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APM 10 MM Ultra Flat

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#1 Jeff B

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Posted 24 September 2017 - 11:01 PM

Finally spent some quality time with theses.  The short version is I very much like them (I used a pair in my Denk II and Mark V).  Indeed a flat field, low distortion, low scatter view right up close to the edge.  Very comfortable combination of eye relief and FOV, much better than my plossls and orthos.  Plays real well with the Denk Powerswitch, no/minimal blackouts.  Neutral in color tone, just like the 15 & 18mm jobbies.  

 

Enjoyed some great views via the TEC200ED of the moon, saturn, Vega, Deneb, Alberio...ranging from 180 to 400X (seeing actually allowed 400x overhead tonight).  No hint of EOFB either.

 

And best of all NO STUPID UNDERCUTS!!!!! 

 

I like them...a lot... and a nice high power compliment to my other eyepieces.

 

Jeff 



#2 Starman1

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Posted 24 September 2017 - 11:43 PM

And:

10mm focal length

60° field of view

16mm eye relief

Foldable rubber eyecup

5 elements in 4 groups

Blackened lens edges

14.7mm field stop

Fully multi-coated

1.25" filter threads

80g



#3 Mike Harvey

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Posted 05 October 2017 - 01:01 AM

I've heard comments to the effect that..."at that price, they CAN'T be very good"!

HA!

These oculars are putting some of the old "classics" to shame!

Do yourselves a favor and don't prejudge. You'll be cheating yourself if you do!


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#4 Peter Besenbruch

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Posted 05 October 2017 - 01:15 PM

Do yourselves a favor and don't prejudge. You'll be cheating yourself if you do!

That's what I like about eyepieces; there are quite a few gems hidden in the lower priced range.


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#5 gezak22

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Posted 05 October 2017 - 04:20 PM

...  Indeed a flat field, low distortion, low scatter view right up close to the edge.  Very comfortable combination of eye relief and FOV, much better than my plossls and orthos.  ...

Can you elaborate on the bolded part? Do you see more with the APM than with an ortho of similar fl? Which ortho were you using?

 

I'm not trying to start a flame war, I'm just curious.



#6 starbase25

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Posted 05 October 2017 - 05:30 PM

I've heard comments to the effect that..."at that price, they CAN'T be very good"!

HA!

These oculars are putting some of the old "classics" to shame!

Do yourselves a favor and don't prejudge. You'll be cheating yourself if you do!

I have tried the 18mm. A Televue Radian was better.

 

18mm APM - eofb / less than stellar edge performance

18mm Radian - No eofb / stellar edge performance

 

Cost-wise, the 18mm APM is only slightly cheaper  than the same 18mm Radian used.


Edited by starbase25, 05 October 2017 - 05:32 PM.


#7 Mike Harvey

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Posted 05 October 2017 - 11:23 PM

Hi Cliff... I'm wondering what scope, or binoculars you were using the 18mms with?

In my f/5.5 (120mm APMs) I find the UFs to be absolutely perfect to the edge. No color issues and tiny stellar points REMAIN tiny stellar points until they just disappear fro the field.

Were you using a shorter (or longer) focal ratio instrument?

 

Mike



#8 Sarkikos

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Posted 06 October 2017 - 05:51 AM

 

Do yourselves a favor and don't prejudge. You'll be cheating yourself if you do!

That's what I like about eyepieces; there are quite a few gems hidden in the lower priced range.

 

That's how I felt about the Paradigms, when I had them.

 

Mike



#9 PJ Anway

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Posted 06 October 2017 - 07:08 PM

Hi Cliff... I'm wondering what scope, or binoculars you were using the 18mms with?

In my f/5.5 (120mm APMs) I find the UFs to be absolutely perfect to the edge. No color issues and tiny stellar points REMAIN tiny stellar points until they just disappear fro the field.

Were you using a shorter (or longer) focal ratio instrument?

 

Mike

I have an 18mm UF that I purchased from Markus at NEAF this spring. I've only used it in my 110mm f/5.6 and it is sharp across the field. Been great for solar too.



#10 russell23

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Posted 06 October 2017 - 07:33 PM

 

I've heard comments to the effect that..."at that price, they CAN'T be very good"!

HA!

These oculars are putting some of the old "classics" to shame!

Do yourselves a favor and don't prejudge. You'll be cheating yourself if you do!

I have tried the 18mm. A Televue Radian was better.

 

18mm APM - eofb / less than stellar edge performance

18mm Radian - No eofb / stellar edge performance

 

Cost-wise, the 18mm APM is only slightly cheaper  than the same 18mm Radian used.

 

I agree.  And the 18.2mm DeLite is even better.


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#11 rockethead26

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Posted 06 October 2017 - 07:33 PM

I agree. My 18s are very sharp across the FOV in my APM 100s. My favorite EP. Comfortable and stunning views.

#12 starbase25

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Posted 06 October 2017 - 08:26 PM

Hi Cliff... I'm wondering what scope, or binoculars you were using the 18mms with?

In my f/5.5 (120mm APMs) I find the UFs to be absolutely perfect to the edge. No color issues and tiny stellar points REMAIN tiny stellar points until they just disappear fro the field.

