Skywatcher Evostar 150ED

[Владимир Николаевич]

Обещанная страница каталога...

ED PRO серия - дублеты, в т.ч. на FPL53 и лантане (125 мм F/7,8)
EDT серия - триплеты на китайском FK61
APO серия - триплеты на FPL53
Так?
Дублет типа 140 мм F/8...9 на FPL53 и лантане предполагается в перспективе? 1:9 улётная штучка для визуальщика.

Мы же обсуждали - не FPL-53, а его аналог FCD-100!
На предыдущей страничке каталога для визуальщиков есть дублет ED 102F11...

[SAY]

Дублет типа 140 мм F/8...9 на FPL53 и лантане предполагается в перспективе?

Вангую что на FPL-53 ничего нового уже выпускаться не будет.

Ну тогда что-нибудь дешёвое экзотическое типа 140/1540 мм на FPL51 и N-K5, FPL53 в 1:7...8 скромно отдыхает.
Да, и фокусёр дешёвый односкоростной 2", дорогие на хрен не нужны.

[SAY]

На предыдущей страничке каталога для визуальщиков есть дублет ED 102F11...

Решили над визуальщиками поиздеваться?

[merfi]

Обзор Даниэля Монси из Америки:
https://docs.wixstatic.com/ugd/0bb5a1_4642ec75dc4444028b7c4deefb13702e.pdf

(кликните для показа/скрытия)

