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APM 150ED review

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#126 edwincjones

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Posted 30 May 2019 - 04:41 AM

............

 

Would the majority of readers here prefer I only compare them to binoculars?  

 

Mike

I suspect that I am like most of the forum readers

that binoculars are my optics of choice

but our telescopes are in the background also

 

I havre posted before my joy of "discovering NGS 253 in 100mm binoculars,

but  seeing in a 22" dob was very impressive also

 

edj
 



#127 ZX12

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Posted 30 May 2019 - 08:39 AM

I can understand that the 12 with binoviewer was brighter and showed more of the planets, but...

What scope, 150 bino or 12 meade with binoviewer, produced the sharpest and cleanest image of the planets?

Binoviewers always degrade sharpness and contrast some amount.

I currently have the mark V and Siebert Elite 45. I also had the Denk 2 supersystem a couple of years ago. All of them cause a little less sharpness and contrast.

Xz 12, i salute you for a exelent thread.

Under ideal conditions the 12" with binoviewer is about equal in how clean and sharp the image of planets appears, but there is more detail seen with the 12" than the APM150.

 

The 150 is more capable than I expected on planets being an ED with a fast focal ratio, and the image quality is quite good at powers up to at least 165x when seeing allows.

 

I want to make sure it's understood that my comparisons are not in any way a definitive statement on what is better or worse, just simple observations under typical conditions here.

Each instrument has it's strengths and weaknesses and I adjust my expectations to allow for what is possible for the design.

 

Next up will be an AP160 that will be compared with and without binoviewers, and then later this summer a CFF 250mm classical cassegrain when it arrives.

 

Mike 


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#128 oldmanrick

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Posted 31 May 2019 - 11:16 AM

 

Would the majority of readers here prefer I only compare them to binoculars?  

 

Mike

Hi, Mike, like other posters, I find that the comparisons of your 150 bino, with various scopes, are interesting and provide information to learn from.

 

I would like to see more of them.

 

Rick


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#129 ZX12

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Posted 10 June 2019 - 09:54 PM

I think this will interest you Rick.

 

The past couple weeks have been limited for good skies, but I had two nights in a row last weekend with excellent conditions and minimal Moon interference.

 

I had an AP130 setup on the EQ mount to help determine how sharp the APM150ED is in excellent seeing.

 

The AP130's focal length is close enough to use similar powers, but I made a 140mm aperture mask for the 150's to bring the focal ratio closer to the 130 and help sharpen the image on brighter objects.

 

On stars brighter than 6th mag. the 150's are not as sharp as a high quality Apo due to slight flaring, possibly from the prisms. Dimmer stars appear close enough to the 130 that the mask is not necessary.

The aperture masks minimize the flaring on bright stars, and also cut back the glare on bright planets.

 

The 150's objectives appear to be well figured and show very sharp Airy Disks which I find not typical of binoculars, but more common in binocular telescopes. 

With the aperture masks in place I would put the 150's equal to the APM120 in regard to star sharpness at low powers and better than the 120 at high powers likely due to the well figured objectives.

 

I spent several hours in the early AM both nights viewing binary stars from 82x up to 275x, and was amazed at how well the 150's performed. The main difference to the 130 is a small amount of flare around the Airy Disks with the 150. Without the aperture mask the flare increases slightly, but not enough to blur the Disk.

Clean splits of binaries down to 1.8" separation are easy for the 150 and I'm sure it can do better.

 

Saturn was at it's highest for my region, allowing some good views at 165x using the 3-6 Nagler's despite the low angle. The image quality in the 150 was excellent. Not quite as perfect as the AP130, but more relaxed with both eyes.

Five of the moons were visible in the 150 at 103x, while the dimmest one remained elusive in the 130.

 

Another impressive view with the 150 was open clusters M11 and NGC7789 with the 12.5 Doctor's at 66x. The amount of tiny perfect looking stars in both is spectacular. 

NGC7789 actually looks very much like a rose, while M11 takes on a three dimensional quality that extends out much further than I've seen in smaller apertures.

That combination of power, field size and two eyes with the 150 is my favorite way to view open clusters in particular.

