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Equipment Discussions >> Binoculars

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Jarrod
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Reged: 01/20/13

Loc: SE USA
Misaligned Pentax 20x60 PCF WP II ?
      #5652628 - 01/30/13 04:01 PM

B&H just delivered. Unpacked the binos and wow, these are well built. Adjust the diopter, achieve focus, and no merging of the circles at MFD. Drat!

At 27 feet, the right tube points 5" to the right of the left tube. If I did my trig right, that means it's .88 degrees off.

Return them for a new set?

Edited by Jarrod (01/30/13 06:00 PM)


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BillC
on a new path
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Reged: 06/04/04

Loc: Lake Stevens, WA, USA
Re: Misaligned Pentax 20x60 PCF WP II new [Re: Jarrod]
      #5652642 - 01/30/13 04:06 PM

Oh, I've seen people happy with much worse than that! As A matter of fact, I'm selling some Ocean Front property just west of Ellsworth, Kansas to one of those guys, this week!

Send'em back; you shouldn't have to deal with that, especially on THAT bino.

BillC


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Jarrod
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Reged: 01/20/13

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Re: Misaligned Pentax 20x60 PCF WP II new [Re: BillC]
      #5652683 - 01/30/13 04:23 PM

Thanks. Yeah if I look at something far away I can merge the images reasonably well. Not sure I'd really have noticed in that case. But yeah, this set is kind of useless for watching birds in the back yard.

Now that I'm paying attention, my Leupold 8x50s are not perfectly aligned either. Probably also 4-5" at 27 feet. But I can merge it at the closer distances for some reason. Is it just the lower magnification? The bigger exit pupil?

I'm going to ask a dumb question. If you close the right eye, look through the left tube at an object, then look through the right tube and close the left eye, should the image be exactly the same if the binos are properly setup? Or is there supposed to be some separation, so your brain gets stereo?

Edited by Jarrod (01/30/13 04:32 PM)


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ronharper
Carpal Tunnel
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Reged: 02/14/06

Re: Misaligned Pentax 20x60 PCF WP II new [Re: Jarrod]
      #5652711 - 01/30/13 04:35 PM

The right barrel should point to a place a few inches to the right of the left barrel if they are parallel, that distance being simply the distance between the centers of the objectives. 5" sounds pretty reasonable, measure your objective spacing and compare.

Not saying you don't have a collimation problem! This distance thing is just not a good test for that, is all. Normal use will tell that much better.
Ron


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BillC
on a new path
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Reged: 06/04/04

Loc: Lake Stevens, WA, USA
Re: Misaligned Pentax 20x60 PCF WP II new [Re: Jarrod]
      #5652770 - 01/30/13 05:00 PM

Quote:

Thanks. Yeah if I look at something far away I can merge the images reasonably well. Not sure I'd really have noticed in that case. But yeah, this set is kind of useless for watching birds in the back yard.

Now that I'm paying attention, my Leupold 8x50s are not perfectly aligned either. Probably also 4-5" at 27 feet. But I can merge it at the closer distances for some reason. Is it just the lower magnification? The bigger exit pupil?

I'm going to ask a dumb question. If you close the right eye, look through the left tube at an object, then look through the right tube and close the left eye, should the image be exactly the same if the binos are properly setup? Or is there supposed to be some separation, so your brain gets stereo?




IF you can switch fast enough and
IF you were not allowing your Spatial Accommodation to get involved in the first place. Don't feel bad; I GUESStimate that that more than 80% of bino users are using instruments that are out of alignment, many of whom don't know binos NEED to be aligned.

BillC


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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: ronharper]
      #5652785 - 01/30/13 05:07 PM

OK, let me do a better job describing what I'm seeing, without jumping to any conclusions. Bear with me - I've never had anything more than an 8-power binocular...