Review by: Daniel Mounsey
Over the course of the past 25 years, I've encountered a pretty vast number of vivid views of
the solar system while comparing telescopes and I've kept a journal over that period. After you
see so many images using various optical systems, you collect a visual archive or frame of
reference from which to gauge other views. For this particular session the seeing started out at
about a 7 and worked its way to an 8. This is where the planets remain pretty still with trifling
air movement. The inversion layer was clearly visible below, over the LA basin and then the
moisture kicked in. These were all tell-tale signs that the seeing would hold. Even atmospheric
dispersion wasn’t an issue worth bothering with even though we had corrective measures on
tap to deal with it. If these Evostar’s remain well figured like this, then I believe there’s something
special on the horizon at a very reasonable price.
as such, are expected to remain so with these production units. When we went into this, we
honestly didn't expect to see what we did, and we were all quite shocked to tell you the truth.
The scope settled down about an hour and a half after setup around sunset. We primarily
switched between a 7mm t6 Nagler at 171x and a 5mm t6 Nagler at 240x for the tests. I suggest
having a 5mm, 6mm and 7mm for planet viewing with this scope. Derek selected one of his
premium Tak diagonals which worked superbly. As the optics settled in more with Jupiter, I was
starting to get the sense that this was a really impressive refractor at any cost, even compared
to premium scopes costing several times more. So, we decided to star test the scope. Even
before I handed Derek a green filter, he could already start to tell the optical figure was indeed
excellent. With the green filter inserted, the star test looked textbook with a very slight amount
of under-correction which is exactly what I was hoping to see since the optics will only improve
in this circumstance. There were no visible signs of unwanted zones, astigmatism, overcorrection,
nothing that stood out to any of us. This really stunned us all. Even in some
premium optics you can find these little optical gremlins from time to time. I usually expect to
at least see something worth mentioning, but that simply wasn't the case here.
I could even see the collimation looked excellent while I focused slightly in and out with Jupiter,
another green flag. According to Skywatcher, there are several adjustable screws on the side of
the cell. Checking collimation on a star with refractors is not always as easy as people may
think, unlike an SCT. So, I usually use planets when the seeing is good and the telescope is
reasonably acclimated to determine if collimation is an issue during observation. With regard to
false color on Vega, when I ran the focus slightly back out, I could see a light greenish tint. In
focus, you see some hints of violet on Vega and other bright stars more so at higher
magnifications. The amount of color an observer sees may also be dependent on their age
and sensitivity to color in the dark, but it's not that objectionable when the telescope was
focused, especially while observing planets where it's mostly color free. The color correction on
and around the globe of Jupiter looked superb and I'm pretty sensitive to false color. With
Venus, you will see false color at night but remember that anyone who has experience viewing
Venus knows that it’s best viewed in broad daylight, which means false color will be far less
noticeable.
All of us were very impressed. Jupiter had amazing surface detail and it was really tack sharp
with surprisingly high contrast. Even our friends Hawk and Luigi were surprised, and both are
owners of exquisite telescopes in their own right. The rusty looking GRS was vivid right at the
edge of the globe as it was starting to make its ingress. The colors on the surface had beautiful
rusts and pastel hues. There was an intricate network of surface features and the globe looked
completely organic as if unhampered or hindered by anything distracting. I remember saying to
the guys how impressed I was. I have a world class FS152 and I have to admit that it doesn’t
have much on this Evostar with planets and I’ve used it over a dozen years. With my Tak, the
color on brighter stars at higher magnifications appear slightly more accurate in color
correction through the FS152 but at several times the cost, it should. At lower magnification for
objects such as star clusters though, the differences are even less noticeable. Most of you
veteran observers who know me, know I've compared a countless number of refractors and
reflectors. The images of Jupiter we saw on this night were beautiful and right up there with
some of the finest optical systems I've ever seen in this aperture class. Even with Saturn on the
rise, at 240x we could easily see the Crepe ring. The Encke Minima was also visible in the middle
of the A ring upon careful scrutiny. At one-point Derek even looked at us all and said... maybe
we should set up the FC125 to see what happens. Derek’s particular FC125 is my favorite 5”
ever because the optical figure is truly world class and a very special specimen. We all knew
though, there would not have been enough time to properly acclimate the FC125 and as a
result, the comparison would not have been fair to the 5".
MECHANICS
Mechanically, I'm pleased with this entire setup including the dual speed crayford focuser at
this price point. It feels smooth and solid. For imaging, there's a DX model and it's the exact
same telescope with a heavier duty rack & pinion focuser and Losmandy style D plate instead of
a Vixen style plate on the standard model. The DX model is also heavier and as a result, should
help the appearance of the balance point look more aesthetic. I did not have a finder attached
on my sample, which would have added a bit of wanted back-weight. For visual work, the
standard focuser is fine in my opinion. Regarding the weight of the OTA, I normally have to use
three 11lb counterweights with my EM200 mount when using my FS152. With the Evostar, I
only needed two counterweights. The OTA is rated at just over 20 lbs and feels considerably
lighter than my FS152 and more like my loaded FS128. I think observers could do okay with
