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Whats your Planet Killer telescope for 2020?

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#326 Jethro7

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Posted 13 July 2020 - 10:32 AM

That, I think, unless that someone is an experienced amateur astronomer and you've made it perfectly clear that the reason the instrument is being given away for free is that it has some serious issues, was not a very nice move. At all. 

 

Issues that most likely are perfectly remediable, but not to the uninitiated. And it has nothing to do with it being an achromat. Exactly the same could have happened to an ED or apochromat (and I've seen it happen to them, too). 

 

 

Clear skies!
Thomas, Denmark

HelloThomas, 

your point is valid I did make that clear to the person that came by to pick it up but it is a moot point now. The individual decided that it was too big and heavy and  he would have to invest in a bigger mount.for a questionable telescope  So I removed the focuser and mounting clamps and put the rest in a garbage dumpster.I just did not want to bring it back home with me to just sit around and collect dust. Pretty bad when free is still too much. 

 

I guess I could have turned the rest into a Diggeridoo, it actually worked okay for that,  it plays in the key of C, LOL... or used the tube to make a model rocket or something. It was not much good as a telescope.

 

HAPPY SKIES AND KEEP LOOKING UP Jethro.

 

P.S. Hay maybe this would be a fun topic on the "Off Topic Observatory" 

"Fun things to make or do with a broken telescope "


Edited by Jethro7, 13 July 2020 - 11:12 AM.

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#327 Astrojensen

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Posted 13 July 2020 - 11:14 AM

It's good that it didn't end up ruining some new budding amateur's start, but it still irks me that you just threw it away without taking the twenty or so minutes it would take to give a recollimation a go. You might have thrown away one of the finest lenses you've ever had in your hands. I know you're laughing, but it can easily happen. I've even seen Zeiss telescopes, where the lens had been turned around and gave HORRIBLE images and all it took was a five-minute job with a screwdriver to turn them back into sublime telescopes. One such telescope had had its lens installed backwards for DECADES and the previous owner had not been able to notice... I just flipped the whole objective 180 and it gave stunning views. 

 

I know most of the 102/1100 achromats are extremely good. A highly experienced observer I know has one that he routinely uses at 400x. 

 

 

Clear skies!

Thomas, Denmark


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#328 daquad

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Posted 13 July 2020 - 01:24 PM

I had one of the Astro-Telescope f/11 achromats. It gave excellent views, but I sold it because it was redundant with my Jaegers 4" f/15.5, which had less CA.  The Astro Telescope, however was beautifully built and planetary/ lunar images were sharp.

 

Jethro, did you get the scope new?  I find it hard to believe that someone didn't mess with the lens before you got it.

 

Dom Q.



#329 Jethro7

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Posted 13 July 2020 - 03:05 PM

It's good that it didn't end up ruining some new budding amateur's start, but it still irks me that you just threw it away without taking the twenty or so minutes it would take to give a recollimation a go. You might have thrown away one of the finest lenses you've ever had in your hands. I know you're laughing, but it can easily happen. I've even seen Zeiss telescopes, where the lens had been turned around and gave HORRIBLE images and all it took was a five-minute job with a screwdriver to turn them back into sublime telescopes. One such telescope had had its lens installed backwards for DECADES and the previous owner had not been able to notice... I just flipped the whole objective 180 and it gave stunning views. 

 

I know most of the 102/1100 achromats are extremely good. A highly experienced observer I know has one that he routinely uses at 400x. 

 

 

Clear skies!

Thomas, Denmark

Thomas,

I dont know how you would collimate if the lens cell has not any collimation points

The lenses were just held in place by a spanner type collar. Well no one mentiond that in a post other than no collimation points on the cell  no point.in trying to collimate. I figured that was that.

 

Ok retrieved it out of the trash dumpster now what?

 

 

HAPPY SKIES AND KEEP LOOKING UP Jethro


Edited by Jethro7, 13 July 2020 - 03:21 PM.


#330 Astrojensen

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Posted 13 July 2020 - 03:36 PM

 

Ok retrieved it out of the trash dumpster now what?

We better take that in a PM, lest we further derail the thread and get it locked. Darkness is falling here, and it's clear, so let's continue via PM tomorrow.

 

 

Clear skies!
Thomas, Denmark



#331 RichA

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Posted 13 July 2020 - 04:58 PM

Best view I ever had of Mars, bar none, was through a customized C14, in its own observatory.  The detail seemed to be about 1/50th the width of the disk or better, when Mars was about 23 arc seconds across.  I was dumbstruck.  Nothing since (and I've seen through top-flight refractors up to 7 inches in diameter) has shown me that kind of detail.

