17 replies to this topic

[cavecollector]

Which are your favorite, most used accessories as sold by Questar? 

[Tbsweet]

For me it’s the full solar filter.

[Absorber]

The Tri-Stand short pier setup

[cavecollector]

Do they still sell the Tri-Stand? I thought they stopped producing them when the company that made them stopped building them for Questar?

[RMay]

Do they still sell the Tri-Stand? I thought they stopped producing them when the company that made them stopped building them for Questar?

While perhaps not officially discontinued, the Tristand has not been produced in a few years now. When I inquired to ask if they might at least ‘open source’ the production specs so others could build them, my request was politely declined.

Ron

[cavecollector]

Fortunately,  there are some amazing photo/video/surveying tripods out there. The Tri-Stand was an inspired design though, I really hope someone will make something similar (or for Questar to sell them again). If designed right, they could used with many other small catadioptric telescopes with fork mounts. A C5 could work great on one. Lots of possibilities in case you're a machinist or manufacturing company. Anyone looking to start a small business making things? 

[RMay]

Fortunately, there are some amazing photo/video/surveying tripods out there. The Tri-Stand was an inspired design though, I really hope someone will make something similar (or for Questar to sell them again). If designed right, they could used with many other small catadioptric telescopes with fork mounts. A C5 could work great on one. Lots of possibilities in case you're a machinist or manufacturing company. Anyone looking to start a small business making things?

It would be interesting to bring a Tristand into a CNC metal fabrication shop, ask them to reverse engineer it and then get a quote for, say, 20 copies…

Ron

[emh52]

Do they still sell the Tri-Stand? I thought they stopped producing them when the company that made them stopped building them for Questar?

I have one, it is a great design, inspired I think, but it is heavy, really heavy, I like it, but for me it is backyard use, not travel that I sort of foolishly thought when I bought it. You can accomplish the same goal with a carbon fiber tripod and a gear head to adjust for latitude easily in a much lighter and compact package for travel. It is a kind of inspired stable design from a bygone era before the lighter stuff today. I do like it has a built-in handle- it needs it. Aside from any patent/copyright issues I imagine it could be replicated if there was a big enough run..... maybe even make it lighter with different fabrication like anodized Al instead of iron, or even partially carbon fiber.

Edited by emh52, 30 May 2024 - 11:22 AM.

[pbealo]

It would be interesting to bring a Tristand into a CNC metal fabrication shop, ask them to reverse engineer it and then get a quote for, say, 20 copies…

Ron

My son fully captured the design in CAD and we went out to bid on having parts made in China. It was not cost effective for low volumes (<100).

 

Peter B.

[DAVIDG]

 My favorite accessory is the TeleVue 1.25" eyepiece adapter that I modified slightly by machining down the top surface so the finder and the scope will both be in focus.

 

                     - Dave 

[Optics Patent]

It would be interesting to bring a Tristand into a CNC metal fabrication shop, ask them to reverse engineer it and then get a quote for, say, 20 copies…

Ron

The same could be said for the entire Questar telescope (mechanical), and this probably should have been done decades ago.

[Optics Patent]

My favorite accessory is the TeleVue 1.25" eyepiece adapter that I modified slightly by machining down the top surface so the finder and the scope will both be in focus.

- Dave

That should be commercialized!

[markmanner]

...

So, my question to all of you with Broadband Questars, what are you doing? ......

I plan on dying when the transmission drops by more than 20%.

. 

Edited by markmanner, 01 June 2024 - 06:45 PM.

[Paul Schroeder]

One thing not mentioned so far are the optical coatings. The Standard coatings last for many decades while the Broadband coatings group starts to drop in performance after about a decade. While they will continue to function for quite a while, the images will continue to dim as the coatings slowly age and fail. You can't just have the Broadband coatings replaced through the typical recoating process like with the Standard. Broadband coatings must be polished off, a very time consuming, laborious process and it's cheaper and faster to just replace the optics.