mounts like the Losmandy GM8 or AVX just for visual work only. In my opinion, the hard case is
a bit too large for practical transport but makes good as a storage case. I measured the
dimensions at 55.5" x 11.5" x 15.5". It does allow plenty of space for accessories though. I
suggest a soft case for more practical transport which is what I use for my FS152. Orion and
Pacific Design soft cases are available. Another thing some observers may want is a
compression ring adapter if they're concerned about the screws used in the visual-back. These
compression ring adapters are available from other suppliers such as ScopeStuff at a reasonable
cost.
Image: Evostar 150ED as it arrived in the case
The Evostar 150ED is one of the most controversial refractors right now because it was decided
that the information about the glass would be undisclosed. Televue has never disclosed what
type of glass they use either but maybe people figured because it's Televue, it doesn't matter.
Okay, so let's talk about that. Seeing some trifling amounts of false color or false color in
general by an observer is not necessarily an evaluation of a refractors performance and I can
attest to that from 25 years of using, comparing, and evaluating countless refractors in the field
side by side. The subject of false color is often misinterpreted because some observers don’t
understand why they're seeing it out of focus in the first place and often, incorrectly assume
the optics must be inferior as a result. This is a big mistake I often see, particularly among
beginners in the forums who read too deeply into these topics.
The ability to distinguish sharp contrast on the surfaces of planets in-focus and resolve fine, low
contrast details is the real evaluation, but very seldom do people talk about this. Perhaps
they're unable to observe for whatever their reasons are. I'm aware of the
observing habits people have and I pay attention to them, even though they may not know it. If
someone walks up to look through my telescope, I will sometimes ask them to take their time.
If that person sits for 15 seconds, chances are they're really not really observing at all. Instead,
what they're doing is just peeking. There's a huge difference between a person who peeks and
a person who is observing. When you sit for good periods of time with your own telescope,
scrutinizing a planet, your eyes and mind can pick up very elusive details that will often go
unnoticed to a person just taking a peek, assuming the seeing allows for it. Even writing down
some observational notes can help.
After spending more evenings with this Evostar 150ED by myself, I have been more impressed
with its visual performance, particularly on deep sky objects such as star clusters, which look
very much like they do in my Takahashi FS152. There are some amazing refractors out there,
but this Evostar can put up one heck of a fight against other premium scopes and we certainly
found that out quick. The smoothness of figure is remarkable, and it amazes me how high the
contrast of the planets look through it after it's acclimated.
SO HOW DOES THE EVOSTAR 150ED REALLY COMPARE TO A PREMIUM ED REFRACTOR?
This is what many people want to know. To put it to the test, we pulled out Hawk’s world class
TEC140 under reasonably good seeing using various magnifications while viewing Jupiter and
Saturn. All of us took turns going back and forth. Everybody, myself included were scratching
our heads. Incredibly, there really wasn't that much difference, in fact all of us had to wait for
really good moments of seeing to make any solid decisions and even then, it was extremely
close. Derek's daughter has young eyes and we asked her to take a look and offer her opinion.
For a while she was liking the TEC140, then she went over to the Evostar and sat for a while and
said.... I like this now! Then she went back to the TEC140 again and said she liked it just a bit
more. In my opinion, the TEC140 had just a very slightly more refined image, but only under the
steadiest moments. Even then, it wasn't by much, in fact Hawk who owns the TEC140 said
multiple times that he couldn't even see much difference and certainly not three times the
price difference. Saturn's globe is covered in a haze of ammonia ice crystals and as a result, has
dull surface contrast on the globe compared to Jupiter. In the TEC140, the globe appeared to
yield just a tad more surface contrast, but the Crepe ring unquestionably appeared to yield a bit
more contrast in the Evostar, probably because of the additional 10mm of aperture. Most of
the time, the seeing caused more of a difference between the two scopes than the scopes
themselves.
Image: Field comparison between the Evostar 150ED, TEC 140ED and Astro-Tech 130ED.
THE EVOSTAR VS OTHER REFRACTORS ON THE MARKET
While you do your research, you will stumble on reviews of the APM 152ED and even a new
triplet that is still questionable for a bit more money, but here's what you may not be aware of
if this is all new to you. The APM 152ED was originally branded in the United States as the Lunt
152ED. This telescope is also part of my review site and was one of the earlier models which
had a good, solid lens cell and as such, got a good review by BillP a very well-known reviewer
and friend of mine. When the Lunt 152ED was launched, I was extremely excited because it was
a chance to help others get into a 6" ED at a relatively affordable price! Unfortunately, because
of quality control issues, a good number of samples I evaluated were out of collimation and
there were other observers who also had to work through the issues with their samples as well.
There were some observers who got some decent samples, but the quality control was still in
question and I ran out of steam dealing with them. Not only that, but most of them had so
much under-correction, they could not even produce a diffraction pattern on the outside of
focus, even in green light after they acclimated for three hours in low deltas. Here is what
should happen when you star test a refractor to check the spherical correction. Usually when a
refractor is still acclimating, the star test will exhibit under-correction. There’s more to it, but
