Large Aperture and ladders..... No go?

[Kunama]

Comfort, quick looks and convenience of little scopes seem to be winning over larger aperture and the wealth of detail they can reveal....

Seeing a beautiful SDM scope listed in the classifieds for some time at an absolute bargain price made me wonder why someone has not jumped on it....

The visual observers seem to be doing so with ever smaller scopes. I can't help thinking that they are missing out on so much. I too spent a long time with various smaller scopes and did enjoy them for lunar and planetary viewing and the challenge of trying to find object with small aperture but I have no hesitation in admitting that when it comes to DSO viewing my fine 5" refractor might as well serve as a finderscope for the 18" Dob.

The difference on galaxies, globular clusters, and nebulae is night and day.....

I am finding I get very little eyepiece time at dark sky nights due to a large queue forming next to "Guinevere" each time I set it up.....

I can understand that the average age of people in this hobby is going up and thus some would struggle with the logistics. I read also that many feel the set up takes too long.
I have yet to see anyone set up an Eq mount and scope and be polar aligned and viewing faster than it takes to wheel out the big dob and have it setup, collimated and the DSC aligned.

Yes, I do need to have a ladder to use on about half of the targets but as long as you get a ladder with a handrail you will be more comfy than standing on the ground.

I am curious how many would like to jump on a scope like the Mary Rose if the Chief Financial Officer would allow it.... Or do you really prefer using a small scope often over a large scope a few times a month?

[FlashDrive]

A lot of truth in those words .... in fact it's quite correct in all aspects.
I would miss the ' fantastic ' views a large Dob offers .

I bet if I got to look thru' a large Dob ( 16" and above ) .. I'd be craving for one, but I'd have to ask my wallet first.

Poppy....:D

[Shiraz]

Thought about getting a big visual scope to replace a 12inch, but eventually decided that it probably doesn't make much difference for looking at the bottoms of clouds with declining eyesight. Funding is not the issue.

Semi-automated imaging from an obs at least gets some results through the few holes that appear (seemingly always about 3am) at this time of year. 200-250mm is enough aperture to be seeing-limited, so that is big enough for imaging.

[Atmos]

The Mary Rose is up there on my wish list and as you say, it is a real bargain! My wallet is just too light at this stage. It would be a very nice replacement for my 12" Orion and ironically enough, probably far more manageable too :lol:

[glend]

Matt you make some important points about the evolution of our hobby, or obsession. Big Dobs have a lot of attraction to visual observers, until the realities of managing them, and their cost, etc emerge. I sold my 16" Dob because, as good as the views were, i was using it less and less due to the hassles associated with it. No doubt that SDM make wonderful 'Objet d'Art' but ease of use, concern about maintaining the finish, transport and security, intrude. As you point out, age has alot to do with our scope ownership decisions, and bad backs, hips, knees, etc lead us to seek less weighty and complex solution. Declining eyesight also mitigates the big advantage of large Dobs, and force many of us into imaging. I know of one person currently getting a very large Dob built, and no doubt it will be spectacular, and i would love to have a look through it (with my one reasonably good eye) but the reality of ladder observation, cost, management, etc will keep my feet on the ground in my observatory. These are only my opinions.

[Kunama]

@ Flash,
You wouldn't even need to take down the scope after viewing with the way your house and yard are set up..... But you might need a 5 step ladder instead of my 3 step...... :D

@Ray, point taken re the winter skies around Ardrossan....

@ Colin, you so need this and the way you reversed that portaloo trailer shows you could transport it :lol: (just for your info, the eyepiece height of the Mary Rose 20"F5 would be a bit lower than my 18"F5.6 so a 3step would suffice)

@ Glen, I agree there are many reasons not to buy a large aperture scope but as you would know, when the "stars align just so" for the perfect dark site, great seeing, great company, there is no substitute for decent aperture.

For me personally one night per month with decent seeing at a dark site justifies the cost, maintenance (there really is very little maintenance) and any 'hassles'..... :thumbsup:

Shhhh! I am currently negotiating with the CFO for the release of $10k..... Though I fear I will lose as the size difference is too close to my current diy job.....

