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Q7 Astro

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#1 JimP

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Posted 14 June 2019 - 05:54 PM

I am always thinking about something  and recently have been thinking about a Questar seven OTA. While my initial thoughts were toward the classic style with control box I know someone who has friend (a couple thousand miles away) who may be willing to sell his Q7. It is the Astro model and will be sent back to Questar for a check up/tuneup. Does anyone have any experience with the Astro model and, if so, what do you think of it?

 

Pyrex mirror and standard coatings. I live at the beach half of the year and so not having the broadband coatings is OK.

 

Double stars primarily, then the Moon and planets.

 

Thanks for any comments.

 

Best,

 

Jim


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#2 agmoonsolns

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Posted 14 June 2019 - 06:18 PM

If you could find one, a version with a Quartz mirror and the standard coatings is the best combination in my book. Whatever you do, do NOT get one with the Cervit mirror. Quartz will give the smoothest surfaces and Cervit the roughest. Long story short, I refuse to ever own another Cervit Q again (for many reasons). I am not saying they are all bad, only that I have seen enough to not want one again.

 

While the Broadband coatings result in a noticeable difference, this difference fades over time and eventually the standard coatings will actually out-perform the BB as the coatings age. Also, after a very long time or if exposed to difficult conditions that age the coatings faster (ocean air), you will eventually need to replace the entire set of optics. This is because BB mirrors can't be re-coated. This is why many Questar buyers tend to avoid buying used BB Questars that are more than about twenty years old. If considering an older BB Q, make darned sure you check the mirror for any coating issues. If you only plan on having it for a few years, then a newer BB Questar would be a wonderful option. If you're thinking of this in terms of decades, then possibly factor in replacing the optics at some point.


Edited by agmoonsolns, 14 June 2019 - 06:20 PM.

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#3 drprovi57

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Posted 14 June 2019 - 06:27 PM

I have a Q7 Astro - used mainly for planets, moon, and solar imaging - occasional visual use.   The optics are superb show nice planetary, lunar, and solar detail (I have a Quark Combo with a front Energy rejection filter).  Here is a picture several setups:

 

On an AVX mount:

JPEG image.jpg

 

Case for Q7:

IMG_0365.jpg

 

Q7 as solar telescope with D-ERF on front and Quark Ha filter on rear with CMOS camera

IMG_0014.jpg

 

Jason


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#4 JimP

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Posted 14 June 2019 - 06:50 PM

Thanks!

 

The Q7 Astro I am considering has a Pyrex mirror and standard coatings. I live at the beach about 5 months a year so BB coatings are out. 

 

Gorgeous serup! Love the color!!

 

Jim


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#5 Toxo144

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Posted 14 June 2019 - 08:14 PM

Jim,

 

Have both the Q7 Titanium Classic and the Q3.5 Anniversary.  Quartz isn't the issue - its seeing and how well the optics were shaped and matched, no matter what the substrate.  I do know this - if I could sell my Q7 Titanuim classic and get a Q7 astro instead, I'd probably do it in a heartbeat.  So long as the Q7 Astro had the star map and moon graphics on the barrel and dew shield.....

 

Good luck with your choice - it's a big decision.

 

Toxo


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#6 Optics Patent

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Posted 14 June 2019 - 09:06 PM

If it’s a good opportunity just buy it. If a better one comes along when you’re more experienced as a user then sell and buy. If you take good care a well purchased Questar is money in the bank.

#7 Gregory Gross

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Posted 14 June 2019 - 10:11 PM

I agree. If you have reasonable confidence in the scope and the seller, if the Astro is the variant of the Q7 that you really want, and if the price is right, go for it. Others may know better, but I rarely see those come up on the used market.

 

For what it’s worth, the Q7 Astro is my favorite of all the seven-inch Questars. It has the optical quality of the Questar name with the versatility of more standard scopes (built to use the diagonal and eyepiece of your choice, etc.).



#8 starblue

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Posted 14 June 2019 - 10:19 PM

... Have both the Q7 Titanium Classic and the Q3.5 Anniversary.  ...  I do know this - if I could sell my Q7 Titanuim classic and get a Q7 astro instead, I'd probably do it in a heartbeat.  ...

Toxo144, why would you want to swap out your Q7 Titanium version? I have the impression that the Q7 Ti cools down considerably faster than a standard Q7, which is the latter's major fault. Am I mistaken on this point? I've gotten contradictory information about how much more quickly a Q7 Ti cools down and stabilizes vs. a regular Q7. Or is there another issue with your Q7 Ti that bothers you?


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#9 JamesMStephens

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Posted 14 June 2019 - 10:58 PM

This sounds like a terrific scope for doubles, planets, and the moon. I don't see how you can go wrong.