this basically causes the diffraction pattern to look fuzzier on the outside of focus. This is
completely normal for nearly all refractors and should be expected. As the optics acclimate, the
star test will normally improve, and the diffraction pattern will slowly become more apparent
outside of focus. Jet streams in the upper atmosphere can also wreak havoc as well as
spherochromatism (use a green filter) and distort the outer rings while outside of focus. So, you
have to be careful not to misjudge the optics prematurely.
The Lunt 152ED's never reached that point and remained in a severe state of undercorrection
permanently for several possible reasons. The result was scattered light around the
planets, almost like a faint halo of light which compromised the surface contrast of the Moon
and planets. Because of these issues and the fact that there really wasn't any way to properly
repair them in the US, the remaining Lunt 152ED’s were sent back overseas and rebranded
under the APM 152ED name you now see today. What about these new triplets you hear
about? Here's another thing you should know if you don't already. Triplets can be even more
complex than doublets. Just because you have a triplet doesn't necessarily mean you will have
better contrast. This is the big mistake I see beginners often make. I've evaluated plenty of
highly color corrected triplets with low contrast, why? Because they can sometimes have
unacceptable amounts of spherical aberration due to poor quality of optical figure. Also, what if
they go out of collimation? You think collimating a doublet is hard? Wait till you try a triplet and
ask yourself this question. Who will service them if they need servicing?
STILL CONFUSED BECAUSE OF ANALYSIS PARALYSIS?
I can’t believe the amount of detail beginners subject themselves to, it’s incredible to see. It
reminds me of that scene in the movie Stir Crazy where Gene Wilder and Richard prior try to
use Karate chops to intimidate other jail-mates when they walk into the jail cell. People that are
beginners get involved in these exchanges about spot diagrams, color index, color curves,
MTF’s, glass types etc. This is very technical and complex stuff that causes beginners to read too
deeply on unexperienced eyes. There are really only a handful of people who truly understand
the implications of these topics and how they may or may not manifest themselves in reality
and even then you need to have experience using a telescope in the field to make any possible
sense of it. It's just not as black & white as beginners think. The color correction for most ED
refractors sold in today’s market are quite good for enjoyable visual observation with most
amateurs, relax. It’s not like you’re going to look in one refractor vs another and say oh my, I
made a mistake! Mistake about what? Because you saw a bit of false color? What kind of
evaluation is that? The real meat & potatoes of any optical system is the spherical correction,
which is the "optical figure". This is what really gives you great contrast. People are so
overwhelmed because there are so many ED refractors to choose from. When I read some of
the comments beginners make in the forums, it’s really easy to spot who’s drinking the Kool-aid
and who is not. Since the Evostar has more spherochromatism than highly corrected triplets
like the Esprit for example, that out-of-focus color can be used to determine focus. What occurs
sometimes is that the seeing conditions can play games with your eyes and mind and here's
where it can trick you sometimes. If the seeing is good, it's easier to find focus because when
you do, the slight bit of false color you see out of focus disappears. But, if the seeing is bad, it's
sometimes harder to find focus and as a result, while moving slightly in and out of focus, you'll
see that bit of color, so don't freak out. Once you're in focus, it's really nice.
PERSONAL INDUSTRY EXPERIENCES
I’d like to share some personal experiences about the telescope industry many people don’t
acknowledge or understand. In order to bring telescopes like this into production at a very
reasonable cost, a good number of them have to be made. Finding acceptable glass in certain
apertures that meet the proper quality criteria have to be acquired as well as several other
technical challenges like research, product development, marketing, etc. People often get ideas
in their head that these companies can just do what they want and it's not that simple.
You wouldn’t believe the frustrations companies and vendors go through with people regarding
their gripes. People these days with internet sales are extremely demanding and vocal about
issues they encounter as if they're quick and easy to fix. It's a very complicated situation.
I've been selling telescopes for many years and I've watched this industry change over night
because of an overwhelming number of mass produced products being imported from
overseas. The more there is to select from, the more dubious and overwhelmed people
become, and the more people feel compelled to research the heck out of things and in many
cases way too deeply. The beginner starts to think more and more and research these
differences to a point where they often can't make a decision at all or are looking too deeply
into something that's being blown completely out of proportion by others. I've seen this
happen countless times because there's so much available information. On that same note,
there's also a great deal of misinformation. A lot of people want to be their own opticians now
and it's a huge trend that's going on. I miss the reviews of Ed Ting and Todd Gross who
conducted fun comparisons and expressed their visual impressions of telescopes back in the
day. They didn't go into these huge fiascos about false color and glass types we now see today.
SUMMARY
In my opinion, the Evostar is an exceptional value. You also have technical service and support
from Sky-Watcher USA should it ever be needed, and I think there's value in that. This refractor
also proved that it was capable of standing up to some of the finest telescopes on the market at
a fraction of the cost. Also, I try to help as many people as I can. If you have any thoughts or
questions, I'm happy to talk with you if I have time available.

