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#26 Kevin Barker

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Posted 20 February 2014 - 02:56 AM

Jim
Whilst the used Tak 78 will deliver superb images and larger TFOV I bet the 6 inch f 5.9 will render deep sky objects (fainter planetary's, galaxies and nebulae) better. Better meaning more and brighter detail visible, more resolution etc

I have an AS80/840 Zeiss Jena lensed scope, It's optics are superb on tightish doubles around 1.5" seperation and brighter medium power planetary viewing etc. It will not however beat even an average 4 inch achromat on deeper sky.

I agree refractors are great for wider skies. My 8 inch Dobsonian for example has a limited fully illuminated field. This is to reduce CO and enhance contrast.

As you say "whatever lights your rocket". I think this is why many of us own an arsenal of scopes.

Kevin

#27 galaxyman

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Posted 20 February 2014 - 11:10 AM

An 8" refractor sure sounds like a fun instrument to use.


Oh yeah :waytogo: :cool:


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#28 PGW Steve

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Posted 20 February 2014 - 03:46 PM

Jim,
I have a 14" LX200R, a 16" Hyperion and a 7" F15. Meade Mak.....Would you agree that the 6" f5.9 provides me with a huge FOV??

#29 Kevin Barker

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Posted 20 February 2014 - 10:42 PM

Steve
Focal length is the key here.
I wrote an article on focal length a few years ago(12 ??) for our local astronomical society for beginning astronomers. From memory I ignored the concept of barlows or focal reducers. I compared the actual field of view with three common eyepieces in four of my telesopes. At the time I think I had a 100/1000 refractor, 203/1200 newtonian, 80/840 refractor and a 152/1800 refractor.

Big fast refractors have quite short focal lengths as do some fast Newtonians. Refractors can often produce a very wide field fully illuminated field with modern wide field eyepieces.

Kevin

#30 Mark Costello

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Posted 21 February 2014 - 09:08 AM

Hi Steve. If I had a scope like that and something like a 30mm eyepiece with an apparent field of view of 80 degrees, I'd be able to frame almost everything and use it as its own finder. I work that way with my 5" achromatic refractor.

#31 Vondragonnoggin

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Posted 21 February 2014 - 10:31 AM

I read the review. It seemed to cover enough material to get an idea how it performs. I don't see what all the extra questioning is about. Particularly from well experienced observers with no interest to begin with in a scope like this:


From Don:

Having owned a 6" f/5 and a 4" f/15, and, now, a 4" f/5.4 apo, I can only say, "to each his own". Chromatic aberration definitely spoils the view of Moon, planets, and bright double stars. Deep sky? You're right.
Anything brighter than about 3rd or 4th magnitude? Give me an apo or a reflector. The 6" f/5 even still had too much false purple for me with the "atom bomb" of minus violet filters, the Baader Contrast Booster. I eventually sold it.


From David:

Even some of the fainter doubles might have some haziness around them which some people might object to. Even my 100mm f/6 doublet has faint almost colorless halos around many doubles that really impacts the view at higher power, especially when trying for very faint companion stars that might get buried in that haze. Indeed, some tighter open clusters or globulars could get a little dose of extra "haze" in them with 8 inches of f/5.9 achromatic doublet to play with, although the aperture would certainly resolve them well. I suspect that my old 8 inch f/7 Newtonian or my friend's 8 inch f/5 RFT probably could probably do a little better planet-wise, although the 8 inch f/5.9 refractor could get true fields of view of up to 2.2 degrees or so with somewhat better edge illumination. Oh well, whatever trips your trigger (especially for around $3000). Clear skies to you.


To sum it up, statements like "to each his own" and "whatever trips your trigger" are indicative of a lack of interest in such an instrument.

What is the purpose of getting more info on something you would never purchase?

I do believe this to be a scope that would never get purchased by someone that knows about CA in a fast achro and finds it objectionable. Also, because of mounting requirements, mass, and cool down, plus expense, I don't believe some newbie unaware of CA is going to rush out to buy a scope like this, so what possible extra info should have been necessary to share that would satisfy whatever the real reasons for the extra questions?

Since there is obviously no interest in purchasing, what motive other than diminishing the review as previously mentioned, is there for extra questioning? Is it so people that don't know about how CA affects viewing high power planetary and brighter objects or a haven't experienced a "haze" as mentioned earlier?

Could do nothing but agree with Mr. Curry's post here. Bottom line - this is a niche scope that would be picked by those that already know their tolerance levels for CA and are ok with what it does good (definitely mentioned in the review) and what it does not so good (again, definitely mentioned in the review).