[casstony]

If I had been able to leave my 16" Lightbridge set up and wheel it out to the observing spot I would have kept it, but the convenience of a go-to, alt/az mounted C11 Edge won over.

I think the C11 or 12" dob are the perfect combination of light gathering and portability (when that compromise is needed).

[sn1987a]

Ladder schmadder :P

[alocky]

I'd have to argue that setting up the big dob is an absolute breeze compared to the imaging gear. It takes me less than 40 minutes to have it collimated and the servocat aligned. On the other hand I've spent hours contorting myself into position to use PA scopes, mucking about with dodgy cables, batteries and inverters, recalcitrant laptops and finding creative new ways to assemble sequences of swear words while Barry is quietly enjoying the view of the heavens through his 28", (and as well as my sideshow) having finished setup some hours earlier...
I don't know what the fuss about ladders is either, most of the time you sit on it and it is perfectly comfortable. As long as you limit yourself to a couple of bottles of wine you should be OK, but I'm ashamed to admit I found out about that (and how Jackie Chan does those tricks on ladders) the hard way.
;)

These days we've got to drive a long way for some dark skies, and I dread the drive far more than setting up my spaceship. Here's me as close to heaven as I want to be.
cheers,
Andrew.

[dreamstation]

Poor timing more than anything. We bought a block of land at the end of last year and are in the middle of planning our house build so money will be tight very soon. We'd love to have a larger aperture, quality built scope like the one in the classifieds but it's probably not ideal spending that sort of money right now.

Maybe in 12 months time we'd be ready to look at something like that. I'd already decided that would be our next big purchase after the house :) It will cost a lot more, and the 2 year wait time will hurt but we'll be in a better position to do that. Can't rush these things I suppose!

[Allan]

Good posting Matt. I'm still in the honeymoon period, so am using the TOA130 more than any other at the moment. But as you say, galaxies, globs, planetary nebula etc, take on a new dimension with every increase in aperture. The best views possible require a ladder, but I don't see that as a deal breaker. Especially with the new generation of fast mirrors, coma correctors and highly corrected eyepieces, very large dobs can be enjoyed at only 2 or 3 steps off the ground.

[N1]

When people give their telescope a name, how does the value it has to them relate to its actual value?

Five hundred dollars per inch is apo territory. :shrug:

[alocky]

Some people name their scopes, some don't. I know people who've given their 60mm refractor a name. And a 20" newt is an APO. In fact it's better than an APO because every wavelength of light will focus at the same spot, not just three.
And once you get into the 6"-8" APO territory where you have a hope of seeing deep sky objects, albeit quite dimly, you will find that the cost function is parabolic, not linear.

[Satchmo]

Matt - my feeling is that to a large extent the demograghic of IIS members leans more towards technology , imaging and smaller telescopes . The body of large aperture lovers are out there . It may pay to advertise in other places - how about Australian Sky and telescope for a start. There are a lot of people of retirement age retiring to country properties who want to satisfy their life long dream of having an observatory and a large scope .

On the ladder issue - I'm not a great fan of them - I am a bit of a wimp - I don't find the experience of standing up near the top of one very pleasant and smaller apertures would win in that regard but wouldn't
have said that when I was younger .

There are of course new players in the medium large field with lightweight 20" fast scopes with GOTO and tracking sub $10K which all add to the range choice available for anyone looking to really `gulp' those photons and any second hand scope unfortunately is going to have to compete with the new.

[glend]

There may not be that many. I agree there are IIS members with large Dobs, and some of them have posted in this thread, but how many new entrants are there in that market segment in the course of a year. IMHO any seller is trying to reach a very small number of prospects, and advertising elsewhere would be wise, even overseas. The market in Australia maybe saturated. Turnover rates are very slow.

[AEAJR]

Interesting discussion.

First, what do you consider large? 14", 16", 20", 25", bigger?

