The Coulter 10" f/4.5 Dob Review - A Classic Retro Dob in 2024. How Does it Fare Today? 

Babe wake up Ed ting posted a video

Ed, you’re one of the very few channel creators on YT whom I’d call erudite. In the late 80’s one of my observing buddies had a blue 13.1” Coulter. He used it a LOT - often with the version 1.0 13mm Nagler. He’s gone now. May he rest in peace. One night he came along with info on NGC 2419 - the intergalactic wandering globular cluster. We each tracked it down with our respective scopes - as always having a grand old time. Before I met him he had a C-8 and did astrophotography out on frozen Lake Ontario. He joked - not far from the truth - that he had no need for a “cold camera” out there at forty below. And he was out there at forty below. I love your channel. Thanks a million for giving a rather prosaic relic its time in the sun.

Coulter brought aperture to the world of amateur astronomy... The first time I saw M51 through a Coulter 17.5 inch I was in shock.

I bought my Odyssey 13.1 inch dob back in 1980 for $300! The best money I have ever spent. I had to wait a year for delivery due to backlog. I hauled that baby to dark sky locations for over 25 years, including a 4X4 trip to Moab Utah. Yes, it was a simple inexpensive telescope, but it was functional and durable. The mirror was slightly less bright when compared to a Galaxy 12.5 inch mirror, but given the price difference, the views from my dob never disappointed. I made a stop-down mask to observe the planets and observed comet shoemaker-levy impacting Jupiter. My buddy and I could visibly see the black impacts from the comet fragments! It was a good scope for the price! Great to see this "ole" girl in such great shape! Brings back wonderful memories, thanks Ed!!!

I remember those adds in Astronomy magazine from years ago early 80's .......................I'm getting old .

My Coulters include: The 4" 'Coffee-Can scope,' a 13.1 mirror that I ordered in 1989 and received 36 months later(!) which I housed in a truss travel scope of my own design that I've taken to Hawaii twice and Chile once, and a 17.5 that was the old blue version that I bought from a club member in 1989 and immediately remade into a truss-Dob. The latter was my main scope and I regularly observed with friends (Steve Gottlieb and Jim Shields--well known observers) that had Galaxy or Zambuto 18-inchers: I kept up just fine. Steve and I hunted down most of the 100 Hickson Compact Galaxy Groups together--and traded views all the time, for example. . . Sure, I own Zambuto mirrored scopes now (10, 12.5, 18) and a plethora of APO's, but I'm not gonna throw any shade on Coulters. I bought the (used) collapsible 'Coffee-Can' scope from a vendor at Riverside TM Conference around 1993; I had to ask what it was before I plopped down the money, as I had never seen one before. Later that weekend, I was standing in line to look through a 40" scope and sparked up a conversation with the guy right in front of me who happened to work for Coulter; he was, in fact, the foreman of the woodshop (in Tecate, Mexico, BTW) where the structures were made. He told me lots of stories: Everybody at Coulter loved the Coffee-Can scope, but they could not make money on it, so it was discontinued. Was it their first scope? Maybe, I don't remember. He said the owner Jim Jacobsen (sp?) had a huge contract with Meade, bought a bunch of expensive optical machinery to gear up, and then Meade backed out. Jacobsen then started making big Dobs with all this equipment. John Dobson's designs revolutionized visual observing: "Nothing beats aperture," as the saying goes: Coulter was the first to capitalize on this while remaining close to Dobson's vision of an 'everyman's scope'--an affordable scope for the masses, in other words. Others followed suit. And when did Al Nagler come out with his revolutionary Naglers? These eyepieces were designed with the fast Dob in mind, which simply did not exist before Coulter.

I had a Odyssey 17.5 inch. It was huge! And heavy. I needed help to set it up. The views were spectacular. I bought it used in 1992 and it had been modified. It had a smaller secondary and a spider to hold the secondary. it was not made to remove the mirror for storage/travel. I rebuilt it into a truss telescope and I could set it up by myself. I could see the California nebula w/ an Oxygen filter., and 11 moons around Saturn.

Our Astronomy club "Texas Astronomical Society of Dallas" recently auctioned off 2 of these in the 8" range, one was a red-tube with a helical focuser the other was blue. They both sold at our club auction for under $100, one going for less than $50

Bought a Coulter 17.5" mirror set circa 1979 or so when they first came out, before Coulter sold completed scopes. It was a REVOLUTION in US amateur astronomy. Sold the mirror, still have the secondary, my biggest is a mere 10" f/7 made by Edmund on an Astrola equatorial mount.

I've wanted to re-coat and maybe re-figure the mirror on my 13" red tube coulter for a while now.

Thanks Ed for doing this very nice review of a very old classic dob. I’m a member of the Coulter Cult. My 13” Red Tube sports a 2 speed 2” crayford focuser, a green laser pointer, telrad finder, a counter weight on the aft end for balance, a bar stool cloth cover for an end-cap, a new dolly with 6” locking wheels and finally - a reverse-engineered StarSense bracket copy using Celestron’s plate solving app. I wish I could show you a photo. When I wheel it out of my garage, it’s like moving a Saturn 5 rocket to the launch pad. Her name is “Big Bertha - United Federation Starship”. It’s a galaxy class starship. Love my Coulter! Thanks for all of your great video reviews Ed!