[SAY]

Обзор Даниэля Монси из Америки:
https://docs.wixstatic.com/ugd/0bb5a1_4642ec75dc4444028b7c4deefb13702e.pdf

Тогда и обзор АРМ-овского 152/1200 мм для полноты картины: https://www.cloudynights.com/articles/cat/user-reviews/first-impressions-of-the-lunt-152mm-f8-ed-apo-r2889
По цене сопоставимы, вторые стёкла разные (в описании скай-вотчеровского указывается «подходящий крон»).
Что касается тестирования, то самую объективную информацию по хромокоррекции визуальщику даёт тест по искусственной звезде из 4-х светодиодов: белый (широкополосный), 560 нм (номиналы 540...550 нм не попадались), 470 нм и 630 нм. Расстояние для 6" апертуры не менее 40 м. Фокусируешься в белом и смотришь что получается в монохроме без перефокусировки (монохром конечно условный, т.к. присутствует полоса пропускания +/- от номинала)

[leviathan]

Что касается тестирования, то самую объективную информацию по хромокоррекции визуальщику даёт тест по искусственной звезде из 4-х светодиодов: белый (широкополосный), 560 нм (номиналы 540...550 нм не попадались), 470 нм и 630 нм. Расстояние для 6" апертуры не менее 40 м. Фокусируешься в белом и смотришь что получается в монохроме без перефокусировки (монохром конечно условный, т.к. присутствует полоса пропускания +/- от номинала)

Так точно. Я как-то по просьбе одного западного ЛА делал тест своей бывшей 100ED, небольшое смещение фокуса наблюдалось только в районе аш-альфа. У него на его 100ED так же вышло.

[SAY]

Что касается тестирования, то самую объективную информацию по хромокоррекции визуальщику даёт тест по искусственной звезде из 4-х светодиодов: белый (широкополосный), 560 нм (номиналы 540...550 нм не попадались), 470 нм и 630 нм. Расстояние для 6" апертуры не менее 40 м. Фокусируешься в белом и смотришь что получается в монохроме без перефокусировки (монохром конечно условный, т.к. присутствует полоса пропускания +/- от номинала)

Так точно. Я как-то по просьбе одного западного ЛА делал тест своей бывшей 100ED, небольшое смещение фокуса наблюдалось только в районе аш-альфа. У него на его 100ED так же вышло.

Идентично (аш-альфа)! Труба цвета шампань (серия перед чёрно-белой).

[leviathan]

У сабжевого можно ожидать серьёзного смещения фокуса в этом (H-Alpha) отрезке. У АРМ даже после 600нм крутой спад вниз:

[SAY]

У сабжевого можно ожидать серьёзного смещения фокуса в этом (H-Alpha) отрезке. У АРМ даже после 600нм крутой спад вниз:

В теории так выглядит. У АРМ на 656,3 нм RMS радиус пятна аберраций немножко превысит радиус диска Эри, у "сабжевого" (если на К10_FPL51) будет внутри диска Эри. Это при фокусировке в белом по минимуму продольной аберрации.
В случае перефокусировки на эту волну соответственно штрель порядка 0,945 у АРМ и порядка 0,9 у "сабжа". У "сабжа" ED линза приблизительно на четверть "пузатее".
Кстати, при фокусировке ахромата 15012 на волне 656,3 нм штрель 0,94, а при фокусировке на нём в белом RMS радиус пятна аберраций на этой волне в 3,8 раза превосходит радиус диска Эри.

