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New Ed Ting review of the AP 175

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#1 Darren Drake

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Posted 20 May 2013 - 11:53 AM

I have always enjoyed Ed's reviews and here is a new one of the AP 175.

http://www.scoperevi...om/page1ag.html

#2 Darren Drake

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Posted 20 May 2013 - 12:14 PM

The challenging double that made them decide to stop Zeta Bootis which he says is 0.8 arcseconds is as I have it a much more challenging 0.49 arcseconds. They should have kept going down the list....

#3 t.r.

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Posted 20 May 2013 - 12:23 PM

Good read, thanks for posting. "Its only competitors for this crown come from AP's other, smaller refractors, and perhaps one of the larger Takahashis like the FCT150"...I'm pretty sure the TEC 180FL I looked through could give it a run for its money though! ;)

#4 Kent10

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Posted 20 May 2013 - 12:54 PM

:) I was thinking the same thing about the Tec 180Fl. I have the Tec 160Fl and hope it is close. Would love to compare.

#5 Lynnblac

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Posted 20 May 2013 - 12:56 PM

Observed Saturn this weekend with a AP175. I agree with Ed's review, an excellent scope.

#6 Eddgie

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Posted 20 May 2013 - 01:33 PM

I like Ed's reviews.

I totally disagreed with his C9.25 review because based on his lofty praise, I bought one, and it was not at all satisfying to use.

But I do like his reviews in general and have passed some time reading them.

Not surprised that he would like the AP 175. Of course the optical quality would be outstanding.

But I doubt that it would be the best view ever. There are many larger, higher quality refractors out there that would do as well or better, I am sure.

There was a time when I really craved a big AP refractor, but Roland Christen talked me out of it. I said planetary performance was near the top of my list and he convinced me instead to go for a 10" custom reflector (which is what he uses.... LOL)

If I were into wide field imaging though, I would be willing to bet that this scope is perhaps at the very very very top of what a large refractor is capable of doing.

Most of the magic in this scope is not to be found by putting an eyepiece into it.

#7 Kent10

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Posted 20 May 2013 - 01:53 PM

Speaking of planetary performance, I have viewed Saturn each night and it is very nice. I can easily see the Cassini Division and various shades of yellow on the planet. I have only viewed from my neighborhood back yard and so the seeing may not always be the best with all the homes. I also think I see the moons quite easily. I keep wondering how much more there is to see through my Tec 160Fl if I do get better seeing, perhaps I should take the scope out of the city. What more can I expect to see with a 6.3" refractor? I realize I might have to be patient and wait for seeing to clear and I have only viewed for a few minutes at a time both mono and in a bino. Thanks.

#8 t.r.

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Posted 20 May 2013 - 02:11 PM

Well, even according to TEC (Yuri) and at least one CN'er, the difference on planetary between the TEC140 and TEC160 came down to slightly sharper clarity of Cassini's...and not much else. :p

#9 Kent10

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Posted 20 May 2013 - 02:25 PM

Right. Thanks t.r. I saw where Yuri said that. So I need a large SCT or reflector to have a chance at seeing much more, like detail in the rings?

#10 Mike Clemens

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Posted 20 May 2013 - 02:32 PM

From the review
"This is the best refractor I've ever looked through, and a good candidate for the best telescope I've ever seen, period."

"it was becoming obvious that the seeing conditions weren't going to allow us to go sub arc-second on this night."

curious combo : )

#11 vahe

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Posted 20 May 2013 - 03:04 PM

Not much substance in that review, Ed has written more in depth reviews in the past.

Vahe

#12 Dwight56

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Posted 20 May 2013 - 03:06 PM

I setup my AP 175 at Thunderbird Park last Saturday night that was May 18th at our Anual Saquaro Astronomy Club Public Star party. I had my AP 175 and 9mm Nagler trained on Saturn the whole night and the comments from the people moving through the various scope lines were amusing. There is really a slide underneath, hey this cannot be that good. to Oh My Gosh and so on. Saturn was showing a wealth of detail. Rings stood out real well, the disk was showing some really nice banding. Last thing before teardown we had to out of the park by 10pm was the moon showing all kinds of detail.

#13 jrbarnett

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Posted 20 May 2013 - 03:25 PM

I don't think so. Ring detail is highly seeing dependent. More often than not what you want is superior optical quality and moderate aperture (5" to 8") to start picking out ring structure details. Larger instruments are more affected by less than perfect seeing. Obstructed instruments are lower contrast than unobstructed ones.

Ergo, you need a moderately large well figured unobstructed scope for planets. Roland uses a 10 MCT of his won design for planets, it is true...but he's IMAGING them. For visual use, you can't do better than a premium quality big refractor for planetary detail.

