescope, a tad inferior then the Zeiss. If you're into high-res planetary "Photography" then that's another discussion.
Now I know you removed the Evostar 150/1200 Apochromatic refractor from your list based on price, but how would it have compared in the standing regarding the categories and requirements (other than price) to the other in this video. I would rather postpone my purchase in order to save a little more to get something that I would let be happy with, planetary viewing and photography.
Sorry I was again too quick for a comment you did indeed report that the import costs are there for something in between that the prices are higher here
When you say 500$ ;it is around 38000 INR .But the reality is that amount will have a multiplication factor in India (3 or 4) . The very next possible thing is " Forget astronomy and get in to Photography". me- Proud owner of a crop sensor mirror less.
Yes, astrophotography, unfortunately, is an expensive hobby. You can try to cut down costs by choosing a newtonian reflector and perhaps a used but good EQ mount. Clear skies Rejith!
Hello from North-Holland (Schagen region). Great Video! Since I watched the sky through my binoculairs last week I have gotten more excited about Astronomy and possibly Astrofotography.. I have watched a few videos since on RU-vid, and saw a lot of people stacking hundreds of images to get an impressive end-result. My question now is, when looking with just my eye through for example the Classic Cassegrain telescope, how much detail will I see from let's say Jupiter and Saturn.. Can you link an example maybe? My second question is, which mount would you suggest with these telescopes? Is there a good price/quality equatorial mount you can suggest? Thank you in advance and keep up the good work!
Hallo :-) and thanks. You will get a decent view of jupiter and saturn if your focal length is about 2000mm or higher. I have another video where I explain how you can exactly calculate your field of view for astronomical objects, depending on your camera and telescope here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-tIFmmn4KdaM.html. I'm working on some videos to actually show you in real life, stay tuned and I hope I can deliver on your question soon. And this is a blog and video on "beginner level mounts" for astrophotography: astroforumspace.com/category/getting_started_astrophotography/ Good luck and enjoy the hobby :-)!
@@AstroForumSpace Thank you! There are just so many possibilities and choices one can make trying to find the right telescope and mount.. it's easy to get completely lost when you're new into astronomie.. XD
@@kmpsgarage8226 en uuhm als je Nederlands spreekt dan kan dat ook natuurlijk :-). Als je vragen hebt, stel ze gerust. Groetjes! Mooi trouwens dat je in Schagen woont. De hemel is daar vast een stuk donkerder.
Kijk ook naar rc telescopen. Zijn een van de beste die je kan kopen en die telescopen voldoen ook aan je punten. Je zal dan wel moeten gaan voor een focal length van ong 1400
I didn't include RC telescopes. They are very good for deepsky, but have a large secondary mirror which makes them less suitable for planetary imaging as compared to the telescopes in the overview. Thanks.
@@konfey3198 zijn goede telescopen hoor. Ik moest een keuze maken anders zit ik uren te kletsen en daar zitten mensen denk ik ook niet op te wachten :-).
@@AstroForumSpace Thank you, i did see that used Mak for $1275. Still, it's not the $1,000 youre showing for new ones. I'm not complaining, just noting that the prices I see and hear from RU-vid channels (like Ed Ting) are always unrealistically low. ? Even though your pricing was 15 months old, the $1,000 new Mak went to $2,200 in that time. Prices are skyrocketing and supplies are low. What's happening?
Hi. I'm using the SW 200/1000 for deep-sky and moon imaging. My daughter has a Skymax 150/1800 and i can only say that this OTA is a dream for the moon, jupiter, saturn and even venus.
Very good video! I have a vintage D 75 mm, F 1200 mm Unitron telescope (1957) with 6 eyepieces from 4 to 25 mm. It is in relatively good working conditions. I am wondering if it would be a good idea to buy new very good quality eyepieces and a barlow eyepiece too. Would that really make a difference in the planetary and some other space objects viewing? Or perhaps keep the old telescope and save some money to buy a new one for home astronomy observation and photography? Would appreciate any suggestions, clear skyes for you all!
Hi Rodrigo, thanks you for your kind feedback. It depends a bit on what you want to do visual versus photography. If you want to get into astrophotography, you'll need a couple of things...a decent equatorial mount to accurately track the stars, a DSLR or dedicated astrophotography camera and a telescope that preferably doesn't suffer from chromatic abberation and such. I wrote a blog about the steps you may want to take to get into astrophotography, perhaps useful: astroforumspace.com/seven-essential-steps-to-start-astrophotography/. Clear skies!
AstroForum Thank you very much for your kind and prompt reply. Do you think for visual observation (not astro photography) the image will improve reasonably with good quality eyepieces and barlow using my old Unitron telescope? In the new refractor telescopes, the triplet lens go only in the eyepieces or also in the main lens? My two sons are studying in Netherlands. Best regards from Costa Rica
@@rodrigobustamantevaz8555 Pura vida:-)! For visual astronomy I think some high quality eyepieces are good enough. You may want to consider a two lens doublet with extra dispersion glass. They have good color correction and are mas barato qué Los APO triplet refractors. Buen dia y cielos despejados :-).
Hi Terry. The Newtonian has an 8" aperture which, combined with the barlow would meet the criteria I mention in the first part of the video. Clear skies!
What is the big difference between the Schmidt and Maksutov Cassegrain telescopes? Which would be better for planetary or deep sky astro photography? Thank you
The MAK has a longer focal length (=higher magnification) and a meniscus plate with a small secondary mirror. I would say maybe slightly better for planetary than the SC's but I'm in the process of testing this out myself.
Hello , did the RC are good for planetary and had a similary aperture of makzutov 180 😅? Im a dobsonian passionate … i have a 10 inch and 16 inch ! But the difference for the profound skies and planetary its an RC or classic cassegrain like GSO ? What difference ?
I returned the RC as it was very hard to collimate. I now own a celestron edge HD, an astromodified SCT, much easier to collimate and long focal length.
Hi philipp, with planetary this is less of an issue I would say, as you will be shooting videos with short exposures - entirely different from deepsky long exposure astrophotography. All the best.
Schmidt Casegrains ar no good for viewing planets, they have huge central obstructions, they give softened, blurry images. However, large aperture like 9,25" or higher SC scopes can give reasonable images for planets. But 8"??? Nope. The only good scope mentioned above that really excels for planetary viewing is Skywatcher 180 Mak-Cass. It has small central obstruction and reasonable aperture. A good long focus Newtonian is also good for planets, I have a Skywatcher 150/1200 it is a good planetary scope for reasonable price. A 200/1200 would be still OK. Faster newtonians like the one mentioned in the video (200/1000) is no good for planets because of large its secondary mirror and small F/diam ratio Wanna see planets? Buy a long focus achromatic refractor or an apochromatic one. Or an Intes Maksutov-newtonian, if you ar not a beginner and have lots of $$$. It costs a lot of money, but planetary viewing is not a cheap hobby.
I started with this one, a celestron 102slt. It has a goto mount that automatically finds objects for you in the night sky and a nice achromat that is good enough for visual (not photography) bit.ly/300lItW. Clear skies
