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Tinkering Beachchairbill

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#51 Gordon Rayner

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Posted 18 September 2010 - 12:07 AM

It is possible to work with a target which is closer than near-infinity, if necessary. The horizontal compensation required ( most people work with the binoculars horizontal) is an exercise in elementary surveying/trigonometry and map reading .

One can make use of a military binocular equipped with a mil scale reticle, together with a target of known dimensions, to calculate the range. A transit or theodolite would be the instrument of choice here, if available, for use with the known target dimension, if a map is not available.

I have used finite targets with 25 x 150. Using a 25 x 150 adjusted to have no measurable horizontal error at a distance of two or three miles, one can then view a target at a quarter mile, or even less, and note an apparent horizontal error of a tree top feature or a building feature, feature on a sign,etc. and record that information for future use on another specimen of the same binocular model, at the same magnification, on the same target.

#52 Mr. Bill

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Posted 18 September 2010 - 12:48 AM

Mr. Bill,

Yep and I forced them to take them back - I just mailed them back with a note at my expense.

BB


Begs the question about the snapped screw and other screw, if not factory then....hummmm ....beginning to have some doubts about Garrett's technical abilities.

Is Cory S. still doing the collimation/repair for Garrett?

:question:

#53 beachchairbill

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Posted 18 September 2010 - 01:12 AM

Mr.Bill,

You would have to ask Cory directly. He did work on my GBT, however I'm sure if he was involved with the collimation process. I do know that he worked on the crevasses but that is as far as I know.

Not sure how you would do the collimation or the equipment involved, however if you did it my way it would take up a lot of time and tender loveing care. I doubt that happend and I would love to know who used all of that blue hot glue and the reason behind it. From what I can tell it sure looks like they tried to cement every screw in place to make sure they never moved out of place. This sure speaks to the quality of the screws that were used.

Beachchairbill

#54 beachchairbill

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Posted 19 September 2010 - 12:29 AM

Hi everyone,

As of tonight the laser beam is dead center throughy both objective lenses. What a job and my patience have been tested on this tinkering project.

Now that I'm here what can I expect to see, better light performance, sharper images, double images and is center the best place to be when viewing through Big Gun Binoculars? Will try to get some of this information tomorrow after my daughters baby shower. She is expecting a boy on November 8. Can't wait to be a Grand Pa..

BB

#55 Rich V.

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Posted 19 September 2010 - 11:18 AM

Well, Bill, it turned out to be much more of an adventure than I expected it would be! Just for the heck of it does the laser stay centered as you swing the turrets through their IPD range? I hope their mechanics are sound and they remain square through their range of movement.

Now that each barrel is aligned on axis you've got them as good as they ought to be; hopefully your binoculars will provide their best sharpness and illumination.

Now the trick is to see how close the barrels are collimated to each other. Give the binoculars a good looking through and see if you have merging issues on distant objects. Take your time and make sure your eyes are relaxed when viewing. I'd expect a double image to some degree (hopefully small!) Using the technique described for the "eyeball collimation" you'll have to determine which way the right image must be moved to merge with the left image and make the necessary adjustment. It will take a bit more of your time and patience but when finished you should have your binocular working at its best.

Keep in mind that this final collimation of the barrels to each other will likely make one barrel slightly off the center mark again but that's just how it goes. There's no guarantee that both barrels will be perfectly mechanically aligned and a small compromise may have to be made for the final collimation.

Hopefully, after this last step, you'll just be able to enjoy your binoculars and your newfound understanding of their internal workings!

Good luck and start enjoying your big binoculars, Grandpa!

Rich V

#56 Gordon Rayner

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Posted 19 September 2010 - 04:15 PM

Can the rhomboid housings be de-linked easily (if necessary), such that they can be swung through arcs larger than the small arcs which are swung by varying the IPD from 56 or 58mm through 72 or 74mm?

If so, does the laser beam remain stationary, or nearly so, on a target screen in front of the objective, during large arcs of the rhomboid housings?

Are the field stops sufficiently well matched that one can use an edge-of- field target to check for alignment?


