Tak 100 dc vs skywatcher 120ed and 150ed

[johnturley]

43 minutes ago, IB20 said:

I haven’t always been so, but I’m starting to creep into the “aperture wins” field especially when it comes to refractors.

https://www.firstlightoptics.com/offers/offer_stellamira-125mm-ed-doublet-f78-refractor-telescope_420375.html recently saw this on offer, nice and light for a 5”…

If the OP is looking for a general purpose scope, I would be inclined to go for one of these while on offer, plus save over £1,000 compared with the price of a Tak FC 100.

John 

[Stu]

56 minutes ago, IB20 said:

I haven’t always been so, but I’m starting to creep into the “aperture wins” field especially when it comes to refractors.

https://www.firstlightoptics.com/offers/offer_stellamira-125mm-ed-doublet-f78-refractor-telescope_420375.html recently saw this on offer, nice and light for a 5”…

It normally does. I prefer the views through my 128mm vs the 100mm, providing the seeing is up to it. The SM125 is very light for its aperture so does counter some of the mount/weight/portability arguments, though to be fair it wasn’t on the OPs list 😉

[Stu]

2 hours ago, Moonlit Night said:

As one might expect.

Anyway, boring scope wars aside, and to return to topic, have you made a decision yet. 

Nobody mentioned scope wars, boring or otherwise, this was a perfectly good post comparing thoughts on scopes the writer had experience of. Please don’t take this down a negative route.

In answer to the 150ED mixed review question, I recall there were some packaging issues which led to review scopes being out of collimation. That was all rectified, not sure if any changes were made to the scope, I think it was mostly better packaging.

[Mr Spock]

That 125mm ED from StellaMira has a hugely tempting price. There's only one left though!

If it wasn't for the fact I can't justify it over the 100mm I have I would snap it up 

[John]

1 hour ago, Stu said:

.... I recall there were some packaging issues which led to review scopes being out of collimation. That was all rectified, not sure if any changes were made to the scope, I think it was mostly better packaging.

Yes, the packaging was improved substantially by Skywatcher. 

In the USA the Skywatcher rep on CN also claimed that the objective lens retaining ring was made more substantial which makes sense because that ring (which did seem rather thin) had shifted in the 2nd example that I was sent, allowing the objective elements to get out of alignment.  

I've never been able to get any confirmation on whether a similar change was implemented on scopes destined for the UK / EU.

Despite my 2 unfortunate experiences I always felt that the ED150 had a lot of potential and from reading reports since from those who now own and use them, that optimism seems to have been borne out 🙂

Edited March 10 by John

[Flame Nebula]

1 hour ago, Stu said:

Nobody mentioned scope wars, boring or otherwise, this was a perfectly good post comparing thoughts on scopes the writer had experience of. Please don’t take this down a negative route.

In answer to the 150ED mixed review question, I recall there were some packaging issues which led to review scopes being out of collimation. That was all rectified, not sure if any changes were made to the scope, I think it was mostly better packaging.

Sorry Moonlit, I somehow missed your question about whether I've made a decision yet. At the moment I'm gathering data. I need to get my choice right ( or as right as possible) balancing a budget against my needs. At present, I think the only decision I've made, is to add the az-eq6 to the list. This is based on the assumption I will get a C9.25 or C11 for planetary AP, and can also use my ed80 on it for dso AP. The main reason I'm looking at a frac option is to fill the gap between my ed80 and 127 mm mak and the sct, primarily due to the mixed reviews of sct I have read on SGL, CN and elsewhere. It seems like they are a good bet for planetary AP, but a 50/50 for visual. Hence, my options are get the C9.25 and see what it's like visually, or assume it will be 'mushy' and get a 4-6 inch frac anyway(as well as the sct). 

Edited March 10 by Flame Nebula

[The60mmKid]

aperture, sharpness, contrast, correction for various aberrations, portability, ease of thermal acclimation, ease of mounting, cost, personal brand preferences, optical design, personal optical design preferences, ergonomic preferences... and a few others, I'm sure.

These are the variables. Different people privilege different ones, different scopes are weaker and stronger in different ones, and different observing/imaging goals make different ones more or less important. That's why the "which do you recommend" threads can elicit various, contrasting opinions (which is fine, of course). In my opinion, what's most useful is trying one's best to figure out which variables matter to them and choosing accordingly.

Edited March 10 by The60mmKid

[Flame Nebula]

5 minutes ago, The60mmKid said:

aperture, sharpness, contrast, correction for various aberrations, portability, ease of thermal acclimation, ease of mounting, cost, personal brand preferences, optical design, personal optical design preferences, ergonomic preferences... and a few others, I'm sure.

