34 replies to this topic

[revans]

Kevin was out of stock on these last week so I bought a pair from his re-seller in NYC, B&H Photo.  They only arrived today because B&H Photo are closed for Passover. Anyway, I enthusiastically unpacked them and put them on a tripod only to discover an extreme case of double vision.

 

Anyone know a quick fix with these binos.  Nothing obvious occurs to me because I don't see a flap to lift up and I don't see slots on the objective rings that would let you turn them.

 

I asked Oberwerk and expect to hear back in the near future, but thought I'd ask here.

 

Rick

[sevenofnine]

Hi Rick!...You likely know this but just in case you don't, Kevin has collimation instructions for the LW model that was replaced by the Explore. You likely need to use a small screwdriver to find a seam in the armoring at the top of the bino's prism. Good luck! 

 

https://oberwerk.com...mariner-series/.

[Chuck2]

Oberwerk Explore binos come with nice carry cases to protect collimation and exceptional outer packing.

Kevin even supplies a collimation certificate with each bino from his Ohio lab, did you receive one? 
If so, chalk the mis-collimation up to gorilla shipping and handling. 
Give Kevin or David a call for your warranty options.

[revans]

Oberwerk Explore binos come with nice carry cases to protect collimation and exceptional outer packing.

Kevin even supplies a collimation certificate with each bino from his Ohio lab, did you receive one? 
If so, chalk the mis-collimation up to gorilla shipping and handling. 
Give Kevin or David a call for your warranty options.

I've traded emails with Oberwerk.  They are just going to send me another pair and I'll return this one.  Apparently it isn't a quick fix.

 

Rick

[Longbow]

Great customer service at Oberwerk !!

[revans]

Well, a family member did me a "favor" and tossed out the packing boxes for the 20x80 Explore so I can't mail them back unless a replacement pair arrived and I used its packing boxes.

 

I haven't gotten any further communications about a replacement pair being on their way so maybe I can fix them myself.  The are not useable as they are, unless monocularly by covering one objective.  I was able to unthread the outer ring on each objective and under it is a ring that has two 1.5mm holes for spanner wrench pins.  

 

I can buy a precision spanner wrench to rotate one or both objectives for $47.99 on Amazon and I more or less suspect I could use them to collimate these binoculars in fairly short order.  The degree of double vision at present is so severe that I couldn't make it worse It would not be a prism adjustment, but an objective adjustment.  Plus, as this tool is adjustable, I could probably fix another pair or two of wonky binoculars I have laying around the house. I can't attempt a prism adjustment because it would mar the outer "skin" of the binoculars and I can't be sure where to try and lift the skin to access the screws. There is a nice discussion of binocular collimation here in an old CN thread.  When I look into the objective end of each barrel, the exit pupil looks round and neither has a cats-eye appearance (even a subtle one).  

 

I'll sleep on the issue.  I recall that I fixed the collimation woes with my Oberwerk BT-82 using a similar process of objective rotation but had to have a tool specially designed for that (it had to grab two slots in the rings) and it won't work on these 20x80s. Someone asked earlier in the thread if I got a collimation certificate with the binos.  Initially I didn't see one but recently I looked again and found a quality checklist on a card that came with the binoculars... so collimation was checked by Oberwerk and given as +/- 30 step arc seconds on 3/18/25.  There is also a warranty card.

 

Update:  So, I did sleep on the idea and decided to buy the adjustable spanner wrench with a set of small metric pins included.  Whether or not it will work for this particular issue.... I can't be sure... but it seems a good tool to have around anyway.  If it works for the 20x80s then great but if not maybe it will work on one of my other pair.  I hope the pin holes exposed by taking off the outer ring will allow objective rotation and that I don't run into a case of Matryoshka dolls (i.e. one ring inside another inside another with only the last one allowing objective rotation...). 

 

I guess there is some truth in the old saying that the Gods help those who help themselves.  I seem to be fixing a lot more things myself these days... just yesterday I had to replace an internal laptop battery inside a case that wasn't user friendly to open up and then fix a complicated locking mechanism on the sliding screen door out onto my deck which couldn't be un-locked and then tinker with these 20x80s a bit more, then replace the whole-house water filter in the cellar and finally to try and figure out why a second laptop couldn't be restarted after an imaging session (I replaced the AC power adapter but that didn't work and I can't power on the computer which had been working fine).  As I get older I am running into too many of these fix-it-yourself projects.

 

Rick

[revans]

The adjustable spanner came and I collimated the binoculars.  They are perfect now.  No double vision at all and both barrels focus.

 

 

 

Sometimes it is just better to fix things yourself and not rely on things beyond your control.