A JTII handheld comparator, or its equivalent, is the tool of choice for seeing at a glance the relationship of the left and right images of the distant target. With such a comparator , there is no need to use comparison of the target position at the edges of the two fields of view, relaxation of the eyes, patience, time, or fatigue.


Congratulations to coach/tutor Rich V.

#57 beachchairbill

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Posted 19 September 2010 - 08:48 PM

Rich V.

If anything the movement is with in the dot if that makes any sense on the in and out movement with the laser on.

I will check your second suggestion tomorrow.

Grandpa, that will take a little time to get use to.

BB

#58 beachchairbill

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Posted 19 September 2010 - 09:52 PM

Gordon,

Are you addressing your qusetion to me or Rich and yes many many thanks go out to Rich for his takeing so much time to coach and tutor not only me but many of the readers on this forum.

BB

#59 Jawaid I. Abbasi

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Posted 19 September 2010 - 10:36 PM

many many thanks go out to Rich for his takeing so much time to coach and tutor not only me but many of the readers on this forum.

BB


That is correct.

#60 Gordon Rayner

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Posted 19 September 2010 - 11:49 PM

Either of you. You have been through enough already. I was thinking about a general situation of this type.

#61 beachchairbill

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Posted 20 September 2010 - 12:41 AM

Gordon,

I now have more to go through so I will refer your question to Rich and if I can help I will add my comments.

Rich,

Since we are back on the subject I might as well tell everyone whah I found tonight.

Several replys ago, Rich asked me if I had any double images after my laser centering work. The answer to this question was resolved tonight. The answer is two fold YES and NO. More YES than NO and now I will explain. At my normal comfort viewing level I have double images both when looking at stars and Jupiter. I can get rid of the double images by pushing the focusers tight to my nose.

I did find that in viewing the star images that they had more sparkle and color than before and that Jupiter was sharper and the band that I could see at 20mm was darker and sharper overall. And yes I had the double window closed.

So my next question is how do I get rid of the double image and what is the process? When I wink I leave my right eye open if this helps.

I will assume that I will have to remove the focuser housing once again and readjust several of the screws. Which way and which ones or is their additional information required first. Lets get this done so that I can enjoy the fall night skies. Orion will be out my kitchen window with in the next hour.

Thanks

Beachchairbill

#62 EdZ

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Posted 20 September 2010 - 05:32 AM

Several replys ago, Rich asked me if I had any double images after my laser centering work. The answer to this question was resolved tonight. The answer is two fold YES and NO. More YES than NO and now I will explain. At my normal comfort viewing level I have double images both when looking at stars and Jupiter. I can get rid of the double images by pushing the focusers tight to my nose.

I did find that in viewing the star images that they had more sparkle and color than before and that Jupiter was sharper and the band that I could see at 20mm was darker and sharper overall. And yes I had the double window closed.

So my next question is how do I get rid of the double image and what is the process?



Unfortunately Bill, the process is that you need to undo what you did.

I stated earlier that you may be attempting this in vain. At least to some degree, that's what happened. It is not uncommon at all for conditional alignment to result in what you origianally saw, beams projecting dots slightly off center. When you had that condition, did you have merged images? By setting laser dots to the center mark you threw off the conditional alignment. You now need to reset it back to where it was or at least partially so.

I'd suggest you realign you binoculars by merging images on point sources. After doing so, go ahead and recheck the centering of the dots if you'd like. Obviously any movement will out of necessity have you find they are not centered. That's OK, leave it. You should be more concerned with merged images than with centered dots.

FWIW, if the mismatched non-merging is considerable, I would NOT attempt to correct all of this by moving one barrel only. If it is off by a lot, then trying to correct with one barrel is going to result in a cats-eye exit pupil and a considerable amount of vignette in that barrel. That's would probably account for why the laser dot images were not centered in both barrels in the first place.

edz

#63 Rich V.

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Posted 20 September 2010 - 10:56 AM

Bill, as I said before, getting each barrel individually aligned as best you can is only part of the picture. I pointed out earlier and Ed has reiterated (though a bit pessimistic, I think), for final binocular collimation, you will have to compromise one side a bit to get perfectly merged images when looking through the binocular. This is because the barrels of the binocular are probably not exactly mechanically parallel even though you have each individual axis very closely centered. One arc minute of mis-alignment is very noticeable at higher magnifications.