 

 


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#332 Don Taylor

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Posted 13 July 2020 - 05:01 PM

Jethro, Thomas.

If you'd like - send me all the pieces and i'll go through it. And i can compare directy to my 102 f11 achro and 102f11ED. Plus I have a wide range of tools and lens spanners and access to a complete machine shop if needed. Plus I have several EQ mounts so can run multiple xcopes on the same tatgets.
I'll get to the bottom of it, report what i find and return to you.
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#333 Kunama

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Posted 13 July 2020 - 05:31 PM

Here’s my scope for the planets for this season.....18” F3.5 with Suchting Precision Optics primary , Ostahowski secondary and SIPS.... with a bunch of Delos eyepieces....

 

and seeing that this is the refractor forum, my backup scope is the 6”F7.9 TMB with some Russian OK4 glass...

 

 

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Edited by Kunama, 13 July 2020 - 05:32 PM.

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#334 ATM57

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Posted 13 July 2020 - 07:09 PM

What you really need is this beastie... and an Illudium Q36 Space Modulator is on order.

I've been trying to get one of those Space Modulators for decades! I even offered Marvin the Martian a Zeiss 40" APO in trade. How did you persuade the Martian to let go of one? I'm jealous 4.gif 



#335 Richard Whalen

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Posted 13 July 2020 - 09:36 PM

My planet killer this year is the same scope I used back in 1999 and every year since, TEC 8" f15.5 #2001 

 

If it aint broke dont fix it.....


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#336 vahe

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Posted 14 July 2020 - 09:23 AM

My planet killer this year is the same scope I used back in 1999 and every year since, TEC 8" f15.5 #2001 

 

Did you know this?  TEC 8” F/15.5 Mak is actually F/15.7, according to Yuri in a post #19789 tec-scopes@groups.io.

.

Vahe



#337 Richard Whalen

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Posted 14 July 2020 - 11:23 AM

Vahe, 

 

It can change according to focus and eyepiece used with moving primary. I think mine can vary from something like f14.8 to f16 or so with the eyepieces I use.

 

Mine is a bit different than the production models being the prototype. If I remember correcly there was one other like mine that went to europe for testing.


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#338 Echolight

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Posted 14 July 2020 - 11:25 AM

My 6 inch achro has been stellar on the planets so far. It's been killing it!

 

Will be getting the C8 tuned up and in on the action very soon.

 

And might ...maybe ....add a little 80 apo to join in on the fun as soon as I find the elusive deal on one.

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#339 25585

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Posted 15 July 2020 - 06:45 AM

Just to add a bit of confusion, I'd like to point out that #4 can also be correct in some cases (light coming from the left). This is called the Steinheil design. It's not as common as the common Fraunhofer design, but some EDs and Fluorites use it. 

 

 

Clear skies!
Thomas, Denmark

Tak FCs are Steinheil I believe (most importantly with their fluorite element as an inner one).



#340 vahe

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Posted 15 July 2020 - 09:12 AM

 

It can change according to focus and eyepiece used with moving primary. I think mine can vary from something like f14.8 to f16 or so with the eyepieces I use.

 

Mine is a bit different than the production models being the prototype. If I remember correcly there was one other like mine that went to europe for testing.

 

I am aware of the effects of moving primary in Maksutovs, my TEC6 for example is an extreme case, it is a native f12 but with primary moving back and forth it goes from f11 to f14 according to Yuri.

What I am finding rather strange is that in their design stage Maksutovs require very precise component spacing down to a fraction of a millimeter, but then with a moving primary all that is totally ignored.

.

Vahe


Edited by vahe, 15 July 2020 - 11:53 AM.


#341 luxo II

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Posted 16 July 2020 - 03:04 AM

Vahe, likewise, I haven't noticed any adverse effects from altering the mirror spacing to shift the focal plane +/- 30mm on a few occasions, though mine are Rumaks.



#342 Spot On

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Posted 24 July 2020 - 01:06 AM

So-- on these manual alt-az mounts (T-Rex/Discman/Rowan) can you move the scope without using the slow-motion controls? I'm assuming yes.

 

I'm in the market for a lightweight alt-az situation with slow-motion controls, but I'd rather have something scalable than have to keep trading up.



#343 luxo II

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Posted 25 July 2020 - 04:13 AM

The SW AZ5, Losmandy AZ8 and Rowan AZ100 all have nice slip clutches so you can push the scope where you wish. The slow motions are for fine adjustments and tracking at high power.