While Jim's (Barnett) line of questioning is similar, I don't believe that he would never consider a scope like this. Might not be first on list of wants, but I could see curiosity to at least give it a go with an open mind. That's just a guess though....

Pointing out the elephant in the room is all fine unless others see it as a miniature elephant that can be ignored mostly.

"See the big elephant!"

"Yeah, but it's not that big and so what, peanuts are cheap"

#32 terraclarke

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Posted 21 February 2014 - 11:56 AM

:waytogo: Jim!

I have found that amateur astronomy is becoming a lot like wine-tasting! That's why I don't go to wine tasting events anymore. :lol:

They say an 8" F5 or F6 Newtonian reflector would be much better, but believe me, if the review was of that sort of instrument on here, you'd have scores of them coming out in droves to complain about coma instead of CA! Sadly, at least in many of these fora, it has become more about sounding erudite than having fun.

I have a 6inch F5 Omni XLT refractor on a heavy duty mount and it is sheer fun and cheep thrills at a dark site. But then, I'm a girl that can have fun at a carnival too.

For some people it's more about spending money than it is, having fun. For the rest of us, it's about spending the money you have, and having fun. To each his/her own.

#33 gdd

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Posted 21 February 2014 - 01:14 PM

On nights when you feel more like viewing in true color than in bright high resolution, you can put on an aperture mask and still have a quite a bit of aperture. Or cut the aperture less aggressively and use a milder filter.

Gale

#34 Starman1

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Posted 21 February 2014 - 06:52 PM

Each scope type has its issues, and each scope type can have its aberrations tamed: a reflector by using a coma corrector, and a refractor by using a minus-violet filter.
That's not a bad thing, merely an adaptation of the observer to the idiosyncrasies of the scope type.
I still think an 8" f/5.9 refractor would be a fun thing to use. Needs a TALL mount, of course.

#35 Rachal

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Posted 21 February 2014 - 11:47 PM

Each scope type has its issues, and each scope type can have its aberrations tamed: a reflector by using a coma corrector, and a refractor by using a minus-violet filter.
That's not a bad thing, merely an adaptation of the observer to the idiosyncrasies of the scope type.
I still think an 8" f/5.9 refractor would be a fun thing to use. Needs a TALL mount, of course.

I image Leslie Peltier would have really liked one to search for comets; I think he used a 6"F10(IIRC). :)

#36 cheapersleeper

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Posted 22 February 2014 - 03:20 AM

Many here see these comments on reviews as a "peer review" process. Not a formal one obviously, but something like that. If that is how you feel, then the line of questioning is perfectly reasonable regardless of whether one has an interest in purchasing the sceope.

I can generally just leave it alone unless someone seems to be really putting false information out there.

B

#37 russell23

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Posted 22 February 2014 - 09:27 AM

The statement that "The notion that “fringing” or “false” color hinders or hampers what you see in a “doublet” is phony baloney nonsense" is not supported by anything in the review. Unless it was compared with an 8" APO or a CA reducing filter was used on the scope to check for differences the statement is speculation.

I think what is meant is that the false color need not ruin enjoyment of the scope. That is a position that is clearly supported by the author's enthusiasm.

Dave

#38 Mr. Bill

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Posted 21 March 2014 - 12:17 PM

I've always toyed with the idea of a large RTF refractor (almost bought the APM 8 inch f/6) but good sense prevailed in the end.

Too heavy, too expensive for what you get in return.

My Orion 10 inch f/4.7 with Paracorr (f/5.4) would "blow the doors" off the Phoenix WFT 204 for a fraction of the cost.

PS...I own an Istar 6 inch f/5 lens set and made a binocular from a pair of Istar 5 inch f/5.5s so I've had some experience with Istar products, which are good value for the money.

:cool:

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#39 Mr. Bill

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Posted 21 March 2014 - 08:23 PM

6 inch f/5 Istar box refractor with binoviewers...

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#40 Mr. Bill

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Posted 21 March 2014 - 09:24 PM

Another 8 inch f/6 refractor reviewed in CN

http://telescoperevi...hp?item_id=1219

#41 JKoelman

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Posted 28 March 2014 - 09:11 AM

So do tell: how did you tame the CA in the scope? Which minus violet filter did you use? That might be an excellent one to use in the 6" f/5.

Forget these filters. Just weld a 30 mm widefield eyepiece into this scope. The title says it all: we are talking a comet hunter!


#42 aa6ww

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Posted 01 April 2014 - 03:05 PM

You only need to look once through his 8" refractor at the Helix Nebula or the North America nebula or the Andromeda Galaxy to know how utterly ridiculous your comments sound. :roflmao:

Ralph


That's my C14 next to his big refractor in one of his photos.


