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APM Ultraflat 30 mm: Initial impression

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#1 ThomasM

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Posted 13 December 2017 - 04:24 PM

Several month ago APM announced the a 30 mm 2" eyepiece of the Ultraflat series. After a lot of discussions and speculation about its unusal design

 

https://www.cloudyni...0-mm-questions/

 

the first eyepieces are now shipped,  I received a pair for binoviewing.

 

My initial  impression,  a very nice eyepiece, slim, almost the same size as the Baader Hyperion  2", a little bit larger aparent field of view. I am now waiting for a clear sky..

 

 

best regards

 

Thomas


Edited by ThomasM, 13 December 2017 - 04:27 PM.

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#2 junomike

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Posted 13 December 2017 - 05:32 PM

Several month ago APM announced the a 30 mm 2" eyepiece of the Ultraflat series. After a lot of discussions and speculation about its unusal design

 

https://www.cloudyni...0-mm-questions/

 

the first eyepieces are now shipped,  I received a pair for binoviewing.

 

My initial  impression,  a very nice eyepiece, slim, almost the same size as the Baader Hyperion  2", a little bit larger aparent field of view. I am now waiting for a clear sky..

 

 

best regards

 

Thomas

What will  you be  using them in?


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#3 Starman1

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Posted 13 December 2017 - 05:42 PM

Several month ago APM announced the a 30 mm 2" eyepiece of the Ultraflat series. After a lot of discussions and speculation about its unusal design

 

https://www.cloudyni...0-mm-questions/

 

the first eyepieces are now shipped,  I received a pair for binoviewing.

 

My initial  impression,  a very nice eyepiece, slim, almost the same size as the Baader Hyperion  2", a little bit larger aparent field of view. I am now waiting for a clear sky..

 

 

best regards

 

Thomas

The quoted field stop diameter is consistent with a 72° field of view.  They quote 70°.


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#4 rogeriomagellan

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Posted 13 December 2017 - 07:11 PM

 

Several month ago APM announced the a 30 mm 2" eyepiece of the Ultraflat series. After a lot of discussions and speculation about its unusal design

 

https://www.cloudyni...0-mm-questions/

 

the first eyepieces are now shipped,  I received a pair for binoviewing.

 

My initial  impression,  a very nice eyepiece, slim, almost the same size as the Baader Hyperion  2", a little bit larger aparent field of view. I am now waiting for a clear sky..

 

 

best regards

 

Thomas

The quoted field stop diameter is consistent with a 72° field of view.  They quote 70°.

 

Hi, Don.

 

Do you feel the same about the 24mm? Would you say that it has two or three more degrees?

 

By the way, I'm glad to see that they're available at EyepiecesEtc. applause.gif


Edited by rogeriomagellan, 13 December 2017 - 07:13 PM.

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#5 Starman1

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Posted 13 December 2017 - 07:47 PM

Yeah, the 24mm quoted field stop size is consistent with a 72 degree field, though they quote 65°.

These are eyepieces that need the flashlight test for AF and star timing for TF and field stop sizes.



#6 ThomasM

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Posted 14 December 2017 - 03:01 AM

 

Several month ago APM announced the a 30 mm 2" eyepiece of the Ultraflat series. After a lot of discussions and speculation about its unusal design

 

https://www.cloudyni...0-mm-questions/

 

the first eyepieces are now shipped,  I received a pair for binoviewing.

 

My initial  impression,  a very nice eyepiece, slim, almost the same size as the Baader Hyperion  2", a little bit larger aparent field of view. I am now waiting for a clear sky..

 

 

best regards

 

Thomas

The quoted field stop diameter is consistent with a 72° field of view.  They quote 70°.

 

The quoted field stop diameter is 38 mm, depending on the correction you expect 64,7 degree ( tangens condition) up to 72.6 degree ( constant angular magnification).  I performed the flashlight test and obtained 72.3 degree ( +/-1.5) .


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#7 ThomasM

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Posted 14 December 2017 - 03:03 AM

 

Several month ago APM announced the a 30 mm 2" eyepiece of the Ultraflat series. After a lot of discussions and speculation about its unusal design

 

https://www.cloudyni...0-mm-questions/

 

the first eyepieces are now shipped,  I received a pair for binoviewing.

 

My initial  impression,  a very nice eyepiece, slim, almost the same size as the Baader Hyperion  2", a little bit larger aparent field of view. I am now waiting for a clear sky..

 

 

best regards

 

Thomas

What will  you be  using them in?

 

A binocular telescope with EMS mirrors for 2" eyepieces.

 

Thomas


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#8 junomike

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Posted 14 December 2017 - 04:00 AM

Thomas, I wasn't sure as I recall you acquiring these

but was curious as to what you planned on using the 2"ers for.

