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Are the new APMs worth it?

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#176 GamesForOne

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Posted 22 April 2014 - 12:12 PM

To be fair....I consider exact centering the star on the disc to be perhaps too stringent. My own criteria is the focused star should be superimposed on the disc, not necessarily centered.


Now you tell me. ;) The focused star is certainly superimposed with my sample.

As far as the rugged build...I think it's possible to build binoculars That are essentially "bulletproof" (and maybe these are) but still if you are going to use various eyepieces, especially high power, it would be nice to be able to tweak the binoculars to correct eyepiece centering errors.


The build is solid. The magnesium shell seems very rugged and yet it is lightweight. I guess time and experience will tell the tale.

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#177 GamesForOne

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Posted 22 April 2014 - 12:23 PM

Rich,

Those are all good questions. Please be patient with me as 1) I have 7 month old twins, and 2) my Pentax XW10s are the shortest focal length EP pair I have at present.

As I said, Powermates work with my Pentax XWs in this bino, so once I have a second 2.5x Powermate I should be in business with down to 4mm focal length. (Anybody here want to sell me a 2.5x Powermate, cheap? :grin:)

Not sure I understand what you mean by divergent vs. convergent error? Also, there is continuing contention as to whether a superimposed star image on the defocus of the opposite must be centered to indicate acceptable alignment.

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#178 Rich V.

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Posted 22 April 2014 - 12:27 PM


To be fair....I consider exact centering the star on the disc to be perhaps too stringent. My own criteria is the focused star should be superimposed on the disc, not necessarily centered.


Now you tell me. ;) The focused star is certainly superimposed with my sample.


The only way to know, as discussed in above posts, is to do this test with an object of known angular size like Jupiter at focus on both sides. Double stars of known separation are good as well. You can then fairly accurately calculate the amount of angular error to see if it is within the accepted (though fairly lax) JTII tolerances also linked above.

Edit: Please read the link to EdZ's collimation standards. He explains the difference between divergent error and convergent error. One you can cross your eyes to "fix" and the other you can't... ;)

Rich

#179 Mike Harvey

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Posted 22 April 2014 - 01:13 PM

This thread is starting to sound like a page from the US government's military procurement planning! (look up the mess we have with the F-35 'all-purpose' strike fighter).

This is a APO BINOCULAR we're talking about. It is not an APO BINOCULAR TELESCOPE (for which you might pay 2 or 3 times as much).

It's a really great product but it won't (like the F-35) do all things for all people in all situations.

I'm enjoying mine and continue to be pleasantly surprised at how good it is.

When Markus first talked about using extremely high power, he was simply trying to show that the lenses were really good. I never got the impression that he was bringing a "Super High Power" binocular to market.
It IS fun to run up the magnification to 150X+ just to show that it can be done...but that's merely a sideshow.

It IS a significant improvement over the "Semi-APO" version and is simply wonderful to use at realistic magnifications (in my book that's somewhere between 25X and 75X...but it can go higher). And jeez...how many among us would have even mentioned 75X and "binocular" in the same sentence before now?

If high-power planetary observing is what you want and expect, then why would you want a binocular? Even at 100X+ (in any instrument) you're not going to see much in the way of detail. Instead, you should buy a custom APO binocular telescope (just check your bank account first). I've used the lower-priced BT's on the market and none of them match up with the APM.

#180 maburas

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Posted 22 April 2014 - 01:48 PM

Well this thread sure got interesting real fast.

1, the old idea of easy adjustment the prisms by removing the shutter besides eyepiece holders was rejected by the manufactur because:
-The binocular is also sold to Militar and have been designed waterproofed...yes the binocular is called now waterproofed
-Militar required strong collimation stable design."


I was under the impression the APO binoculars were designed and manufactured specifically for APM as a custom order?

Also, I recall the product page on APM's site saying the binoculars are "not gas [assuming they mean nitrogen] filled". I'm still something of a beginner, but my assumption based on the way I've seen binoculars advertised is that waterproof binoculars are sealed (pressurized) and filled with nitrogen. Assuming the above statement about them being waterproof is correct, does that imply that APM orders them without the waterproofing option, or perhaps that the initial production run wasn't waterproofed, or is there something I'm missing?

Product page for reference: http://www.apm-teles...-aperture-an...

