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Premium Dob?

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#51 Mike B

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Posted 30 January 2014 - 01:12 PM

I think it’s fair to say that every telescope comes with some compromises, premium or not. It’s up to you to know what you value most, and to seek the product that delivers that best, within your budget. Likewise it’s up to you understand which compromises you’re not willing to deal with.



A very astute & well-worded piece of advice...
:grin:

I then made it a point to go to every star party (public & private) and to look through every telescope that I could, to get a good feel for the equipment we have available to us. Perhaps 50 to 60 telescopes total, to date.

... and there was its actual implementation! :waytogo:

Unfortunately, without having done the latter (a.k.a. "research", or "homework"), the former is well-nigh impossible to accomplish effectively- especially by someone relatively new/inexperienced to the "hobby". Hence, the iterative process of buying + selling scopes, looking for the "right one" suited to each individual, as is so typical of we enthusiasts.

But hey- i s'pose it's all good for the economy!
:lol:

#52 OwlsNSpace

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Posted 30 January 2014 - 06:10 PM

I'm getting rid of my Mazdaspeed 3 partly because I bought a 12-inch dobsonian scope. The replacement will be a full-size truck.

#53 TCW

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Posted 30 January 2014 - 07:38 PM

Small cars are good until you get rear ended at 50mph. I know!

#54 okieav8r

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Posted 30 January 2014 - 08:16 PM

Folks, we're getting way off topic with the automotive discussion. Lets get back onto the original topic, please.

#55 Pinbout

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Posted 30 January 2014 - 08:27 PM

Right. Premium. Dobs...norman fullum...premium?

#56 TCW

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Posted 30 January 2014 - 09:38 PM

What ever you say pilgrim. ;)

#57 davidpitre

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Posted 30 January 2014 - 10:48 PM

I have found that it’s generally true… you get what you pay for in this industry. I say that with some caution, because it’s not always the case, and it doesn’t attempt to judge value, but it is definitely the trend. To date, I haven’t looked through a mass-produced dob, and been too impressed (I know there are folks on CN who will disagree, but these are my honest experiences).

Yes my experience has been a bit different. Though I own several very good custom mirrors, I have used quite a number of custom mirror telescopes that were mediocre. I was sold one genuinely bad 18" from a well know maker. Consistency really does vary from mirror maker to mirror maker. There are a number that are dependably good, and some that are generally good, some consistently mediocre. In my experience (scopes bought and borrowed) the more recent GSO and Synta mirrors and generally good . I have bought several chinese 8" and 10" dobs to donate to charity auctions over the past few years, and have been impressed with each mirror. The last 8" was a gem.

#58 Jon Isaacs

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Posted 30 January 2014 - 10:53 PM

I'm getting rid of my Mazdaspeed 3 partly because I bought a 12-inch dobsonian scope. The replacement will be a full-size truck.


Shneor Sherman had a Mazda 323 that he used to haul his 22 inch. My 16 inch fits in our '99 Honda Accord though it's a tight fit..

In general "premium" Dobsonians are trusses and they can be transported in a smaller car than a similar tube scope. My 12.5 inch has a foot print that 19" x 20" and nested is about 28". The entire scope takes up less space than the base of a 12 inch Apertura or Orion Dob..

For me, that's one of the big advantages of "premium" Dobsonians.

Jon

(12.5 inch F/4.06 in a Ford Escort Station Wagon)

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#59 Thomas Karpf

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Posted 01 February 2014 - 08:04 AM

Yes my experience has been a bit different. Though I own several very good custom mirrors, I have used quite a number of custom mirror telescopes that were mediocre. I was sold one genuinely bad 18" from a well know maker. Consistency really does vary from mirror maker to mirror maker. There are a number that are dependably good, and some that are generally good, some consistently mediocre.


Yup. Which is why, when I upgrade to a premium dob, I am going with a mirror manufacturer for whom I've seen NO negative reviews. That way, I'll just get a mirror that WORKS.

#60 Bob S.

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Posted 01 February 2014 - 09:19 AM


Yes my experience has been a bit different. Though I own several very good custom mirrors, I have used quite a number of custom mirror telescopes that were mediocre. I was sold one genuinely bad 18" from a well know maker. Consistency really does vary from mirror maker to mirror maker. There are a number that are dependably good, and some that are generally good, some consistently mediocre.


Yup. Which is why, when I upgrade to a premium dob, I am going with a mirror manufacturer for whom I've seen NO negative reviews. That way, I'll just get a mirror that WORKS.