When I'm focused on something at or near the MFD (25-40 feet or so), my brain *can* merge the two images. But I don't see a single circle, I see the "binocular mask" shape thingy that they use in movies to show that someone is looking through binoculars. So I see a stereo image in the center, plus partial left- and right-eye images on the left and right edges of the view. When I look at something farther away, I see a single circle - stereo from edge-to-edge. The view is perhaps ever so slightly oblong, or it could be my imagination...

Until today, I've never even thought about the fact that binoculars, unlike eyeballs, cannot change the point in space where they converge. So it makes intuitive sense to me that such artifacts could be possible. But I have no idea how 20x binocs are really supposed to behave in this regard.

And yes, the objectives are about 4.5" apart when set to my IPD of ~60mm. Which is the offset I measure between the left and right eye images when I alternately close my left and right eyes while fixed on an object 27' away.

Edited by Jarrod (01/30/13 05:14 PM)


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BillC
on a new path
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Reged: 06/04/04

Loc: Lake Stevens, WA, USA
Re: Misaligned Pentax 20x60 PCF WP II new [Re: Jarrod]
      #5652798 - 01/30/13 05:12 PM

"When I'm focused on something at or near the MFD (25-40 feet or so), my brain *can* merge the two images. But I don't see a single circle, I see the "binocular mask" shape thingy that they use in movies to show that someone is looking through binoculars."

At "25-40 feet" you are STILL crossing your eyes a little. And when you do, you will see that "'binocular mask' shape thingy that they use in movies." It's just optics doing what optics do.

Now look at a small target a mile or more away. If your bino is near collimation, the field stops wont be obtrusive.

BillC


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Jarrod
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Reged: 01/20/13

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Re: Misaligned Pentax 20x60 PCF WP II new [Re: BillC]
      #5652953 - 01/30/13 06:24 PM

Someone just clued me in to the term "Master Card effect". That is what I'm seeing. I have never seen that with a pair of binoculars before, but I have never critically looked through anything more than a 10x before today. It's getting dark and the weather is nasty. More looking tomorrow.

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BobinKy
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Reged: 04/27/07

Re: Misaligned Pentax 20x60 PCF WP II ? new [Re: Jarrod]
      #5652966 - 01/30/13 06:31 PM

Quote:


Return them for a new set?





Yes, do it tomorrow, without delay.


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Jarrod
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Loc: SE USA
Re: Misaligned Pentax 20x60 PCF WP II ? new [Re: BobinKy]
      #5652973 - 01/30/13 06:33 PM

Bob! So I take it from that comment you don't see the master card effect in your set, when viewing objects within 40-50' of you?

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BillC
on a new path
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Reged: 06/04/04

Loc: Lake Stevens, WA, USA
Re: Misaligned Pentax 20x60 PCF WP II ? new [Re: Jarrod]
      #5652998 - 01/30/13 06:48 PM

Bob:

Did you say anything about that, or simply suggest that Jarrod return the bino?

Jarrod:

You're welcome to reinvent the wheel all you want. However, the optical wisdom gained over that last 400 years suggest that you pick a REALISTIC distance--6,000+ feet and not 40 to 50. It DOES make a difference!

BillC


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BillC
on a new path
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Reged: 06/04/04

Loc: Lake Stevens, WA, USA
Re: Misaligned Pentax 20x60 PCF WP II ? new [Re: Jarrod]
      #5652999 - 01/30/13 06:48 PM

Bob:

Did you say anything about that, or simply suggest that Jarrod return the bino?

Jarrod:

You're welcome to reinvent the wheel all you want. However, the optical wisdom gained over that last 400 years suggests that you pick a more REALISTIC distance--6,000+ feet and not 40 to 50. It DOES make a difference!

BillC

Edited by BillC (01/30/13 06:51 PM)


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hallelujah
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Re: Misaligned Pentax 20x60 PCF WP II new [Re: Jarrod]
      #5653031 - 01/30/13 07:03 PM

Quote:

Someone just clued me in to the term "Master Card effect". That is what I'm seeing. I have never seen that with a pair of binoculars before, but I have never critically looked through anything more than a 10x before today.