 

Jim


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#10 RMay

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Posted 15 June 2019 - 01:57 AM

Some 30+ years later, I still remember the first time I looked at the moon through a Seven (visibility was superb as we were at elevation in Arizona)... my thought was, “This must similar to the view the Apollo astronauts had looking out the cabin windows of the lunar lander on their way to the moon.” It’s an amazing scope.

#11 Matt Looby

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Posted 15 June 2019 - 02:32 AM

While I have never observed through a Q7, I am absolutely certain, it would not best an Intes-Micro 703, so if the choice is a Q7 Astro,

 

I'd suggest a Russian Mak.

 

Matt

 

 

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#12 Toxo144

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Posted 15 June 2019 - 02:38 AM

Starblue,

 

NO model of the Q7 cools any more quickly than any other.  What they ALL need is a way to circulate filtered air on the back of the primary mirror.

 

The control box is a REALLY cute feature on the 3.5, but is in my experience unnecessary  on the 7.  What most of us want is a big honker top quality 2" diagonal on the back of a 7 that can accept ANY eyepiece, camera, video cam, binoviewer, or whatever you want.  At the FL of the 7, the control box finder is much less desirable that a finder scope, telrad, or laser finder up top.  And the control box barlow, while convenient, is nowhere near the quality of a good TV Powermate, Vernonscope Dakins, or whatever suits your fancy.  Most of us who own a Q7 want to load the back with the stuff we CAN'T load on the back of the 3.5 - and the control box is just extra weight and drag, and takes up valuable back focus that is often needed elsewhere.

 

The control box on the 3.5 helps make it the most portable, complete, high quality "Observatory in a Box " ever made, and I wouldn't change anything about that.  But you don't buy a Q7 for convenience.  You buy it for the power that comes from all that extra aperture up front with great Mak-Cass optics behind it.  The Astro 7 is just a more direct approach  for those of us who want to customize  what we want to use on the back of the scope - and there is a lot out there to choose from.

 

At least, that's how I see it after years of experience.  I'm sure there are other Q7 owners that feel differently,  and I respect their well-founded viewpoint.

 

Cheers!

 

Toxo


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#13 drprovi57

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Posted 15 June 2019 - 08:19 AM

Starblue,

 

NO model of the Q7 cools any more quickly than any other.  What they ALL need is a way to circulate filtered air on the back of the primary mirror.

 

The control box is a REALLY cute feature on the 3.5, but is in my experience unnecessary  on the 7.  What most of us want is a big honker top quality 2" diagonal on the back of a 7 that can accept ANY eyepiece, camera, video cam, binoviewer, or whatever you want.  At the FL of the 7, the control box finder is much less desirable that a finder scope, telrad, or laser finder up top.  And the control box barlow, while convenient, is nowhere near the quality of a good TV Powermate, Vernonscope Dakins, or whatever suits your fancy.  Most of us who own a Q7 want to load the back with the stuff we CAN'T load on the back of the 3.5 - and the control box is just extra weight and drag, and takes up valuable back focus that is often needed elsewhere.

 

The control box on the 3.5 helps make it the most portable, complete, high quality "Observatory in a Box " ever made, and I wouldn't change anything about that.  But you don't buy a Q7 for convenience.  You buy it for the power that comes from all that extra aperture up front with great Mak-Cass optics behind it.  The Astro 7 is just a more direct approach  for those of us who want to customize  what we want to use on the back of the scope - and there is a lot out there to choose from.

 

At least, that's how I see it after years of experience.  I'm sure there are other Q7 owners that feel differently,  and I respect their well-founded viewpoint.

 

Cheers!

 

Toxo

as an owner of a Q7 Astro as well as a 50th Q3.5 - I agree totally.  the Q7 astro was not designed to be as portable or, perhaps as convenient, as a Q3.5- the Q7 was designed to take advantage of its excellent optical and mechanical quality (virtually "zero" focus shift and rock steady images) - Q7 with its great back focus and use of 2" optical devices is both a great visual and imaging scope.   It will not disappoint -- the Q7 Astro was designed for binoviewing and imaging in mind.  You can also attach a 2" motorized focuser from either moonlite or FeatherTouch - very convent to get precise focusing for imaging - plenty of back focus

 

Jason


Edited by drprovi57, 15 June 2019 - 08:21 AM.

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#14 Optics Patent

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Posted 15 June 2019 - 12:50 PM

How important is it to put the diagonal right at the back plate of an Astro as opposed to at the axial port of a control box? Wider field?

#15 Optics Patent

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Posted 15 June 2019 - 02:17 PM

Toxo makes a good case for why one might be happy without all the control box features that add ~$1500 to the price of the scope.  I've never used an Astro, but I've used other scopes with separate finders.  I find the Questar convenience from a single eyepiece comfortable, and don't forget that the $1500 savings is reduced by whatever finder one chooses to buy instead.

I'm not sure there's any reason to assume that the internal Barlow is of lower quality than the external Dakin Barlow that Vernonscope presumably supplies (as they do all Questar eyepieces).

