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102mm f/11 Refractor

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#151 Galicapernistein

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Posted 14 December 2020 - 09:08 AM

I think I get what you're saying, but I'm not sure. I also think that both statements hold true for any focal ratio, BTW. There is no intrinsic difference between how a very short focal ratio and a very long focal ratio objective focuses light and light rays coming from an eyepiece is only reasonably parallel for a point source and then only if truly focused for infinity. I'm nearsighted, so my eyepieces are actually focused as if I was observing something only 35cm's away. 

 

 

Clear skies!
Thomas, Denmark

Starting at around F8 or 9, the converging rays extend all the way to the eye, which means additional photons can be used to create the optical image. Any ray diagram will show this, but bizarrely, all the ray diagrams I can find online are drawn with the eye looking off axis.



#152 Jethro7

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Posted 14 December 2020 - 10:18 AM

With such statements above, I think your Edge HD is out of whack and needs alignment.
I do find the best view on the moon isn't at 350-400x. Far from it.
I have added the extension back into the 102, and now only use it in mono. It does look more like something you would use to shoot down planes, as I've added a bit of weight in the back end to move the scope up the az mount [lickity split].

I'm only in bino on the Edge now.

Hello ris242,

My SCT is collimated just fine, it has more to do with the nature of SCT's. It was my first real scope. I dont care for the SCT's that much any more, the views are not terrible but softer, and I love the pin point stars viewed through a refractor and the views through the Dob are so much wider fields of view.  I guess I still keep it around for night vision Astronomy simply because the focuser is in the rear where I can sit comfortably behind the SCT. I will probably eventually dispense myself of the C8 Edge all together in favor of a ultra fast Astrograph for NV Astronomy. My Az8 set up does look like antiaircraft gun lol.gif  I have not tried a binoviewer on my Altair 102ED, maybe next year at some point. I am in the Q for a upgraded NVD and will be receiving it in Febuary. Unfortunately the Altair 102ED F/11 has too high of a focal ratio to be any good for NV Astronomy but I want to try it anyway with the extention removed, even if I already know the out come of that experiment. Last night I ordered a AT60ED from Astronomics ( IN STOCK )  One came up used last night on CN Classifieds and while I was checking the price of new one on Astronomics, "holy crap" in stock and only $50.00 more for a new one. I will piggyback that scope onto the Altair 102ED as second scope and a super Star finder. ( Thank you Don) The NVD will work with the AT60ED, the scale will be small enough that I may be able to fit whole Nebulae into the eyepeice. It would be nice if one scope did everything but it is also more fun to own several types of scopes, so you can have your own Star Party. For me it is much too late to save myself from the extremely addictive nature of Refractor telescopes.

 

HAPPY SKIES TO YOU AND KEEP LOOKING UP Jethro


Edited by Jethro7, 14 December 2020 - 10:30 AM.

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#153 Mihai

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Posted 14 December 2020 - 05:33 PM

Apart from the better mechanics of the 102mm f/11 ED,is it also sharper and with better contrast then the Skywatcher/Orion 100mm ED f/9 ?

#154 zirkel 2

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Posted 27 December 2020 - 05:28 AM

Hi alls,

 

Just ordered the TS 102 F / 11 achromat that I could compare with my Orion 100 F9 ED.
Why? attractive price and exemplary optical/mecanical finish (the glasses come ***from Ohara (Japan) and the multicoated objective is built into a high-quality, temperature-compensated and adjustable cell) and just the desire to see a good achromat ... I know, I'm crazy ;-)

 

***Usually BK-7 / F2 (Schott label) for Fraunhofer achromat, the Ohara equivalent gives S-BSL7 / S-SIM2, if this is really the case...

 

Note : i also found this page from the original United Optic, some interesting info.


Edited by zirkel 2, 27 December 2020 - 05:46 AM.

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#155 Jethro7

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Posted 27 December 2020 - 09:18 AM

Hi alls,

 

Just ordered the TS 102 F / 11 achromat that I could compare with my Orion 100 F9 ED.
Why? attractive price and exemplary optical/mecanical finish (the glasses come ***from Ohara (Japan) and the multicoated objective is built into a high-quality, temperature-compensated and adjustable cell) and just the desire to see a good achromat ... I know, I'm crazy ;-)

 

***Usually BK-7 / F2 (Schott label) for Fraunhofer achromat, the Ohara equivalent gives S-BSL7 / S-SIM2, if this is really the case...