I can wait for the unveiling....grin.gif



#9 lylver

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Posted 14 December 2017 - 05:41 AM

So, ... waiting for the review

this one should receive the name of "late ultra-flat" for everything... wink.gif



#10 Starman1

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Posted 14 December 2017 - 02:08 PM

 

 

Several month ago APM announced the a 30 mm 2" eyepiece of the Ultraflat series. After a lot of discussions and speculation about its unusal design

 

https://www.cloudyni...0-mm-questions/

 

the first eyepieces are now shipped,  I received a pair for binoviewing.

 

My initial  impression,  a very nice eyepiece, slim, almost the same size as the Baader Hyperion  2", a little bit larger aparent field of view. I am now waiting for a clear sky..

 

 

best regards

 

Thomas

The quoted field stop diameter is consistent with a 72° field of view.  They quote 70°.

 

The quoted field stop diameter is 38 mm, depending on the correction you expect 64,7 degree ( tangent condition) up to 72.6 degree ( constant angular magnification).  I performed the flashlight test and obtained 72.3 degree ( +/-1.5) .

 

Consistent with constant angular magnification, i.e. designed for astronomy!



#11 ThomasM

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Posted 14 December 2017 - 04:09 PM

Thomas, I wasn't sure as I recall you acquiring these

but was curious as to what you planned on using the 2"ers for.

I can wait for the unveiling....grin.gif

I am using the 2" eyepieces with this binocular telescope:

 

https://www.cloudyni...telescope-r3059

 

Thomas


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#12 junomike

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Posted 14 December 2017 - 06:01 PM

Thomas, I recall that thread and discussion but had totally forgotten about it. 

Absolutely stunning.  PM sent!



#13 ThomasM

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Posted 27 December 2017 - 06:33 AM

 

Meanwhile I could do a test under the sky, in a f/6.5 refractor the eyepiece is sharp to the edge, very nice. I compared it with a Baader Hyperion aspheric 36mm and Masyama 32 mm. No comparison, the egdge sharpness is very much better, the Masuyama on the other hand has a visibly larger field of view. Field stop of the APM UF 30 is very sharp. As you can see the size and weight ( 540 g) are similar to the Hyperion 36 mm. A key part of the UF 30 mm is the big entrance lens (40 mm diameter) of the reducer (it is not a Barlow type Smyth lens, it is a reducer!). In that sense the UF 30 differs from all other eyepiece on the market, it is a really new design. According to the designer, the first element is made of very high index glass, that might be the reason why it has a slight yellow cast.

All in all, a very nice eyepice, especially for binoviewing.

 

Thomas

Attached Thumbnails

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  • P1000731B_klein1.jpg

Edited by ThomasM, 27 December 2017 - 06:53 AM.

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#14 Tamiji Homma

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Posted 27 December 2017 - 10:27 PM

Thanks, Thomas for the review.

 

Can you comment on APM UF 30 inward focus distance requirement comparing to Hyperion Aspheric 36mm?

I am hoping that APM UF 30 can come to focus to infinity with my inward focus challenged binoscope.

 

Tammy



#15 Starman1

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Posted 28 December 2017 - 12:18 AM

Can't tell exactly, but it looks like the focal plane for the 30mm is below the shoulder by several millimeters.

As such, it should require out focus compared to eyepieces with their focal planes at the shoulder.



#16 lylver

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Posted 28 December 2017 - 02:34 AM

So ?

Any lateral color, pincushion, distorsion ?

what about color fidelity (saturation, except the light yellow cast you said)

approximative transmission versus similar EP ?

Try a defocus on a set of colored bright stars (Rigel, Fomalhaut, Vega, Capella ...), the common double Albireo.

A jump on M15 ...


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#17 rogeriomagellan

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Posted 28 December 2017 - 08:09 AM

 

 

Meanwhile I could do a test under the sky, in a f/6.5 refractor the eyepiece is sharp to the edge, very nice. I compared it with a Baader Hyperion aspheric 36mm and Masyama 32 mm. No comparison, the egdge sharpness is very much better, the Masuyama on the other hand has a visibly larger field of view. Field stop of the APM UF 30 is very sharp. As you can see the size and weight ( 540 g) are similar to the Hyperion 36 mm. A key part of the UF 30 mm is the big entrance lens (40 mm diameter) of the reducer (it is not a Barlow type Smyth lens, it is a reducer!). In that sense the UF 30 differs from all other eyepiece on the market, it is a really new design. According to the designer, the first element is made of very high index glass, that might be the reason why it has a slight yellow cast.

All in all, a very nice eyepice, especially for binoviewing.

 

Thomas

 

Thanks for the pictures, Thomas.



#18 ThomasM

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Posted 28 December 2017 - 11:53 AM

Thanks, Thomas for the review.

 

Can you comment on APM UF 30 inward focus distance requirement comparing to Hyperion Aspheric 36mm?

I am hoping that APM UF 30 can come to focus to infinity with my inward focus challenged binoscope.

 

Tammy

Tammy, no problem, the APM UF offers 4 mm more focus distance. What binoscope for 2" are you using?

 

Thomas



#19 ThomasM

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Posted 28 December 2017 - 11:56 AM

So ?

