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Equipment Discussions >> Binoculars

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Rich V.
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Reged: 01/02/05

Loc: Lake Tahoe area, Nevada, USA
Re: MASTER CARD effect new [Re: Jarrod]
      #5653399 - 01/30/13 11:03 PM

Jarrod, I'd be more concerned about the alignment when the binocular focused at infinity. That's the reference the binos are aligned to.

As you focus on closer targets, your eyes must cross a little to merge each image to adjust for parallax, the closer, the more so. That happens with all binoculars; some more than others by design.

Do you see stars or the Moon double when you first put the binos up to your eye? Your eyes should be able to relax "just as if you were gazing out into space". No crossing or straining!

If you still feel you're straining to keep a merged image, don't hesitate to send them back.

Rich


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BobinKy
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Reged: 04/27/07

Re: MASTER CARD effect new [Re: Rich V.]
      #5653448 - 01/30/13 11:57 PM

Jarrod...

If I am not mistaken, you bought the Pentax 20x60 for viewing the night sky. Why not wait until you have a clear night and begin with viewing a bright star, planet, or the Moon. Then decide if you like the view.

To answer your question about the mastercard effect on close focusing--with the Pentax 20x60 I really do not remember, as I am always looking at targets 1000 yards away or in the night sky. If Stan says he sees the mastercard effect with his Pentax 20x60 and other binoculars at close focus, then that is good enough for me. The effect must be there--I have just not paid any attention to it. I guess I am more concerned about what I see than how I see it.

Relax and enjoy. You have 30 days for the trial period. And B&H Photo is an excellent online vendor who will work with you. You can also contact Pentax and ask them a few questions. Here is the link for Pentax Sports Optics: Customer Support. Remember Pentax has a very nice "Worry Free" warranty on their products.

Best of luck.


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Man in a Tub
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Reged: 10/28/08

Loc: Fogpatch, CA
Re: MASTER CARD effect new [Re: BobinKy]
      #5653477 - 01/31/13 12:39 AM

About three years ago, I received a query about this effect from a member who had just bought a Brunton Eterna 15x51. I had never thought to focus my 15-power Brunton inside my apartment. Sure enough, it was just like in the movies, and unlike my Celestron Skymaster 20x80 at the time, the Brunton was (and remains) collimated.

Using a high-power binocular for close viewing strikes me as almost the inverse of wanting fantastic views of planets — that is, a similar misuse with inevitable frustration.


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hallelujah
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Reged: 07/14/06

Loc: North Star over Colorado
Re: MASTER CARD effect new [Re: Man in a Tub]
      #5653509 - 01/31/13 01:24 AM

Quote:

Using a high-power binocular for close viewing strikes me as almost the inverse of wanting fantastic views of planets — that is, a similar misuse with inevitable frustration.




Todd,

Well shucks, I use more than one 20x binocular, close up, for backyard viewing of birds & squirrels and such.

I have yet to reach the point of frustration.

Thanks for pointing it out, now I know what I have been missing all these years.

BTW, if I want Fantastic Views of the Planets, with my 20x binoculars, I'll just hang one of my astronomy books
on my fenceline & view it from approx. 35'-40' away.

Stan


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Jarrod
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Reged: 01/20/13

Loc: SE USA
Re: Misaligned Pentax 20x60 PCF WP II ? new [Re: Jarrod]
      #5665941 - 02/06/13 08:04 PM

My p-mount arrived today (hurray) and there is some sky to look at tonight, so I was finally able to take these out for a look.

Junk. My initial reaction last week was correct. I saw two jupiters, partially overlapping, diagonally (so, very close together). But if I then defocus the right tube, the two jupiters snap FAR APART. A bit more than half the radius of the FOV, so somewhere between 0.5 degrees and a degree. If I then refocus the diopter while still viewing they *almost* snap back together. Amazing what the brain tries to do for you....

Back they go for another set. Wish me better luck this time.

Edited by Jarrod (02/06/13 08:05 PM)


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BobinKy
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Reged: 04/27/07

Re: Misaligned Pentax 20x60 PCF WP II ? [Re: Jarrod]
      #5665980 - 02/06/13 08:40 PM

Jarrod...

