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New 152 MM APM APO in the house!

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#126 stevew

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Posted 12 August 2018 - 12:29 PM

Here is my test report, looks really close to the Stellarvue 70MM.

Judging by your test report, this scope is 1/4 wave with a .93 strehl, am I correct?

Is this type of figure typical of these APM152 ?


Edited by stevew, 12 August 2018 - 12:33 PM.


#127 janapier

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Posted 12 August 2018 - 12:37 PM

Judging by your test report, this scope is 1/4 wave with a .93 strehl, am I correct?

Is this type of figure typical of these APM152 ?

Shouldn‘t Strehl 0.93 mean better than 1/6 wave?


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#128 starman876

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Posted 12 August 2018 - 12:39 PM

Judging by your test report, this scope is 1/4 wave with a .93 strehl, am I correct?

Is this type of figure typical of these APM152 ?

I have seen a few test reports and they all look about the same.   For that kind of money considering what one is getting is not a bad price.  I cannot say I have seen worse for more money.  There is only one other 6" ED scope in this price range.  I would presume the lens would perform better with FPL -53 ed element, but than the price would be much higher.  This scope seems to be a compromise of performance and cost.  What I call a good engineering value.


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#129 Bomber Bob

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Posted 12 August 2018 - 12:42 PM

I ordered mine with the 2.5" focuser. Do you think it will have the same issue?

 

Nope.  The only thing I've seen with the small (50mm & smaller) current finder brackets is that some have a tab at the back of the base, but that can be filed down to slide all the way in -- and the mount has 2 thumbscrews to hold it in place.



#130 Bomber Bob

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Posted 12 August 2018 - 12:48 PM

APM tests / reports on 100% of the objective.  Based on posts here & elsewhere, other vendors don't do that.

 

The only disappointment I've had with mine has been just 4 decent sessions in 8 months, but even I can't blame APM for that.


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#131 Bomber Bob

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Posted 12 August 2018 - 12:51 PM

Judging by your test report, this scope is 1/4 wave with a .93 strehl, am I correct?  Is this type of figure typical of these APM152 ?

 

I think that's APM's minimum standard.  And again, APM tests 100% of the objective.


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#132 jay.i

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Posted 12 August 2018 - 01:02 PM

APM tests / reports on 100% of the objective.  Based on posts here & elsewhere, other vendors don't do that.

 

The only disappointment I've had with mine has been just 4 decent sessions in 8 months, but even I can't blame APM for that.

The only one I know of who wasn't testing at 100% was Stellarvue. I read maybe somewhere in the Vendor forum that this was apparently due to problems with their interferometer causing reflections within the lens cell or something, which has since been fixed, and now they do all of their tests at 100% OD? Yes it's great that APM does their tests at full aperture, though it doesn't make me want one of their 152s based on the results I've seen, but if I was in the market for a 6" refractor that didn't break the bank, it's on the short list of things to try. At that size of a lens, compromises have to be made, unless of course you don't mind forking over more hard-earned cash and maybe upgrading your mount for a triplet.


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#133 roadi

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Posted 12 August 2018 - 01:03 PM

Judging by your test report, this scope is 1/4 wave with a .93 strehl, am I correct?  Is this type of figure typical of these APM152 ?

 

I think that's APM's minimum standard.  And again, APM tests 100% of the objective.

Does this mean that measuring only parts of an objective is common or the norm? What about Rohr's site with tests reports, how can you tell how he's measuring? 100% area or only partially? shrug.gif 



#134 stevew

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Posted 12 August 2018 - 01:04 PM

Shouldn‘t Strehl 0.93 mean better than 1/6 wave?

I'm not sure, as I am not great with reading these test reports. That's why I was asking.

I have two Kuming United refractors an 80mm and a 110mm. The 110mm has a very good figure, and the 80mm is diffraction limited.

I always liked the fit and finish of the Kumning United scopes compared to other scopes in their price range.


Edited by stevew, 12 August 2018 - 10:07 PM.


#135 janapier

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Posted 12 August 2018 - 01:14 PM

I'm not sure, as I am not great with reading these test reports. That's why I was asking.

I have two Kuming United refractors an 80mm and a 110mm. The 110mm has a very good figure, and the 80mm is ok.

I always liked the fit and finish of the Kmning United scopes compared to other scopes in their price range.

http://www.rfroyce.com/standards.htm


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#136 hfjacinto

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Posted 12 August 2018 - 01:56 PM

I think 93 strehl is pretty good, my stellarvue says 97, but I’m iffy as to whether it’s 95 or 100% of the optics tested.
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#137 daquad

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Posted 12 August 2018 - 02:01 PM

Ok, Wednesday looks partly cloudy, although there is a good chance seeing won't be great. I'm going to set up the 152MM for visual. Here are the objects I am going to go to:

Moon

Saturn

Vega

Epsilon Lyra

IC 7662

M39

 

I'll also try to image the moon (as I won't be able to do visual and DSO AP).

 

I'm planning on using the following eyepieces:

31MM Nagler

20MM ES 100*

9MM ES 100*

5.5MM ES 100*

3.5MM Nagler

 

The diagonal will be the Baader Max Bright.

 

I might use a Celestron OIII filter for IC 7662

 

I'm not going to do 600 power or look for faint fuzzies, I'm 17 miles west of NYC the moon is a faint fuzzy wink.gif

 

Thoughts?