These are the variables. Different people privilege different ones, different scopes are weaker and stronger in different ones, and different observing/imaging goals make different ones more or less important. That's why the "which do you recommend" threads can elicit various, contrasting opinions (which is fine, of course). In my opinion, what's most useful is trying one's best to figure out which variables matter to them and choosing accordingly.

Absolutely spot on. In terms of my preferences, visually I'm drawn to doubles and planets. Of course this might expand with time. For dso AP obviously, these will include more fuzzies 🙂

[Deadlake]

Well I'll put my 2 cent in as an owner of a C11 and various APO's. 

The last time I went out, although the sky looked like it could support the C11  the moisture content in the air was high. Meaning getting the dew heater out, a C11 should always be used with a dew shield  even in summer to keep the correct as clean as possible. 

I passed on the C11 and instead pulled out a 105 and 130 mm APO..

Again, the previous viewing night I enjoyed was away and I was in a bit of a rush to get to the club night after my daughter had drifted off to sleep.

Again I went with a 105 mm APO as that meant transporting less equipment.

Don't get me wrong when it's a good night and I'm looking at DSO's the C11 is brilliant, however other nights even when I'm not looking at DSO's or other faint objects then for multiple reasons and APO every time. The C11 is a secondary scope due to it's size... 

[Flame Nebula]

1 minute ago, Deadlake said:

Well I'll put my 2 cent in as an owner of a C11 and various APO's. 

The last time I went out, although the sky looked like it could support the C11  the moisture content in the air was high. Meaning getting the dew heater out, a C11 should always be used with a dew shield  even in summer to keep the correct as clean as possible. 

I passed on the C11 and instead pulled out a 105 and 130 mm APO..

Again, the previous viewing night I enjoyed was away and I was in a bit of a rush to get to the club night after my daughter had drifted off to sleep.

Again I went with a 105 mm APO as that meant transporting less equipment.

Don't get me wrong when it's a good night and I'm looking at DSO's the C11 is brilliant, however other nights even when I'm not looking at DSO's or other faint objects then for multiple reasons and APO every time. The C11 is a secondary scope due to it's size... 

Thanks deadlake. This is partly why I wonder if the C9.25 may be a 'better' flagship scope for me, as I'm sure planetary AP will be similar to the C11. But, also your post adds to my suspicion that I need a really good frac, capable of good views on doubles and planets. In theory I could mount both the sct and frac on AZEQ6 at same time, use the frac until the sct has 'caught up' with cool down, then switch to that. The az-eq6 does offer multiple options in this regard. 

[The60mmKid]

1 minute ago, Flame Nebula said:

Absolutely spot on. In terms of my preferences, visually I'm drawn to doubles and planets. Of course this might expand with time. For dso AP obviously, these will include more fuzzies 🙂

That's great, especially since many scopes will provide enjoyable, albeit different, views of doubles and planets. Speaking for myself, it took me a while to figure out what it is that I like and want in telescopes. I love my 60mm refractor because they views of certain objects it provides are so sharp and beautiful. Its lack of aperture doesn't bother me at all because I know the function of aperture and I know I don't need it for that type of observing.

But when I'd want to find fainter open clusters from darker skies, I loved a 10" f/4 dob that I owned. It took forever to thermally acclimate with its full-thickness mirror, but that didn't bother me at all because aperture and FOV (not sharpness) were the important variables for that type of observing.

The "aperture wins" argument doesn't impress me. The important part is knowing what aperture does to the image... its function. And knowing what sharpness does to the image... And contrast... And so on. This takes experimentation over time.

My advice (which may not be worth anything since I'm some random internet person!) is not to get a massive scope that may pose a struggle to use and to sell. I recommend trying out small/medium scopes of various optical designs and attributes first. Then, you'll get to know what you want and can pick the scope of your dreams.

[Deadlake]

12 minutes ago, Flame Nebula said:

Thanks deadlake. This is partly why I wonder if the C9.25 may be a 'better' flagship scope for me, as I'm sure planetary AP will be similar to the C11. But, also your post adds to my suspicion that I need a really good frac, capable of good views on doubles and planets. In theory I could mount both the sct and frac on AZEQ6 at same time, use the frac until the sct has 'caught up' with cool down, then switch to that. The az-eq6 does offer multiple options in this regard. 

I think the C9.25 and the C11 are the same faff to set up etc, maybe a little weight saved.

I have just put some insulation on the C11 to see if that helps with stopping currents forming in the tube, cloud and moisture as stopped any observations so far. 