I got into the hobby a year ago. I have an 8" Orion XT8i Intelliscope. For me this was as big as I wanted to go. I could have had a 10" but I wanted the scope to be very convenient at a weight I could easily lift as a unit, so I went for the 8 and am glad I did. It lives on a cart in my garage. I can roll it out to the observing location in front of my house with ease.

Naturally I am already dreaming about a bigger scope.

12 to 16" SCTs look wonderful but are just too expensive.

If I stay with a Dob design, which is likely, it will probably be a 14" truss Dob as this is the tallest I can put on a cart and roll it out of my garage while vertical. Also I can reach the eyepiece on a 14 without a ladder. And if I want I can take a truss dob apart for transport. The Orion XXL14I or G are the target scope for the next upgrade some years down the road.
http://www.telescope.com/Telescopes/Dobsonian-Telescopes/Dobsonian-Telescopes-with-Free-Shipping/Orion-SkyQuest-XX14g-GoTo-Truss-Tube-Dobsonian-Telescope/pc/1/c/12/sc/398/p/101888.uts?refineByCategoryId=398

If I went bigger than that I would want to have a permanent observatory. I don't see that ever happening, but that XX14i or XX14G are real possibilities.

[Kunama]

I would consider 16"F4.5 and larger to be "Large scopes"
10"-15" medium and 8" down to be smallish....

[Satchmo]

I don't believe the scope has any drive system , but you certainly wouldn't get change these days from $10,000 for a bespoke 20" mirror !

[Kunama]

Quite right, my mistake, it does seem to be a Push To rather than GoTo.
:thumbsup:

[StephenRH]

I have been following this thread with much interest. Right now, Peter Read, SDM Telescopes is building my 28" f/3.3. Among other factors, it depends on what you observe as to whether a big dob is for you. I observe variables and look forward to getting down to mag 16.5+. Most of the stars I observe are in the South to West quadrant. Because stars move in a westerly direction as the night proceeds, I don't need to look directly overhead. I have a small ladder and may need to go to the second step. But not often.

From what I read above, two of the disadvantages with a big dob are transporting it and the set up time. These are not an issue for me. I have an observatory at my place, about 100 metres up the hill from the house. I won't be moving it around as it will be set up permanently.

One big advantage in getting one made by SDM is that Peter contours it to your specific needs and he is doing just that for me. When it arrives, I will post pictures and give a report.

Stephen Hovell
Pukemaru Observatory
341 Snelgar Road, RD 2
Kaitaia, New Zealand 0482
+173° 20' 07.67" -35° 05' 39.52"

[Kunama]

Sounds like an excellent spec scope for your setup. I might have to take a trip to Kaitaia ;) now that we have an international airport here in Canberra.

As for the ladder issue, it really is mostly a non issue. I find that at least half the time I am actually standing on the ground to view my targets, and when on the ladder it is usually only the second step. I watch many people with shorter scopes hunched over their eyepiece, a posture that I would find very tiring very quickly. I prefer to stand upright using the ladder handrail as a leaning post and the tray at the top for my coffee cup, eyepieces and snacks.

At outreach events I tell the guests to keep both hands on the handrail saving errant fingers poking into my Naglers. Your scope at 28x3.3, or 92.4"FL will be quite a lot lower than mine. Should be under 80" focuser height at zenith.

Look forward to seeing your photos in due course :thumbsup:

[el_draco]

I've owned everything from small refractors through to a 29" newt. The 29 was the best, hands down, and was a killer scope on anything I looked at. I get frustrated on small scopes and am currently building a 22" newt. to complement a 14" SCT. Drama comes from usability and so an observatory is a must. That's what stops most people I suspect.

[barx1963]

The discussion on setup times is interesting. Big dobs are often seen as inconvenient and hard to setup, but I know I can put my 20" together in about 20 minutes including collimation and alignment of the Argo(if I am organised and don't muck around).
Having recently been playing around with some imaging gear, I would guess the equivalent time for it is closer to 60 minutes if everything works ok.

Malcolm

[Stonius]

Curious; why the change from 29" to 22"?

[AEAJR]

Perhaps a little off topic but what would motivate one to own such a large telescope?

Is this still just a hobby or do you actively participate in global astronomy efforts? Perhaps the near earth object type program or something like that?