#181 GamesForOne

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Posted 22 April 2014 - 01:49 PM

If high-power planetary observing is what you want and expect, then why would you want a binocular?


Why not? Why do I need APO objectives for a 25x view?

I explained one of my reasons behind wanting to use the binos at higher magnification in an earlier post. No, it will not be my only planetary instrument, but it will be one of them. My area of the USA often doesn't support 200x+ due to poor seeing anyway so why waste my time setting up a telescope, eq mount, etc.?

Also, I might want higher mags on other objects like globs or galaxies to resolve more detail.

If I can consistently merge an image at 100x with these I will be satisfied. If I can go higher I will be very pleased. I haven't been able to test such yet with my sample as I do not have the necessary EP pair(s).

Furthermore, the first words on the APM web page description for these binos:

"This binocular is made for very high power use."

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Michael Mc

#182 Mr. Bill

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Posted 22 April 2014 - 01:51 PM


To be fair....I consider exact centering the star on the disc to be perhaps too stringent. My own criteria is the focused star should be superimposed on the disc, not necessarily centered.


Now you tell me. ;) The focused star is certainly superimposed with my sample.
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Michael Mc


Your defocused disc is larger than I normally use. My defocused disc would be about half the diameter of your illustration and your focused star would be slightly off the disc.

The only pair of binoculars I have or had since I began using this test several years ago (other than my BinoBox which I can obviously tweek in easily) is my trusty Fuji 10x50s. Those are dead nuts centered... on axis.

:cool:

#183 garret

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Posted 22 April 2014 - 01:53 PM

If high-power planetary observing is what you want and expect, then why would you want a binocular? Even at 100X+ (in any instrument) you're not going to see much in the way of detail. Instead, you should buy a custom APO binocular telescope (just check your bank account first).



A 105mm Bino telescopes is yours for Euro 8300,-, yes 5300,- MORE then the APM 100mm APO bino!
And still we are not satisfied.

Garrett

#184 Mr. Bill

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Posted 22 April 2014 - 01:57 PM

One up ya....$40K includes drawer full of ep pairs.

This is the owner of S&S Optica at 2012 Okie-Tex SP.

:shocked:

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#185 GamesForOne

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Posted 22 April 2014 - 01:59 PM

Your defocused disc is larger than I normally use. My defocused disc would be about half the diameter of your illustration and your focused star would be slightly off the disc.


I've tried to explain this twice already... The focused star never moves off the disc. As I increase or decrease the defocus size, the focused star image moves with it and the relative distance of the focused star from the center of the defocused disc to the edge stays the same.

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#186 Mr. Bill

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Posted 22 April 2014 - 02:12 PM


Your defocused disc is larger than I normally use. My defocused disc would be about half the diameter of your illustration and your focused star would be slightly off the disc.


I've tried to explain this twice already... The focused star never moves off the disc. As I increase or decrease the defocus size, the focused star image moves with it and the relative distance of the focused star from the center of the defocused disc to the edge stays the same.

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Michael Mc


Sorry...need to go back and review earlier posts again.

Next clear night I'll play around with the BinoBox and see if I can duplicate this.

#187 Rich V.

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Posted 22 April 2014 - 02:22 PM


Your defocused disc is larger than I normally use. My defocused disc would be about half the diameter of your illustration and your focused star would be slightly off the disc.


I've tried to explain this twice already... The focused star never moves off the disc. As I increase or decrease the defocus size, the focused star image moves with it and the relative distance of the focused star from the center of the defocused disc to the edge stays the same.


Yes, the relative distance of the focused star from the center of the de-focused star should be the same. However, at some point closer to focus, the disk of the de-focused star will become so small that the two images must change their relationship and eventually diverge into two separated points when both are at focus. Of course if the focuser somehow changes the axial relationship between sides as it is turned to focus, all bets are off.

I still like comparing both sides in focus.

Rich

#188 Mr. Bill

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Posted 22 April 2014 - 02:24 PM

Further clarification from Markus...

1, CA…yes the new Bino use FK61 and not Fluorite and yes it is 100 mm and not 82 mm ….but in-focus the new 100 mm is same color free as the 82 mm fluorite and it does NOT show the CA to your eyes as shown with the I-Phone ! There fore I stay by my statement , the shown CA is not from the Bino but from the imaging set up behind the bino.