If you are using visually I would think of another mount then the AZEQ6, I had a SXP2 which carries more weight and weighs a lot less but was such faff to setup compared with an AltZ I moved to an AZ100.

Maybe focusing on the mount might also make you observation a bit easier...

Also, C11 has a huge focal length that gives a huge image scale. Thats not a feature you will get with a refractor.

Edited March 10 by Deadlake

[Flame Nebula]

6 minutes ago, The60mmKid said:

That's great, especially since many scopes will provide enjoyable, albeit different, views of doubles and planets. Speaking for myself, it took me a while to figure out what it is that I like and want in telescopes. I love my 60mm refractor because they views of certain objects it provides are so sharp and beautiful. Its lack of aperture doesn't bother me at all because I know the function of aperture and I know I don't need it for that type of observing.

But when I'd want to find fainter open clusters from darker skies, I loved a 10" f/4 dob that I owned. It took forever to thermally acclimate with its full-thickness mirror, but that didn't bother me at all because aperture and FOV (not sharpness) were the important variables for that type of observing.

The "aperture wins" argument doesn't impress me. The important part is knowing what aperture does to the image... its function. And knowing what sharpness does to the image... And contrast... And so on. This takes experimentation over time.

My advice (which may not be worth anything since I'm some random internet person!) is not to get a massive scope that may pose a struggle to use and to sell. I recommend trying out small/medium scopes of various optical designs and attributes first. Then, you'll get to know what you want and can pick the scope of your dreams.

Hi, everyone's opinion is appreciated. 😀 The more opinions, the better the decision may be ( unless all the opinions are factually incorrect of course, but I'm not talking to people who believe in faked moon landings, flat earth etc.... 😆). 

The path I'm taking is designed to leave the option of adding a (6-8 ") newt to the az-eq6 or if the fever kicks in later on, a 12"f5 newt. I think the latter would only happen, if I ran out of doubles and fuzzies with smaller scopes. 🤣 I have read some mouth watering reports about 12" dobs though......

 

[Flame Nebula]

10 minutes ago, Deadlake said:

I think the C9.25 and the C11 are the same faff to set up etc, maybe a little weight saved.

I have just put some insulation on the C11 to see if that helps with stopping currents forming in the tube, cloud and moisture as stopped any observations so far. 

If you are using visually I would think of another mount then the AZEQ6, I had a SXP2 which carries more weight and weighs a lot less but was such faff to setup compared with an AltZ I moved to an AZ100.

Maybe focusing on the mount might also make you observation a bit easier...

Also, C11 has a huge focal length that gives a huge image scale. Thats not a feature you will get with a refractor.

Thanks deadlake, I'm interested in getting into dso AP too using my ed80, so the az-eq6 seems good for that too. In theory, I could go down the Heq5 route for that, and the nexstar evolution route for C9.25, although I've heard some reports of issues looking at zenith objects with the latter. Also, the az-eq6 allows two scopes to be mounted. 

[IB20]

1 hour ago, The60mmKid said:

The "aperture wins" argument doesn't impress me. The important part is knowing what aperture does to the image... its function. And knowing what sharpness does to the image... And contrast... And so on. This takes experimentation over time.

Oh don’t get me wrong. My 8” dob doesn’t perform in winter purely cos of my local seeing conditions and housing configuration. Come summer or when the temperature differential isn’t too big between house and outdoor it’s a fantastic scope, mind. Doesn’t stop me reaching for the 76Q a lot of the time, having a small premium grab n go is such a pleasure to own and observe with.
 

I’ve recently acquired 4 and 5” APOs just to experiment, for targets like clusters, improved planetary grasp and tighter doubles. I just enjoy owning telescopes however, I’m one of those types…

[mikeDnight]

8 hours ago, Moonlit Night said:

Some of the claims about various brands of telescopes from various companies and parts of the world and supposed magnification need taking with a pinch of salt btw. Consider your seeing conditions and the laws of physics. It will stand you in good stead. 

 Taking things with "a pinch of salt" is a touch on the superstitious! It's true though that not all telescopes, even of equal aperture, are equal, even if the brand sings loudly from the rooftops of its own greatness. I fell for one such American manufacturers boastful claims and bought one of their 4" refractors back in 2007. "It Is What You Want It To Be!" they claimed. Well it wasn't, and couldn't even reach 200X and maintain acceptable levels of planetary definition. It was gutless and powerless!  By contrast, the mostly Japanese manufacturers, tend to offer little more than a whisper of their scopes abilities. They leave that to their countless delighted customers.