 

If you want something light the AZ5 is good, the AZ8 is heavier and the AZ100 even more so.

 

The AZ100 with encoders and Nexus DSC is the best bar none, for portable gear.


Edited by luxo II, 25 July 2020 - 04:15 AM.

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#344 Illinois

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Posted 26 July 2020 - 06:12 AM

My planet killer is 16 inch Dobsonian and SW 150 ED refractor. I like ES 5.5 mm 100 eyepiece for my SW 150ED and it’s 218 power.  It’s sweet power for most nights! 



#345 luxo II

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Posted 26 July 2020 - 06:43 AM

I'll see your 218X and raise you to 600X...


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#346 gnowellsct

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Posted 26 July 2020 - 02:59 PM

So-- on these manual alt-az mounts (T-Rex/Discman/Rowan) can you move the scope without using the slow-motion controls? I'm assuming yes.

 

I'm in the market for a lightweight alt-az situation with slow-motion controls, but I'd rather have something scalable than have to keep trading up.

Discmounts are worth considering (alt-az).  No slo mo needed. Very stable.  I use the DM6 with 5" apo.

 

But frankly if you want to settle in for planet viewing you are better off with a tracking mount.  

 

I got this one without tracking because I wanted it to FORCE me to simplify.  And it worked.  However, I only use it "from time to time."

 

Greg N



#347 gnowellsct

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Posted 26 July 2020 - 03:03 PM

I'll see your 218X and raise you to 600X...

I was having a good time viewing Jupiter at 180x through my 92mm CFF which handled the magnification with great aplomb.  

 

I thought about how I would attempt to draw what I was seen....some nice finely etched detail, hint of a festoon, and a long translucent worm running from the SEB up to just short of the North Pole, in a zig zag.  This is 0.51mm exit pupil for 180x.

 

Now in the C14 I could see much more at 224x.  And I was at 1.6 mm exit pupil and there was no translucent worm.    

 

So...I'm not too enthusiastic about ultra high magnifications.

 

Greg N


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#348 Jethro7

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Posted 27 July 2020 - 02:32 AM

Hello, Everyone,

I had a swell time tonight, viewing Jupiter and Saturn, with my AT102ED mounted on a AZ8. I mostly just use my Baader Zoom with Barlow on this scope. Viewing Jupiter at about 100X gave the best views.

Jupiter will be too low on the Horizon soon and the viewing will get tough. I still have that dog of a scope the Astro Telescopes 102mm Not so Super Planetary. That Thomas, was going try to help me fix it but never got back to me. oh well. I guess I will hang on to it maybe some day someone may have new set of lenses that I can buy and get it working.

HAPPY SKIES AND KEEP LOOKING UP Jethro

20200721 041549

Edited by Jethro7, 27 July 2020 - 02:34 AM.

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#349 213Cobra

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Posted 27 July 2020 - 03:40 AM

Have a good-seeing, steady sky tonight under the Los Angeles COVID-19-truncated-but-still-obscuring light dome. With Jupiter and Saturn so well positioned I took it upon myself to heave three scopes at the current planetary celestial theatre show:

 

Takahashi FOA-60Q f/15

LOMO 80/600 f/7.5

Takahashi FSQ-106ED w/ Q1.6X Extender for f/8

I even later brought out the RedCat 51 with Barlowed Baader Zoom (BBZ).

 

Did I need all those separate views? No, not in the least. But I wanted to remind myself that we should all be much more concerned about refining our observing acuity than buying more aperture. I say this because I am getting from the least of these apertures more revelation in Jupiter and Saturn banding than I got from larger optics 40, 50 and 60 years ago. Contrast is exquisite, right now;; air is steady; GRS and Cassini are unmistakable even at smaller apertures.

 

Phil


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#350 Starman81

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Posted 29 July 2020 - 10:39 AM

I was kind of shocked to read so many posts in the refractor forum (many from bona fide refractor enthusiasts​) advocating the use of their large aperture dobs/newts/SCTs for the purpose of 'planet killing'. So this was a really beneficial thread to me as it reiterated time and time again two very important lessons to keep in mind: 

 

1) Use the biggest aperture you have available to observe planets. Resolution and brightness count! 

 

2) Use binoviewers to observe planets. Two eyes are better than one!

 

To that effect, I dusted off my Ed Jones EQ Platform and got the STS 11 (my biggest gun) and the Denk BV'ers ready. The seeing was not great but the experience was still pretty awesome. 

 

With great hesitation, I post a picture of the rig here in the refractor forum! scared.gif

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