All the Common Solid Tube Dobsonian Reflector Telescopes Compared!

we're here with all the common sizes of solid tube dobsonians the four and a half inch the six inch the eight inch the 10 inch and the 12 inch we're here to determine which one of these might be right for you let's get started now the dobsonian reflector is of course one of the simplest and most recommendable telescopes out there i don't know if very many people who don't like these even people who have thirty or forty thousand dollar telescope rigs usually have one of these in reserves where just when they wanna take something out and go observing these are also the most economical of the designs by a far margin if bang for the buck is what you're looking for look no further for example the eight inch model in the middle here sells for about four hundred dollars now try pricing an eight inch mid caster grain or my goodness try pricing an 8 inch refractor if you can even find one for sale now again these are the most common sizes of solid tube dobsonians you see on the market there are a few uncommon sizes for example mead and orion occasionally have sold a 16 inch version of these telescopes and i don't have one of those and i'm glad i don't have one of those the optical tube alone weighs a hundred pounds and the base weighs close to 80. for comparison 80 pound is approximately the weight of this entire 12-inch dobsonian and let me tell you it was not a lot of fun bringing this telescope into this room from the garage also celestron had a 17 and a half inch version of this star hopper there have been solid tube dobsonians from discovery as well and not to discount the ones from coulter which later became myrnahan those are vintage telescopes as well but by and large if you see a solid tube dobsonian out there there's an overwhelming chance it's one of these sizes now there aren't going to be any big revelations here all of these telescopes are good all of them are suitable for serious amateur astronomers there's just the question of which one or which ones are suitable for you so let's get started now first up we have the four and a half inch clash of dobsonians and there are two different versions of these there's the table top unit exemplified by the star blast this is these this is the telescope that you see everywhere and then there's the floor standing model exemplified by the orion xt 4.5 now i don't have an xt 4.5 with me but i do have this one that i made that has very similar dimensions i built this telescope out of optics that i got at a trade show some primary and secondary mirror in their cells came in a little box for about thirty dollars i thought it was really cute and i built a telescope out of it the only thing i really changed is i made these side bearings a lot larger than the ones you typically see on a commercial dobsonian it seems as though you can't make those things big enough the bigger they are the smoother the telescope motions now if you're looking for a four and a half inch newtonian the one thing you want to be aware of is that you don't descend into the department store grade telescopes some of them kind of dip down in there but if you stay above a certain level the star blast is a good place to start it's about two hundred dollars if you try to spend about that much money it avoids the problem of descending into the junk scope territory there's a couple of issues with these none of them are really serious but you do want to be aware of them number one as you can see they are quite low in the ground i think you can see the xt6 over to the right side of the frame the eyepiece height there is much more suitable for an adult this is going to be uncomfortable for you even for a seated adult it's going to be a little bit low but for a kid it's almost the perfect height now if you had the tabletop model your big problem is going to be finding something to set it on if you're new to astronomy that's a bigger issue than you might think you're all just going to set it on something yeah when you finally get the telescope out there you're going to see the difficulties in finding something i suggested using a big plastic tub that you can set the telescope on and when you're not using the telescope you can put it inside the tub the second issue with these telescopes is they tend to come with these plastic focusers now they're not great but you don't really have a lot of choice here and it's hard to find replacements for these focusers so got to be careful to baby those things and again if you have a kid make sure he doesn't you know reef on this thing too hard if he can't find focus a lot of times what people will do is they'll just keep turning the focus or either all the way in or all the way out until the focuser breaks these star blasts are the telescopes that we place in libraries we have over 150 of these placed in local libraries in new hampshire where you can check them out like a book for two weeks and i can tell you the two major things we wind up repairing number one somebody leaves the finder on for weeks on end and the batteries run out we have to go in and replace the batteries number two somebody tries to turn the focuser too hard and they break it and again spare parts are very hard to find so take care of that focuser and here we are with the xt6 a modern classic so many of us got our starts with a six inch newtonian reflector and this is a great bargain at 300. the tube weighs 13 pounds and the base weighs 20. you're looking at about 34 pounds all told with the finder and the eyepiece on it it's very transportable and it doesn't take up much space now those of you who aren't used to astronomy or you're new to the hobby telescopes always look bigger and bulkier in person than they do in pictures or in videos so when you get this thing don't be surprised if somebody in your household say a significant other says wow that's kind of big it's okay because what you can do is put this up like this and store it in a closet if you think about the actual amount of real estate the telescope takes up is quite small it's just the vertical type things you can stuff this thing in the closet with this with the tube up like this now again it's very lightweight and you're not going to have any problem getting this thing around