I've always toyed with the idea of a large RTF refractor (almost bought the APM 8 inch f/6) but good sense prevailed in the end.

Too heavy, too expensive for what you get in return.

My Orion 10 inch f/4.7 with Paracorr (f/5.4) would "blow the doors" off the Phoenix WFT 204 for a fraction of the cost.

PS...I own an Istar 6 inch f/5 lens set and made a binocular from a pair of Istar 5 inch f/5.5s so I've had some experience with Istar products, which are good value for the money.

:cool:



#43 norcaltakguy

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Posted 02 April 2014 - 07:08 PM

Yea, after "blowing" my dough I have finally settled down to a multiple "set-up" that meets my thirst for aperture AND a solid "super" sized refractor...

#44 norcaltakguy

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Posted 02 April 2014 - 07:35 PM

Hey ya Terra...

Ya know, if I actually knew what I was doing some 13 years ago, I would have landed on a 300 Mewlon, snagged a FS152 and called it a day...Astronomy to me was never about the expense, I repeat, Astronomy to me has never been about the money/COST, I love everything this hobby affords, even though I pursued it like a drunken sailor ( once upon a time LOL)... That said, I have blown through many scope types, many mounts types, many eyepiece collections ( 3 total, + all the LE Takahashi's when I owned my last 2 Mewlons, 210 and another 250) PLUS all the "brick-brack" you need to view ( filters, adapters, tables and chairs and LETS not forget Software, YIKES)...But with all I have done, my quest for the sky is ever present, no matter what I own and use, to me it's all about viewing, NOT owning astro gear!!! I am now in my late fifties ( FYI, calculated in dog years LOL), so I am down to my last set of scope types which to me I HOPE will take me to the end of my journey, into my golden years as an amateur astronomer!! In conclusion, I wanted to share my experience about a wonderful piece of gear, NOT Boast OR act like a pompus *BLEEP* just because I own a Big refractor...If no one here has had the honor to view though a lens system of this size, don't LOSE your cookies and get all technical, IT'S a Blast, IT'S a Beast to look through and IT'S MORE fun looking through an 8" piece of glass than maybe a BIG Dob ( Alvin Hueys 31 was the BOMB!!!)..Thank YOU each and everyone for your comments and criticism ( I am laughing ), but do yourself a big huge favor, GET OFF the COUCH, turn the friggin TV set off, GET out of these forums and go outside and LOOK into Space, The Universe is calling, Can YOU Hear IT??? Clear and darker skies, James E. ( aka NorCal Tak GUY)

p.s. That XLT refractor is a Monster, 2 of my viewing buddies own the 6" and the 5", LOVE em!!

#45 norcaltakguy

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Posted 27 April 2014 - 11:43 AM

I actually purchased a minus violet filter ( 2" Williams Optics) for that simple reason, to eliminate existing false color and to bring additional contrast to various objects ( nebula and clusters)...That said, unless you have looked through a refractor of this size, making remarks regarding it's optical quality and OR ability is simple non-sense, why? Because it's size simple takes over what it lacks in elements ( a third lens to correct )...I use a Bak 4 prism diagonal, which when used in a "doublet" helps compensate for it's lack of full correction ( that false color term again )...I use 2" explores, the 5.5, 9, 14, 19,( 100 degree ) and I top off my eyepiece collection with a 24 and 30 explore ( 82 degree), a 35 ( 78 field ) as well as a 41 TV Pan and a 56 Plossl Meade ( I enjoy the 56 over the 55 TV, although I TRULY miss my 50 Tak)...Again, I have only used the Istar in minimal skies( 3.5 to 4 transparency, in the outer suburbs of Elk Grove / Sacramento) so again the jury is still out regarding a complete viewing report until I can get this scope into some very dark skies and see what she will do...All in all I am not trying to convince anyone of anything, merely stating that it's general performance as a refractor surprised the heck out of me, 8" or NO 8", it's a very good scope!! p.s. Dear Mr. Curry, YOU are simply a good guy and one person I will personally thank...A "Complete" Viewing report is coming, be patient group!

#46 jrbarnett

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Posted 27 April 2014 - 03:59 PM

Pretty much an 8-inch is an 8-inch is an 8-inch. Anyone who has familiarity with *any* 8" aperture (C8 SCT, 8"f/6 Dob/Newt, etc.) will understand something about what's visible with another 8-inch even if of different design. Sure there are differences - one has a shorter focal length and produces wider TFOVs with a given eyepiece than another, one has false color that other lacks, one can be easily carried in one go, mount included, etc., but there are similarities too, which IMO grossly outweigh the differences in performance terms.