Or is this still a personal hobby for the owners of these very large telescopes?

I am not being critical? Quite the contrary, I would love to have something like this if I could afford it and if I had a place for it.

So why such large scopes?

[N1]

OK, my 8" GSO dobsonian mirror APO cost me about half of my 70mm Vixen APO, both second hand. So yeah I guess the cost function is not linear... still tryin to work out the shape of the parabola though :P

I'm still tryin' to see any DSOs though it too, but I'm fairly optimistic now I :rofl:

[alocky]

Don't get me wrong - one of my favourite pastimes is trying to reproduce O'Meara's observations of the Messier objects with my 4" achro. But from the city this requires every trick I've learnt over 35 years of observing and my eyes are definitely getting worse. Then I look at the same objects through a 25" to give my eyes a treat.
The advantage of aperture is that many of the ESO catalogue galaxies are much more interesting than those in the messier list.

Oh yes - another of the myths about big dobs- they are not more affected by light pollution.
Cheers,
Andrew

[N1]

All good Andrew :)
On topic, I agree with others that it's the convenience factor that makes smaller scopes so attractive to many, both physical and temporal in nature. I just love the ability to observe instantly, i.e. less than a minute to get started. Partly thanks to club membership, I now have everything from 2" through to 18" at my disposal (2" increments) and there is a time for each of these. Combination is key perhaps, and I'm fairly certain the OP (Hi Matt!) still feels that way too. My standard setup for out-of town observing is a dob and a small refractor mounted separately.

There also are areas of visual observation that rely less heavily on aperture than deep sky.

Also agree on the LP thing. That one is less a matter of aperture than exit pupil, I think.

[sopticals]

I might have a "little dig here".

Why do folks prefer a 22 megapixel camera over a 4 megapixel one????

Having experience with apertures 30mm(1960) to 838mm(2016), I have to say Aperture Does Matter. If it didn't, I would still be happy with 30mm.
My current stable (see signature), includes 4"(102mm), 14"(356mm), 25"(635mm) and 33"(838mm) apertures. I have owned a bunch of 6", 8", and a 12" dobs and newts, and find viewing through anything less than about 12" is like peering into the focuser wearing dark glasses.

Maybe I am an "apertureaholic", (well, yes I must confess I am).But, I make no apology, its a fact. Started with making my own 6-7"mirrors when I was a youngster. After going from 30mm to 76mm(my first reflecting telescope[commercial Japanese]) it was wow! when pointed it into the night sky. Same with my first homebuilt 6" (like doubling the pixels), wow!, and same through each size increase.

Did a "head to head to head" very recently, (14",25",33") dobs (forget the 4" refractor). Subjects Moon, Jupiter, Mars, Saturn. At this point in time neither 25 or 33 have mirror coatings (so tested in "skinny dip form").

The pixel analogy works well as the apertures were compared. The 25" and 33" so far as fine detail on Luna "smoked" the 14" so far as the detail sharpness is concerned. Even when magnifications were matched.

Again take the pixel analogy. When an subject/object/image is captured in a 2 megapixel camera (I had one once), and you blow up the image by a large amount, (take for instance a 2" aperture telescope at 250x), all that happens beyond 25x per inch(where all info that aperture can give you is available,) (50x), beyond that the visual image is just stretched, and when stretched far enough becomes blurred and a pain to look at (empty magnification), BUT, increase the aperture (pixels) and the same 250x in a 25" aperture (10x per inch as compared to the 125x per inch with the 2"aperture). The difference is like "day and night".

I have aperture "as my friend" and like to maintain a large exit pupil and so can avoid the eye floaters that occur for most around the less than 1.5mm. Prefer to keep magnifications in larger scopes at 12x per inch, 2mm exit pupils, to provide, bright sharp images. I feel I don't require to use more than 12x per inch to access full information from a 25" scope. [I am still able at 71 years able to resolve naked eye some of Luna's larger craters when positioned on the terminator, (not difficult when the moon is well placed at sunset or sunrise, before flaring is a problem).]