 A top end 4" refractor will have reached its resolution limit at around 200X, and that is down to the "laws of physics"! But, if the optical quality is there in the first place, there's nothing preventing that maximum resolution limit from being magnified way beyond 200X, increasing the image scale for ease of observation providing it remains reasonably sharp and doesn't lose definition or contrast. Local seeing conditions can make or brake even a top end refractors ability to deliver its best. Because of this I've been able to observe discernable albedo features, cloud and ice on Mars while it has been only 4.3 arc seconds diameter; use 474X on Venus, and over 300X while observing the Moon. Double stars love high power, and the magnifications of 500X, and even 1000X while maintaining a textbook image were totally truthful, and neither lies nor exaggeration as your post implies. 

 A good source for the OP to consult regarding refractors would be ScopeViews by Roger Vine. It's well worth perusing for an honest, in depth appraisal of how each performs.

[mikeDnight]

Double post, sorry! 

Edited March 11 by mikeDnight

[Flame Nebula]

30 minutes ago, mikeDnight said:

 Taking things with "a pinch of salt" is a touch on the superstitious! It's true though that not all telescopes, even of equal aperture, are equal, even if the brand sings loudly from the rooftops of its own greatness. I fell for one such American manufacturers boastful claims and bought one of their 4" refractors back in 2007. "It Is What You Want It To Be!" they claimed. Well it wasn't, and couldn't even reach 200X and maintain acceptable levels of planetary definition. It was gutless and powerless!  By contrast, the mostly Japanese manufacturers, tend to offer little more than a whisper of their scopes abilities. They leave that to their countless delighted customers.

 A top end 4" refractor will have reached its resolution limit at around 200X, and that is down to the "laws of physics"! But, if the optical quality is there in the first place, there's nothing preventing that maximum resolution limit from being magnified way beyond 200X, increasing the image scale for ease of observation providing it remains reasonably sharp and doesn't lose definition or contrast. Local seeing conditions can make or brake even a top end refractors ability to deliver its best. Because of this I've been able to observe discernable albedo features, cloud and ice on Mars while it has been only 4.3 arc seconds diameter; use 474X on Venus, and over 300X while observing the Moon. Double stars love high power, and the magnifications of 500X, and even 1000X while maintaining a textbook image were totally truthful, and neither lies nor exaggeration as your post implies. 

 A good source for the OP to consult regarding refractors would be ScopeViews by Roger Vine. It's well worth perusing for an honest, in depth appraisal of how each performs.

Thanks Mike, 

I'm interested if non tak refractors can achieve this on double stars? Thanks for the Roger Vine link. I'll give it a look. 

[Flame Nebula]

1 hour ago, Flame Nebula said:

Thanks Mike, 

I'm interested if non tak refractors can achieve this on double stars? Thanks for the Roger Vine link. I'll give it a look. 

So, I read the Roger Vine article. Interestingly, the 100DC came out well. I checked the DZ version on FLO, and it's a grand more! I really do like sharp images, but not prepared to pay 50% more. I also  wonder how much more the SW 150ED would give me for the same price as the 100DC. In theory I'd get 250-300 x on jupiter with good image quality, compared to 200ish for the 4". 

[John]

1 hour ago, Flame Nebula said:

So, I read the Roger Vine article. Interestingly, the 100DC came out well. I checked the DZ version on FLO, and it's a grand more! I really do like sharp images, but not prepared to pay 50% more. I also  wonder how much more the SW 150ED would give me for the same price as the 100DC. In theory I'd get 250-300 x on jupiter with good image quality, compared to 200ish for the 4". 

Jupiter rarely responds well to really high magnifications, whatever the capabilities of the scope.

In all the scopes that I've owned (up to 12 inch in aperture) around 200x is about the highest magnification that I've found really useful when observing Jupiter. 

Saturn, Mars, Venus etc are a different proposition. You seem to be able to throw more magnification at them and get decent results. Not Jupiter though.

Edited March 11 by John

[mikeDnight]

 The late great E.E. Barnard claimed that 180 X was the best power for Jupiter even when using the Great Yerkes Refractor. There's just something about that particular planet that doesn't play well at much above that power; I think it's the massive amount of complex detail that gets lost in the fight between high power and atmospheric turbulence that does it. 

 There is a definite jump in performance between a 4" and a 5", but not so great between a 5" and a 6". As regards the DC vs DZ, there's very little in it unless you're an imager, and its certainly not worth the £1000 difference in price IMHO. The DC/DF and DL versions (if you could find the latter) will all deliver silly high powers if the night allows. You dont need Takahashi either, as there are other top end brands out there. An old Vixen FL102 would hold its own against any 4" Tak! 