It is noticable with my Pentax PCF WP 20x as well as my Pentax PCF WP II 20x.
Not as exaggerated with my Pentax PCF WP 16x60.

Very noticable with my Minox 10x44 Porro.

I experience it when focusing at the closest distances.

http://www.google.com/imgres?imgurl=http://criticsandbuilders.typepad.com/.a/...

Stan

Edited by Erix (01/30/13 11:48 PM)


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Jarrod
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Loc: SE USA
Re: Misaligned Pentax 20x60 PCF WP II ? new [Re: BillC]
      #5653070 - 01/30/13 07:32 PM

Not trying to reinvent the wheel. I'm sure these things are obvious to an expert but I am just trying to understand if what I'm seeing with this set is because of optics "doing what they do", or some alignment issue. Bob has this same set so I was curious if he noticed it as well.

I will do as you suggest when there is daylight and it isn't raining out. The furthest thing I can see from my window is less than 100 yards away, and although the effect is much reduced at that distance I don't believe it is completely gone.


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Jawaid I. Abbasi
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Reged: 06/19/07

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Re: Misaligned Pentax 20x60 PCF WP II new [Re: hallelujah]
      #5653072 - 01/30/13 07:32 PM

This is normal if viewing less then suggested. For a close look; buy Pentax papelio and you will nt see the effect.

It seems to me that the error is within the 150"-200" (correct me if I am wrong)

Edited by Erix (01/30/13 11:49 PM)


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Jarrod
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Reged: 01/20/13

Loc: SE USA
Re: MASTER CARD effect new [Re: Jawaid I. Abbasi]
      #5653088 - 01/30/13 07:42 PM

Thanks for confirmation Stan. Jawaid, yes I think you are right - the furthest I was able to look with these today was about 200' at most and while the effect was greatly reduced it isn't 100% gone at that distance. It sounds like this is the norm for this model and I simply shouldn't plan to bird with it in my backyard.

That's OK, I put the Canon 10x30 IS on my Amazon wishlist today


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hallelujah
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Re: MASTER CARD effect new [Re: Jarrod]
      #5653110 - 01/30/13 07:52 PM

Quote:

Thanks for confirmation Stan.

It sounds like this is the norm for this model and I simply shouldn't plan to bird with it in my backyard.




I have used my Pentax 20x60, for birdwatching, from my backyard, for many years;
maximum focusing distance, within my backyard, is approx. 60'.

I have no problems with the views.

Stan


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BillC
on a new path
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Reged: 06/04/04

Loc: Lake Stevens, WA, USA
Re: MASTER CARD effect new [Re: Jarrod]
      #5653125 - 01/30/13 07:57 PM

"the furthest I was able to look with these today was about 200' at most and while the effect was greatly reduced it isn't 100% gone at that distance."

So, if it is REDUCED at THAT distance, there's probably a chance that objects seen at more than a mile will be right on. And, if they're right on with you just staring, you're good to go. Many a problem has had it's origin in ill-formed opinion.

Good luck and happy viewing!

BillC


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Jarrod
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Reged: 01/20/13

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Re: MASTER CARD effect new [Re: hallelujah]
      #5653158 - 01/30/13 08:33 PM

Quote:

I have used my Pentax 20x60, for birdwatching, from my backyard, for many years;
maximum focusing distance, within my backyard, is approx. 60'.

I have no problems with the views.




Now that you mention it, I was clearly reading 12 point helvetica from 27' across the house, with the master card effect. I guess I could just ignore it. But then this removes an excuse to get the Canons

Quote:

Many a problem has had it's origin in ill-formed opinion.




Yes indeed.


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GlennLeDrew
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Re: MASTER CARD effect new [Re: Jarrod]
      #5653286 - 01/30/13 09:55 PM

Binoculars are (normally) axially aligned so as to be parallel at infinity. At close distances, parallax causes the image displacement you noted. This is perfectly normal.

Do not return until you verify collimation for a *very* distant target!


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