On the planets, Jupiter (now lowering in my N West [evening]), 25" and 33" showing more than 14", (even as uncoated optics). Didn't get to use 33" on Mars and Saturn due to too much elevation for my current ladder (have to organize a suitable viewing platform, (even though the 33" is f4.1-don't know how folks manage with 36"f5 Obsessions and similar). Again 25 over 14 was"no contest". The smaller scope showed the Martian features, but not as sharply as the 25. (BTW with the 25 being f3.8 I only need a couple of steps on the small ladder to access the zenith). At the time of the 25 v 33 shootout (Jupiter),was watching an upcoming occultation of Io, so was watching this small sphere (easily resolved by both scopes) approach the Jovian limb. It was two steps up the 33 and down over to the other scope (no ladder needed), back and forth until the moment of occultation (happened whilest at the focuser of the 25- was beautiful).

Saturn: even though the 14 easily was able to show Cassini division, planet banding, planet shadow on the bands, the extra aperture of the 25 "aced it" with its superior resolution.

Pic: comparing 3" with 33" (mirror sizes).

Stephen

[Kunama]

Absolutely! My TOA130 and Binovues with Tak LE eyepieces or a pair of 14mm Delos are still my weapon of choice for lunar viewing as well as the 3 bright planets. :thumbsup:

[AEAJR]

Thanks for the detailed response.

So, for you this is still a hobby, a pleasurable pass time. You are not involved in any form of scientific research.

BTW, there is one area were your camera pixel analogy breaks down. Whether a 2 MP camera or a 20 MP camera, I don't need a ladder to use it or a truck to move it or a building to house it if I don't want to take it apart after each use. ;)

[Atmos]

That's a really good post Stephen, I have always wondered if I would want to go over the 25" mark but so far the biggest telescopes I've looked through is the 18" Guinevere :P

[el_draco]

I had the 29" back in 1984. At that point it was probably the biggest privately owned scope in Oz. I sold it to pay for my first Uni. degree... real hard to part with it!

I have been building up again slowly for a few years now and I scored a set of 22" mirrors a while back at a price I could not refuse. OTA is well on the way to completion, observatory is under construction...

I'd kill for a monster again but the 22" will be kick arsenal as it is.

[el_draco]

For visual observing, aperture is king. In the 20"+ range, planetary detail is stark on most targets. DSO's show a lot of detail and many targets are just gob smackingly beautiful.... 47 Tuc and The Tarantula are beyond words, as I am sure others will testify. Some things require a bit of care. Sirius is off limits without filtering, you get retinal burn-in :lol: So, detailed visual views= big scope

The scope I am building now will also be a science/education instrument. Lot of work to do yet, but getting there. Accurate tracking with a big scope is harder and consequently more expensive. You don't want to set that over and over again, so you need an observatory. Comes down the all mighty $

Thats been my experience actually.

[glend]

Sorry i don't buy the pixel argument. Imagers know the important factor is not how many mega pixels you can cram onto a sensor but the optimal relationship between pixel size and the focal length of the scope, (see info on the Nyquist Criteria), as well as many other factors such as low noise performance, light sensitivity (QE) of the sensor etc.
People can, and do, create all sort of arguments to justify their scope choices, but the hard core aperture chasers ignore the realities of the Seeing conditions and what can be gained, or not, by increasing aperture. Bigger is not always better.

[alocky]

Seeing is only an issue for planetary, and even then I have never seen a smaller scope provide a better view in the same conditions. And I have had plenty of opportunities to compare them.
My point earlier was that the setup of a small newt on an equatorial mount is far more onerous than setting up a big dob. It's really not that bad, and once you are setting up a truss dob it doesn't matter if it's a 16" or a 30". Same amount of work.
As for justifying the expense, I do supernova searching, although I know I cannot compete with the host of automated search scopes, I do it anyway. I also have a friend who asks me to confirm planetary nebula visually, but ultimately, I bought it because I wanted it, and the 18" mirror I ground cured me of wanting to make anything bigger. The only person whose opinion I'm interested in regarding my purchasing choices is my wife, who is usually just glad it's not another racing motorcycle... And glen, that is not in response to your comment :)
Cheers
Andrew.