 The SW120ED is a fabulous scope, but there's a new kid on the block with Askar, and they not only offer great prices, they offer large apertures too. Check them out! What about a 7" Askar as a planetary scope? The best views of Mars that I ever had was through a 8.5" achromat at my local astronomy club back in 2003. The 8.5" was the only scope out of what must have been dozens of scopes of various designs that were on the field that night, that out-gunned my FS128, and many had much greater apertures. The detail in the 8.5" was too intricate to ever draw with precision, so with that in mind, I'd consider the 7" Askar Apo rather than the 6" ED. I was the proud owner of a 6" Takahashi many years ago, which new would have cost over £10,000.00, and can tell you that 5" to 6" doesn't offer any wow factor, but jumping to 7" will certainly pack a noticeable punch. 

Edited March 11 by mikeDnight

[davidc135]

There is a thread over on CN where one Askar 185 was so so in the indoor Ronchi test being a bit over-corrected with a wide central hill. Whilst the owner felt his 150 apo showed a bit more planetary contrast, he still thought the Askar was no slouch and was pleased with his purchase, especially given the price. But he bought it more for DSOs.

I expect the 8.5'' achromat, in spite of CA, got the best out of its aperture by having an excellent figure and it may be that it's that consistency which suffers with lower priced large apo objectives.

No doubt there will be more indoor tests/field reports on the 7'' Askar in the near future.

David

[Flame Nebula]

1 hour ago, mikeDnight said:

 The late great E.E. Barnard claimed that 180 X was the best power for Jupiter even when using the Great Yerkes Refractor. There's just something about that particular planet that doesn't play well at much above that power; I think it's the massive amount of complex detail that gets lost in the fight between high power and atmospheric turbulence that does it. 

 There is a definite jump in performance between a 4" and a 5", but not so great between a 5" and a 6". As regards the DC vs DZ, there's very little in it unless you're an imager, and its certainly not worth the £1000 difference in price IMHO. The DC/DF and DL versions (if you could find the latter) will all deliver silly high powers if the night allows. You dont need Takahashi either, as there are other top end brands out there. An old Vixen FL102 would hold its own against any 4" Tak! 

 The SW120ED is a fabulous scope, but there's a new kid on the block with Askar, and they not only offer great prices, they offer large apertures too. Check them out! What about a 7" Askar as a planetary scope? The best views of Mars that I ever had was through a 8.5" achromat at my local astronomy club back in 2003. The 8.5" was the only scope out of what must have been dozens of scopes of various designs that were on the field that night, that out-gunned my FS128, and many had much greater apertures. The detail in the 8.5" was too intricate to ever draw with precision, so with that in mind, I'd consider the 7" Askar Apo rather than the 6" ED. I was the proud owner of a 6" Takahashi many years ago, which new would have cost over £10,000.00, and can tell you that 5" to 6" doesn't offer any wow factor, but jumping to 7" will certainly pack a noticeable punch. 

Hi Mike, 

The 140 mm apo triplet that Askar do, looks very tempting, and same price as the 100 Dc. I could only find one short review, but the owner seemed very impressed. Same price as the SW 150ed too. A triplet may take longer to cool, I hear. True? I would be sorely tempted to get this scope over the 4" tak, or sw120. I suspect it would be vastly superior to my 127mm mak. 

[johnturley]

8 hours ago, Flame Nebula said:

So, I read the Roger Vine article. Interestingly, the 100DC came out well. I checked the DZ version on FLO, and it's a grand more! I really do like sharp images, but not prepared to pay 50% more. I also  wonder how much more the SW 150ED would give me for the same price as the 100DC. In theory I'd get 250-300 x on jupiter with good image quality, compared to 200ish for the 4". 

If the SW 150 ED performs anything like the Esprit 150, you will see a lot more detail compared to the 100 DC.

John 

[JTEC]

14 hours ago, Flame Nebula said:

the nexstar evolution route for C9.25

Just on this point. I’ve owned this combo and would advise against it.  The Evo is a nice mount but overstretched with the 9.25 OTA. The C9.25 OTA was excellent but putting it on that mount was definitely imv a step too far.  As you say, there are problems with clearance at higher elevations, especially with, for example, a 2” diagonal in place.  This makes binoviewers and other attachments at the eyepiece end more or less out of the question unless you’re content to observe only at modest elevations. On top of that, high power viewing that was well within the capabilities of the very good OTA was badly affected by the wobbliness of the combination - Celestron should have stopped at the 8.