Got 15x70 binocular yesterday, read in some articles that there might be collimation issue for ones ordered online.
Can someone help on steps to check if binocular has collimation issue? if so then how to fix it?
Hi Yuvi…try to see some distant object(or maybe even the moon). Alternatively open and close each eye and ensure that the object is occupying the same position in the field of view of each eyepiece. This is a rough way and is called the blinking test. If you want to do this in a slightly more accurate way, defocus one side and see if the focussed star on one side is in the center of the defocussed star.
I do not think it’s easy to collimate a binocular. Unlike a reflector telescope, there are too many parts involved and it maybe better to ask the vendor itself.
Thanks for the response!
I tried the method you have mentioned, Moon I could see clearly with craters in it!
But when I tried to see Sirius star it appeared little smudged with few prism colors like Red and Blue!
And also when looking at 3 stars of Orion, they appeared to be double!
So this is what how they will appear huh? This is my 1st time seeing them through Binos so unsure on whether that’s what they look like or fault in binocular!
Ordered Bino through Amazon, so if fault with bino means will then request for replacement before that return period!
But when I tried to see Sirius star it appeared little smudged with few prism colors like Red and Blue!
This is chromatic aberration. Its presence and intensity depends on the brand and model of your binocular.
And also when looking at 3 stars of Orion, they appeared to be double!
That’s weird. Does this also happen while seeing Sirius?
So this is what how they will appear huh? This is my 1st time seeing them through Binos so unsure on whether that’s what they look like or fault in binocular!
It’s hard to answer this without using the binocular in person. Maybe we can wait for some regular binocular user to answer this?
cc: @steinmani
Adjust your binos for inter pupillary distance.
I would suggest any of the methods shown in youtube for focusing binoculars for each eye. Sharp image should be obtained image for each eye
And also check with terrestrial objects before stars.
Double image may be due to many reasons. Collimation is one of them. You cannot collimate properly without equipment ( done by professional).
Most good brands are collimated well, out of box unless suffered mechanical damage. For practical purposes, forget about collimating binoculars. Check the other reasons. Your eyes having different power may be reason too( can be corrected to some extent with diopter adjustment) or you may have to wear glasses or fold/unfold eyepiece rubber cups.
Minor variations, our brain will adjust.
Most importantly, relax yourselves and your eyes and get lost in the image and the detail. ( Needs practice and getting used to your equipment).
I also went through this. Now I just pick up and watch.
Happy viewing.
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