You said a few posts ago that when you swing the focusers as in IPD adjustment the dots remained "within itself" which I take as rotation, not moving in an arc. That's good as it means your turrets are aligned properly and square. Your binoculars will not be "conditionally aligned" after you've merged the images. There's no rotating "tilted" prism involved. That's the one saving grace of this design over adjustabe Porro II turret designs that do create "conditional alignment". The downside of this design is all the fussing you've had to do to get them right in the first place.

Getting back to the double image, you will now have to "un-align" one side very slightly to achieve binocular collimation and merged images. The easiest way is to determine which way the right image would have to move to merge with the left image (please re-read my instructions for this). You will have to open up the right side once again and make very small adjustments until you are satisfied that the images merge perfectly at your proper IPD so you're not unintentionally crossing your eyes. By now, you should have a pretty good idea which way the prism must tilt to move the image one way or the other. This will hopefully be a very small amount compared to the adjustment you had to make to center the individual axes, so you are not throwing the binoculars way off of their best individual alignment. The original alignment you did was not in vain, IMO; they should have been closer in the first place.

Be patient, you are almost there!

Rich V

#64 beachchairbill

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Posted 21 September 2010 - 12:52 AM

Rich V.

Your not going to believe this, however I've had to stop my collimation process because my Garrett 5000 tripod head is wobbeling all over the place. So much so that I had to remove the GBT from the tripod for fear that the head might fall off. I can't figure out how to tighten the turret that allows you to turn the GBT. It's like being on a rocking horse.

I will write to Zach in the AM and ask him for instructions on how to tighten the darn thing. I will not send them back for repairs.

What happend to the LUCK OF THE IRISH.

I was able to look at a target about a half mile away and noted that while looking through both ep's that the left ep shows the target at 8 o'clock a half inch from center and the right ep shoes the target at about 2 o'clock about a half inch from center. I will use the right tube to make my adjustements. Looks like I need to turn in, I think.

BB

#65 EdZ

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Posted 21 September 2010 - 06:02 AM

pull the entire center column out of the tripod. With the rubber cap removed from the bottom of the center column tube, look up into the bottom of the tube. There is probably a spreader nut inside, under the bottom of the top plate. There is in my Bogen. They get loose sometimes. Tighten it. You need a very long shaft with a socket head. I used an old rotisserrie shaft from a grill. Fit my 3/8 socket pretty close. Allowed me to get right up in there and tighten the nut. That was years ago. hasn't come loose since.

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#66 GlennLeDrew

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Posted 21 September 2010 - 12:28 PM

the left ep shows the target at 8 o'clock a half inch from center and the right ep shoes the target at about 2 o'clock about a half inch from center.


It would be better to estimate angular offset rather than expressing it in linear measure, such as "inches". The latter requires to know the effective distance from which the target appears. But this is essentially impossible to determine, as the eye's accommodation can place the image from as close as several inches to beyond infinity (if one is far-sighted or can relax the focusing muscles sufficiently.) A half inch at, say, 10 inches is a much larger angle than 1/2 inch at 100 feet.

A familiarity with the naked-eye size of the Moon--1/2 degree--supplies a ready-made estimator of angular offset. You need only mentally superimpose this mental image on the view. (By the way, the Moon's apparent angular diameter is very close to the size of an Aspirin tablet held at arm's length.)

#67 Rich V.

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Posted 21 September 2010 - 01:26 PM

It also helps to know what magnification you are using for your comparison.

1/2° apparent at 25x vs. 1/2° apparent at 75x is considerable. The higher the mag. the larger the displacement and the more accurately you can collimate, so use your shorter focal length eyepieces.

I use my 5mm (150x) eyepieces for collimation as they don't get much use otherwise.

Rich V

#68 beachchairbill

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Posted 21 September 2010 - 03:48 PM

Thanks ED
Thanks Gordon
Thanks Rich V

I used my 20mms last night before shake rattle and roll. Will look at the moon tonight if I can fix my tripod.

Most of my work will be done with the GBT on the tripod to save time. Hope EDZ's suggestion works.