ПС. По части наблюдений Солнца с узко-полосным фильтром в ахроматы. На 656,3 нм у 10201 штрель 0,99, у 1201 - 0,97. У ED-шек СВ на FPL53 и кроне только у сотки лучше чем у ахромата 1201, 120-ка на отличный (более 0,95) не тянет, только на умеренно хороший.

[Infinity]

Вобщем, выводы для визуала неоднозначны для этой трубы? Он будет хуже по коррекции чем 120/900ЕД?

[Denis Volodin]

Почитав записи уважаемых SAY и Владимира Николаевича (картинку из каталога) и посмотрев на сайт TS прихожу к выводу что Skywatcher Evostar 150ED это тоже самое UO 150 ED Pro. Трубы разные с фокусером, маркетинг разный, а объектив тотже - use of two special glasses (FPL53 and lanthanum glass).
Да и по ценам если посмотреть почем/что и где то TS 150 ED (онже UO 150 ED Pro) будет стоить как Evostar  150ED - это из анализа цен на TS.

Единственное не понятно почему немчура (у них ведь орднунг в мозгу как бы  ) сует ED рефракторы  в раздел апохроматов? У них ведь есть разбел ED рефракторов, в котором живет Evostar 150ED. Чтото тут не ладно.

[leviathan]

use of two special glasses (FPL53 and lanthanum glass)

Нет там "волшебного" FPL53.

[Denis Volodin]

use of two special glasses (FPL53 and lanthanum glass)

Нет там "волшебного" FPL53.

Ну как же нет - есть  . Тут и ранее SAY ссылку давал http://apm-telescopes-englisch.shopgate.com/item/333632313430 . Ну TS ладно ворюги , ну APM вроде ещё не были такими. Или были?
Надо немчуру знакомую поспрашивать , может в суд подать  ... Тока скажите как определить стёклышки - FPL53 или нет?

[leviathan]

Так по ссылке 125мм телескоп !

[Denis Volodin]

use of two special glasses (FPL53 and lanthanum glass)

Нет там "волшебного" FPL53.

Ну или если методом "от обратного" с учетом вашего мнения, ссылаясь на правду про Evostar ED150 -"Dublet objective with a lens of low-refraction ED glass and a suitable matching crown glass element for a contrasty image without chromatic aberration" получается что немчура из ТS вместе с UO вешают нам лапшу на уши.

[Denis Volodin]

Так по ссылке 125мм телескоп !

Совершенно верно  Холмс. Следующий по списку идёт 150ED Pro.

[Denis Volodin]

Обещанная страница каталога...

ED PRO серия - дублеты, в т.ч. на FPL53 и лантане (125 мм F/7,8)
EDT серия - триплеты на китайском FK61
APO серия - триплеты на FPL53
Так?
Дублет типа 140 мм F/8...9 на FPL53 и лантане предполагается в перспективе? 1:9 улётная штучка для визуальщика.

Мы же обсуждали - не FPL-53, а его аналог FCD-100!
На предыдущей страничке каталога для визуальщиков есть дублет ED 102F11...

Владимир Николаевич, уточните в ED PRO используется FPL53 или FCD-100?

[Denis Volodin]

ED PRO серия - дублеты, в т.ч. на FPL53 и лантане (125 мм F/7,8)
По моему там 53 и не пахнет. В 125мм вопрос.

https://www.apm-telescopes.de/en/telescopes/refracting-telescopes-ota/apochromates/ts-optics-photoline-125mm-f-7.8-fpl53-lanthanum-apo-2.5-focuser
Зачем Лудесу врать? FPL51 с лантановым кроном не стыкуется, а с лантановым флинтом - так себе полу-апо (АРМ 152/1200 мм).

А FCD-100 с лантановым флинтом или кроном стыкуется?  вдруг супер пупер апо получился 

[Владимир Николаевич]

В АПО используется FCD-100 это аналог FPL-53

[библиограф]

А FCD-100 с лантановым флинтом или кроном стыкуется?

Да, стыкуется!
https://www.telescope-optics.net/apo_refractor.htm