Binocular collimation

[GazzMeister]

Good evening Everybody

Just today I received a pair of brand new 20x80 triplet binos from AOE. Now while I am extraordinarily pleased with the optics, the pleasure turns to dismay when I open both eyes at once... The image jumps dramatically when I open one eye at a time. There is a bit of play at the end of each individual tube. The main part that is moving is around the brace at the objective end. I have no experience with braced binos so it's quite possible I'm overlooking something basic, but it does appear that the tubes aren't parralell. The binos were packed quite well in the box they came in so I don't think they got banged on the way down (from Syd to Canb). I have only heard good things about AOE so I'm thinking it might just be a dud pair OR I'm overlooking something really obvious.

Thanks for any help in advance

Gareth

[StarLane]

It maybe that the pin/screw in the join where the two objective braces meets the central shaft is loose.
I have the exact same pair but have not had this problem.

Mine have a problem with the right hand eye lens (diopter control) being very loose. I can move it up and down and left and right. It changes the collimation if I bump it and the eye lens ends up on the wrong angle to the rest of the optics, makes me go cross eyed. As long as I make sure it's in a certain position (which I have since worked out) all is OK. I'm still happy with them, they are great for the money.

Your problem sounds like something as simple as a fastener somewhere in the brace. Have a close look around and see what you can find, or call AOE....

[Mick]

I have the 20 x 80LW's and they have the same problem as your binos. AOE exchanged them but the replacement binoculars have the same problem as well so I don't use them. The optics are good but the focus mechanism lets them down.

[chris lewis]

It is a bit of a concern that the binos as described above are in such poor condition when brought new.
In the first instance the binos should not have such flexion to the point of such obvious mis-alignment and in the second the diopter should not be loose like that. You should not have to adjust the eyepieces each time you use them and they should not lose collimation if you bumb them.
Both should have been returned as they are new and under warranty. You deserve better then what you got.
Normally collimation can be achieved via the 2x set screws under the rubber prism housing - that is after making sure the front objectives are set correctly. Adjusting the prisms should b the last thing.
You can get 'merged' collimation where there is no obvious double vision but 'cats eyes' are still displayed at the exit pupil [ look at the exit pupils from 12-24 inches away ] - 'cats eyes' also means loss of light - not good. True collimation will display nice round exit pupils and fully merged images. If you still have cats eyes at the exit pupil after adjustment they should be returned.
AOE have a 12 month warranty and usually sell high quality well collimated binoculars sourced from the Kunming factory in China.
Article on collimation below. [Oberwerks are form the same Kunming factory]

http://www.oberwerk.com/support/collimate.htm

[Roger Davis]

PLEASE EVERYONE NOTE: Before you go grab your jewellers screwdriver/hex key, not all collimation problems can be fixed just by adjusting the collimation screws!! There is also a condition known as "leaning field" where prisms are not perpendicular. This can be a dangerous operation as you can chip your prisms if you do not perform the operation properly.
POINT: Don't collimate them yourself, take 'em back!

[GazzMeister]

Thanks for the responses everyone

So, I'm assuming that there should be no play between the ends? I've figured out that by gently pushing and or puling the tubes towards/away from one another they sometimes come into perfect alignment, unfortunately they lose collimation again quite quickly. Does anyone know where I would take a pair (in Canberra) for a professional to look at them? If there is some easy-fix to the solution instead of sending them back it would be worth it. As I said in my OP, for what I paid I'm very very happy with the optics (plus the binos look cool :-) and from all the good things I've heard, it must just be a couple of dud ones floating around for all the good ones.

Thanks again and clear skies

Gareth

[StarLane]

I've thought of sending mine back and getting a replacement, but I thought the next pair will be exactly the same (as Mick has now confirmed). The sloppy diopter control and ordinary focus system is what I expected with a pair of binos in this price range, and they all must be like that. If I purchased a pair of $800 binos I guess all needs to be perfect. I paid $219 for 20x80 fully multi coated triplets with Bak4 prisims, a sloppy diopter control thats controllable when you get used to it, is OK for the money. I will use these only afew times a year so I could not justify spending anymore on a set of binos. If my issue gets annoying I will send em back before the warranty runs out, at the moment it's useable.
But GazzMeister should send his back for repair or replacement.

[Roger Davis]

I know I said "send them back" and I meant it.
If we consider binocular improvements as evolution, then these type of binoculars are on a branch line heading for extinction. To make binoculars affordable to the masses quality and robustness has been dropped (excuse the pun). I mean it! One of the tests done on early binoculars (Zeiss, Ross, Barr & Stroud) was to drop them onto a bed of covered sand from a couple of feet to ensure that they would hold collimation. You cannot do that with modern binoculars. Just thought I'd mention I do this for a living, I also am a subscriber to the Binocular list and am currently restoring a 20x120 Jap WWII binocular (my third).