Accordingly, the only real "non-sense[sic]" here is the suggestion that one has to look through a particular design of 8-inch scope in order to have anything pertinent to say about it. I've looked through a 36-inch achromatic refractor. I've never looked through a 36" reflector. Nonetheless I know that were either mine, I'd rather have the reflector to escape the loads of false color present in the big achromat (17,600mm focal length). While I've never looked through a 36" reflector, having used other smaller but still large reflectors, I know how much difference a lack of false color makes on many targets in big aperture scopes. That is, though I've never looked through the hypothetical 36" reflector, my experience with 20" and 25" reflectors has some relevance when it comes to picking between a 36" achromat I have used and a 36" reflector that I have not used.

- Jim

#47 galaxyman

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Posted 28 April 2014 - 11:45 PM

You only need to look once through his 8" refractor at the Helix Nebula or the North America nebula or the Andromeda Galaxy to know how utterly ridiculous your comments sound. :roflmao:

Ralph


That's my C14 next to his big refractor in one of his photos.


I've always toyed with the idea of a large RTF refractor (almost bought the APM 8 inch f/6) but good sense prevailed in the end.

Too heavy, too expensive for what you get in return.

My Orion 10 inch f/4.7 with Paracorr (f/5.4) would "blow the doors" off the Phoenix WFT 204 for a fraction of the cost.

PS...I own an Istar 6 inch f/5 lens set and made a binocular from a pair of Istar 5 inch f/5.5s so I've had some experience with Istar products, which are good value for the money.

:cool:


That's the problem Ralph is that negative comments come from those who never looked the particular scope of conversation. It's almost like they doubt the review or the owner.

In fact I think many who are negative, observe more here on Cloudy Nights then actually under the stars where it counts.



Karl
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Chesmont Astronomical Society - www.chesmontastro.org
Galaxy Log - http://www.youtube.c...r/GalaxyLog4565
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Telekit (Swayze optics) 22" F/4.5 Dob
Homemade (Parks Optics) 12.5" F/4.8 Dob
Vixen 5.1" f/5 reflector
TMB/APM 8" f/9 Refractor”The Beast”. One great DEEP SKY achro
ES 6" f/6.5 achro. Good one
Celestron Omni XLT 102 refractor.
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#48 davidpitre

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Posted 29 April 2014 - 07:14 AM

Pretty much an 8-inch is an 8-inch is an 8-inch. Anyone who has familiarity with *any* 8" aperture (C8 SCT, 8"f/6 Dob/Newt, etc.) will understand something about what's visible with another 8-inch even if of different design. Sure there are differences ...

Agreed. While there are certainly differences, it is just silly to say one is vastly different than another. 8" of aperture is 8". While 1 has a wider field and another a bit more contrast, it is still 8". And when you compare 2 with 8" of aperture at the same focal length, there just ain't a lot to yell about.

#49 galaxyman

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Posted 29 April 2014 - 08:05 AM

Actually David I have, and the refractor goes a bit deeper (like galaxies). Just the other night hit 15.2 mag galaxy with the 8" refractor.

Owned one 8" SCT and two very good 8" reflectors, and none has shown the detail or went as deep in DSO's as the 8" refractor.


Karl
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Chesmont Astronomical Society - www.chesmontastro.org
Galaxy Log - http://www.youtube.c...r/GalaxyLog4565
Galaxy Log Blog - http://galaxylog.blogspot.com/
HASB - http://www.haveastellarbirthday.com
Telekit (Swayze optics) 22" F/4.5 Dob
Homemade (Parks Optics) 12.5" F/4.8 Dob
Vixen 5.1" f/5 reflector
TMB/APM 8" f/9 Refractor”The Beast”. One great DEEP SKY achro
ES 6" f/6.5 achro. Good one
Celestron Omni XLT 102 refractor.
Celestron 10x60mm Binos

#50 Starman1

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Posted 29 April 2014 - 01:33 PM

Actually David I have, and the refractor goes a bit deeper (like galaxies). Just the other night hit 15.2 mag galaxy with the 8" refractor.

Owned one 8" SCT and two very good 8" reflectors, and none has shown the detail or went as deep in DSO's as the 8" refractor.


Karl
E.O.H.

Makes sense. A reflector would have to have enhanced coatings to even come close to the refractor's transmission (if using a dielectric star diagonal), and the SCT's secondary is just too large to show the same detail as easily.






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