Scott Hamilton
super member
Reged: 05/22/03
Posts: 144
Loc: Germany
|
|
The Binoculars I'm using (KRONOS 20X60's) were
purchased used at a Garage sale so I have no idea
what kind of treatment they might have received
in the past.
I have always had a problem lining them up with a
celestial object by sighting over the longitudinal
rotation pin and then bringing the binos into position
for viewing. It has always been necessary to move them
to the left to actually see whatever was aimed at.
Delving into this problem a bit deeper has brought a
unexpectied finding. Lining the binoculars up on a
long thin vertical object such as a pole and then
bringing them back into alignment with my eyes results
in the left ocular striking the bridge of my nose.
The binos have to be rotated to the right which of
course causes the target object to move out of view to
the left.
Could this be a collimation problem? I have noticed a
small wedge shaped dent on the front retaining ring which
screws onto the barrel indicating that the binos were
dropped and landed on the sharp edge of something.
I can find no collimation screws of any kind and presumably
the binos would have to be taken apart for this problem to
be addressed. What would the risks be if I were to attempt
this myself?
Scott
--------------------
49 53 5 N
08 16 1 E
GSO 8" Dobsonian Reflector
KRONOS 26 x 70 Binoculars
|
EdZ
Professor EdZ
Reged: 02/15/02
Posts: 12601
Loc: Cumberland, R I , USA42N71.4W
|
|
Scott,
First question is how much are these binoculars worth?
$100, $200, $400???
That will help you evaluate your risk.
Now to address the potential collimation problems.
It is very possible to have the images in the two barrles aligned with each other while the barrles themselves may be severely out of alignment with the mechanical axis.
If one of the barrels is bent due to a drop, that barrel is no longer in line with the mechanical axis. In order to align the images, the image in the other barrel would need to be adjusted off the optical axis to align with the barrel that is off the mechanical axis. Not a good situation. The end result of this situation would be images that could be merged, but they are bent at an angle to the mechanical axis and optical axis.
You mentioned that you cannot find collimation screws. Are the binocs covered with rubber or a leatherette covering. If so, the screws might be covered by this outer layer. I have found this to be true of several pair of binocs that I own. It is also possible that the prism ajustment screws are inside on the prism shelf.
If the barrel is bent, then image alignment will never solve the off-axis problem.
If they were once dropped and knocked out of alignment, it is possible that someone adjusted them to re-align the images by adjusting the wrong barrel. In this case two wrongs don't make a right.
To get back to the risk, you are only at risk for what you paid. You would not want to dismantle the binocs without a book showing some diagrams.
If the barrel is bent you will not be able to correct the problem.
If the barrel is not bent, then
If the prism tilt screws are inside on the prism shelf probably you will not be able to correct the problem, but the problem can be fixed by a repair service.
If the prism screws are on the outside, you would need to remove some of the outer coating to get at them.
Read the articles in the CN Reviews How To section describing collimation. Those articles show where toi look for the collimation screws.
edz
--------------------
Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
|
Scott Hamilton
super member
Reged: 05/22/03
Posts: 144
Loc: Germany
|
|
Hi Ed,
thanks for the assessment. I guess the binoculars have a
street value of around $25, but the replacement cost is more
like $150. That's what is giving me pause.
That and the fact that there are no visible collimation screws
on the outside of the barrel housing. The outer surface is aluminum
with a leather-like surface treatment, so there is nothing to trim
back. This is whiy I surmised that the binocs would have to be taken
apart.
I'll check the article - I did give a cursory view before I
discovered that I had this problem. Now I will be motivated
to read it more closely.
Scott
--------------------
49 53 5 N
08 16 1 E
GSO 8" Dobsonian Reflector
KRONOS 26 x 70 Binoculars
|
EdZ
Professor EdZ
Reged: 02/15/02
Posts: 12601
Loc: Cumberland, R I , USA42N71.4W
|
|
Scott,
The risk is not so great in value, so if you do decide to go inside, do not disassemble the eyepieces from the eyepiece end of the binocs.
This next procedure describes how to get inside. Do this ONLY if you cannot locate prism tilt screws on the outside of the body AND you can determine that the barrel is not bent AND you want to try to re-align by yourself.
Look down the hole where the tripod adapter screws in to hold binocs when mounted. Deep down inside that hole you will see a screw. You need a long thin screwdriver to get at it. That is the screw that holds the entire eyepiece assembly onto the binoculars. Loosening that screw allows you to turn the focus dial as if you were focusing the eyepieces "out" until the shaft screws completely out.