[sn1987a]

I don't believe in aperture fever .......I....I can stop any time I want. :P

[Derek Klepp]

An interesting thread Matt. I have my 16" Skywatcher Dob set up to wheel out .Hadn,t used it for a while so I rolled it out and viewed Omega Centauri I,ll keep it for another year.All my other scopes are converted in some way to image the Sun.
When I first purchased this scope I set it up and showed the kids the moon there reaction was ten fold that when compared to the smaller apertures.
I know as we age eyesight declines but with todays DSLRs the views are fantastic and you can always hook up a video camera when light pollution intervenes. As much as I enjoy all the electronically assisted Astronomy nothing quite beats trying to tease out the detail in a Galaxy as you return to it year after year.
Cheers

[Stonius]

Does video-assisted astronomy help with light pollution? I did not know this.

[N1]

Barry, what happened to your main scope? :P

[glend]

Barry, that's a serious case of Dob Addiction! How do you decide which one to use, or are you running between them?

[alocky]

He used to bring all three of them out and set them up, which again should be an indication of how relatively painless setting up a dob is. But I think the fact that the 28 always beats even a magical zambuto 20" is the reason I only ever see the Webster these days :-).
And even after setting all his scopes up he'd have time to sit down and chuckle at me being garrotted by a USB cable while wrestling with my equatorial...
Cheers
Andrew.

[sn1987a]

I use the 20"f4 Ultralight and the 28"f4.2 Webster the most. The 16" f4.5 Dobstuff and 18"f4.2 Plettstone I use less often because Aperture rules :D.

I used to have a 16" Lightbridge but I threw it down the tip because it was rubbish. If you want a good dob buy a secondhand premium or brand new. I feel my aperture fever is sated for the moment but never say never :P.

[alocky]

You need to break the 30" barrier Barry...
You could always sell the questar :-)

[The_bluester]

To go back a couple of pages. Budget is really my only stopper in getting something really big. Every time I get a look through a big dob I am just blown away by the difference in detail and brightness compared to my C925.

If I had the budget I would have an obs by now and it would have a couple of piers and a large enough unoccupied area to house a great big dob.

[sn1987a]

C'mon Andrew you know the 30" barrier is impossible to break. The mass of money required now is so large that it would instantly collapse into a debt singularity destroying all other scopes, eyepieces, Questars or even Unitrons in the vicinity.

I can't sell the Questar anyway I need it to chock the trailer. :P

[glend]

Perhaps single piece mirrors are all that is holding you back. If you went to a James Webb type design using mirror tiles the only constraint would be your ability to construct a supporting framework. Imagine arriving at a site with your trailer and pushing a button to have your folded mirror array unfurl like a blooming flower. That will put the other big dobs in the shade.
On that note, what does the future look like for larger transportable scopes?

[FlashDrive]

Barry... you need to be put in a ' Home ' :lol::P

[Satchmo]

Get into bino Newts and you can relive the whole aperture fever journey again , but with more field of view per square inch of total optical surface area ;)

[sn1987a]

Are you still grinding and selling mirrors Mark?

[StephenRH]

Ed, for me it is a hobby. But it's not "just a hobby". I love getting outside - well in my observatory anyway, under a starry sky and fresh air. Radio going. Coffee in the thermos. For me, it represents freedom. And if I am first to see a star erupt, or be first to pick up a fade of RCBs (I observe close binary stars called U Gem variables, and carbon stars called R CrBs) it is exciting. There was one star that I was first to see erupting in over 50 years.
I am a member of AAVSO and it's great to be part of the wider international community of amateurs.
I am retired and live by myself so I can stay up as late as I like.
Looking forward to getting my big scope. It will be FUN!!!

Cheers
Stephen :)

[el_draco]

... and I thought I had issues...:rofl::rofl::rofl::rofl:

[ausastronomer]

Hi Matt,

The Mary Rose has Argo Navis DSC's with 10K encoders, but it does not have Servocat drives on it. The Servocat Drives on their own are worth > $3,000. As someone else mentioned a 20" mirror alone is well north of $10k let alone a complete premium telescope structure with a known exceptional quality mirror. The Mary Rose is a bargain at the asking price.