 

So, my question to all of you with Broadband Questars, what are you doing? Buying spare optical sets and sending Tony life extension products so he will be around to replace the optics? What are you doing to protect your investment?

 

Just out of curiosity, has anyone thought to call Cumberland to see how they're doing and find out if there are any situations in which they would consider making and selling optical sets for Questar owners who can't get them any other way?

Is there any objective way to measure how much performance degradation occurs with older broadband coatings?  I have a 1971 Questar with broadband coatings; upon visual inspection there are no obvious issues, and images don't appear inordinately dim.

 

That being said, I don't have a late model Questar handy to serve as a point of reference.  

 

It would be interesting to hear if anyone's actually measured light throughput on an older instrument like this, and then compared it to the throughput on a newer unit.

 

Many thanks,

 

Paul

[98105dude]

Perhaps Cumberland has a way of knowing WHO'S calling before they pick up. Signed - proud member of the Grubby Public 

[gwd]

Is there any objective way to measure how much performance degradation occurs with older broadband coatings?  I have a 1971 Questar with broadband coatings; upon visual inspection there are no obvious issues, and images don't appear inordinately dim.

 

That being said, I don't have a late model Questar handy to serve as a point of reference.  

 

It would be interesting to hear if anyone's actually measured light throughput on an older instrument like this, and then compared it to the throughput on a newer unit.

 

Many thanks,

 

Paul

I have a 1987 with broadband coatings.  How do I tell that the coatings have deteriorated?  I continue to use the scope frequently is what I do.   How much degradation am I missing?  Is it time to replace the corrector and primary?   When I sent it to Questar for a tune up around 2008 or so, Questar told me the 30 year old coatings were still good.   

 

Whenever I do a side by side with other scopes, even much larger ones I'm almost never impressed enough with the other scopes to think I shouldn't have gotten the Questar.   Exception:  One time at a star party a guy loaned me a 10 inch homemade Dobsonian that I would have traded my Questar.  The Dobsonian had the obvious coma in the outer field and the annoying spikes but the whole package balance and smooth operation came together perfectly.    The guy who loaned it to me said it was built by a very experienced ATM'er who ground the primary by hand.   

[gwd]

 My favorite accessory is the TeleVue 1.25" eyepiece adapter that I modified slightly by machining down the top surface so the finder and the scope will both be in focus.

 

                     - Dave 

I just got one of these and mine seems different.  What I have to do is move the eyepiece out a bit to get it to focus in the finder.  Also I can't get it to finder focus with a filter screwed into a non-questar Vernonscope eyepiece.   The filter plus adaptor raises the eyepiece out too far.   

[NC Startrekker]

I have a 1987 with broadband coatings.  How do I tell that the coatings have deteriorated?  I continue to use the scope frequently is what I do.   How much degradation am I missing?  Is it time to replace the corrector and primary?   When I sent it to Questar for a tune up around 2008 or so, Questar told me the 30 year old coatings were still good.   

 

Whenever I do a side by side with other scopes, even much larger ones I'm almost never impressed enough with the other scopes to think I shouldn't have gotten the Questar.   Exception:  One time at a star party a guy loaned me a 10 inch homemade Dobsonian that I would have traded my Questar.  The Dobsonian had the obvious coma in the outer field and the annoying spikes but the whole package balance and smooth operation came together perfectly.    The guy who loaned it to me said it was built by a very experienced ATM'er who ground the primary by hand.   

Hi George. In most cases, the first signs of degradation of BB coatings appears around the edge of the mirror. To me it looks like small rust stains that slowly expand over time. Although I have seen a couple of examples where it appears as small spots randomly across the face of the mirror. Depending upon the cause and the environment you use and store your Q in, it could take years before it becomes bad enough to seriously compromise your views. This is a good thing since BB coated mirrors can’t be recoated; they have to be replaced entirely. This is why Questar highly suggests standard coatings if you plan to use your Q in or near a salt water environment. Under those conditions, failure is greatly accelerated. Best.  Alan