558 replies to this topic

[SkipW]

what does fishing have to do with Questars?

Questars are a cheaper hobby.

[NinePlanets]

It depends on how you fish.

[rcwolpert]

I think I see a fast triplet in Bob's future.  

I wish my sky was as transparent as I am! 

[Joe Cepleur]

Yes. Think about how much some people spend on — I am afraid to list examples, for fear of being flamed. Almost anyone who prioritizes having good optics can afford to. After that, it becomes matching budgets to interests. What does one want? 115 Questars for $350,000? 1 Questar for $3,000? or, the experience of exploring the views through many different telescopes? There are many valid approaches to astronomy.

I have a friend who bought a case full of new eyepieces a few years ago, at $800 each. He figured that if he did not buy what he wanted, he'd only buy again later, increasing the cost. For people attracted to the lure of Questarian perfection, the $3,000 purchase can be a modest, money-saving means to a lifetime of the desired approach to astronomy.

[rcwolpert]

Perhaps when I get my new refractor!

 

Uh... Bob... What you up to down there??

 

I think there will be some coming and going of telescopes.  Long refractors in heavy wooden cases are not what I need at this time. Plus, I need something with a bit more aperture than the Questar (which is staying with me till the end).

[Terra Nova]

I wish my sky was as transparent as I am! 

You’re gonna love it Bob. I was playing with mine again just the other day (when it was clear! ).

[CHASLX200]

Yes. Think about how much some people spend on — I am afraid to list examples, for fear of being flamed. Almost anyone who prioritizes having good optics can afford to. After that, it becomes matching budgets to interests. What does one want? 115 Questars for $350,000? 1 Questar for $3,000? or, the experience of exploring the views through many different telescopes? There are many valid approaches to astronomy.

I have a friend who bought a case full of new eyepieces a few years ago, at $800 each. He figured that if he did not buy what he wanted, he'd only buy again later, increasing the cost. For people attracted to the lure of Questarian perfection, the $3,000 purchase can be a modest, money-saving means to a lifetime of the desired approach to astronomy.

I want one for 1.5K max. Not going 2k or more ever.

[Terra Nova]

I want one for 1.5K max. Not going 2k or more ever.

I think you’ve said that several times. And even if you got one, I have no doubt it would soon be consigned to your long list of once upon a time telescopes. Just stick with the Corvette and the boat. I think you’re better off.

[CHASLX200]

I think you’ve said that several times. And even if you got one, I have no doubt it would soon be consigned to your long list of once upon a time telescopes. Just stick with the Corvette and the boat. I think you’re better off.

I got 300 more scope to go and please go check out my thread on the refactor section and see all the peeps that use freaky high powers and even in Q's they can hold up to 450x easy in a 3.5".

[Joe Cepleur]

I got 300 more scope to go and please go check out my thread on the refactor section and see all the peeps that use freaky high powers and even in Q's they can hold up to 450x easy in a 3.5".

.

That's almost 130x per inch. How are you using that power? Fair game for generating Airy disks, but remarkable for seeing details on extended objects. The general wisdom is that 50x per inch is the highest generally possible, although TeleVue says that, even with its superior refractors, 30x per inch is the most anyone should expect under real-world conditions.

[CHASLX200]

.

That's almost 130x per inch. How are you using that power? Fair game for generating Airy disks, but remarkable for seeing details on extended objects. The general wisdom is that 50x per inch is the highest generally possible, although TeleVue says that, even with its superior refractors, 30x per inch is the most anyone should expect under real-world conditions.

Just saying a Q3.5 can take 450x on a few objects for fun. Try a star or Venus or the moon.  Normal high would be around 200x or so.

[deSitter]

.

That's almost 130x per inch. How are you using that power? Fair game for generating Airy disks, but remarkable for seeing details on extended objects. The general wisdom is that 50x per inch is the highest generally possible, although TeleVue says that, even with its superior refractors, 30x per inch is the most anyone should expect under real-world conditions.

As speculated above - people very likely see differently. Yes as a matter of strict resolution, you max out around 50-60x per inch. After that things not only get bigger, they get dim and fuzzy. But if your visual system is more motion oriented, you may prefer sheer size to straight resolution. I have an AO scope that can actually do 100x per inch without serious uglies, although it is of no use to me on the sky.

 

-drl

Edited by deSitter, 17 February 2024 - 11:57 AM.

[Bob Campbell]

I think you’ve said that several times. And even if you got one, I have no doubt it would soon be consigned to your long list of once upon a time telescopes. Just stick with the Corvette and the boat. I think you’re better off.

It would be freaky sharp, that's for sure .  

 

Bob

[starman876]

It would be insane.  I will say no more

[Joe Bergeron]

I want one for 1.5K max. Not going 2k or more ever.

I don’t blame you. If I had already blown $350K on telescopes like you, I’d be more frugal too. 

[Bob Campbell]

I don’t blame you. If I had already blown $350K on telescopes like you, I’d be more frugal too. 

ouch!  (touche)

[Terra Nova]

.

That's almost 130x per inch. How are you using that power? Fair game for generating Airy disks, but remarkable for seeing details on extended objects. The general wisdom is that 50x per inch is the highest generally possible, although TeleVue says that, even with its superior refractors, 30x per inch is the most anyone should expect under real-world conditions.

Joe, That’s way too low for max mag with a TV. I’ve routinely pushed my 4” (Genesis SDF) to 180X with a 3mm Delite, and even my little 70mm Pronto handles 120X without breaking a sweat with my 4mm Delite, and it’s usually fine up to 150X with the 3mm. (Targets: Venus, Jupiter, Saturn, and Mars).

[Terra Nova]

Just saying a Q3.5 can take 450x on a few objects for fun. Try a star or Venus or the moon.  Normal high would be around 200x or so.

I will admit to 300X (100X per inch) with the FC76 on Jupiter and also ε₁ and ε₂ Lyra. That’s my absolute, extreme limit. I almost always stick with 50X to 60X per inch as my upper limit. I don’t care much for the weird, dark, pulsating field and blobby images that happen at extreme limits. When I didn’t know better, I used to try to push my 60mm Mayflower to 280X with the 0.965” 5mm S.R. Eyepiece and 2X barlow that came with it way back when. The only think it really worked with was the moon and that view tho BIGGER, wasn’t better than the 140X sans barlow view. Those experiments pretty well cured me of such dalliances long ago. In most cases, I consider it a Fool’s errand. I’m really not interested.

Edited by Terra Nova, 18 February 2024 - 12:11 PM.

[Joe Cepleur]

Well, gosh; in my memory, it was on TeleVue's Web site that I found the comment that 30x per inch was a typical maximum power, given atmospheric conditions, but now I can not find the page again! It's been years. I did find this, which confirms a similar idea:

https://www.televue...._page.asp?id=79

"For determining maximum power, a good rule of thumb is to use no more than 60x per inch of aperture for scopes with apertures up to 6". Higher magnifications may still be pleasing but will not likely reveal any additional detail. Realistically, the atmosphere will usually limit your planetary observing to a maximum magnification of about 300x, no matter how large your telescope aperture."

My guess is that the better and smoother the optics, the less scattered light mushes over-magnified images, so the better they appear. I have seen this phenomenon myself, where a larger image reveals no more detail, but is easier to see simply because it is larger. Anyway, that might explain how owners of fine optics insist that such high powers improve images beyond what the available resolution might be thought to allow.

[starman876]

Well, gosh; in my memory, it was on TeleVue's Web site that I found the comment that 30x per inch was a typical maximum power, given atmospheric conditions, but now I can not find the page again! It's been years. I did find this, which confirms a similar idea:

https://www.televue...._page.asp?id=79

"For determining maximum power, a good rule of thumb is to use no more than 60x per inch of aperture for scopes with apertures up to 6". Higher magnifications may still be pleasing but will not likely reveal any additional detail. Realistically, the atmosphere will usually limit your planetary observing to a maximum magnification of about 300x, no matter how large your telescope aperture."

My guess is that the better and smoother the optics, the less scattered light mushes over-magnified images, so the better they appear. I have seen this phenomenon myself, where a larger image reveals no more detail, but is easier to see simply because it is larger. Anyway, that might explain how owners of fine optics insist that such high powers improve images beyond what the available resolution might be thought to allow.

you are arguing common sense limits that most agree with.  However, going to insane powers is not common sense so this is an argument that does not make any sense. 

[Kasmos]

Recently I've been going thru some old Sky & Telescopes and I believe a very old Astro Physics ad said they were good for up to 100x per inch. I was kind of surprised it was stated this high in the ad and I suppose just mentioning this ads to more comotion.

Edited by Kasmos, 17 February 2024 - 02:58 PM.

[Joe Bergeron]

Recently I've been going thru some old Sky & Telescopes and I believe a very old Astro Physics ad said they were good for up to 100x per inch. I was kind of surprised it was stated this high in the ad and I suppose just mentioning this ads to more comotion.

Their early advertising was on the optimistic side. 

[davidmcgo]

My 1995 AP 130 EDT is useful at 586x on Mars at opposition in good seeing for detail around the polar caps and the desert regions.   Mars is so bright that higher magnifications help without distorting the view by color filters.  Klee Barlow and a 5mm Takahashi LE work really nicely.  Plus for doubles right at the resolution limit look like snowmen.

 

Jupiter some detail in and around the Great Red Spot is seen well at 380x or more.

 

So not overly optimistic advertising.  Just need to use judgement and experience what the benefits of real high power are and it may just be a certain feature on an object that it helps.

 

Dave

Edited by davidmcgo, 17 February 2024 - 03:26 PM.

[CHASLX200]

Recently I've been going thru some old Sky & Telescopes and I believe a very old Astro Physics ad said they were good for up to 100x per inch. I was kind of surprised it was stated this high in the ad and I suppose just mentioning this ads to more comotion.

100x per inch is the norm with 6" and smaller fracts with fine optics on some objects. Just not Jup.

[oldmanastro]

I am lucky to have many nights of excellent seeing but the most that I have been able to push the 3.5" Questar is about 325x. This is excellent considering the scope aperture. On the other hand the ETX-90 (US made) tops out at 250x max. This is on nights were the seeing is really superb. I go into very high powers only while observing double stars not extended objects. Per inch of aperture the Questar in the best telescope in my group at handling high power. I have no APOs or ED refractors and still believe in the rule of 50 to 60x per inch.