Getting them apart is easy. Putting them back together is tricky. You first need to insert the shaft into the focus wheel and screw it in to a point where you can then insert the retainer screw thru the tripod adapter screw hole and tighten things up. But here is the trick. You may need to screw the shaft in several times and stop one turn shorter each time until you end up with the proper range of focus from close to infinity. How close focus you get may not matter to you, but if you can't achive focus at infinity after you have put them back together, you need to unscrew the retaining screw and make a small adjustment. Trial and error, no serious risk.
Once you have the entire eyepiece assembly off, you can take off the prism housing covers. In order to align the prisms in binoculars that do not have external prism adjustment screws, you need to re-install the eyepieces while the prism housing covers are removed. This will allow you to see thru the binoculars to perform the alignment while you have open access to the prisms. The prims are strapped to a shelf. the shelf is screwed in place inside the binocular body. But the prism shelf will also have prism tilt screws. These are the screws you want to get at.
IMO, you will find screws under the covering on the outside of the binocular, even if you need to break thru the covering or peel back a portion of it. I think you should exhaust all attempts at this before you go inside. However, for $25 worth of equipment, a little experimentation won't hurt.
edz
--------------------
Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
|
Scott Hamilton
super member
Reged: 05/22/03
Posts: 144
Loc: Germany
|
|
Hi Ed,
well I spent about 1,5 hours with by binoculars and your collimation article as well as your posts in front of me, and I have come to the conclusion that KRONOS has taken great pains to prevent ham-fisted amateurs from getting anywhere near the critical components of their products. There is protection after protection built in every step of the way.
There are definitely no adjustment screws anywhere on the outside of the housing. I scraped of the black crinckle/crackle finish at a few suspect points where there appreared to a bit of unevenness or a bubble but all I did was to remove point - nothing underneath.
After removing the little round cover disk from the front of the rotation pin I was confronted ba another disk (by the way there is no 1/4" hole for a mount adaptor). There were two holes at opposite sides of the disk about 1mm in diameter and the teensy-weensiest set screw I have ever had the displeasure of having to deal with. I got it off with one of my jeweler's screwdrivers in the hope of being able to rotate the disk by putting a pointed object into one of the holes and moving it laterally.
Well, as you can expect, it wouldn't budge and it seems obvious that KRONOS does not want anyone without special tools getting past this point. The same is true of the objective lenses - there are retaining rings which are screwed onto the inside diameter thereby compressing the lenses onto a stop to hold them in place. Again the arrangement is two slots at opposite sides of the rings.
I suppose I could slant a screw driver into one of the slots and tap it with a hammer but I don't remember reading anything to the effect that this would allow anything useful to be done, as all of the interest seem to revolve around the prisms.
So I guess the only thing left to do is to try and find an address where I can have them checked out by a professional.
I certainly thank you for your kind assistance and hope I can return the favor in some form some day,
Regards,
Scott
--------------------
49 53 5 N
08 16 1 E
GSO 8" Dobsonian Reflector
KRONOS 26 x 70 Binoculars
|
**DONOTDELETE**
|
|
this bino is collimated by eccentric objective lens bearings. There are no adjustment screws.
kind regards
|
Simon S
super member
Reged: 01/07/07
Posts: 110
Loc: Crawley West Sussex UK
|
|
Before you do any of this, I would check the objective bells have not cross threaded. I know this binocular and they are not that strong.
Below is a picture of your binocular and where to check for cross threading.
Hope this helps.
Edited by Simon S (11/26/08 10:22 AM)
|
binman
member
Reged: 09/16/08
Posts: 95
Loc: UK
|
|
they are indeed collimated with eccentric rings around the objective there are no adjustment screws for the prisms, as simon says the objective bells could well be damaged from a fall or just miss threaded, they may also just be loose or undone slightly. i doubt the prisms are to blame as theres nowhere for them to go if they are securely clipped and punched in place.
--------------------
opticron "imagic" BGA SE 8x42 roofs plus
helios "apollo" 15x70 porro's mounted on a
manfrotto 055xb tripod with 501HDV head
|
EdZ
Professor EdZ
Reged: 02/15/02
Posts: 12601
Loc: Cumberland, R I , USA42N71.4W
|
|
I remember this conversation being more recent. dates must have been altered somehow.
BTW, this binocular pictured above looks nearly identical to a Celestron 20x80 Giant that I own. Don't know if it is the same or not. Mine is about 10 years old. It has no prism screws AND it has no eccentric rings.