so you see this little string there it always gets hung up on that knob you can't avoid this but it's good to have it there because you're going to pull this thing down to initiate the tension on the telescope like this other than that goes up and down it goes left and right and you can get your a lot of observing in with a six-inch telescope again for the money really really hard to beat there is one item that i do want to bring to your attention that causes me to recommend the eight-inch these days as opposed to the six inch and it has nothing to do with the telescope or the aperture itself starting around 2008 orion and some of the other manufacturers of these telescopes switched from a metal focuser to this plastic focuser it drives me crazy because if this thing still came with a metal focuser this would be the telescope i would recommend for most beginners it is the same focuser that's in the star blast and in the xt 4.5 and while i didn't complain about it too much in the freak in the previous segment here i'm finding a plastic focuser to be a little bit harder to forgive in a 300 6-inch telescope as opposed to a 200 four and a half inch telescope and i can tell you if you use this thing a lot and i hope you use it a lot you're gonna be carrying the tube around and i can guarantee you at some point you are going to bang some part of the tube on a door jamb the hatchback of your car uh the door of your car if you hit the focuser you're gonna you might wind up damaging the thing and again spare parts are becoming very hard to find now on mine what i wound up doing is i went on ebay and i found some anonymous sellers on china that had metal focusers i got them and i've been replacing them on all of my telescopes now i don't know how reliable this is because you don't know what you're getting in at least one case i sent my money to somebody in china and i never got anything other than that the six-inch dobsonian for this amount of money you can get so much done for very little outlay and i highly recommend this telescope now you can check some of the alternate sources you're talking zumell apertura antares i'm sorry if i'm leaving out your favorite but there are other alternate sellers of the same basic product and sometimes they come with better accessories so check that out if you're inclined and here we have it the telescope i've been recommending as the best beginners telescope for 15 20 years or so this is the 8-inch dobsonian i have the orion xt8 version but again there are other clone models out there isn't really much to say it's just a bigger version of the six it does have a nice two-inch metal focuser you can put your big eye pieces in there four hundred dollars about proximate retail on this thing the weight of the tube grows between 13 and a half pounds to about 20 pounds for the 8 inch model interestingly the basis of both the six and the eight are about the same weight at at twenty pounds so the only thing that really grows is the weight of the optical tube now the difference in weight between the six and the eight is about six or seven pounds and you may think to yourself that's not a lot it's about the weight of you know a little bit less of than the weight of a gallon of water say but again if you've been around telescopes for a while the numbers don't always tell the story this is bigger it's wider it's more cumbersome you're gonna feel that six or seven pounds a lot more than the numbers might suggest other than that the eight inch version gathers about fifty percent more light than the six inch version it's not a huge revelatory difference but little things like dim galaxies which may have been a smudge in the eyepiece become slightly brighter smudges in the eyepiece other than that there isn't much to say at four hundred dollars it's really hard to find any other telescope in this price range that can give you so much telescope for so little money and it's still my number one recommendation for beginning astronomers one thing i like to say is the eight inch dobsonian is cheap useful and it will teach you a lot and it will keep you busy possibly even forever and here's the 10-inch the extra-large version of the 8-inch 53 and a half pounds total the weight of the tube grows from 20 to 30 pounds interestingly the weight of the base only goes up a couple of pounds so we're starting to get a little top heavy with this thing but still manageable the 10 inch is popular for people who have really dark skies who are willing to put up with a little extra weight and bulk to get that extra light carrying capacity again you have a two inch focuser for those big nice eyepieces that you want to put into it balance starts to become a bit of a problem if you put heavy eyepieces in here this may tend to want to creep down on you when you don't want it to some people put some sort of weighting system on this thing just be aware it could happen to you if you start putting very heavy eyepieces on the front now this particular xt10 has been rebuilt and i guess we should address this now because i'm seeing this with the tens more than any of the other sizes people who have been told that the eight is the correct first telescope to buy will often supersize the thing to a ten just because they want a little bit extra then they're not prepared for the extra bulk and weight they use it a few times and it winds up you know in the basement somewhere the basement may flood which is what's happened to this one and water and particle board don't mix or put another way they mix a little bit too well if you know what i mean anyway it gets to the point where somebody a significant other says just get that thing out of the house and that's how this one wound up getting sold now this base has been completely rebuilt by a club member and you could tell he did a really good job he found a template of an existing xt10 and just cut out the parts to match them exactly now with the 10-inch telescope we come to our first and probably only point of controversy with these dobsonians starting with the 10 inch size the weight of the telescope starts to get a little bit too heavy for this bearing that moves this way keep in mind it's only 30 pounds for the tube but the baseboard has to carry the weight of almost the entire rocker