Hey Ed, Glad I found your channel! I remember the Planetarium had a 13.1 Coulter that we used in an Astronomy class I took thru UNH back in the 90s.

A great look at a classic. Coulter rode the wave of interest in Dobs and big aperture observing that started in the 70s. Before Coulter if you wanted a big Dob you had to make it, likely grinding your own mirror from porthole glass, such as John Dobson did. The early Coulter Dobs like the one you tested were copies of Dobson’s original design. I was at the Riverside Telescope Maker’s Conference in 1980 when Coulter owner Jim Jacobson (?) unveiled the 13.1 inch. A photo is on p. 127 of the current edition of The Backyard Astronomer’s Guide. I bought one shortly after, picking it up at Coulter in Idyllwild, CA, and using it for the first time at the campsite in Mt. Palomar! I remember Jim asking if it would be possible to see all the NGCs in a 17.5-inch, then in planning or with advertising starting - he wanted to know what they could claim you could do with an even bigger scope! I think I said yes? The odd mirror sizes I think were a result of maximizing the number of round disks you could cookie cutter out of a sheet of glass.

My first real astronomical telescope was a red Coulter Odyssey 8”, purchased around 1990, with an eyepiece from a cheap pair of binoculars mounted in a piece of PVC tube. I put a serviceable focuser from University Optics on it (I think it was a threaded 2” model) and happily used it for around 6 months. I then sold it and bought a Celestron/Vixen C80 on a Super Polaris mount. While the images weren’t quite as bright, the improvement in sharpness and contrast blew me away. With a very few exceptions (including, very briefly, an 18” Coulter!) I’ve been a refractor guy ever since.

I remember drooling over those Odyssey ads, but never had the $ to buy one. Still a fond memory.

I had the 13.1" in 1982. I Ioved it. It was a huge revolution when most of us where using 6" scopes. It was hard to move to the observing site, but damn it was easy to use. It was much smoother than any newer dob I have used. And the optics were good! I had a red one later, and it wasn't nearly as good.

I bought a 13 and 10 red tubes last year off Craigslist in a package deal. 13 was not sharp on moon or planets but ok for galaxies, nebulas and brighter large clusters. Never used the 10in. They have been recently replaced with a 16in Starfinder Dob I got for $500.

I recently picked up a 13” coulter from my astronomy club. The OTA and rocker base were in rough shape the the optics were good. I’m planning on building a truss frame dob for it.

Such a beautiful telescope.

A 10" Coulter was my first serious telescope. The next one was a C10 Meade, similar to the other telescope in the picture. I got tired of using star catalogues, multiple finderscopes, and the bump-bump-bump of trying to track sky objects. And photography was out of the question. Still, I have fond memories of that Coulter.

Thanks Ed. Your scope reviews are always informative and enjoyable. And also the source of 99 percent of my current scope knowledge. Looking forward to you next video.

I like these reviews of the older newts! I know what you mean by not wanting to haul heavy scopes out and in. The 13.1" rarely makes it out of the garage...

Man, I love these reviews and explanations. These are just the best on the whole internet.

I have an 8" red coulter and I have no complaints.

I plan on keeping a eye out for 1980's odyssey telescopes and grab them puppies up right quick!!!! Another great video!

I've had the same scope on 2 occasions! Decent scope! I call them 10in cannons!

I remember seeing the ads in Astronomy. I wanted one so bad.

I always enjoy your reviews.

This would be a great telescope for someone who could refigure the mirror and have new coatings applied.

That scope is in amazing condition! It looks like it's never been used in 40 years. Even a Coulter can look awesome if you take care of it.

Ooh! My Coulter story: I debated getting one for a few years. Finally I broke down and ordered one - I think it was a 13”? Anyway, after being on the waiting list for several months, they declared bankruptcy. I never got my Coulter, but at least the CC company refunded my deposit.

I like the Orion XT10 what a beast .

Neat. I think I saw a red Coulter for sale on EBay.

Very interesting. Don't think I want to own one, but interesting to hear the history of this company.

Thanks Ed. I had the 13.1” model in the blue Zolatone finish. The mirror didn’t cool very well in that cell. I replaced the cell and primary mirror with a Discovery one.