Basically the particular model Celestron Giant that I own has no means of collimation adjustment. The lens can be moved in the metal lens cell by removing the entire cell from the front of the binocular. The retaining ring that holds the objective lens in place is on the INSIDE of the metal cell. After loosening the retaining ring, the objective lens can be wiggled perhaps a fraction of a mm to one side or the other. By trial and error adjusting both objectives got it very closely merged.
edz
--------------------
Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
|
GlennLeDrew
professor emeritus
Reged: 06/18/08
Posts: 633
Loc: Ottawa, Ontario, Canada
|
|
I've taken apart a Kronos 20x60 with no problems whatsoever. The prisms are mounted to a shelf which is integral to the body housing. In manufacture, besides the usual squaring-up of each prism pair, foil shims are used to remove residual angle errors inherent to the prisms themselves. Now, this was a while back, but I seem to remember that the prisms were not 'locked' rotationally with cement or by punching the edge of the recess. They were held in place by a *very* stout length of spring steel bearing down on the prism's apex. It did seem to me that a forceful shock *could* cause a prism to slip a small amount within its recess. But I wouldn't be surprised if the objective's eccentric adjustment could accommodate this, as long as a prism was not rotated about the optical axis (resulting in image rotation.)
--------------------
Home-made 11X50 right angle bino, 8.1 deg. FOV
Modified 26X100 bino, 3.5 deg. FOV
Mediocre minds discuss people. Good minds discuss events. Great minds discuss ideas.
|
DJB
Pooh-Bah
Reged: 02/23/05
Posts: 1269
|
|
Hi Ed,
That is amazing that there is no means of collimation! Perhaps the mfg. tol. were so tight not to require much in the way of adjustments. Anyway, you got it right.
Also, I never knew that Celestron made such a (large) binocular in the European configurtion. I thought most, if not all, were of the "American" design.
Best regards.
Dave.
|
Simon S
super member
Reged: 01/07/07
Posts: 110
Loc: Crawley West Sussex UK
|
|
These Kronos binoculars do have collimation adjustments, I too am amazed that some do not!
|
BillC
on a new path
Reged: 06/04/04
Posts: 2111
Loc: Washington, USA
|
|
Quote:
These Kronos binoculars do have collimation adjustments, I too am amazed that some do not!
You have a right to be . . . You're wrong!
The first ring you see, is applying thrust pressure on eccentrics.
Just a thought.
Bill
PS thoughts of Kronos and precision do not belong in the same sentense! 
--------------------
William J. Cook, Chief Opticalman, USNR-Ret.
Founding Editor, Amateur Telescope Making Journal
20-year vet. of Captain's Nautical Supplies, Optics Dept. Mgr.
Optics Machanic, WG11-3306, Ft. Lewis, Tacoma,WA
Yata, Yata, Yata . . .
|
Jim Rosenstock
Carpal Tunnel
Reged: 07/14/05
Posts: 2413
Loc: MD, south of the DC Nebula
|
|
Quote:
PS thoughts of Kronos and precision do not belong in the same sentense!
Good to see you're feeling better, Bill.... 
|
BillC
on a new path
Reged: 06/04/04
Posts: 2111
Loc: Washington, USA
|
|
Still talking like a wino, dragging (partially) my right foot and very weak and sleepy. BUT, have so much more to be thankful for than I could ever remember!
Have a great holiday!
Bill
--------------------
William J. Cook, Chief Opticalman, USNR-Ret.
Founding Editor, Amateur Telescope Making Journal
20-year vet. of Captain's Nautical Supplies, Optics Dept. Mgr.
Optics Machanic, WG11-3306, Ft. Lewis, Tacoma,WA
Yata, Yata, Yata . . .
|
DJB
Pooh-Bah
Reged: 02/23/05
Posts: 1269
|
|
Hi Bill C.,
Sleep can cure much. I recommend it, as your body can
recupe so vastly during sleep times.
When my back troubles me (at least once every day),
I take a nap. Can't beat it. Take care.
Best regards,
Dave.
|
Simon S
super member
Reged: 01/07/07
Posts: 110
Loc: Crawley West Sussex UK
|
|
Quote:
Quote:
These Kronos binoculars do have collimation adjustments, I too am amazed that some do not!
You have a right to be . . . You're wrong!
The first ring you see, is applying thrust pressure on eccentrics.
Just a thought.
Bill
PS thoughts of Kronos and precision do not belong in the same sentense!
 You saying this is not a collimation adjustment
|
BillC
on a new path
Reged: 06/04/04
Posts: 2111
Loc: Washington, USA
|
|
No. I'm say you CAN collimate it because there seems to be eccentric rings underneath the retainer. I must say I am very surprised; must late model binos are of the push/pull variety!
Good luck,
Bill
--------------------
William J. Cook, Chief Opticalman, USNR-Ret.
Founding Editor, Amateur Telescope Making Journal
20-year vet. of Captain's Nautical Supplies, Optics Dept. Mgr.
Optics Machanic, WG11-3306, Ft. Lewis, Tacoma,WA
Yata, Yata, Yata . . .
|
Previous
Index
Next
Threaded
Edit
Reply
Quote
[Re: 