Cheers,
John B

[ausastronomer]

Come on Barry get serious, there is no life threatening ladder work involved with that arsenal of telescopes :D

You need to climb the "Stairway to Heaven" :eyepop:

Cheers,
John B

[ausastronomer]

Here is our arsenal of telescopes we supply at Ozsky every year. Every scope bar one (my 14"/F4.5) requires a ladder. Some larger than others.

The largest scope on the field is a 30"/F4.6 SDM which has an eyepiece height of just over 12 feet at the zenith.

This is what the American visitors want, they spend a lot of money to come here and observe the wonders of the Southern Sky. They are all very experienced observers. They don't come to observe through 4" refractors (nice finderscopes), they come here to observe through large aperture high quality dobsonians from 14" to 30" in aperture.

Cheers
John B

[ausastronomer]

This is me up the ladder at the eyepiece of the 30"/F4.6. Being a short arse this scope gets my feet a long way off the ground when pointed near the zenith. Well worth the climb for the views it provides. Not quite the "Stairway to Heaven".

Cheers,
John B

[ausastronomer]

Here is the Stairway to Heaven.

This is me at the eyepiece observing M51 in Larry Mitchell's 36"/F5 Obsession at TSP in 2007. The image was taken by Alan Dyer.

This scope has an eyepiece height in excess of 15 feet at the zenith. The climb up the ladder seems never ending, as does the climb down. Climbing up the ladder and observing can be quite a daunting experience. Many observers get 1/2 way up the ladder and freeze. it's not an easy thing to do in the dark for people not used to climbing ladders to observe. The views are something to behold and oh so worth the climb.

For size reference the finderscope (the white telescope on the mirror box) is a 6" Newtonian (A 1980's vintage Celestron Comet Catcher).

Cheers,
John B

[tempestwizz]

A bit late to chime in, but I don't need any ladder for my 18" F3.5 dob!

(Just need clear skies - which seem to come around only between November to end of January here.)

[sn1987a]

John you terribly misunderestimate me. You should try my undersized by a lot, at zenith, "Stairway of death" - Andrew loves it! :D

[AEAJR]

The photo you included gave me chills. So much big glass!

I had an opportunity to attend a club observation night on Thursday and there was a 20", masked to 19", truss Dob that was set-up, complete with rolling staircase. Some really nice views. They keep it in a locked building on the site and roll it out when they want to use it.


So, big scope guys, where do you keep them? How do you use them?

I have figured out that I can fit a 14" Orion XXL14I or G on a cart in my garage and just clear the garage door to roll it out to my sidewalk observation location. So, for now, that would be as big as I would go.

If I had a 20+ inch beauty I would want to use it as often as possible.

I presume you have some kind of observatory where your big scopes lives, all set-up and ready to go.

I understand that a truss design can be taken apart and moved but I am sure you are not taking 20+ inch scopes out, building them, observing for an hour or two then taking them apart to put away.

Do you keep them set-up and use them often? Or do you have a 10" Skywatcher sitting in the garage, hidden so no one will know, that you use every day and these are just for national holiday celebrations?

[AstroJunk]

My tiny twenty isn't even much of a challenge for an 80 year old...

[sn1987a]

I just leave mine set up and roll 'em in and out as needed. A 20" with wheelbarrow handles will fit fine under a garage doorway. I even bring my 28 to the backyard in and out of a double door patio area :D

[glend]

I am happy there are so many enthusiastic big dob fans, but there is a difference between being an enthusiast and the realities of living with one, or more, of them.
Most 80 year olds would not be able to do that on their own, and not to rubbish the achievement, even now, in my late sixties, i would not want to be up on the ladder on a damp cold night when the ladder is soaked in dew. The reality is that big dobs are a younger man's thing. Sure there are some exceptions, but as in my case, once your over 65 the big dob usually has to go for many reasons. Enjoy it while your young, and you won't really miss it later on when your dodgy knees and arthirisis won't permit you to use ladders, and your eyesite has diminished to the point where you can't use its reach, and you have had to switch to imaging to stay in the game. When you do finally try and sell it you will find few buyers and all will expect to pick it up for next to nothing, so they are usually a bad return on the investmant - yes even SDMs. Thats the facts.