2, The collimation test we do at 100 x , we do with a set of tested eyepieces at infinity star. The collimation is perfect enough, when you look into the eyepiece set and there is not even a fraction of a second, where your eyes moving to merge…you look in and it is from first moment a relaxed view. It proofed that such collimation is also good enough for higher power like 150 x …still it might be the case that it does not 100% perfect match the Rich V. performance test requirements…..but non of the other high end binoculars does this match and it is not needed .

3, the big prisms are in fact mounted that there is no place for any movement in any direction. Therefore if somebody get a misaligned bino of this model where stars do not merge , than it left this way our place and we will show responsibility

#189 GamesForOne

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Posted 22 April 2014 - 02:43 PM

Yes, the relative distance of the focused star from the center of the de-focused star should be the same. However, at some point closer to focus, the disk of the de-focused star will become so small that the two images must change their relationship and eventually diverge into two separated points when both are at focus.


As I focused any separation was imperceptible to my eyes. The points merge with the Pentax XW10. Perhaps higher magnification would reveal some separation, but with the 10mm EP it looks pretty good to me.

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#190 Rich V.

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Posted 22 April 2014 - 03:05 PM

Well, Michael, if it merges naturally at these mags I certainly wouldn't give it further thought.

There are only two reasons to be concerned about collimation in binoculars; one is you see double images, the other is you see merged images but you're getting a headache or feeling strain because your eyes are straining to merge even though you may not realize they're doing it.

If this isn't happening, there's nothing to be concerned about at this point... ;)

Enjoy,

Rich

#191 Mr. Bill

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Posted 22 April 2014 - 03:09 PM


Yes, the relative distance of the focused star from the center of the de-focused star should be the same. However, at some point closer to focus, the disk of the de-focused star will become so small that the two images must change their relationship and eventually diverge into two separated points when both are at focus.


As I focused any separation was imperceptible to my eyes. The points merge with the Pentax XW10. Perhaps higher magnification would reveal some separation, but with the 10mm EP it looks pretty good to me.

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Michael Mc


Sounds like you don't have a problem merging, so if it was me, I'd call it good enough (at least at 60x) which is as far as I care to go with magnification in a binocular, as I stated in a post above. After that, binoviewers.

The thing that puzzles me about your test is that if the two focused stars ARE separated as in Rich's test, the center of the defocused star shouldn't shift position.

In my test, as one star is defocused to a disk, the edge of the disc "grows" and reaches a point where the edge of the disc is coincident with the focused star.

This doesn't seem to be the case with your observation where the defocused disk center moves as you increase the size of the disc, maintaining relative position as opposed to absolute position.

Am I missing something?

:question:

#192 Mr. Bill

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Posted 22 April 2014 - 03:36 PM

2, "The collimation test we do at 100 x , we do with a set of tested eyepieces at infinity star. The collimation is perfect enough, when you look into the eyepiece set and there is not even a fraction of a second, where your eyes moving to merge…you look in and it is from first moment a relaxed view. It proofed that such collimation is also good enough for higher power like 150 x …still it might be the case that it does not 100% perfect match the Rich V. performance test requirements…..but non of the other high end binoculars does this match and it is not needed ."


But wouldn't an objective, repeatable metric such as my test be better than what appears to be a highly subjective determination that is anecdotal at best?
This depends on a judgement, not measurement.

3, "the big prisms are in fact mounted that there is no place for any movement in any direction. Therefore if somebody get a misaligned bino of this model where stars do not merge , than it left this way our place and we will show responsibility"


Who makes the final decision as to whether its collimated or not? Back to an "opinion" vs. metric that both parties can measure.

#193 Gordon Rayner

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Posted 22 April 2014 - 05:48 PM

Deja vu: Everybody who gets into this topic at this depth should have either a JTII rhomboidal image combining comparator, or equivalent, and/or a reversed binoviewer with its eyepieces removed and a weak colored filter added to one side to aid image pathway identification .



Mr. Ichiro Kamakura was the president or chairman of JTII during its later years, ( Kamakura Koki make the Fuji and Nikon 14 x 40 stabilized(,but not the Fuji gyro Stabiscope), the M22 second-tier military 7x 50,and many other binoculars, in Japanese, Sino-Japanese, and perhaps other(Filipino? Korean?) environments)probably after the 50s or 60s heyday of the oval yellow stickers "JTII Passed".

