Needed - easy way to check collimation (1 Viewer)

[temmie]

Just curious: you said the Zeiss seemed correctly aligned. Did you confirm this with a star test as well?

 

[Elpha8888]

I tested my Zeiss SF 10x42 with the star test, the star was not perfectly central and this is acceptable, should not cause any issues. They were a pleasure to use and don't get to worried about it.
The EDG were absolutely perfect may add.
If you are using a Zeiss then a Swarovski, I would say that your eyes need to adjust and settle between the two, give them some time, do some tests.

 

[Allen]

I didn't check the Zeiss with a star test but don't need to. I could tell the Swaros were out just by looking through them and then taking them away from my eyes....one eye felt like it was having to 'bounce' back to try and get normal vision, almost nausea inducing. I've used enough bins to know thats symptomic of a problem with the specific set of bins as long as I've set the diopter right. Swarovski have now confirmed the same.

 

[Tringa45]

Just center anything in the right objective of the binocular, and then see if it is centered in the left objective. If it is, the alignment is ok.

Dennis,

To avoid slanging you on the open forum I wanted to PM you, but see you have blocked this.
I wonder if you actually read threads before posting your worthless 2 cents.
Joachim posted a really excellent test and then this "contribution".
There are various tolerances for collimation but I believe the ISO ones are around 5 arcminutes.
How on earth are you going to get anywhere near to verifying this with an object in centre field?
I see too that on another thread you are repeating the same nonsense of "better glass". With several hundred different optical glass sorts from various manufacturers this is just naive speculation and none of us know.

John

 

[dorubird]

Hi,

search a bright star on the night sky, focus on it (or two, if things are really bad) and turn the diopter to the end of its range. So you will have a bright dot (the in-focus tube) and a large disc (the out of focus tube). The dot should be in the center of the disc if the instrument is correctly collimated.

The idea is to prevent the brain from merging the images of the tubes... since there is no star but a diffraction disc, it doesn't merge...

Joachim

Hi,
this operation is only useful if each separately scope/tube is individually collimated by it self (The right objective must be perfectly in the optical axis with the right eyepiece, and the left objective must be perfectly aligned with the left eyepiece).
But, many times, in order to have a collimated image between the two tubes together at the time of point star focusing, the manufacturers deliberately slightly sacrifice collimation of each individual tubes (so this decentered it is noticed only when defocusing star, but it is colimated with other tube only when the star ar point focused). So, if a single scope/tube it is not collimated by it self, the defocused circle is decentered from the focused star point, but the two tubes binos still be collimated together

 

[Allen]

My bins are back from Swarovski and perfectly collimated now. But for my education, how/where is the collimation made even on factory output? Is each pair manually collimated? In my simple mind there are 2 x tubes with the lenses in a predetermined position so a mirror of each other. So what is it that gets adjusted to collimate? Or are left and right tube lenses already slightly differently positioned to align? Wanting to learn!

 

[Maljunulo]

Dennis,

To avoid slanging you on the open forum I wanted to PM you, but see you have blocked this.
I wonder if you actually read threads before posting your worthless 2 cents.
Joachim posted a really excellent test and then this "contribution".
There are various tolerances for collimation but I believe the ISO ones are around 5 arcminutes.
How on earth are you going to get anywhere near to verifying this with an object in centre field?
I see too that on another thread you are repeating the same nonsense of "better glass". With several hundred different optical glass sorts from various manufacturers this is just naive speculation and none of us know.

John

I think his method only works if the object in the center of the field is a mountain goat.

 

[tenex]

how/where is the collimation made

I think it's fine-tuned by adjusting a small amount of play in the mounting of the objectives, and always assumed that was done manually, at least on higher-end instruments.

 

[Maljunulo]

Prisms, I think, in a porro.

Not sure in a roof, decentered lens maybe?

 

[pat mitchel]

In older porros-but good ones- the objectives are mounted on eccentrics that can be turned like a clock to subtly change the placement of the objective in relation to the rest of the optical train. Also, some binocular adjusted the tilt of the individual prism with small pieces of a soft metal (lead? Tin?) that fit under the edge of the hypotenuse" side of the prism. Then they had the prisms on a tray and you could tilt the whole tray with screws at 3 places to effect a change. I happened to get an out of alignment 12x60 cabelas intensity roof and in my exploratory found under the armor found 3 screws holes spaced approximation 120 apart, around the body just to the rear of the hinge area. Found adjustable screws that must tilt the roof prism assembly to align. Never got the alignment completely right as it fell out with large changes in the IPD setting but for the range of my IPD it's fine.

 

[hopster]

Hi,
this operation is only useful if each separately scope/tube is individually collimated by it self (The right objective must be perfectly in the optical axis with the right eyepiece, and the left objective must be perfectly aligned with the left eyepiece).
But, many times, in order to have a collimated image between the two tubes together at the time of point star focusing, the manufacturers deliberately slightly sacrifice collimation of each individual tubes (so this decentered it is noticed only when defocusing star, but it is colimated with other tube only when the star ar point focused). So, if a single scope/tube it is not collimated by it self, the defocused circle is decentered from the focused star point, but the two tubes binos still be collimated together

This is confusing. I have used a star point source and the binocular on a tripod and the sharp image seems to be mostly within the blurred one on two different optics, but it's to some extent dependent on things like (1) where in the FOV the star is - I try to use exact centre (2) IPD (3) where the eyes are relative to the eye pieces. The blurry image even seems to move around in the FOV as the focus is changed.

It does not seem easy to get a very precise and repeatable result as all of the above shift the relative positions of the sharp and blurry images somewhat. Any suggestions?