 

Note : i also found this page from the original United Optic, some interesting info.

Hello Zirkel,

You wont be disapointed. They are a awesome scope. Yeah, you probably are crazy but you are amongst friends here.

I have the Altrair version of that scope and it is one of my favorites.

 

HAPPY SKIES AND KEEP LOOKING UP Jethro

 

20201225 164216

Edited by Jethro7, 27 December 2020 - 09:38 AM.

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#156 zirkel 2

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Posted 09 January 2021 - 06:27 AM

Hi,

 

TS 102 F/11 Achromat is in my house

https://regardsversl...-mm-f11.html?m=


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#157 Astrojensen

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Posted 09 January 2021 - 11:50 AM

Apart from the better mechanics of the 102mm f/11 ED,is it also sharper and with better contrast then the Skywatcher/Orion 100mm ED f/9 ?

I don't know, but I know that my 102mm f/11 ED is VERY sharp and high contrast, so they are probably at least on par in that regard. 

 

 

When used with improved M68 extension tubes, the mechanics of the 102/1122 ED leaves the Sky-Watcher crying in the dust. 

 

 

Clear skies!

Thomas, Denmark


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#158 vkhastro1

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Posted 09 January 2021 - 12:10 PM

I don't know, but I know that my 102mm f/11 ED is VERY sharp and high contrast, so they are probably at least on par in that regard. 

 

 

When used with improved M68 extension tubes, the mechanics of the 102/1122 ED leaves the Sky-Watcher crying in the dust. 

 

 

Clear skies!

Thomas, Denmark

Definitely agree, amazing contrast !

I removed the binofriendly OTA tube section and replaced it with Baader M68 Extension tubes on the focuser.

This quickly allows you to transform the scope from mono mode to binofriendly mode or vice versa.


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#159 Gofr

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Posted 09 January 2021 - 01:02 PM

Apart from the better mechanics of the 102mm f/11 ED,is it also sharper and with better contrast then the Skywatcher/Orion 100mm ED f/9 ?

TS claims their 102 F11 ED is on par with a F8 FPL53 doublet, so theoretically the Skywatcher doublets at F9 would have slightly better CA control. Ofc the F11 scopes have other benefits that naturally come with longer FL. All in all, it's probably a wash between the two, but only someone that has experienced both can say for sure.


Edited by Gofr, 09 January 2021 - 01:02 PM.


#160 REC

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Posted 09 January 2021 - 03:02 PM

I have a C102mm f/9.8 f/1000mm and it really puts up some nice sharp stars for a cheap Acro. Beefed up the focuser with a WO 2" heavy duty crayford focuser and it has become my #1 used scope. I keep it next to my kitchen patio door and observing in two minutes! I love my BV set up in it as well. With a 34mm EP, it's great to sweep the MW!


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#161 Jethro7

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Posted 09 January 2021 - 07:12 PM

Hi,

 

TS 102 F/11 Achromat is in my house

https://regardsversl...-mm-f11.html?m=

Hello Zirkel,

Congrats, stand by to be happy. It is good to know that these scopes are still being manufactured. These long focal lengh scopes dont seem to be in vogue right now and I really dont understand why exactly. I guess they are misunderstood. What they can do is a marvel. Enjoy that scope my friend. 

 

HAPPY SKIES AND KEEP LOOKING UP Jethro

 

P.S. These scopes dont seem to have any bad habits. 


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#162 Binofrac

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Posted 10 January 2021 - 04:21 PM

 

P.S. These scopes dont seem to have any bad habits. 

Mine does. It summons the clouds regularly!


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#163 Jethro7

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Posted 10 January 2021 - 04:38 PM

Mine does. It summons the clouds regularly!

Hello Binofrac, 

I guess that is true. Come to think of it, my scope affects the Jetstream causing it to dip down till it's right over me. LOL..

 

HAPPY SKIES AND KEEP LOOKING UP


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#164 zirkel 2

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Posted 11 January 2021 - 01:19 PM

I just received my 8X50 finder scope straightened for the 102 F / 11, with the following mini dovetail: https://www.teleskop....php/info/p6752

The two screws provided are not the right diameter, too big ... and those present on the PO telescope in the planned location, too short!