Sorry to hear about the condition of your first pair of Pentax 20x60. B&H should make this right--and I am sure they will. Please keep us posted.


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Jarrod
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Reged: 01/20/13

Loc: SE USA
Re: Misaligned Pentax 20x60 PCF WP II ? new [Re: BobinKy]
      #5689837 - 02/19/13 10:10 PM

Got the new set in this afternoon. How picky am I (should I) be? I took them out tonight and tested on Jupiter again...this set is much, much better than the first set. But it is not perfect. Still off by probably a tenth of a degree or so. The edge of the fuzzy defocused right eye image of Jupiter is juuust kissing up against the focused left-eye image.

There is quite a bit of CA when looking at Jupiter. A surprising amount, in fact. So far I'm not able to resolve the bands with this bino. The view of the moon was spectacularly sharp, though. Much more crisp than my Zhumell 25x100. My 12YO was particularly impressed by that view.

Bright stars are flaring quite a bit. I think I need a new eyeglasses prescription...it's been a couple of years and the astigmatism in my right eye has become worse than the current correction. So it's hard for me to say how much is the bino vs. my eyes. Faint stars are looking pretty good though.


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hallelujah
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Reged: 07/14/06

Loc: North Star over Colorado
Re: Misaligned Pentax 20x60 PCF WP II ? new [Re: Jarrod]
      #5690453 - 02/20/13 09:21 AM

Quote:

I think I need a new eyeglasses prescription...it's been a couple of years and the astigmatism in my right eye has become worse than the current correction.
So it's hard for me to say how much is the bino vs. my eyes.
Faint stars are looking pretty good though.




Do yourself a favor and get your eyeglasses updated.

Stan


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steveyo
super member


Reged: 03/13/12

Loc: Upstate NY
Re: Misaligned Pentax 20x60 PCF WP II ? new [Re: hallelujah]
      #5690646 - 02/20/13 11:11 AM

Just FYI:

I rcved a pair of the Pentax 20x60s from Adorama a couple days ago, and see no double image whatsoever on Jupiter, or Saturn. Wobbly because no tripod, but tack sharp, perfectly merged images.

My eyes are slightly and differently near-sighted, but no astigmatisms (yet).


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Jarrod
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Reged: 01/20/13

Loc: SE USA
Re: Misaligned Pentax 20x60 PCF WP II ? new [Re: steveyo]
      #5690683 - 02/20/13 11:34 AM

Steve - what I was speaking of was testing collimation by defocusing one tube relative to the other and viewing a bright point of light against a dark background with both eyes. This will cause your brain to not merge the two images, exposing even minor collimation issues (the dimmer, out-of focus blob should sit right on top of the sharp point of light if perfectly collimated). With both tubes focused, I don't see double with this replacement set. I did, however see pretty significant chromatic aberration when viewing Jupiter. Do you see any CA on jupiter through your set (and eyes)?

By the way, yesterday I stumbled on this review of the 20x60 PCF WP II by EdZ. I thought I should link to it here since it answers the original question I had about overlapping images at MFD on this binocular quite clearly. I'll quote the most relevant excerpt:

"The barrel images do not overlap at close focus, but almost no binoculars do. This has more to do with close focus than anything else and really has nothing to do with small exit pupil or collimation. Typical 20x binoculars, regardless of what is posted as close focus, have a real closest usable focus of about 75 ft. (20m). They will show the field circles of the barrels will not completely overlap at least out to 200 feet (60m). This is common to most binoculars, and especially prominent in higher powered binocs."

Edited by Jarrod (02/20/13 12:02 PM)


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steveyo
super member


Reged: 03/13/12

Loc: Upstate NY
Re: Misaligned Pentax 20x60 PCF WP II ? new [Re: Jarrod]
      #5690781 - 02/20/13 12:29 PM

Ah, got it. Sorry to have mis-understood. I did not notice much CA but I didn't give them a thorough test yet, either. I viewed the moon and then Jupiter in the daylight (which I was surprised to be able to view). In the dark, I viewed just Saturn, when I had a moment before my running partner arrived at 5:40AM. As I said, I had no tripod, so, even braced on a stump, the image was jumping with every heartbeat and breath.

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