blurred image ,but only....

[rory]

when i use both eyes. i can view with one or the other fine,reasonably sharp images. but when i use both eyes,the images become more blurred.

ive tried refocussing using the cover one eye,then the other and then both . but wont quite get there.

so i was wondering is there a chance its an eyesight issue ? or collimation or something ? starting to worry it's my eyes,as the images are fine until i open both eyes,or is there a common mistake?

thanks for any advice.

[Slangers]

Have you focused each eyepiece separately? The central (main) focuser on binoculars is generaly used to get itright for one eye and then the eyepiece focuser on the other side is used to get the balance right.

[rory]

yes, ive close right eye, focus with centre wheel, then close left eye and focus the eyepiece that twists,then open both and tweak the centre again. i can focus with either,but image blurs when i use both eyes, although i dont notice on daylight use.

i hopeing its a collimation issue or something. otherwise my eyes are nakered ! lol

[BinocularSky]

OK, firstly, to get critically good focus, don't close your eye, but cap the objective on that side of the binocular -- this means that both eyes stay relaxed. If the problem persists, it is almost certainly a collimation problem -- use of two eyes should be an improvement on the monocular view. The night sky is a much more rigorous test of optical quality than just about anything the daylight can throw at you. There are some tests for collimation in the "Choosing and Using" section of my Binocular Sky website (see sig).

[rory]

okay, thankyou tetenterre, cheers all.

[rory]

" the binocular sky" nice site, thank you.