Were you using a shorter (or longer) focal ratio instrument?

 

Mike

12 inch F/5



#13 Jeff B

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Posted 10 October 2017 - 11:50 AM

 

...  Indeed a flat field, low distortion, low scatter view right up close to the edge.  Very comfortable combination of eye relief and FOV, much better than my plossls and orthos.  ...

Can you elaborate on the bolded part? Do you see more with the APM than with an ortho of similar fl? Which ortho were you using?

 

I'm not trying to start a flame war, I'm just curious.

 

Sure.  With my 10mm Plossls and orthos, the AFOV is narrower and my eyes are tight, right up close the eye lens (I use bino-viewers).  I have to position my head very carefully to take in the the whole FOV.  With the 10mm UF, the AFOV is greater as is the eye relief and with that combination, I find it much easier to position my eyes over the lenses while still being able to view the field stops even though the UF's are more prone to black-outs if I don't hit the proper eye relief (though interestingly, the 1.3X and 2.0X positions of my denk power switch mitigates the black outs to a considerable degree, a nice surprise).   

 

Jeff


Edited by Jeff B, 10 October 2017 - 11:51 AM.


#14 gezak22

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Posted 10 October 2017 - 02:28 PM

 

 

...  Indeed a flat field, low distortion, low scatter view right up close to the edge.  Very comfortable combination of eye relief and FOV, much better than my plossls and orthos.  ...

Can you elaborate on the bolded part? Do you see more with the APM than with an ortho of similar fl? Which ortho were you using?

 

I'm not trying to start a flame war, I'm just curious.

 

Sure.  With my 10mm Plossls and orthos, the AFOV is narrower and my eyes are tight, right up close the eye lens (I use bino-viewers).  I have to position my head very carefully to take in the the whole FOV.  With the 10mm UF, the AFOV is greater as is the eye relief and with that combination, I find it much easier to position my eyes over the lenses while still being able to view the field stops even though the UF's are more prone to black-outs if I don't hit the proper eye relief (though interestingly, the 1.3X and 2.0X positions of my denk power switch mitigates the black outs to a considerable degree, a nice surprise).   

 

Jeff

 

So you are only commenting on viewing comfort, and on planets the Ultra Flat shows nothing that the orthos don't show, right?



#15 Jeff B

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Posted 10 October 2017 - 10:38 PM

 

 

 

...  Indeed a flat field, low distortion, low scatter view right up close to the edge.  Very comfortable combination of eye relief and FOV, much better than my plossls and orthos.  ...

Can you elaborate on the bolded part? Do you see more with the APM than with an ortho of similar fl? Which ortho were you using?

 

I'm not trying to start a flame war, I'm just curious.

 

Sure.  With my 10mm Plossls and orthos, the AFOV is narrower and my eyes are tight, right up close the eye lens (I use bino-viewers).  I have to position my head very carefully to take in the the whole FOV.  With the 10mm UF, the AFOV is greater as is the eye relief and with that combination, I find it much easier to position my eyes over the lenses while still being able to view the field stops even though the UF's are more prone to black-outs if I don't hit the proper eye relief (though interestingly, the 1.3X and 2.0X positions of my denk power switch mitigates the black outs to a considerable degree, a nice surprise).   

 

Jeff

 

So you are only commenting on viewing comfort, and on planets the Ultra Flat shows nothing that the orthos don't show, right?

 

Well, not quite.  The UF's show a considerably larger FOV that's highly corrected out towards the edge.   



#16 gezak22

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Posted 10 October 2017 - 10:44 PM

I get that, but I on axis, does the ultra flat show more planetary details than the orthos?



#17 Jeff B

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Posted 11 October 2017 - 02:59 PM

I get that, but I on axis, does the ultra flat show more planetary details than the orthos?

No, they are just as good in that regard as my U.O. HD orthos and I was specifically looking for differences in sharpness.  Low scatter with a neutral-to-cool color tint too, like the HD's as well.  My Silver Top Plossls are just as sharp with, perhaps, a little more scatter but also slightly warm in color tint in comparison.  I didn't see any differences really in limiting magnitude between eyepieces either, though I didn't spend a lot of time in that regard (one of my favorite tests is observing Saturn's moons, especially when they are close to the ring system or planet).  

 

I very much enjoy the 10mm UF's, at least in the contexts of the instruments used so far (TEC200ED, C11, TEC140ED, SW120ED)  all of which have fairly "slow"  focal ratios.  Ignoring seeing for the moment, I've found that the instrument(s) used for eyepieces comparisons and magnifications, are are very important when making comparisons.  

 

Jeff


Edited by Jeff B, 11 October 2017 - 03:10 PM.


#18 gezak22

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Posted 11 October 2017 - 05:06 PM

That sounds very encouraging.

 

I have a 10 mm Ultra Flat on order, and hope to find a 9 mm Pentax Ortho. I already have two other 10 mm orthos (Fujiyama, Zeiss 0.965") and hope to have a shootout between them in my 11" Edge (and 3x barlowed 5" Apo) as soon as conditions allow.

 

If the Ultra Flat keeps up with the others, I would happily keep the UF because of the eye relief.


Edited by gezak22, 11 October 2017 - 05:06 PM.



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