 

I think the best argument is on price and value, looking at the whole scope.  There is a good argument that the scaling up of the self-contained mount for the Seven isn't an ideal fit, and the $7000 price isn't ideal when you consider that you still need to spend thousands on a suitable mount.  A $9500 Astro on a fine $3000 GEM plus some finder costs ($13k) saves a bundle for the same image as a mounted Classic for $18,000 plus ~$3000 for a mount for the mount ($21k).  Of course, the used market is what it is, and hobbyists have fun assembling systems for a Classic more affordably, maybe about the cost of a sensible new Astro system.  I think the big difference is an emotional one - is one in love primarily with observing, or with Questar?


Edited by Optics Patent, 15 June 2019 - 02:19 PM.

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#16 bobhen

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Posted 15 June 2019 - 03:07 PM

I think if I wanted a high-end, multi-thousand dollar 7-8” Mak specifically for the moon, planets and double stars, I would call Marcus at APM and have him build one to my specifications including: making it F20 with a small CO, incorporating rear-mounted fans and spec an optical wave front like 1/8 wave or better, etc.

 

Pricy, yes. 

 

Bob


Edited by bobhen, 15 June 2019 - 03:08 PM.


#17 RMay

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Posted 15 June 2019 - 03:13 PM

When I was working with Q back in the early 1980s I remember Julius telling me that some scopes were spec’d (or at least tested) to 1/24 wave. Have any of you heard of or tested scopes to achieve this spec? (and sorry; I don’t recall if he was referring to the 3.5 or Seven, or a particular scope).

Thanks,

Ron

#18 JimP

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Posted 15 June 2019 - 05:14 PM

Oh well, the Q7 Astro I was looking at sold right out from under me! LOL!!

 

I take that as a sign from the Heavens. 

 

I certainly do not want any other make Maksutov than a Questar right now. I have plenty of other scopes and do not need anything at all. My decision has only to do with Q3.5 or Q7 and which configuration I like best and can afford. Used only.

 

I guess I would have to say a significant part of this is a love for Questar. Guilty your honor.


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#19 Kevin Barker

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Posted 15 June 2019 - 05:24 PM

Jim
Two things to consider re q 3.5 or 7 is your likely ease and frequency of use. For example I am camping at a remote scenic spot overnight. I have my Duplex 3.5". Last night between showers I observed the moon and Jupiter. Using a picnic table and the scopes legs. Had to pull it in after 20 min as a shower approached. To his morning I checked out the sun.
Not so easy with a 7". Either Astro or classic.

Edited by Kevin Barker, 15 June 2019 - 05:26 PM.

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#20 Optics Patent

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Posted 15 June 2019 - 05:52 PM

JimP I’d suggest you also consider the Q5 option if you have happy alternatives for the upcoming months. Estimate $5k for the barrel for use on you mount maybe in the next year then another $5k for the drive/mount.

Buy something smart used that you can resell at break even for a Q5 if superior performance with ready portability makes sense for you in the long term.
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#21 Toxo144

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Posted 15 June 2019 - 06:43 PM

WOW!  Looks like Questar 7 scopes sell fast!  Maybe I will sell my Q7Ti and get an Astro 7......so long as I can get the moon and star map on the outside.

 

Toxo



#22 Toxo144

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Posted 15 June 2019 - 07:26 PM

@Optics Patent,

 

I'm not saying the Questar control box  Barlow is "bad."  I DO find the screw-on barlow from Vernonscope MUCH more convenient to clean, and it really DOES deliver the magnification it says it does.  This can be a little iffy with the control box Barlow, with ranges from 1.6 to 2.0.  And the TV Powermate comes in several Barlow magnifications, so you can really tune it up - or down - as sky conditions permit.  Again, "customizable."  This is especially important for anybody that wants to do Lunar or planetary imaging with video on a Q7.  Those dust donuts on the control box Barlow can drive an imager nuts!!

 

Cheers!

 

Toxo


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#23 JMKarian

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Posted 15 June 2019 - 07:45 PM

JimP

Questar Astro 7 - Quartz
Exceptional contrast on globular clusters, my favorite targets.

No regrets

John

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#24 Toxo144

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Posted 15 June 2019 - 09:17 PM

John,

 

GORGEOUS setup - I'd say that AP mount makes a GREAT accessory for a Q7!!

 

Toxo


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#25 JimP

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Posted 16 June 2019 - 07:39 AM

I agree with all your thoughts although I will be 69 in September and waiting to buy a new Q5, if it ever materializes, is not an option for me. Looking for used only at this point.

 I am leaning toward a Q3.5 Duplex or, if lightening should strike, a used Q7 OTA. I would love a Q7 Astro like the one in John’s picture above. Now that is a Gorgeous telescope!!

 

Jim




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