[Kunama]

@Jonathan, what brand of ladder is that?

@Glen, I agree that there will come a time when the big scope is no longer a viable option due to mobility....
As for the perceived investment value..... The views and the pleasure that even my little 18"F5.6 has given me in just one year of ownership are worth the price of admission. I couldn't care less about depreciation. By the time I am no longer able to use this scope, I expect I will have had many more hours at the eyepiece and if I cannot use it I will happily give it away to someone who cannot afford one.

I timed my set up a few days ago.... From the time I opened the back door of the van, rolled out the scope, set up my trusses and UTA and collimated the scope a total of only 8 minutes had elapsed. Then it was a matter of switching on the fans and boiling the billy while waiting for some stars to appear for DSC alignment.....

[sopticals]

Keep my 25"f3.8 (only needs two steps at zenith), and 33"f4.1 (11 feet at zenith-still working on an idea for viewing platform for, 45deg Alt and above), in my 110m2 "Total span" garage/workshop.

Picture of 33" ready to roll out. Base board is wheeled. At age 71 "deployment" in and out of shed is not an issue, (easier to move than my "wheel barrowed" 25").

Stephen.

[ausastronomer]

Most of the 40 plus people who attend OZSKY every year and have done for the past 12 years are aged between 55 and 75. The reason is that this is generally the age demographic with the time and money and able to make the trip. There are a couple of exceptions who prefer to keep their feet on the ground, but most of them have no issues climbing the ladders to observe and its something they expect to happen knowing they are going to be using large aperture dobs.

I am almost 60 and still use my 14" and 18" dobs on a very regular basis and will continue to do so for many years to come.

Just for the record, Larry Mitchell is 70 and still uses his 36"/F5 Obsession on a very regular basis and being of older design and construction it is a behemoth that takes some handling.

Cheers,
John B

[AstroJunk]

I found a double sided ladder in Bunnings and moved a number of the steps on one side to the other to make half depth steps. Makes viewing actually more comfortable than standing on the ground as you can lean into the ladder and rest that way.

Added a grab handle and an eyepiece tray too, as well as putting it on spring loaded castors which allow you to wheel it around when not standing on it.

My only criticism is that the actual treads are a little deep so don't leave much foot room between the half steps. I have been meaning to fix that for over 10 years!

[Kunama]

That is my plan as well, the half steps are handy to get really comfy. Thanks!!

[Wavytone]

Just wait till the wind blows... the scope will weathervane and knock you off the ladder.

Prepared for a fall in cold weather ? It will do more damage than you realise... Good luck IMHO.

[sn1987a]

When the wind starts getting that bad its time to give it away for the night and have a cup of tea :P

[sn1987a]

This is my 20" f4 in my backyard on Saturn right now, I'm 6'1 and my eye is roughly level with the eyepiece. Wind or rain don't bother this baby! :)

[Kunama]

I grew up in -30°C temps, not much in Oz is going to worry me......
The arctic blizzards didn't bother me too much either..... IMHO. :thumbsup:

[Atmos]

Or get out the 5" :P

[AEAJR]

You guys are amazing!

[sn1987a]

I don't have one that small .. oh hang on yes yes I do :sadeyes:

[AEAJR]

Sure you do. I bet everyone in this thread has a small scope somewhere and I bet they get some sky time too.

[MattT]

To get back to the question asked…Ladders are fine but if I ever want a big flector I'd want one that is very portable and takes up little space when folded down, like one of Alex's creations or an 18" Skywatcher ultralite with tracking and GOTO. The 20" has great optics by all accounts, the rest is too bulky for my likes.

My 2 cents FWIW.

[UniPol]

Not only amazing but amazingly amazing:eyepop: