529 replies to this topic

[Jon Isaacs]

Okay, you enjoy using your achromats. So what. People still enjoy driving their Chevy Corvairs. And the Corvair is well known to be one of the worst cars ever made. Heck, there are even Corvair clubs. But the fact that you enjoy using your achromats does not make them better refractors or better tools in which to enjoy the heavens than the more advanced apochromatic refractors. Logic dictates that you would get even more enjoyment by using a better tool.

 

Granted, this is a hobby. And folks can use whatever they want and whatever they like. But enjoyment cannot really be quantified. But performance can be. And if you are talking about pure performance and only performance, then the achromat falls behind. You might not "feel" like you are missing out, but when it becomes to pure performance, of course you are.

 

In the end, enjoyment from a hobby is probably paramount. But let's not confuse "enjoyment" with "performance". One can certainly derive enjoyment from using and inferior instrument. But one cannot deny, that when it comes to "performance", compared to the apochromat the achromat is the inferior instrument and the inferior design.

 

Bob

 

 

I really don't get it.  You are the guy who uses a 102mm F/5 achromat instead of an NP-101.  You've had it is for 20 years???  

 

It is all about making the most of the tools you have, choosing the right tool for the job.  Does a 4 inch F9 ED scope perform better on globular clusters than a achromat 6 inch F/8 ?  I don't think so. Visually,  does a 20 inch Dob blow a 5 inch APO away viewing galaxies and globulars and the planets.. I think so.. That's performance. 

 

The Corvair thing, poorly designed cars and telescopes of every generation are poor performers.  

 

Jon

[maniack]

One can certainly derive enjoyment from using and inferior instrument. But one cannot deny, that when it comes to "performance", compared to the apochromat the achromat is the inferior instrument and the inferior design.

Performance of an achromat depends on what you're looking at with it. The performance of the 90mm f/5.5 SV48P is better than the 80mm f/7 AT80ED I used to have in two important ways. First it gathers more light, showing dimmer objects. It also has a wider true field of view (not by much, but ~10% shorter focal length is noticeable).

 

The SV48P is also superior in 2 ways mechanically - it's shorter and lighter. For me this means it fits on in a medium-size camera backpack and rides better on an AZ-GTi or other lightweight mount head. Oh and the SV48P is also cheaper.

 

So for wide-field views I use it for it's superior than the 80mm ED or its EDL apo sibling. For high magnification I have better options that are in the same weight category but do a lot better than these 3" scopes on solar system objects at least (splitting doubles are a mixed bag) - for example my C5.

 

Now one could argue that you can make a ~90mm f/5.5 apo that does the wide-field just as well as the SV48P but does high magnification better. The Astro-tech AT92 was the closest option and cost ~8x the price of the achromat while being noticeably heavier. The Sharpstar 94EDPH was also a similar option at a lower price point, and the TS rebrand is still available. Borg has a fast 90mm doublet, but in addtion to being even more expensive it seems like the Borg doublets do exhibit a small amount of CA. And none of these would be noticeably better than the SV48P for wide field visual viewing.

[Phil Cowell]

Sharing opinion is what was provided. Your level of tolerance for defects is markedly different from mine and both viewpoints are equally valid.

 

A point of what is a minimum acceptable product differs between users and taking into account the users existing stable in the OP’s profile. The OP is obviously knowledgeable about optics based on his known selection of instruments. 
 

I can get a wider field of view using my Tak BabyQ plus reducer without all of the obvious defects inherent in ST80. Again it depends on your tolerance for accepting defects. To use an existing measure (AQL) based of data available about the OP from their profile. 

No I wouldn’t drive a Corvair either.

 

Share our own experiences, our own opinions, that is what the OP asked about.  

 

 

Optical perfection is not necessary to joyfully observe the universe. 

 

Jon

Edited by Phil Cowell, 25 March 2025 - 08:17 AM.

[bobhen]

 

I really don't get it.  You are the guy who uses a 102mm F/5 achromat instead of an NP-101.  You've had it is for 20 years???  

 

It is all about making the most of the tools you have, choosing the right tool for the job.  Does a 4 inch F9 ED scope perform better on globular clusters than a achromat 6 inch F/8 ?  I don't think so. Visually,  does a 20 inch Dob blow a 5 inch APO away viewing galaxies and globulars and the planets.. I think so.. That's performance. 

 

The Corvair thing, poorly designed cars and telescopes of every generation are poor performers.  

 

Jon

But I'm not under the delusion that a TV 101 apo would not be a better performer than a 102mm F5 achromat. The 102mm F5 achromat is strictly a one-trick pony. Whereas, a TV 101 is a wide field, low power, deep sky scope and a high power planetary scope and an imaging scope. That's the apo advantage. 

 

It's not about comparing a large scope to a much smaller scope. It's about the inherent design advantages of the apochromatic refractor over the limitations of the achromatic refractor.  As I said, having an achromat is better than having no telescope at all. But having an apochromat is much better still.

 

This discussion is not about the performance advantage of a 20" Newtonian over a much smaller apo or achromat, it's about: what one should expect from an achromat. And the bottom line is: one should expect less performance from an achromat than from a same-size apochromat.

 

Getting less performance doesn't mean that one cannot still enjoy an achromat. I've owned a few. But there's a reason that apos (while more expensive) are far more popular with serious (not beginners) imagers and observers than are achromats. And that reason is, observers and imagers find the apo advantages are so significant that they are worth paying for.  

 

I've compared my old Astro-Physics 152 F9 triplet with an A Jaegers 152 F15 achromat side-by-side on Jupiter. The view in the eyepiece was not even close. I also observed Jupiter with a 4" F15 Edmund Scientific refractor. The view was certainly enjoyable. But the view was not in the same league as in my Takahashi FC-100DF Fluorite doublet; better view also means even more enjoyment. And the Tak is much lighter and much shorter to boot. 

 

Yes, poorly design cars and telescopes are poor performers. But people still enjoy their poorly designed Corvairs. And the achromat, when compared to the apochromat, is also the poorer design. People still enjoy them but that enjoyment does not change the fact that the achromat is the poorer design and has all the limitations of that poorer design. 

 

Bob

Edited by bobhen, 25 March 2025 - 08:00 AM.

[Russell Swan]

But I'm not under the delusion that a TV 101 apo would not be a better performer than a 102mm F5 achromat. The 102mm F5 achromat is strictly a one-trick pony. Whereas, a TV 101 is a wide field, low power, deep sky scope and a high power planetary scope and an imaging scope. That's the apo advantage. 

 

It's not about comparing a large scope to a much smaller scope. It's about the inherent design advantages of the apochromatic refractor over the limitations of the achromatic refractor.  As I said, having an achromat is better than having no telescope at all. But having an apochromat is much better still.

 

This discussion is not about the performance advantage of a 20" Newtonian over a much smaller apo or achromat, it's about: what one should expect from an achromat. And the bottom line is: one should expect less performance from an achromat than from a same-size apochromat.

 

Getting less performance doesn't mean that one cannot still enjoy an achromat. I've owned a few. But there's a reason that apos (while more expensive) are far more popular with serious (not beginners) imagers and observers than are achromats. And that reason is, observers and imagers find the apo advantages are so significant that they are worth paying for.  

 

I've compared my old Astro-Physics 152 F9 triplet with an A Jaegers 152 F15 achromat side-by-side on Jupiter. The view in the eyepiece was not even close. I also observed Jupiter with a 4" F15 Edmund Scientific refractor. The view was certainly enjoyable. But the view was not in the same league as in my Takahashi FC-100DF Fluorite doublet; better view also means even more enjoyment. And the Tak is much lighter and much shorter to boot. 

 

Yes, poorly design cars and telescopes are poor performers. But people still enjoy their poorly designed Corvairs. And the achromat, when compared to the apochromat, is also the poorer design. People still enjoy them but that enjoyment does not change the fact that the achromat is the poorer design and has all the limitations of that poorer design. 

 

Getting less performance doesn't mean that one cannot still enjoy an achromat. I've owned a few. But there's a reason that apos (while more expensive) are far more popular with serious (not beginners) imagers and observers than are achromats. And that reason is, observers and imagers find the apo advantages are so significant that they are worth paying for.

“Getting less performance doesn't mean that one cannot still enjoy an achromat. I've owned a few. But there's a reason that apos (while more expensive) are far more popular with serious (not beginners) imagers and observers than are achromats. And that reason is, observers and imagers find the apo advantages are so significant that they are worth paying for.”

 

However, I am still going to use my C8 over any 80mm or 102mm apochromat for visual observation requiring greater image scale and resolution. 
 

If I want a wide field, lower power option a good achromat is nearly as good as the apo. If the apo is to be your only scope, then sure, get the best refractor you can afford. 

Edited by Russell Swan, 25 March 2025 - 08:48 AM.

[maniack]

I can get a wider field of view using my Tak BabyQ plus reducer without all of the obvious defects inherent in ST80. Again it depends on your tolerance for accepting defects.

How's the view in the eyepiece compared to the ST80? The difference in brightness must be quite significant. I wonder what diagonal is usable with the reducer.

Of course I'm being a bit facetious here. It's obvious you are an imager. Jon is a pure visual observer, as am I. The considerations are quite different for these use cases.

[kmparsons]

Ha Ha! It would be impossible for me to care less whether someone "hates" one or all of my telescopes! I used to post on a site where we discussed religion. Woo. Talk about rancor. Nothing like that occurs here on CN.

 

Anyway, some years back, I purchased a SV 80/9D f/9 achromat brand new for $349. It will eventually pass to someone else. Weeks after I'm dead! It's views wow me every time. It compares very favorably to my SV 80mm FPL-53 triplet, which cost over five times as much. What can you expect from an achromat? Well, if you get a good one, you can get most satisfying views for a decent price. 

[Refractor6]

Okay, you enjoy using your achromats. So what. People still enjoy driving their Chevy Corvairs. And the Corvair is well known to be one of the worst cars ever made. Heck, there are even Corvair clubs. But the fact that you enjoy using your achromats does not make them better refractors or better tools in which to enjoy the heavens than the more advanced apochromatic refractors. Logic dictates that you would get even more enjoyment by using a better tool.

 

Granted, this is a hobby. And folks can use whatever they want and whatever they like. But enjoyment cannot really be quantified. But performance can be. And if you are talking about pure performance and only performance, then the achromat falls behind. You might not "feel" like you are missing out, but when it becomes to pure performance, of course you are.

 

In the end, enjoyment from a hobby is probably paramount. But let's not confuse "enjoyment" with "performance". One can certainly derive enjoyment from using and inferior instrument. But one cannot deny, that when it comes to "performance", compared to the apochromat the achromat is the inferior instrument and the inferior design.

 

Bob

 

 

Performance is just fine with either of my achromats Bob. My detailed observing log tells all about what I saw in very good detail what I observed last summer in particular in 152 F/8 achromat that lived outside most nights during that time period.

 

Some things never observed before in splendid detail at the eyepiece.  So performance wise nothing lacking for this observer with his achromats...

[Phil Cowell]

I don’t do visual, augmented astronomy is my are of enjoyment, but I can tell you the ST80 would look like carp compared to the Tak Baby Q. The star bloat on an image would be readily apparent to anyone with imaging experience. As for diagonal you’d need a 2” focuser on the ST80. 
 

Achro’s especially a fast Achro like the ST80 has visual star bloat as well. That might not bother some it depends how critical the user is, the same with how critical the user is with CA. That was one of the reasons I dumped mine when I did visual. It’s inherent with a fast Achro. I think if you looked through the Baby Q with its much better corrected optics and wider field of view with its native reducer side by side with the ST80. You’d agree the ST80 is obviously inferior and it would be obvious to anyone with experience. Thats even with the ST80 using a TSFLAT2. Before “the yes but the price” deflection gets thrown by someone (not yourself) the OP has several high end refractors already cost doesn’t appear to be a primary motivator. 
That’s not even including a fast Achro being a one trick pony. Try using an ST80 during the day without any solar optimization. Like a bad meds day. 

Again honest answer without any lipstick on it.

 

How's the view in the eyepiece compared to the ST80? The difference in brightness must be quite significant. I wonder what diagonal is usable with the reducer.

Of course I'm being a bit facetious here. It's obvious you are an imager. Jon is a pure visual observer, as am I. The considerations are quite different for these use cases.

Edited by Phil Cowell, 25 March 2025 - 11:15 AM.

[saemark30]

I like a high performance 6" or 7" apo but I don't expect them to be affordable in my lifetime.

[Psion]

Years ago I did a review on a 6" achromat. Too bad Chromacorr is no longer commonly available. It was very successful in the test (Google translated).

 

https://posec-astro-...&_x_tr_pto=wapp

[PKDfan]

As has been said...you can expect very little difference under 100X.

Just don't go fast ratio speed with a large achro and then use high power.


A small achro should be long and then will be a perfect starter scope for a child.
It really can't get any better for a parent...cheap and decent views (if keeping at 100X and under) then upgrade if they show a real passion for the hobby.


No APO needed here AT ALL !!



CSS
Lance

[Sketcher]

More thoughts:

 

From an achromat I expect enjoyable visual observing sessions under my night (and sometimes day) skies.  And that's precisely what I get.  I've never been disappointed in their performances.

 

But of course, there are plenty of others who would be disappointed in the performances of some, if not all of my achromats.  People differ from one another.  And that pretty much rules out any "simple" responses to the topic questions.

 

I've never taken two telescopes out at the same time in order to compare/contrast them.  I take out only what I intend to use for my visual astronomical purposes -- to make observations of this universe's celestial wonders.  When I'm concentrating on what I'm seeing, I'm concentrating on what I'm seeing.  And that's usually about detecting the most that I'm able to detect when using whatever telescope I happen to be using.

 

The above may sound like pointless rambling, but in a way it's at the heart of this matter -- for me.  I observe.  I don't compare/contrast different telescopes.  And an achromat can be used as an observing tool just as any other telescope type can be used as an observing tool.

 

How did this hobby/forum turn into a "nothing but the best" club?  Or an "aperture is everything" club?  OK, so it hasn't, at least not completely, but there really is a very noticeable strong emphasis on "nothing but the best" and "aperture is everything" around these parts.  And where does that leave that strong "workhorse" of astronomical telescopes -- the achromat refractor?

 

Have so many of us really forgotten our origins in this hobby?  Or perhaps many here grew up wealthy enough that they could afford the "best" starting on day one.

 

I started out poor.  My first real telescope was a cardboard-tubed refractor with a plastic focuser, a plastic dew shield, and (more likely than not) a plastic objective -- possibly just a singlet.

 

I remember what that was like.  So, I try to make it clear to others that one can still accomplish a great deal in this hobby through the use of modest equipment.  A telescope needn't be of the highest quality nor of the greatest aperture.  But just saying that is like trying to swim upstream fighting against a strong current.

 

One should not expect an achromat to be a "hobby killer".  One should not expect an achromat to be an outdated toy.  One should not expect an achromat to be unworthy as a serious optical instrument.

 

Sometimes I feel that the hobby that I started out with has died.  Whatever happened to being able to enjoy a 60mm achromat?

 

 

Telescopes are not hobby-killers -- not even 60mm achromats with 0.965-inch eyepieces on temperamental mounts.

 

So, let's dismount from our high horses and walk around the block (there are no blocks where I live  ) a few times wearing a pair of worn out smelly old tennis shoes.  Let's stop giving others the impression that if one is  unable to afford the "best" or the "biggest" then they don't belong in "our" hobby.  We don't own this hobby.  It's for anyone who wants to partake.

 

[PKDfan]

More thoughts:

From an achromat I expect enjoyable visual observing sessions under my night (and sometimes day) skies. And that's precisely what I get. I've never been disappointed in their performances.

But of course, there are plenty of others who would be disappointed in the performances of some, if not all of my achromats. People differ from one another. And that pretty much rules out any "simple" responses to the topic questions.

I've never taken two telescopes out at the same time in order to compare/contrast them. I take out only what I intend to use for my visual astronomical purposes -- to make observations of this universe's celestial wonders. When I'm concentrating on what I'm seeing, I'm concentrating on what I'm seeing. And that's usually about detecting the most that I'm able to detect when using whatever telescope I happen to be using.

The above may sound like pointless rambling, but in a way it's at the heart of this matter -- for me. I observe. I don't compare/contrast different telescopes. And an achromat can be used as an observing tool just as any other telescope type can be used as an observing tool.

How did this hobby/forum turn into a "nothing but the best" club? Or an "aperture is everything" club? OK, so it hasn't, at least not completely, but there really is a very noticeable strong emphasis on "nothing but the best" and "aperture is everything" around these parts. And where does that leave that strong "workhorse" of astronomical telescopes -- the achromat refractor?

Have so many of us really forgotten our origins in this hobby? Or perhaps many here grew up wealthy enough that they could afford the "best" starting on day one.

I started out poor. My first real telescope was a cardboard-tubed refractor with a plastic focuser, a plastic dew shield, and (more likely than not) a plastic objective -- possibly just a singlet.

I remember what that was like. So, I try to make it clear to others that one can still accomplish a great deal in this hobby through the use of modest equipment. A telescope needn't be of the highest quality nor of the greatest aperture. But just saying that is like trying to swim upstream fighting against a strong current.

One should not expect an achromat to be a "hobby killer". One should not expect an achromat to be an outdated toy. One should not expect an achromat to be unworthy as a serious optical instrument.

Sometimes I feel that the hobby that I started out with has died. Whatever happened to being able to enjoy a 60mm achromat?



Telescopes are not hobby-killers -- not even 60mm achromats with 0.965-inch eyepieces on temperamental mounts.

So, let's dismount from our high horses and walk around the block (there are no blocks where I live ) a few times wearing a pair of worn out smelly old tennis shoes. Let's stop giving others the impression that if one is unable to afford the "best" or the "biggest" then they don't belong in "our" hobby. We don't own this hobby. It's for anyone who wants to partake.

Hi Sketcher !

AMEN !!

You ALWAYS make sense so Thanks for your time to educate people with very little experience --Especially the big Dob crowd who seem to believe bigger is always better.

As far as the 'death' of the 60mm achro, its truely a despicable thing.

Luckily the manufacturers are waking up to the fact that a small refractor is a Tremendously valuable asset.

My vintage 60mm half-apo B&L spotter and my 62mm Evolux do things the Best largest smoothest mirror can ever hope to achieve.




Clear Steady Skies
Lance

[Mike W]

 

More thoughts:

 

From an achromat I expect enjoyable visual observing sessions under my night (and sometimes day) skies.  And that's precisely what I get.  I've never been disappointed in their performances.

 

But of course, there are plenty of others who would be disappointed in the performances of some, if not all of my achromats.  People differ from one another.  And that pretty much rules out any "simple" responses to the topic questions.

 

I've never taken two telescopes out at the same time in order to compare/contrast them.  I take out only what I intend to use for my visual astronomical purposes -- to make observations of this universe's celestial wonders.  When I'm concentrating on what I'm seeing, I'm concentrating on what I'm seeing.  And that's usually about detecting the most that I'm able to detect when using whatever telescope I happen to be using.

 

The above may sound like pointless rambling, but in a way it's at the heart of this matter -- for me.  I observe.  I don't compare/contrast different telescopes.  And an achromat can be used as an observing tool just as any other telescope type can be used as an observing tool.

 

How did this hobby/forum turn into a "nothing but the best" club?  Or an "aperture is everything" club?  OK, so it hasn't, at least not completely, but there really is a very noticeable strong emphasis on "nothing but the best" and "aperture is everything" around these parts.  And where does that leave that strong "workhorse" of astronomical telescopes -- the achromat refractor?

 

Have so many of us really forgotten our origins in this hobby?  Or perhaps many here grew up wealthy enough that they could afford the "best" starting on day one.

 

I started out poor.  My first real telescope was a cardboard-tubed refractor with a plastic focuser, a plastic dew shield, and (more likely than not) a plastic objective -- possibly just a singlet.

 

I remember what that was like.  So, I try to make it clear to others that one can still accomplish a great deal in this hobby through the use of modest equipment.  A telescope needn't be of the highest quality nor of the greatest aperture.  But just saying that is like trying to swim upstream fighting against a strong current.

 

One should not expect an achromat to be a "hobby killer".  One should not expect an achromat to be an outdated toy.  One should not expect an achromat to be unworthy as a serious optical instrument.

 

Sometimes I feel that the hobby that I started out with has died.  Whatever happened to being able to enjoy a 60mm achromat?

 

 

 

Telescopes are not hobby-killers -- not even 60mm achromats with 0.965-inch eyepieces on temperamental mounts.

 

So, let's dismount from our high horses and walk around the block (there are no blocks where I live  ) a few times wearing a pair of worn out smelly old tennis shoes.  Let's stop giving others the impression that if one is  unable to afford the "best" or the "biggest" then they don't belong in "our" hobby.  We don't own this hobby.  It's for anyone who wants to partake.

 

My 60mm Jason under the Christmas tree led to mapping the moon for science fair then astronomy club in JR high that got me in touch with the Mohawk Astronomers (now Albany Area Astronomers) and 60 years later I still observe at our dark site. I wish schools would still have astronomy clubs etc., with all the huge telescopes on earth and in orbit you would think schools would wake up? Give your kid, grand children a 60mm refractor! (not that 60mm scopes are just for kids)

Edited by Mike W, 25 March 2025 - 02:02 PM.

[Jon Isaacs]

But I'm not under the delusion that a TV 101 apo would not be a better performer than a 102mm F5 achromat. The 102mm F5 achromat is strictly a one-trick pony. Whereas, a TV 101 is a wide field, low power, deep sky scope and a high power planetary scope and an imaging scope. That's the apo advantage.

 
Bob:
 
Here's the thing.  You were comparing achromats to Chevy Corvairs and yet there you are, using a Chevy Corvair..  
 
The thing of it is, an 102mm F/5 achromat does a pretty good job at low magnifications, a 100mm F/15 achromat does a pretty good job at high magnifications.  The difference between the achromats and an APO like the NP-101, the NP-101 does an excellent job at low and high magnifications.  It also weighs 12 lbs and costs over $4000 for the barebones scope.
 
I am with you on using the 102mm F/5 Achromat.  
 
And by the way, the observer is a big part of performance.. Uncle Rod, viewing the craterlets in Plato with an ST-80, that's performance.
 
Jon

I don’t do visual, augmented astronomy is my are of enjoyment, but I can tell you the ST80 would look like carp compared to the Tak Baby Q. The star bloat on an image would be readily apparent to anyone with imaging experience. As for diagonal you’d need a 2” focuser on the ST80. 
 
Achro’s especially a fast Achro like the ST80 has visual star bloat as well. That might not bother some it depends how critical the user is, the same with how critical the user is with CA. That was one of the reasons I dumped mine when I did visual. It’s inherent with a fast Achro. I think if you looked through the Baby Q with its much better corrected optics and wider field of view with its native reducer side by side with the ST80. You’d agree the ST80 is obviously inferior and it would be obvious to anyone with experience. Thats even with the ST80 using a TSFLAT2. Before “the yes but the price” deflection gets thrown by someone (not yourself) the OP has several high end refractors already cost doesn’t appear to be a primary motivator. 
That’s not even including a fast Achro being a one trick pony. Try using an ST80 during the day without any solar optimization. Like a bad meds day. 
Again honest answer without any lipstick on it.

 
Does a Baby Q with a focal reducer even come to focus with a diagonal and the 31mm Nagler?  Have you ever tried it?
 
When was the last time you looked through an ST-80 with a 2 inch focuser, a TSFLAT2 and the 31mm Nagler?  Have you ever looked though one?  
 
Reading threads like this, it makes me want to toss my fancy scopes in the dumpster.  I would rather be a skilled observer like Sketcher than someone who cannot appreciate a decent scope and make meaningful observations.. 
 
40 years ago baby Qs did not exist, fast apos did not exist, 31mm Naglers did not exist.  Amateur astronomers were still observing, the views were just not a perfect but perfection is unnecessary when observing the universe.. 
 
Jon

[Refractor6]

Does a Baby Q with a focal reducer even come to focus with a diagonal and the 31mm Nagler?  Have you ever tried it?

 

When was the last time you looked through an ST-80 with a 2 inch focuser, a TSFLAT2 and the 31mm Nagler?  Have you ever looked though one?  

 

Reading threads like this, it makes me want to toss my fancy scopes in the dumpster.  I would rather be a skilled observer like Sketcher than someone who cannot appreciate a decent scope and make meaningful observations.. 

 

40 years ago baby Qs did not exist, fast apos did not exist, 31mm Naglers did not exist.  Amateur astronomers were still observing, the views were just not a perfect but perfection in unnecessary when observing the universe.. 

 

Jon

[Tony Flanders]

I don’t do visual, augmented astronomy is my are of enjoyment ...

Ah, that explains a lot. The human visual system is really good at tuning out visual defects. Which is a very good thing, because few of us have eyes that are anywhere near perfect, and perfect viewing conditions are rare indeed.

When I view through my Tele Vue Ranger at 100X I can only see false color on the brightest stars, and even then only if I really look for it. With a photo, the false color is impossible to miss.

[Refractor6]

Ah, that explains a lot. The human visual system is really good at tuning out visual defects. Which is a very good thing, because few of us have eyes that are anywhere near perfect, and perfect viewing conditions are rare indeed.

When I view through my Tele Vue Ranger at 100X I can only see false color on the brightest stars, and even then only if I really look for it. With a photo, the false color is impossible to miss.

  This is where the problem of mixing visual {eyepieces} and imaging {camera} expectations as the same thing as I mentioned in my earlier post for what you see in the end result with each.....two very different things.

[Tony Flanders]

One should expect less performance from an achromat than from a same-size apochromat.

Well sure, of course, doh ...

But suppose you choose to hold cost rather than aperture constant. Should one expect less performance from an achromat than a same-cost apochromat? It depends.

 

For astrophotography, quite possibly yes. For visual observing of galaxies and nebulae, an achromat should out-perform an APO of the same price by a large margin. And a Newt of the same price should out-perform both of the above by an even larger margin.

[Refractor6]

Years ago I did a review on a 6" achromat. Too bad Chromacorr is no longer commonly available. It was very successful in the test (Google translated).

 

https://posec-astro-...&_x_tr_pto=wapp

  That was a great read....

 

 My 2005 152 F/8  Antares evaluation sample was made by the same maker Jinghua. Antares never carried the F/8 as a production model but carried the same model as in the review. After Antares stopped selling them ES sold the scopes next.

 

 Same impressive quality of a star test at high power as seen in your review.

[Phil Cowell]

No one has stated only the best. I’ve not seen only the biggest here. But it also doesn’t mean a rush to the bottom of the pile either.
Imagers probably spent more time observing their captures so please it’s not just visual being the most “elite”  If you ever want to see how detailed an analysis an object can get submit an image you take to the advanced imaging forum for critic.
I remember the old days back in the late 60’s on and LP has killed those days for much of the population. But today’s instruments are a welcome improvement over what was available then and price adjusted for inflation has made it cheaper now.
You have your threshold of tolerance others have different ones. 
Based on the information of the op that is known a response to give by yourself and others. They just come from different perspectives and tolerances.
Clear Skies.
 

More thoughts:
 
From an achromat I expect enjoyable visual observing sessions under my night (and sometimes day) skies.  And that's precisely what I get.  I've never been disappointed in their performances.
 
But of course, there are plenty of others who would be disappointed in the performances of some, if not all of my achromats.  People differ from one another.  And that pretty much rules out any "simple" responses to the topic questions.
 
I've never taken two telescopes out at the same time in order to compare/contrast them.  I take out only what I intend to use for my visual astronomical purposes -- to make observations of this universe's celestial wonders.  When I'm concentrating on what I'm seeing, I'm concentrating on what I'm seeing.  And that's usually about detecting the most that I'm able to detect when using whatever telescope I happen to be using.
 
The above may sound like pointless rambling, but in a way it's at the heart of this matter -- for me.  I observe.  I don't compare/contrast different telescopes.  And an achromat can be used as an observing tool just as any other telescope type can be used as an observing tool.
 
How did this hobby/forum turn into a "nothing but the best" club?  Or an "aperture is everything" club?  OK, so it hasn't, at least not completely, but there really is a very noticeable strong emphasis on "nothing but the best" and "aperture is everything" around these parts.  And where does that leave that strong "workhorse" of astronomical telescopes -- the achromat refractor?
 
Have so many of us really forgotten our origins in this hobby?  Or perhaps many here grew up wealthy enough that they could afford the "best" starting on day one.
 
I started out poor.  My first real telescope was a cardboard-tubed refractor with a plastic focuser, a plastic dew shield, and (more likely than not) a plastic objective -- possibly just a singlet.
 
I remember what that was like.  So, I try to make it clear to others that one can still accomplish a great deal in this hobby through the use of modest equipment.  A telescope needn't be of the highest quality nor of the greatest aperture.  But just saying that is like trying to swim upstream fighting against a strong current.
 
One should not expect an achromat to be a "hobby killer".  One should not expect an achromat to be an outdated toy.  One should not expect an achromat to be unworthy as a serious optical instrument.
 
Sometimes I feel that the hobby that I started out with has died.  Whatever happened to being able to enjoy a 60mm achromat?
 
 
 
Telescopes are not hobby-killers -- not even 60mm achromats with 0.965-inch eyepieces on temperamental mounts.
 
So, let's dismount from our high horses and walk around the block (there are no blocks where I live  ) a few times wearing a pair of worn out smelly old tennis shoes.  Let's stop giving others the impression that if one is  unable to afford the "best" or the "biggest" then they don't belong in "our" hobby.  We don't own this hobby.  It's for anyone who wants to partake.

Jon,
  I read here on CN in a review the Baby Q does. I can’t vouch for that as I’d not waste the optic or time for that. It is a superb f3.9 imaging with Reducer/Flattener.

You know I no longer do visual the nearest is NV and EAA so why are you asking irrelevant questions, It would be like asking you when was the last time you recently used a false color palette for multi color astronomical imaging with a recent CMOS astrophotographic camera over multiple nights? Use was not indicated in the question.
 
Have not enjoyed the underwhelming experience of owning an ST80, why would I subject myself to further wasted time and disappointment? I don’t subscribe to the misery loves company approach by recommending something I personally wouldn’t use.
 
Have you even looked through a Baby Q?
 
I have owned and used an ST80 and it well I’ll not comment further on it keeping things polite. I’m very familiar with reducers and flatterers but the reality of a simple physics baseline if the item you start with is not very suitable for purpose, you’re just applying lipstick to a suid.
 
As for your comment maybe you should toss your fancy scopes in the dumpster. They can keep my ST80 company.
 
I do appreciate decent scopes and use them for one of the functions for which they are designed for despite your attempted puerile remark, I’m an augmented methods amateur astronomer.
40 years ago is 40 years ago, not now. The question the OP asked did not include anything about 40 years ago. Folks observed with what was available then but times have changed, just some folks are still stuck there. Things have moved on.
 
 
 
 

Does a Baby Q with a focal reducer even come to focus with a diagonal and the 31mm Nagler?  Have you ever tried it?
 
When was the last time you looked through an ST-80 with a 2 inch focuser, a TSFLAT2 and the 31mm Nagler?  Have you ever looked though one?  
 
Reading threads like this, it makes me want to toss my fancy scopes in the dumpster.  I would rather be a skilled observer like Sketcher than someone who cannot appreciate a decent scope and make meaningful observations.. 
 
40 years ago baby Qs did not exist, fast apos did not exist, 31mm Naglers did not exist.  Amateur astronomers were still observing, the views were just not a perfect but perfection is unnecessary when observing the universe.. 
 
Jon

The human eye is also carp at night. A very large percentage of its sensors aren’t even triggered at night.
 
I used to do visual and had an ST80 as an example which showed plenty of false color under 100X with stars also showing some star bloating something imaging tends to make you cognizant off. The camera is much more sensitive than the eye. EAA also using a camera makes the defects inherent in an Achro readily apparent.
 

Ah, that explains a lot. The human visual system is really good at tuning out visual defects. Which is a very good thing, because few of us have eyes that are anywhere near perfect, and perfect viewing conditions are rare indeed.

When I view through my Tele Vue Ranger at 100X I can only see false color on the brightest stars, and even then only if I really look for it. With a photo, the false color is impossible to miss.

[Mike W]

C/A is the easiest abb. to post process out but harder with a one shot color............

[Phil Cowell]

Star bloat can also be removed but it’s still there visually. Most post processing of bloat tends to over or under compensate.

 

C/A is the easiest abb. to post process out but harder with a one shot color............

Edited by Phil Cowell, 25 March 2025 - 07:17 PM.

[Russell Swan]

I don’t do visual, augmented astronomy is my are of enjoyment, but I can tell you the ST80 would look like carp compared to the Tak Baby Q. The star bloat on an image would be readily apparent to anyone with imaging experience. As for diagonal you’d need a 2” focuser on the ST80. 
 

Achro’s especially a fast Achro like the ST80 has visual star bloat as well. That might not bother some it depends how critical the user is, the same with how critical the user is with CA. That was one of the reasons I dumped mine when I did visual. It’s inherent with a fast Achro. I think if you looked through the Baby Q with its much better corrected optics and wider field of view with its native reducer side by side with the ST80. You’d agree the ST80 is obviously inferior and it would be obvious to anyone with experience. Thats even with the ST80 using a TSFLAT2. Before “the yes but the price” deflection gets thrown by someone (not yourself) the OP has several high end refractors already cost doesn’t appear to be a primary motivator. 
That’s not even including a fast Achro being a one trick pony. Try using an ST80 during the day without any solar optimization. Like a bad meds day. 

Again honest answer without any lipstick on it.

No one is claiming an achromat is not inferior to an apochromat. All else being equal, everyone would take the apochromat over the achromat. However we do not require an apochromat to view deep sky objects at low to mid magnifications. Those more experienced visual observers buy an achromat with that purpose in mind. The expense of an apochromat for that purpose is unnecessary. 
 

Your application for a such a telescope may be different where an apochromat is preferred or even required of a refractor telescope.