 

The Scutum region is incredible to pan across using the 14mm Delos at 58x. The 150 brings out the true density of stars that occupy this region. You can pan around for hours and lose track of time very easily.

 

There was also an interesing pattern of satellites moving past the bottom edge of M11 that took on the appearance of a triangular shaped ship seen from an angle.

 

I'm planning on the AP160 for the next session to see how bright the images are of DSO's compared to the 150's.

 

Mike   


Edited by ZX12, 10 June 2019 - 11:08 PM.

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#130 starzonesteve

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Posted 10 June 2019 - 10:03 PM

That was a great read, Mike. Thanks for sharing your experiences. I'm blown away by how good the 150s seem to be. I'm going to take the time to more accurately measure my IPD to see if I am close to being in the game with this instrument. 

 

I have only been able to split binary stars down to 1.0" arc second under pretty good seeing with my 20" quartz mirrored dob, so you are doing ridiculously well to make it to 275x while maintaining that kind of visual fidelity with these APM 150s. Just awesome!

 

Steve


Edited by starzonesteve, 10 June 2019 - 10:04 PM.


#131 ZX12

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Posted 10 June 2019 - 11:07 PM

Thanks Steve.

 

My 160mm refractor has split pairs down to 1" when seeing allows, but the APM150 is probably going to find it's limit with bright pairs closer to 1.5" and dim pairs possibly 1.2" is my guess.

 

The 140mm masks also remove the slight amount of color seen on the brightest stars as well.

 

Mike



#132 oldmanrick

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Posted 11 June 2019 - 12:01 AM

I think this will interest you Rick.

 

 

Indeed it does, Mike!

 

Seems like the more knowledge you gain about the 150 the more impressive it becomes.  Your descriptions of the views of Saturn and moons, and of star resolution in open clusters was particularly impressive, as was easily splitting binary stars down to 1.8".

 

I'm really wanting to get my hands on one of these 150's.  I'm probably going to give up on the SD version eventually, unless I hear something more positive about it becoming a reality.  The ED sounds so good that the extra money for the SD would probably be largely wasted anyway.

 

Thank you for taking the time and effort to make these comparisons, and to record your thoughts and observations about them.  It certainly gives the rest of us who are also interested in this awesome instrument a better picture of its capabilities.  Any and all information is greatly appreciated!

 

Rick



#133 ZX12

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Posted 11 June 2019 - 09:07 AM

Thanks Rick.

 

I'm also very surprised and impressed that the ED can perform this well, as I was not planning on using it to split binary stars or view the planets at high powers. 

 

It's worth stressing that while the APM150 is very capable optically, the seeing plays a larger part with an F/5.5 150mm in image quality compared to my slower F ratio Apo refractors.

I've experienced the same effect with an Espirit 100ED refractor. Excellent image quality at F/5.5, but much more prone to image breakdown than my Tak FS102 at F/8. 

 

What is interesting with the 150 despite the same fast F ratio, is that the critical focus zone is not as fussy as my smaller APM binoculars

   

The binocular prism plays a part in the final image quality as well, so the SD glass may not be the answer in getting that level of perfection the highest level scopes achieve. 

 

You certainly would have a hard time trying to see that difference in views of open clusters, galaxies and nebulae.

 

Mike

 


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#134 ZX12

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Posted 12 June 2019 - 10:03 PM

Another night of good seeing allowed some views of the double transit of Jupiter with the APM150, and also some time with the NPB filters to view the Veil Nebula and M27.

During mid transit I had the 6mm Delos in for 137x. I caught the second half of the transit because of some trees to the south blocked an earlier view.
Seeing improved at times to allow some amazing views of the two moons and their shadows.

 

The shadow of Ganymede was razor sharp, but the moon itself was indistinct from the planet until near the end of it's transit where it appeared as a white disk.
Io was visible for most of the transit as a white disk that stood out clearly against the planet. The shadow was clipped by the moon and was not as distinct when seeing dropped back.

There were moments when the detail level on Jupiter was so good that I counted at least 12 bands across the planet along with detail in the bands edges. When the seeing would peak out I could also see several of the white ovals.

Once the Moon set and darkness was back, I switched out to the 17.3mm Delos with the NPB filters and swung the 150 over to the Western Veil Nebula. Most of the nebula was very apparent and especially bright near 52 Cygni. 