Have Chinese copies of the JTII comparator yet appeared?If they have been produced, but not offered for sale to the general public,the reason for such a situation should be obvious.

#194 Mr. Bill

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Posted 22 April 2014 - 06:16 PM

Deja vu: Everybody who gets into this topic at this depth should have either a JTII rhomboidal image combining comparator, or equivalent, and/or a reversed binoviewer with its eyepieces removed and a weak colored filter added to one side to aid image pathway identification .


Right, Gordon.... :john:

#195 GlennLeDrew

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Posted 22 April 2014 - 06:36 PM

Gordon beat me to it.

Relying on eyes alone to assess collimation is truly hit and miss. I've learned this the hard way after 20 years of tweaking, fixing, designing, building and using binos. What might seem fine initially could end up being off sufficiently to induce eye strain.

I recommend to build your own collimation checker. (More below.)

Or use a reversed binoviewer, as Gordon points out. However, rare is such a device which exactly superimposes the two images it delivers when reversed. If such image separation is present, you should account for this when checking your bino's collimation.

A collimation checker, or comparator, can be made from a small mirror and piece of glass. Each lies immediately behind an eyepiece, tilted at the same 45 degrees, and mutually parallel. You look throught the clear glass for a direct view, and the other image is sent over by the mirror, reflected from the clear glass and hence merged with the direct view. To better balance image brightness (not strictly necessary), a filter could be placed ahead of the clear glass so as to attenuate the direct image.

The simplest construction results from dimensioning to your own IPD. Adjusting the comparator simply involves looking at any distant source through it alone. Tilt either element until image fusion occurs. A useful device could be taped together plastic or card stock--seriously.

The clear glass can be a microscope slide. The mirror could be cut from a larger one; even a second surface type should not introduce a sufficiently strong double reflection as to sow confusion.

I'm shocked to read of Markus relying on eyes alone to assess collimation.

I assert again my firm belief that any bino employing interchangeable eyepieces should incorporate no-tools user collimation. This can be executed such that on one side only up-down adjustment is possible, and on the other only left-right. This guarantees that it's *utterly impossible* to naively introduce a systematic miscollmation. My next two bino projects (120mm and 127mm, for club members) are designed to effect collimation thusly, via small external knobs, one for each side.

#196 Andresin150

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Posted 22 April 2014 - 06:45 PM

I wish I where in your club Glenn!

#197 Gordon Rayner

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Posted 22 April 2014 - 07:16 PM

If one searches with Nuer and/or Dinka, either with the CN searcher, or with the enhanced Google search for CN, photos of a JTII in my custom housing( with JPL surplus titanium screws,no less!) and some right angle prism plus beamsplitter prism homemade comparators, similar to the ones Glenn just discussed, can be seen.

My homemade ones superimpose two halfmoon shaped beams. One is waxing,and the other is waning. These function, but the full round superimposed beams from the JTII are more comfortable, and can cover a larger IPD range around a chosen midpoint interpupilary distance.

JTII made 58 or 60, 64 or 65, and 70 or 72mm versions. I have only the 64 or 65mm version. The larger the exit pupils under test, the wider the IPD range around the midpoint which can be tested.

#198 Mr. Bill

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Posted 22 April 2014 - 07:21 PM


I'm shocked to read of Markus relying on eyes alone to assess collimation.


Agreed...but my test allows a quick quantitative, repeatable check. I don't think the end user wants to have to build special equipment to access collimation.

#199 Rui Caratão

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Posted 22 April 2014 - 07:21 PM

Photos from Iphone could be inducing CA, some compact cameras also induce CA with my ED spotter specially if I use the camera zoom. However I am eager to know how the new APO handle CA above 100x....usually ED glass that is not fluorite or have Fl elements starts to show CA above 100x if induced properly.

For those who never experienced the semi-Apo, wich are the reasons for the former dont handle high mags, besides CA? Collimation? to much spherical aberration degrading resolution and overhall image?

#200 Rich V.

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Posted 22 April 2014 - 07:33 PM

I don't think the end user wants to have to build special equipment to access collimation.


But maybe it would be worthwile for someone in Markus' position to build a collimation jig for his shop since he's in the business of selling binocular telescopes.

Think of the confidence it could inspire from his customers to know their BTs had been "Checked for precise collimation on our shop's comparator before shipping". ;)

Rich






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