Tom, In theory, I fully agree with your inclination to go with an optician that has no negative reviews. However, I do not know of any single optician that enjoys that reputation. None! The reason I say this is that there are many variables that are sometimes out of the control of the optician. For example, if a mirror blank has strain in it that does not reveal itself in a careful evaluation, then the mirror has the possibility of changing figure. If an optician's mirror is coated improperly, again, you have the chance of some deviation from what the optician was intending.

I think the bottom line is that we need to consider the totality of an optician's work to get a sense of who is capable of providing us with the highest chance of getting the "premium" performance we are looking for and paying for. In my personal opinion, I think there are likely no more than about 5 professional opticians (in the USA) making parabolic mirrors for the amateur community that can deliver the goods time after time. This rough guesstimate is based on closely following the Newtonian threads for the past 12 years and having tried/owned hundreds of Newtonian telescopes. I think it has taken both experiences and hearsay to have formulated my opinions. As always, other peoples experiences may not correlate well with mine possibly because of where they observe and what structures the mirrors go into? That is the nature of the beast and why there remains some "crapshoot" aspects to the endeavor of obtaining a premium dob. Bob

#61 Paul R.

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Posted 01 February 2014 - 12:41 PM

Yup. Which is why, when I upgrade to a premium dob, I am going with a mirror manufacturer for whom I've seen NO negative reviews. That way, I'll just get a mirror that WORKS. [/quote]

I must say that over the twenty years I've been doing this I have been incredibly lucky. I've owned(do own) two outstanding Parks mirrors, one Wilkerson Galaxy mirror that was equally incredible, and lastly my current Pegasus optic that based on repeated star testing, and hours and hours of observing has me convinced of a strehl in the upper 90s..jaw dropping views night after night when the atmosphere cooperates and MORE IMPORTANTLY..when the optics can keep up with the dropping air temperature...

High quality, high magnification views in addition to requiring superb optics, ALSO requires superb support,collimation, ventilation, baffling..and as recently uttered by Issacs, 'attention to detail' and preparation...These above characteristics are common with higher end telescopes.

Unfortunately to some degree..you INDEED get what you pay for. Personally the majority of these scopes of the Orient...are just made as cheap as possible...Optics are generally decent, but the scope's themselves are just putrid, especially if you are used to high quality, well designed instruments. I love my small scope, a couple friends and myself designed and built it...using basic materials..It MUST employ good quality plywood, square build, well designed bearing surfaces/materials...these are the most needed fundamental aspects of any dob that needs to be sound.

#62 pga7602

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Posted 01 February 2014 - 02:29 PM

In my personal opinion, I think there are likely no more than about 5 professional opticians (in the USA) making parabolic mirrors for the amateur community that can deliver the goods time after time.


Would love it if you would name off your top 5.

#63 Mike B

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Posted 01 February 2014 - 02:33 PM

:gotpopcorn:

#64 StarJuice

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Posted 01 February 2014 - 03:26 PM

:gotpopcorn:

#65 Pinbout

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Posted 01 February 2014 - 04:12 PM

His top two are Lockwood and zambuto :grin:

#66 Starman1

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Posted 01 February 2014 - 07:40 PM

I'm getting rid of my Mazdaspeed 3 partly because I bought a 12-inch dobsonian scope. The replacement will be a full-size truck.

I carry my 12.5" in the back of my VW GTI, with enough room to spare for a passenger and about 15 other cases and bags. I've carried a 16" in there.
If I had a full-sized truck, my scope would be a 30".
You don't need a big vehicle for a 12" scope.

#67 Starman1

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Posted 01 February 2014 - 07:45 PM

Small cars are good until you get rear ended at 50mph. I know!

Depends on the car. My VW GTI was hit in the rear at about that speed by a Lexus SUV, and i hit the car ahead and so on with 5 cars involved. I survived with only bruises, but the car had $14000 damage.
I watched Gerhardt Berger hit a wall at 185mph in a Formula 1 race and he came to in the helicopter and had only bruises and cuts.
It's not if the car is small, it's if it's built to take impacts.

#68 Starman1

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Posted 01 February 2014 - 07:52 PM

One of the things you may find with a premium mirror is improved contrast.
Suppression of scattered light follows from good eyepieces and good scope design, but it also follows from mirror smoothness. I did not believe this myself until I upgraded my mirror to a top optician's handiwork and discovered the difference. Your skies need to be dark enough to see it, and your eyepieces, too.

So, tack up one more reason for the preium scope: contrast.
As well as all the reasons heretofore mentioned.

#69 Pinbout

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Posted 01 February 2014 - 08:04 PM

but when you upgraded to a thinner mirror how much did that throw off your balance on your teeter dob.

#70 Bill Weir

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Posted 01 February 2014 - 11:26 PM

but when you upgraded to a thinner mirror how much did that throw off your balance on your teeter dob.