What a beautiful scope! By the way, I was born in 1980 lol

Ed I hope you will also review the Svbony 102 ED doublet and 122 ED triplet someday :)

Ed, i just noticed that the first generation 10" explore scientific hybrid truss dob is still available for $599($629 for non costco members) and $649 direct from ES (and who knows, Scott might give me a deal since I put in 5 years of service with OPT). Can you think of any reason NOT to buy this scope? I had a HUGE run of bad luck a few years ago, losing my van that was loaded with a handfull of scopes, including my xt8, a couple mounts, some eyepieces and filters, my counterweights, so I can't use my c4r on my main mount which wasnt in the van, and a bunch of music instruments/gear. The car I got stuck with probably can't handle my beat up 10" starhopper, which really needs the primary recoated anyway, and certainly not my meade 10" LX premiere in its huge trunk case and the huge wedge which i would rather not remove from the field tripod. It might fit my powerstar C8, which is in the original black plastic case, but if so, it would be cutting it close, and when I would go out in the van, I could bring the dob for aperture and a wider field, as well as the C8, if I had to choose one to take to dark skies, I would prefer a 10" with fresh coatings on the mirror to an old C8. I do still have most of my dob relevant eyepieces, and most importantly, a paracorr, which i can't really benefit from if i can't truck the starhopper to any decent skies anyway. So naturally, this scope is very appealing to my situation, unless there are significant optical or mechanical issues. Why are they offering something like this for the same price essentially as most 8" solid tube dobs are nowadays? I do have some extra electric guitars I could try to sell to cover the cost, and I will also need an $85 shroud unless cheaper options are available . I have some heavy eyepieces, orion 28mm megaview (uwan/pwa), 20mm WO XWA, and 14mm 4k UWA, as my heaviest and most dob relevant. With the paracorr, will that scope hold still, or need weights added to the rear? I could live with the red dot it comes with, but will probably want to mount a telrad, and maybe even a 50mm finder if it fits wherever the red dot mounts to. I am however, mostly a telrad/rdf guy, but have no problems using optical finders as well, and like you I prefer straight through, but both of my vintage SCTs have nice right angle polar reticle finder scopes, remeber those? I have a celestron 9x50 straight through on a vixen stalk, can that be adapted to the ES? Or does it have that funky meade style finder shoe that most other ES scopes have? I suppose I could borrow the shoe from my hopper, the seller gave me such a good deal on that beater scope that he kept the metal shoe and stuck me with a plastic one. But it is a little lighter which could help. That is if the holes line up and the screws are long enough. I know these are a lot of questions, and not with an abundance of brevity. Can you tell I am on the spectrum? :) Anyway, seeing this, after looking at the costco website to give more info to a commenter on your xt6 video, who said the xt6 was totally blowing away his costco special omni 102, I got excited when I saw they still had the ES10s. I am pretty sure the guy's scope was completely bottlenecked by the 90deg erect prism diagonal, which are even worse than 45deg erect diagonals, and let him know even a basic star mirror or star prism diagonal (don't knock star prisms, they aren't that bad and are usually better than cheap mirrors that come with scopes) would improve the views of the omni bringing it closer in performance to the dob, and a nice wider field companion to the xt6. Keep that in mind the next time a commenter mentions costco. My first scope 20 years ago, 2004, was a costco nexstar 80gtl, and it also came with just a 90deg erect prism. I think all costco refractors come that way, to avoid returns from the masses who freak out when they see everything reversed when used terrestrially. They have a nasty diffraction spike, reduced contrast and light throughput, and anything wider than a 25mm plossl will vignette. The 32mm plossl was one of the first things I bought for that scope and it was immediately apparent. And when i got a modest star diagonal for it, everything else improved as well. Anyway, I hope you can provide a little insight on this, as it might be the solution that gets me back out there, or a first step at least. Thanks!

The secondary bar is called the lawn mower blade.

As always great information. Have you ever reviewed a 10in f5.6 deep space explorer? I have seen most of your videos. Don't think I have seen one with that scope. Tom ostahowski hand turned the mirrors form my investigations. I have one, sent it to him for mirror recoating. Did lots of rebuild. I consider it a VERY good investment. Thank you in advance

Hey Ed, I noticed one of the old ads in the video showed a EQ mount for the Odyssey. First time I've seen or heard about that. Do you know anything about them?

Hmm but the takahashi does take much better images... 😂 sorry Ed 😅

Last night through my 4 inch F7 FPL-51 refractor I looked at 8 to 10 magnitude galaxies, some looked brighter others less so but M101 was imposible to see even if its a magnitude 7.8 galaxy.

Hello Mr ting. I recently acquired an old meade 10" starfinder. I was wondering if you had one and if you might be able to review it?

I had a Coulter 17” red tube for a while. Gigantic would be charitable. Optics were horrible. Sold it within 6 months.

Blast from the past.

I'm grinding a 10" blank with a target of 4.5 up at Chabot. I haven't decided on the type or style but want to use it to take pictures, I mean astro. Any suggestions? I have 3 4'' Newts.

0:00 I have a 13.1 mirror from the early run, is it worth getting re coated?

I live in central FL and always need 120x to split castor. Is this normal, and why should this be? I’d figure that splitting a semi-tight double (for me, at least) would be the same anywhere.

And here I am debating if I should get a Celestron C6 or C8 with my girlfriend, she wants me to get a C5, what a girlfriend right?

You call it the 10". But everybody knows it's 10.1".

little hint, maybe you know this one already: paint a mark on the side of the mirror, and one on the rockerbox-bottom where the mirror sits. with this marking you can place the mirror in the same orientation every time, and possibly reduce the need for collimation due to differences in the thickness (and thus reflection angle) of the mirror.