Any lateral color, pincushion, distorsion ?

what about color fidelity (saturation, except the light yellow cast you said)

approximative transmission versus similar EP ?

Try a defocus on a set of colored bright stars (Rigel, Fomalhaut, Vega, Capella ...), the common double Albireo.

A jump on M15 ...

The APM UFF hast some pincushion distorsion, I think it is intended because for astronomical application constant angular magnification is the best choice.

What do you mean with color fidelity/saturation?

 

Thomas



#20 Tamiji Homma

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Posted 28 December 2017 - 04:47 PM

 

What binoscope for 2" are you using?

 

Hi Thomas,

 

It is 95mm Swarovski spotting scope objective lens with EMS, compact, lightweight binoscope built by Matsumoto-san.

It is inward focus challenged and it has short 2" sleeve so long 2" nose piece eyepiece may not come to focus to infinity.

 

Tammy



#21 ThomasM

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Posted 28 December 2017 - 05:49 PM

 

 

What binoscope for 2" are you using?

 

Hi Thomas,

 

It is 95mm Swarovski spotting scope objective lens with EMS, compact, lightweight binoscope built by Matsumoto-san.

It is inward focus challenged and it has short 2" sleeve so long 2" nose piece eyepiece may not come to focus to infinity.

 

Tammy

 

Hi Tammy,

 

I saw the pictures, a very nice instrument. If the Baader Hyperion 36 gets into focus you should have no problem with the APM UFF 30 mm.

 

Thomas



#22 lylver

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Posted 29 December 2017 - 03:50 PM

 

So ?

Any lateral color, pincushion, distorsion ?

what about color fidelity (saturation, except the light yellow cast you said)

approximative transmission versus similar EP ?

Try a defocus on a set of colored bright stars (Rigel, Fomalhaut, Vega, Capella ...), the common double Albireo.

A jump on M15 ...

The APM UFF hast some pincushion distorsion, I think it is intended because for astronomical application constant angular magnification is the best choice.

What do you mean with color fidelity/saturation?

 

Thomas

 

Color rendition is essential when viewing with a big exit pupil. If the longitudinal & lateral color is mastered : you will get nice image like the panoptic gives.

If the chromatism is not well mastered, you will see luminosity difference but the target will not be colorful. It is a nice feature when viewing star cluster, or planetary nebulae. You can even reach galaxy colors for the brighter. M33 is nice when you start to get some of his colors (dobson 400+RKE 15). The blue snowball ... M57 lagoon.



#23 ThomasM

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Posted 01 January 2018 - 06:06 AM

 

 

So ?

Any lateral color, pincushion, distorsion ?

what about color fidelity (saturation, except the light yellow cast you said)

approximative transmission versus similar EP ?

Try a defocus on a set of colored bright stars (Rigel, Fomalhaut, Vega, Capella ...), the common double Albireo.

A jump on M15 ...

The APM UFF hast some pincushion distorsion, I think it is intended because for astronomical application constant angular magnification is the best choice.

What do you mean with color fidelity/saturation?

 

Thomas

 

Color rendition is essential when viewing with a big exit pupil. If the longitudinal & lateral color is mastered : you will get nice image like the panoptic gives.

If the chromatism is not well mastered, you will see luminosity difference but the target will not be colorful. It is a nice feature when viewing star cluster, or planetary nebulae. You can even reach galaxy colors for the brighter. M33 is nice when you start to get some of his colors (dobson 400+RKE 15). The blue snowball ... M57 lagoon.

 

I don't know if this answers your question. Meanwhile I had a change to look at the moon with a 160 mm  f/6.5 refractor. Very nice view, free of any coloured edges.



#24 lylver

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Posted 01 January 2018 - 09:19 AM

 


 

I don't know if this answers your question. Meanwhile I had a change to look at the moon with a 160 mm  f/6.5 refractor. Very nice view, free of any coloured edges.

Ok Thomas, thanks, it is partially helpful (identify only lateral color), i think we have to find it by ourselves.



#25 rex-racer

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Posted 01 January 2018 - 09:06 PM

 

 

Meanwhile I could do a test under the sky, in a f/6.5 refractor the eyepiece is sharp to the edge, very nice. I compared it with a Baader Hyperion aspheric 36mm and Masyama 32 mm. No comparison, the egdge sharpness is very much better, the Masuyama on the other hand has a visibly larger field of view. Field stop of the APM UF 30 is very sharp. As you can see the size and weight ( 540 g) are similar to the Hyperion 36 mm. A key part of the UF 30 mm is the big entrance lens (40 mm diameter) of the reducer (it is not a Barlow type Smyth lens, it is a reducer!). In that sense the UF 30 differs from all other eyepiece on the market, it is a really new design. According to the designer, the first element is made of very high index glass, that might be the reason why it has a slight yellow cast.

All in all, a very nice eyepice, especially for binoviewing.

 

Thomas

 

When you describe the performance of the EP - is this in bino mode or mono? I ask because some binos use a tele extender etc. before coming to focus.




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