box as well and there's almost no amount of teflon you can place down in there that can make this motion completely smooth believe me i've tried amateurs have tried it's not completely ever right so as a result some manufacturers have put an alternative azimuth tracking system here involving a sort of lazy susan metal mount with some ball bearings in it you'll know if you have one of these because you can hear it work this one doesn't have one of those now on these ball bearing type lazy susan mounts you're going to hear strong opinions on both sides i have a strong opinion of this of my own i can't stand those things now for me the problem is the opposite this motion starts to get a little too easy and you know that the manufacturers know that it's too easy because some of them actually will put a breaking mechanism that you can clip on that reduces the friction and wins back some of the friction that you lost by going to this lazy susan type mount i think the brake makes it even worse because it's not completely even all the way around now i do want to point out people will disagree with me on this and they really like the lack of friction if you're thinking about buying a model that has one of those see if you can try it out first to see if you like it everybody's a little bit different one test of a dobsonian is to take it and then move it up at a 45 degree angle when you do that you are engaging both axes at the same time it should go up smoothly as the axes have the same amount of friction in them which this one kind of doesn't i'm having to compensate a little bit as i do this like i say 53 pounds for the entire telescope and 600 dollars as opposed to 400 for the 8 inch at about 41 pounds now if you get one of these these could be useful i had one of these for a very very long time and used it a lot a good combination is to have perhaps a six inch and a ten inch if you can afford it and if you have the space and here we have the big guy the 12 inch 900 83 pounds for the entire assembly 50 pounds in the tube and 33 in the base this is really getting to be about the largest that you want to buy in a solid tube dobsonian format and really starting with about the 12 inch size you want to consider going to a truss type of dobsonian instead now a lot of the same issues i described with the 10 are with the 12 as well except they're magnified quite a bit the balance on this thing is never completely right i have a set of these button magnets that i put on the front and the back depending on what i have on the front here you put a telerad here this gets heavier you put a red dot finder it gets lighter you put a big eyepiece on it gets heavier again so you're always balancing a little bit this one has a system where you tighten this here and there's a tensioner on the other side as well i don't love the design i think i like the orions a little bit better and again this motion here starts to get very stiff as well no matter how much teflon you put down there there's just really a lot of mass here that you have to move and it's tough if you have to make a really tiny adjustment to center something now another thing i want you to be aware of and this is true of all the dobsonians but more so with the 10 and 12. like i say it really doesn't take up that much space real estate wise well this one's starting to get a little big it's mostly tall so what i've seen some people do is they will take the telescope off the bearings turn it upside down and just set it right on the ground board here they'll just set it right here and whatever that space is at the bottom you win that amount of vertical space back in a closet or wherever you're going to store it i'm not going to do it it's just too heavy for me to do this but the problem with doing this is that the weight of the telescope starts to sag the ground board and if you look at this this is the same roughly half inch class particle board it just can't bear the weight over time this is what happened to this one somebody did that set it down for like i don't know a year or two the ground board warped when i got it there were some major you know maneuvers that had to be done to get it back including putting several more teflon pads down there now i know maybe you're not going to do this but if you buy a used one you want to be sure and ask the person if it was stored in that fashion just something to watch out for if you want one of these things again right now the only one of these that's available in the orion catalog is the in telescope version that's the one with the push to electronics if you don't find it if you're not finding one in a pure non-electronic version again check one of the alternate sources your zoom l aperture antares and some of the others should be should be around nine to eleven hundred dollars and again this is a big telescope i have this on a rolling dolly in the garage you can build one yourself just get a big piece of plywood and bolt some casters to it set the telescope on it that way you don't have to take the thing apart to take it out of the garage i just roll the thing out even though it's just about as easy for me to roll out the 12 as it is for me to take the 8 inch outside i'll usually take the 8 inch just because it's smaller and lighter so there you have it an overview of all of the common sizes of solid tube dobsonians hopefully i've given you enough information to help you decide which one or which ones are right for you thanks for watching and i'll see you soon

Channel: Ed Ting

Views: 62,273

Rating: 4.9548426 out of 5

Keywords:

Id: -qVXy7SDDo4

Length: 18min 26sec (1106 seconds)

Published: Sun Oct 25 2020

Reddit Comments

[u/flossy_malik]

Loved it. I just ordered an 8-inch Dobsonian, and the video made me feel more confident about my decision.

[u/gilmore42]

Just ordered the AD8 last week.

[u/imahik3r]

It was an interesting video, but all it covered was mass. Almost nothing about what you can see or tracking ability/difficulty. :(

[u/snakesoup88]

Got the 10in truss explore scientific from Costco recently. Some HW was downgraded, most notably the fine focus knob. Overall, a very good price for a truss dob.

[u/__Augustus_]

This IMO should be linked in the sticky post

[u/ThreeDarkMoons]

One day I'll get that 8". One day..