What is the thread? M4? M5? if I understood correctly i must be around 5 mm in length ...

 

Thx !

 

4mgt.jpg


Edited by zirkel 2, 11 January 2021 - 01:21 PM.


#165 ris242

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Posted 11 January 2021 - 02:39 PM

I just received my 8X50 finder scope straightened for the 102 F / 11, with the following mini dovetail: https://www.teleskop....php/info/p6752

The two screws provided are not the right diameter, too big ... and those present on the PO telescope in the planned location, too short!

What is the thread? M4? M5? if I understood correctly i must be around 5 mm in length ...

 

Thx !

 

 

Which scope do you have?

Cause mine is exactly like this one in the link below.......... came with the dovetail and can be positioned left or right

 

https://www.teleskop...AP-Focuser.html



#166 zirkel 2

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Posted 11 January 2021 - 02:46 PM

I have a 102 mm F/11 TS Achromat, isn't same focuser, only left position possible. Not finder dovetail with this refractor.

#167 jena100

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Posted 12 January 2021 - 07:12 PM

I have a Zeiss Jena AS 100/1000 that I bought new in 1995. It came from Jena to me in March of that year. Is there some CA? Yes. Does it bother me? No. I had it at Mt. Wilson one night when Tom Cave (Cave Optical) was there. He spent some time with it at high power. He told me "This is a very good telescope". I do not need any other test report.

 

I have it mounted on a AP MACH1 in a 6' Homedome observatory. With my 40 mm eyepiece I have a 2 deg. 20 min. field at 25X.

 

I first wanted a Zeiss telescope in 1947. It took a little time.

 

Robert P. Branch

Upland, CA


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#168 BuffaloTri

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Posted 13 January 2021 - 12:57 PM

I used to own a Canadian Telescopes 102mm/f11.  I think this was the same telescope which was also sold as Astro Telescopes.  This was my first real refractor, and I bought my first premium eyepiece specifically for this telescope (Pan 35mm).  One of my favorite astronomy memories involved this telescope.  I sat on the ground one fall and watched a shadow transit on Jupiter.  I didn't know that there was such a thing as a shadow transit before I saw it in the eyepiece.  I continued to watch the transit until the little white dot of the moon appeared in the purple halo around Jupiter.  The whole experience was wonderful.

 

Eventually I bought a TSA 102 and sold the long achromat.  I regret selling that telescope even though I stopped using it.  I guess that is the power of nostalgia.



#169 LDW47

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Posted 13 January 2021 - 09:04 PM

I used to own a Canadian Telescopes 102mm/f11.  I think this was the same telescope which was also sold as Astro Telescopes.  This was my first real refractor, and I bought my first premium eyepiece specifically for this telescope (Pan 35mm).  One of my favorite astronomy memories involved this telescope.  I sat on the ground one fall and watched a shadow transit on Jupiter.  I didn't know that there was such a thing as a shadow transit before I saw it in the eyepiece.  I continued to watch the transit until the little white dot of the moon appeared in the purple halo around Jupiter.  The whole experience was wonderful.

 

Eventually I bought a TSA 102 and sold the long achromat.  I regret selling that telescope even though I stopped using it.  I guess that is the power of nostalgia.

And now Canadian Telescopes as a whole are long gone !  I dealt with them quite a few times, I bought a 102mm, f6.25 from them, it puts out a great performance.



#170 Jethro7

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Posted 14 January 2021 - 05:07 AM

Hello Zirkel 2,

It appears that at least with the new version of the TS 102ED F/11, that it has a different focuser.  My Altair uses the exact focuser that is on my Astrotech 102ED. For what it is worth. It has always annoyed me that the location of the starfinder shoe is so far back on the focuser where it is the most awkward to use.  I wonder who decided that this location would be the industry standard? I moved the shoe up a bit on to the extention tube, where it is out of the way and much easier to use. But now I have changed directions a bit and piggy backed a AT60ED on to the Altair to fill the star finder role and this arrangement has turned out to be a joy to use in more ways than just having a single use starfinder scope.

 

ENJOY THAT AWESOME SCOPE AND KEEP LOOKING UP Jethro

 

20210114 041727

 


Edited by Jethro7, 14 January 2021 - 05:36 AM.



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