Binocular repair?

[maxd]

Hi, thanks in advance for any help. i have a pair of 100 x20 binos, big n heavy and unfortunately my kids have knocked them onto the floor, alignment out, ive tried to tinker but probably made it worse.

is there any where i can send them to to be realigned and probably gas filled again?

what sort of price  am i looking at etc.

cheers for any help

Tony

[almcl]

You could try East Coast Binocular repairs.

I used them a while ago and while they weren't particularly quick, the quality of the repair (on a 50 year old pair of Solar Ross binos) was outstanding.

[Cosmic Geoff]

I did manage to tweak the alignment of a pair of Bresser binoculars which I bought at Lidl. They had two alignment screws on each side hidden under the rubber. They were clearly too cheap to send to a repairer. I had the objective of a vintage telescope replaced and it cost me over £100.

[tony210]

I have suceesfully realigned some Swift and other binoculars. If the prisms have small adjustment slug screws then observing any changes when viewing a star is an excellent way to go. The terrestial improvements were startling- Tony.

[DaveL59]

just be aware that prism tilt isn't the only collimation method, some use eccentric rings for example. Also worth checking after a bump that the prisms are in fact properly seated before you try adjusting the screws, one may have shifted and just need to be reseated.

Edited February 15, 2020 by DaveL59

[maxd]

hi, sorry for the late reply, thanks for the advice everyone, i have tried to use the adjust emnt screws, seems fine terrestrial, when looking at starfields,  all kinda 'off' makes my eyes kinda 'funny' so something is off, maybe ill try as siggested and look inside and see if the prisms been knocked out of place, is there an easy colllimation method i could use?

thanks again

Tony

[DaveL59]

you'll never really get true collimation unless you have access to the correct gear, unfortunately. Best you'll achieve is to correct the alignment for your own eyes and if lucky they'll still work ok for others if using close to the same IPD (inter-pupil distance) as yours. Doesn't sound too far off tho if you're able to use them in daytime, tho might after extended viewing. I had one pair where it felt like my eyes were being ripped out as soon as I looked thru them!

Have you adjusted on both sides or just the one?

Ideally you want a distinct distant target with bold horizontal and vertical line (A roof or gutter and downpipe say or at night a street lamp) that you can focus on with the binos mounted so they aren't shifting position while you check/adjust.

Then try to see how well the 2 images appear on first glance, or better, use a card to blank one objective and see how it looks when the card is removed while looking through them (winking one eye will show the difference too but blanking with a card works better if you can do it). That initial image should show how far out and what direction the 2 sides are from each other. Problem in daylight is the brain can quickly merge if not too far out and they may seem fine. At night tho there's no background data so you end up with doubles of stars offset and then its a strain to get a decent view.

Trick is to figure which side is out and then try to adjust it to bring it back into alignment, but that's not so easy as it may sound. Once you're sure the prisms haven't become dislodged then you could try checking the image of the exit pupil in the eyepieces and adjust only the side that is most off-centre. Once you have them adjusted so you can comfortably view without getting eye fatigue, test against a single distant streetlamp and then the stars as a double-check. You'll likely find that a further minor tweak may be needed to get them just-so.

I realise those who know real collimation will cringe at the above, but if it makes them useable again for you then it might be worth a go. Just take things slow, don't force the tilt screws and make small adjustment then check the effect and repeat. You should back the tilt screw off if you do need to reseat a prism so you start from a neutral setting and then adjust from there. Do keep track of how far you've moved the screws tho and listen carefully as you don't want to damage the prisms by overdoing things 🙂 

 

Edited February 21, 2020 by DaveL59

[DaveL59]

should ask, are the objective barrels still properly square to the body? or has one jumped a thread and so slightly skewed?

A pic of the binos in question might help. Its just possible that one barrel just needs to be unscrewed and refitted properly threaded. Shoulda asked that earlier, sorry

[maxd]

hi, thanks again for this advice, the main objectives are ok, ill give the slow approach another go and see where it leads me.

cheers

Tony

[maxd]

hi just had another go, prisms do not seem out of place, close up 1/4mile image seems great except for some chromatic aberration which seems increased with further distance objects but focus seems great.

could it be the main objectives?

thanks

Tony

ps they are ASA 25x100 BAK4 prism binos.  sems likemone of the main tubes was not as tight again the main body, again all clear/aligned, in focus during the day, need to try at night, heres to clear skies.

Edited March 1, 2020 by maxd

[DaveL59]

if the main tube screws into the main body then that could've jumped a thread and be slightly offset, that'd throw the images out of line for sure. Might be worth laying a marker (masking tape) on the barrel and body then unscrew it and carefully screw it back so it is correctly threaded and tightened up. The markers should align once done. Then re-check but if that was the cause you will have to re-adjust the prisms as they'll be out of place.

Am guessing they're not a unibody? Can't find ASA when I google the description so can only guess at the shape/build.

Edited March 1, 2020 by DaveL59