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150pl - is it really an apo killer?

Alan White

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Alan White

Alan White

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2 minutes ago, F15Rules said:

Hi Alan,

Don't know about being an Apo killer, but certainly a neck killer!??..

Dave

Dave on a equatorial mount I fully agree, but alt Az or dob, perhaps not a neck killer......but a back killer quite probably.

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ronin

ronin

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Many scopes claim the title but the reality is that few come close.

Scopes are often quoted on "The most" or "The biggest", it is certain that people buy a scope on one of the two conditions. Refractors do not reallly fall into either. They are not the most aperture or the greatest magnification. But a good apo will give the best image, and no-one really listents to that.

A mirror reflects all wavelengths equally so in that respect any mirror should be apochromatic, but there is also the quality of the resultant image to take into account. An apochromatic blur is kind of irrelevant so the quality of any mirror has to be taken into account. Now does a mas produced Skywatcher or GSO mirror match an OOUK one? That answer is easy - no it doesn't but the OOUK cost a lot more.

All objectives are a bit of a compromise. Is a parabola the best, Hubble is Hyperbolic, also a parabolic mirror is, from what I read, an approximation. The parabolising is performed on the center, so the edges are therefore spherical.

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nightfisher

nightfisher

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I always hear good things about the 150PL but not ever tried one, (strange) i think you might struggle on AZ mount due to length of tube hitting tripod, not sure if a long pillar extension would really help 

I often thought the GSO 150 F6 newt was a good compromise but in the real world a Maksutov is going to be very hard to beat

 

 

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John

John

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The nearest I've come to comparing the 2 scope types was when I owned an Intes MN61 6" F/6 maksutov-newtonian and the Skywatcher ED120 at the same time for a few months. The Intes would be at least as good as a good 6" F/8 newtonian I reckon  because it has a tiny central obstruction (19%), no secondary supports and excellent Russian optics. It's images really were "refractor like".

I compared these 2 scopes "back to back" quite a few times and found very, very little difference between them in planetary, lunar and double star performance. The 6" mak-newt did a little better on deep sky objects with the additional 32mm aperture scoring there.

In the end I decided to keep the ED120 because it cooled down quite a bit quicker and was lighter so easier to mount steadily.

The great thing about a standard 6" F/8 newt is that it's a relatively low cost item to buy and try. I've seen the Skywatcher 6" dobs for as little as £100 on the used market. Thats a lot of performance per £ :smiley:

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cotterless45

cotterless45

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I had a 150Pl and regretted parting with it. 6" f8 and 8" f6 are sweet spots for observing. For a standard SW , the planetary views, especially at opposition were wonderful. There's just something good about 1200mm which gives you a chance at required magnifications.

On an eq mount it was a lovely bit of kit, punching well above its cost. If you're dithering about getting one , go for it. I'd put on it par with my 102 M Vixen.

I wouldn't be making comparisons with apo's. It would be like comparing a Ferrari with a Fiat Panda. Both will get you to the same place, but the journey and looks you get might be different !

Nick.

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Chris

Chris

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Love my 6" f/8, for the modest sum they cost, I doubt you'd get better performance....maybe a 4" Mak would come close? I adore refractors but have to be completely honest in saying long newts are apo like - very contrasty due to small central obstruction, zero CA, and flat to boot! Only thing against is diff spikes on bright objects...that's it! 

I'm not sure I agree with the comments about them being uncomfortable? My most comfy setup is my 150p EQ3 which is very comfy as long as you have the focuser pointing away from the counter weight bar...I used to hate Newts on an EQ until I learned this trick!

 

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johninderby

johninderby

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The 150PL is pretty good. Great value for money. Had one but replaced the mirror and secondary with OOUK 1/10 pv ones. Now that really was a great little scope. Really noticeable improvement in performance over the stock mirror.

However the 150PL  is quite inexpensive and you won't go wrong buying one. 

          John

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Peter Drew

Peter Drew

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All Newtonian mirrors are apochromatic, the large part of the high price you pay for an apochromatic lens is to get it as false colour free as the mirror. Once that is achieved, the design characteristics of a refractor give it an edge over a similar aperture reflector.   :icon_biggrin:

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Alan White

Alan White

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24 minutes ago, Peter Drew said:

All Newtonian mirrors are apochromatic, the large part of the high price you pay for an apochromatic lens is to get it as false colour free as the mirror. Once that is achieved, the design characteristics of a refractor give it an edge over a similar aperture reflector.   :icon_biggrin:

Peter, at what price point does that happen?

Are we looking at a Tak or a Skywatcher?

 

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Moonshane

Moonshane

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I have a 120ED and a 6" f11 Newtonian with 1/10PV mirrors.

I love both and the newt probably edges the views of Jupiter and doubles in all honesty but I tend to use it far less than the 120ED. often the reason is that the 120ED remains out after solar sessions so I just keep using it. There's always more to consider than what's 'best'. The newt is a lot more cumbersome and fussy in the wind but worth the effort when I use it. I use binoviewers with both.

It's great to have both and for £160 used I'll not be parting with it - in fact this one is an 'upgrade' from the 1/6PV one I sold for £100!

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Peter Drew

Peter Drew

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13 minutes ago, Alan White said:

Peter, at what price point does that happen?

Are we looking at a Tak or a Skywatcher?

 

As quoted, similar quality, so in terms of, say, a OO high spec mirror and a Tak objective. A good 6" F8 Newtonian should match or beat a common 6" F8 achromat on lunar and planetary detail.   :icon_biggrin:

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John

John

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1 hour ago, Alan White said:

....Are we looking at a Tak or a Skywatcher?

 

Don't underestimate the Skywatcher ED refractors - my ED120 compares very well with my far more expensive Tak and TMB / LZOS refractors. Not outclassed at all :smiley:

Edit: I ought to add that I'm referring to the optics here. There is more of a gap between the scopes in terms of build and finish quality.

 

 

 

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Alkaid

Alkaid

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+ 1

I only sold my 6" F8 as it was too much of a handful negotiating stairs and sharp corners in a small house.  Other than that, it performed beautifully with regards to optics.  Didn't need much collimating either.  Being long, it does catch the wind and on a typical breezy night vibration was sometimes a distraction.  Mine was under-mounted on an EQ5.  It's ok on that mount...but a HEQ5 would be much better.

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