Will check now to see if Zach answered my e-mail.

BB

#69 beachchairbill

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Posted 21 September 2010 - 05:22 PM

Hi everyone,

Received an e-mail from Garrett with directions on how to repair the tripod. ED you were close and I did check this nut, however it was nice and tight. Had fun making a device to handel my screw driver. Used the mast from one of the wooden ships that I am building the HMS Victory. Kenny would know a lot about this ship.

I was very pleased with the response from Garrett and here are the instructions that they sent to me with pictures.

"First, extend the center colum of your Series 5000 tripod several inches by turning the crank. Next, thread the head clockwise onto the 3/8" stud on top of the tripod center column until it is finger tight. Finally, look in the smaller of the two pockets inside the padded tripod case - you will find a small silver allen wrench that can be used to tighten the three set screws under the round plate at the top of the tripod center column ( see snap shots).

These instructions were right on the money and I also found another slide on plate that I can attach to one of my other binoculars - who knew.

Back in business

Beachchairbill

#70 daniel_h

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Posted 21 September 2010 - 05:24 PM

Bill which axis is wobbly on the tripod head have just received mine & it seems solid & also has levers for tightening
Post a pic maybe of the problem area & I'll offer advice if zac G hasnt got back to you

#71 EdZ

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Posted 21 September 2010 - 05:39 PM

Hi everyone,

Received an e-mail from Garrett with directions on how to repair the tripod. ED you were close and I did check this nut, however it was nice and tight. Had fun making a device to handel my screw driver. Used the mast from one of the wooden ships that I am building the HMS Victory. Kenny would know a lot about this ship.

I was very pleased with the response from Garrett and here are the instructions that they sent to me with pictures.

"First, extend the center colum of your Series 5000 tripod several inches by turning the crank. Next, thread the head clockwise onto the 3/8" stud on top of the tripod center column until it is finger tight. Finally, look in the smaller of the two pockets inside the padded tripod case - you will find a small silver allen wrench that can be used to tighten the three set screws under the round plate at the top of the tripod center column ( see snap shots).

These instructions were right on the money and I also found another slide on plate that I can attach to one of my other binoculars - who knew.

Back in business

Beachchairbill


Oh, so your head was coming loose. Different story altogether. I thought the whole top plate was loose and it was rocking in the center column.

edz

#72 beachchairbill

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Posted 22 September 2010 - 05:13 PM

Hi everyone,

EDZ, my head has been loose for many years. The Garrett Tripod 500 is back in working order and the GBT has been mounted on it once again.

Last night after coaching swimming, I decided to start the collimation process and here is how it went. I first took a look at Jupiter and its three moons to check how bad the collimation misalignment was and to note which tri screws had to be turned inside the right focuser and in what direction they needed to be turned. For this check I used the 20mm Meade EPs.

After I was satified that I knew the direction, I removed the 20mm ep from the right focuser and unscrewed the large screw holding the right focuser.

continued

#73 beachchairbill

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Posted 22 September 2010 - 05:20 PM

housing. I removed the housing from the GBT and had a look at the tri screws-scary. I started my adjustment by turning the 2 o'clock screws a quarter of a turn to the the left and reassembled the focuser and inserted the 20mm ep. Boy was I sweating this move. BINGO, Jupiter and itsthree moons had moved closer to the other Jupiter and three moons.

continued

#74 beachchairbill

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Posted 22 September 2010 - 05:25 PM

Now I was getting excited, however, it was back removing the 20mm ep, unscrew the large holder screw and then remove the focuser housing again.
I did this process four times before Jupiter was no longer a double image, however, I still had to contend with the three double moons.

continued

#75 beachchairbill

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Posted 22 September 2010 - 05:36 PM

At this time I decided to wait for ORION which would pass by my kitchen window later in the evening. When ORION arrived,
i concentrated my views on Betelgeuse which was a jewel in the night sky last night. My first peek immediately told methat I needed further collimation adjustment. By now you should know the drill and it took three additional tri screw adjustments until I had this yellow and red sparkling star merged. At this point I stopped to enjoy M42 for a while.

This whole process was performed with the kitchen window up.

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