Helder, you will be surprised at how well M15, 13 and especially 22 are resolved with that scope.  

 

Dom Q.



#138 jay.i

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Posted 12 August 2018 - 02:32 PM

I think 93 strehl is pretty good, my stellarvue says 97, but I’m iffy as to whether it’s 95 or 100% of the optics tested.

On the SV Zygo reports there's a small box that says "OD %" which usually says 95 but might say 100 on yours.



#139 starman876

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Posted 12 August 2018 - 04:13 PM

When I see my APM 152 this week I hope the weather will be clear so I can check it out on Mars and Saturn.  I already know the  ES 127 triplet performs better than the AT102.  With the bigger aperture and being a triplet I am not surprised.  On the other hand that makes that ES127 for the price one of the better deals out there at $1000 less than the APM 152 ED.


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#140 Starman81

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Posted 12 August 2018 - 05:03 PM

Syed, 2 orders have been placed yesterday. Did you order your yet?

 

 

I gotta time it so I don't upset the CFO. wink.gif  But you've sold me.  smile.gif

 

Exactly! With another baby on the way (#2 for us) and having to get a bigger place soon, it's looking like Mission Impossible...

 

When I got my SW 120ED and saw what it could do and was thrilled, I told myself, 'observe with this for 10 years before going bigger'... It's only been 3 1/2 years...


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#141 hfjacinto

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Posted 12 August 2018 - 07:50 PM

Hey, as I read the Intellicast forecast, tonight should work just fine for the planets.  I'm just saying. grin.gif

Its been raining on and off all day, the only night and that is questionable is Wednesday.



#142 RAKing

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Posted 13 August 2018 - 09:32 AM

Exactly! With another baby on the way (#2 for us) and having to get a bigger place soon, it's looking like Mission Impossible...

 

When I got my SW 120ED and saw what it could do and was thrilled, I told myself, 'observe with this for 10 years before going bigger'... It's only been 3 1/2 years...

Smart plan!  I am going on nine years with a TEC 140 - maybe I should consider a bigger scope?  cool.gif  

 

Congrats on the coming addition!

 

Ron


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#143 rockethead26

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Posted 13 August 2018 - 09:34 AM

Smart plan!  I am going on nine years with a TEC 140 - maybe I should consider a bigger scope?  cool.gif

 

...

 

Ron

Nah!


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#144 SteveGR

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Posted 13 August 2018 - 10:13 AM

I have seen a few test reports and they all look about the same.   For that kind of money considering what one is getting is not a bad price.  I cannot say I have seen worse for more money.  There is only one other 6" ED scope in this price range.  I would presume the lens would perform better with FPL -53 ed element, but than the price would be much higher.  This scope seems to be a compromise of performance and cost.  What I call a good engineering value.

What do you mean by "perform better with FPL-53"?  If you're talking about color correction, okay.  If you are talking about lens figure, then no.  I ask because you were replying to someone citing the 1/4 wave and Strehl numbers.



#145 hfjacinto

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Posted 13 August 2018 - 10:56 AM

The 2 scopes I had tested the stellarvue and the APM both came in at 1/4 wave and 93 and 97 Strehl. Honestly I think the stellarvue was tested at 95%. Of all my refractors the 120 is probably the best (so far). Looking through various refractors including a few TEC 140 very few had much difference in view (and one Tec had to go back as it was badly miscollimated and had other issues). I would be surprise if the mass market scopes aren’t all in the same 1/4 ~90 strehl range. With the outliers being in the 80’s to mid 90’s. But since the vast majority (including the premium brands) aren’t tested we won’t really know the population variation.

#146 starman876

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Posted 13 August 2018 - 01:09 PM

What do you mean by "perform better with FPL-53"?  If you're talking about color correction, okay.  If you are talking about lens figure, then no.  I ask because you were replying to someone citing the 1/4 wave and Strehl numbers.

Better color correction would mean more of the image focused at the same point and would provide better detail of the image at the eyepiece.  A better figure would also help with doing that.  So I am not sure what you mean by your statement.



#147 hfjacinto

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Posted 13 August 2018 - 03:33 PM

The one item that I had to resolve with the APM 152 was because of the finder. Not that I use a finder much, but I like to have one. So this was my original finder (and I honestly hated this finder) as as soon I turned the scope it was no longer in alignment, also being 2 screws and a spring, it was never solid. The finder shoe being tight really pushed to get a different one.

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#148 hfjacinto

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Posted 13 August 2018 - 03:38 PM

Since I was using the 60MM finder as a guide scope and it worked really well, I decided to order the 50MM as a finder https://agenaastro.c...cuser-50mm.html . You do have to supply your own eyepiece. Since my largest 1.25" eyepiece is an 11 MM Nagler, it has to work.

 

The scope is 190MM Focal Length (f3.8) with the Nagler I get 5.61*

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#149 hfjacinto

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Posted 13 August 2018 - 03:39 PM

The dual rings along with the smaller shoe fit perfectly on the APM 152MM. Wednesday still looks like first light.

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#150 jag32

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Posted 13 August 2018 - 04:39 PM

Hfjacinto, would you mind sharing any photos of the finderscope on your APM152?




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