- Jim

#14 Kent10

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Posted 20 May 2013 - 03:32 PM

Great Jim. Thanks. I do enjoy the view of Saturn but I also want more now. So I will keep looking and also look forward to the day I can take the scope to a nicer location. I have been learning about seeing by viewing the moon each night. I saw the Collins, Armstrong and Aldrin craters the other night but only for a couple of minutes. It was easy then but later I could not see them at all. Same with the Plato craterlets. Nearer full moon I could easily see 4 but the last couple of nights I can only barely make out something and that is because I know where to look. It should get easier in the coming days I think.

#15 johnnyha

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Posted 20 May 2013 - 03:42 PM

You cannot really test on a night of bad seeing.

#16 Mike Clemens

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Posted 20 May 2013 - 03:45 PM

> Ring detail is highly seeing dependent.

I had a 4" TMB with binoviewer, 1.7x corrector and fantastic 8.3mm olympus eyepieces under absolutely 10/10 sustained stable skies ONCE (the only time in 10 yrs I thought - these are absolutely perfectly stable skies) and the ring detail was impressive. I had viewed Saturn Many times before with the same scope but this was one step beyond. I started splitting doubles immediately and noted how I could place secondaries sometimes onto primary 1st diffraction rings and make them look like little pieces of jewelry with stones.

#17 Kent10

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Posted 20 May 2013 - 03:56 PM

True. I am just not sure yet what really good seeing is I think. I know really bad seeing and I have had some adequate seeing (I think). But I probably have never experienced really fine seeing and that is what I have to look forward to.

#18 Sgt

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Posted 20 May 2013 - 04:13 PM

I have read that beyond a certain size, the thermal inertia of a big slab of glass in a triplet become difficult to manage and become a limiter of performance. What is the experience of the big apo people?

#19 Mike Clemens

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Posted 20 May 2013 - 04:47 PM

I am sure it would be a problem if you have very limited viewing time, or no chance to thermally accomodate the scope. I have always given my scopes an hour or two outside in their case to come to temp. and I have only seen more and more detail as I have purchased progressively larger refractors. At some point (I say around 175mm), planetary details get markedly easier for my eyes.

#20 Kent10

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Posted 20 May 2013 - 06:15 PM

> Ring detail is highly seeing dependent.

I had a 4" TMB with binoviewer, 1.7x corrector and fantastic 8.3mm olympus eyepieces under absolutely 10/10 sustained stable skies ONCE (the only time in 10 yrs I thought - these are absolutely perfectly stable skies) and the ring detail was impressive. I had viewed Saturn Many times before with the same scope but this was one step beyond. I started splitting doubles immediately and noted how I could place secondaries sometimes onto primary 1st diffraction rings and make them look like little pieces of jewelry with stones.



Thanks Mike. I look forward to the day I have great seeing. Right now it is too convenient for me to view from my backyard. I can set up everything in under 5 mins. But when I have more time I will take the scope out somewhere dark and calm :) I am sure there will be a point where I won't be able to stand the poor seeing any more. It does cool down here pretty fast though because it is dry desert so I hope my Tec 160Fl can keep up.

#21 bratislav

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Posted 20 May 2013 - 07:20 PM

Not much substance in that review, Ed has written more in depth reviews in the past.


Star testing a refractor (even APO) using extrafocal images in polychromatic light is a monumental waste of time.

#22 jrbarnett

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Posted 20 May 2013 - 10:45 PM

That may well be, but I don't think there are any amateur triplets in existence large enough to put that proposition to the test.

- Jim

#23 clintwhitman

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Posted 21 May 2013 - 05:46 AM

Jim I agree with your "refractor being the best"!
Even though it happens only once in awhile. With the right seeing and the 228mm AP triplet refractor. Once you can break 600 power it is a game changer for viewing any of the planets!
I did like Ed's commentary of the way everything gets quiet and you start to breath deeply.
The 4 views I remember most have all been through refractors. Knee buckling views at 5/5 seeing
Jupiter in Robert Provins 7" AP at 500x
Jupiter in John Pons 10" Zeiss, Ganymede Transit at 650 Xs
Mars in The Pearl 9" AP at 720 Xs The Best, held for 1 hour.
Saturn in the Pearl at 750 Xs

(aveman

#24 t.r.

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Posted 21 May 2013 - 06:57 AM

Ya know, the seeing really can't be overstated as the limiting factor for planetary performance regardless of unobstructed aperture used. I have seen for myself, in average seeing a couple of times, where a 5" apo did as well as a 7" apo in side-by-side comparisons, where only the brightness of the planet differentiated the view. Having viewed through 3-7" apos, my most memorable view came from a 4" Genesis refractor while in Seoul, S. Korea. Known for its smog, this too means very stable seeing in the summers there and I had two fantastic sessions, one while viewing intricate micro detail on Jupiter at 260x in the Genesis (it wanted more magnification) and the other while viewing Saturn at opposition in an 8" SCT no less, at 325x...the rings looked grooved like a vinyl record! :bow:

#25 JimP

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Posted 21 May 2013 - 08:12 AM

Excellent report. Gorgeous telescope. I'd love to have one but, for the time being, I'll settle for my AP 130 GT.






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