I have only seen the filaments that clearly in larger reflectors, though not in such a relatively wide field. (1.5 degrees)

The Eastern Veil was even better. Rather than try to describe it, I adjusted one of my photos of the nebula to give the best impression that my memory can provide. Not as many stars visible, but as close as it appeared to the nebula itself.

Most of the filaments between were also visible as I panned across the two halves.

M27 was very bright and had strong definition with direct vision. It's hard to describe just how effective the filters are when coupled with a 150mm bino that keeps the image from getting to much background darkness, so I will again use a photo adjusted to match what I could see.

 

The field size is an estimate and star counts are less than what is in the photo.

 

Keep in my mind this is from an orange zone with limiting magnitude on the best nights around +5.8. 

Mike

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  • veil.jpg

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#135 oldmanrick

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Posted 12 June 2019 - 11:46 PM

Interesting!  I too was watching Jupiter last night.  With my 100mm Lunt APO ED, and 6.5 Morpheus (85X), I was able to see the shadow of Io during moments of the best viewing.  Also, during a few fleeting glimpses of great viewing I thought I saw the whitish disc of Io.  Also watched Ganymede emerge from in front of the planet.  At that time the shadow of Io was still about mid-planet, but way up to the north on Jupiters face.  I could only see two bands distinctly, and little to no detail.

 

Your 150's continue to impress!

 

Thanks for the writeup and photos.

 

Rick 



#136 winterprillan

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Posted 13 June 2019 - 12:06 PM

Another night of good seeing allowed some views of the double transit of Jupiter with the APM150, and also some time with the NPB filters to view the Veil Nebula and M27.

During mid transit I had the 6mm Delos in for 137x. I caught the second half of the transit because of some trees to the south blocked an earlier view.
Seeing improved at times to allow some amazing views of the two moons and their shadows.

 

The shadow of Ganymede was razor sharp, but the moon itself was indistinct from the planet until near the end of it's transit where it appeared as a white disk.
Io was visible for most of the transit as a white disk that stood out clearly against the planet. The shadow was clipped by the moon and was not as distinct when seeing dropped back.

There were moments when the detail level on Jupiter was so good that I counted at least 12 bands across the planet along with detail in the bands edges. When the seeing would peak out I could also see several of the white ovals.

Once the Moon set and darkness was back, I switched out to the 17.3mm Delos with the NPB filters and swung the 150 over to the Western Veil Nebula. Most of the nebula was very apparent and especially bright near 52 Cygni. 

I have only seen the filaments that clearly in larger reflectors, though not in such a relatively wide field. (1.5 degrees)

The Eastern Veil was even better. Rather than try to describe it, I adjusted one of my photos of the nebula to give the best impression that my memory can provide. Not as many stars visible, but as close as it appeared to the nebula itself.

Most of the filaments between were also visible as I panned across the two halves.

M27 was very bright and had strong definition with direct vision. It's hard to describe just how effective the filters are when coupled with a 150mm bino that keeps the image from getting to much background darkness, so I will again use a photo adjusted to match what I could see.

 

The field size is an estimate and star counts are less than what is in the photo.

 

Keep in my mind this is from an orange zone with limiting magnitude on the best nights around +5.8. 

Mike

Mike, are those pictures really accurate of what you did see of m27 and veil nebula, with the 150? In a orange zone?

That´s impossible. The detail is like from a photo.



#137 ZX12

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Posted 13 June 2019 - 12:42 PM

The photo shows more details than I can see by eye, but it is a close representation of the relative brightness of the nebula to the sky background as seen through the APM150 with NPB filters.

 

Without filters I can see the Veil, but it is faint most nights due to the brightness of the sky.

 

M27 is bright in the APM150 without filters, but with the NPB it really pops out and gives the nebula better definition.

 

I'm located in an orange zone according to the light pollution map, but my proximity to the ocean allows somewhat better skies than you would expect.

M31 is seen on the best nights, and I have also seen  M33 with averted vision a few times.

 

One of the most impressive views of the Veil prior to this was with the APM 70 at a very dark site in northern Maine. I didn't have any filters, yet the nebula was very prominent with good detail.

 

Mike




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