His Teeter came with the Zambuto so I imagine Rob dealt with that in the build. I think he was referring to his previous 12.5" Discovery and in all honesty that had what many consider a very good mirror in it.

Bill

#71 Starman1

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Posted 02 February 2014 - 02:25 AM

but when you upgraded to a thinner mirror how much did that throw off your balance on your teeter dob.


His Teeter came with the Zambuto so I imagine Rob dealt with that in the build. I think he was referring to his previous 12.5" Discovery and in all honesty that had what many consider a very good mirror in it.

Bill

Yes, you're right.
I am sure other mirror makers than Carl Zambuto make really good mirrors.
But if someone asks about contrast, having a smooth finish instead of rough makes all the difference in the world.

Nothing beats sub arc-second seeing or really dark skies, though.

#72 Jon Isaacs

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Posted 02 February 2014 - 09:04 AM

Nothing beats sub arc-second seeing or really dark skies, though.



Exactly. My personal thinking goes like this:

I am not so concerned about having the finest quality anything. Decent quality is good enough for me. What I want is for my equipment to be setup so that it "works" for me.

"Works" includes a number of factors but I liken a telescope to a pair of shoes. The best pair of shoes is not the pair with the best leather or finest craftsmanship but rather the shoes that fits my foot and is comfortable all day long.

So in making a telescope "work", it's knowing and understanding the little things and the big things and putting together a system that makes for a pleasurable and effective experience at the eyepiece. In my world a comfortable chair is more important than a fancy eyepiece or a near perfect mirror. To be sure, one can have both but that chair is something that is important 100% of the time and pays dividends each and every moment, good seeing, bad seeing, bright skies or dark skies.

Knowing my equipment is critical in not only getting most out it optically but also making it work. I figure it takes a minimum of two years to get to know and understand and telescope, it's like making friends.. I have had my 25 inch for about 2 years and it's really starting to "work". I have it working... in this case the key was the ladder.. modifying and resolving issues with the ladder made this big elephant are good friend and a joy to be with.

In my mind there is too much emphasis on the quality of the optics and not enough emphasis on the quality of the viewing experience.. I am happy with a decent scope that's a pleasure to use. When the skies are dark or when then the seeing is excellent, I will have my scope ready to go so it is the best it can be, that's plenty good enough for me..

Jon Isaacs

#73 Pinbout

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Posted 02 February 2014 - 09:56 AM

but when you upgraded to a thinner mirror how much did that throw off your balance on your teeter dob.


His Teeter came with the Zambuto so I imagine Rob dealt with that in the build. I think he was referring to his previous 12.5" Discovery and in all honesty that had what many consider a very good mirror in it.

Bill


thats funny I keep forget that part of his story...I'll probably ask him this same question 5 more times before remember. :lol:

#74 Starman1

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Posted 02 February 2014 - 10:42 AM

Danny,
Welcome to the CRS** sufferers group.
I've had it for years.
It starts when you walk from one room into the next to get or do something but you forget why you went in there.
It continues when your wife asks you to get something at OSH and you go there and get 10 things and come home and she reminds you the one thing you forgot to get was the one thing she asked for.
It gets really bad when you tell her the same joke for the 20th time (old married couple: "Number 59! Ha.ha.ha!")
Or you buy more of the same thing you were reminded to buy last time only to discover you'd already bought it.....twice!
Yes, CRS sufferers are the heartbreaking tragedies of the modern world.

** "Can't Remember Stuff"

#75 Thomas Karpf

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Posted 03 February 2014 - 10:55 AM


Yup. Which is why, when I upgrade to a premium dob, I am going with a mirror manufacturer for whom I've seen NO negative reviews. That way, I'll just get a mirror that WORKS.


Tom, In theory, I fully agree with your inclination to go with an optician that has no negative reviews. However, I do not know of any single optician that enjoys that reputation. None! The reason I say this is that there are many variables that are sometimes out of the control of the optician. For example, if a mirror blank has strain in it that does not reveal itself in a careful evaluation, then the mirror has the possibility of changing figure. If an optician's mirror is coated improperly, again, you have the chance of some deviation from what the optician was intending.


Valid points, granted.

Carl Zambuto is the mirror maker I will (most likely) be using. Nowadays, he slumps his own glass, so he KNOWS that there is no strain in his blanks. And, I believe he's currently looking into coating his own mirrors.

I've seen exactly two somewhat negative reviews regarding mirrors Carl Zambuto has worked on, and in both cases they were mirrors he was asked to refigure, and he therefore had no control over the strain in those mirrors. I've seen absolutely no negative reviews regarding anything he has done in the last decade.






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