 

Rick

[pat in los angeles basin]

That's impressive to me that the "entry level"  astro bino has eccentrics. The celestrons  at that level  seem to be a fixed lens with prism tilt or tray tilt.. Well done!  Pat

[Cali]

You were able to collimate the binocular by adjusting the objectives?

 

- Cal

[revans]

You were able to collimate the binocular by adjusting the objectives?

 

- Cal

 

Both exit pupils were perfectly round so I doubted that I had a prism misalignment issue caused by shipping.  I put my attention on the objectives. I removed the outer retainer; and then two inner rings with pin holes for the wrench.  The third inner ring is what moved the objective around and it had spanner wrench pin holes.

 

It was a simple process.  I rotated the objective until I was in perfect collimation.  It took all of about a minute and I was done.  No more double vision and these binoculars really perform well.  I couldn't be more pleased with them now that they are collimated.

 

It is better actually to rotate an objective (or both if needed) because a prism adjustment might result in some light loss and you might create a cat's eye pupil trying to collimate that way.  It is a lot more tricky than objective rotation. But if you have to, then you have to I guess.  In my case, I didn't need a prism tweak.

 

Rick

[pat in los angeles basin]

Since you have the good fortune to adjust the correct objective, might you purchase my next lottery ticket as my luck is such that I typically choose the wrong side first!     Regards, Pat

[Cali]

"I put my attention on the objectives. I removed the outer retainer; and then two inner rings with pin holes for the wrench.  The third inner ring is what moved the objective around and it had spanner wrench pin holes."

 

I can't recall reading about this on CN in the past. Congrats on your efforts.

 

- Cal

[fishhuntmike]

Outstanding effort and very nice spanner tool!
My 15x70 explore binos came last week and were spot on. Thanks for sharing your solution. Ive tweeked all of my BTs with a cheap spanner wrench from amazon and never needed to touch them since.

[revans]

Thanks for the kind words folks.  I really like these Oberwerk 20x80s (now that they are collimated anyway).  They have a lot of nice features but the best thing is how light weight they are compared to competing brands.  And the optics are really tremendous.  I can hold these in my ZGC with an adjustable table for my elbow support and hold them pretty steady for nearly 5 minutes.  That is the best thing about them.... they can be used handheld with some planning.

 

I like the design of the objective lens and its retaining rings which make it very easy to adjust collimation.  What a fantastic product.  I just had the misfortune of getting one put out of whack by shipping, but that is probably a rare occurrence.  I would definitely buy these again.  They really did fill a gap in my little collection.

 

Rick

[Dale Smith]

Well done, Rick! Very glad to hear you've got these in working order. Enjoy the views!

[revans]

Well done, Rick! Very glad to hear you've got these in working order. Enjoy the views!

When I go out to observe in the ZGC with my height adjustable elbow support table, I'll use the 15x70 Explore for general viewing and the 20x80 Explore as a support binocular to confirm targets and look for more detail.  Both binoculars can sit comfortably on the tray table top. 

 

I had tried to do this last year using my 15x70 Deluxe and Zeiss 20x60 IS.  But the 15x70 Deluxe was a little heavy in the hands and the 20x60 IS was too light starved to be a great astronomy binocular for most deep sky targets.  I think the current setup I'm using is going to be an improvement over what I could do last year. 

 

The 15x70 Explore and 20x80 Explore are pretty inexpensive binoculars, but no other binoculars I've come across pack so much observing potential into such small weights, while preserving very good quality optical views.  The 15x70 remains my most favored instrument but now I have a practical hand held support binocular to go just that little bit further in depth and detail.  I shouldn't have to get up every five minutes and walk over to my BT-82 to get that target confirmation and extra detail that I want.

 

And the thing that made this combination possible was using the triple combination of a ZGC, a full length 3" thick mattress for it, and a hospital bed style adjustable height tray table on wheels ($50 on Amazon), whose table top can just slide over the ZGC while you are reclining in it and lying on the 3" thick mattress/pad and whose wheels pass under the ZGC simultaneously.  This combination provides maximum viewing comfort at all viewing altitudes from the horizon to the zenith, essential elbow support for steadiness using these binoculars hand-held, and it eliminates the motion from our breathing that causes tremors in the binocular FOV.  I don't have to hold my breath while observing with binoculars in the ZGC any longer. 

 

There is only one basic necessity I haven't found a good practical solution for... the need to get up and re-orient the ZGC to a different part of the sky periodically.  This is annoying and for now the best solution I have found is simply to be content with studying one quadrant of the sky per observing session.  

 

There is also the periodic need to consult a chart which had meant my running inside to consult Stellarium periodically.  But I can do that on my smartphone now as long as I turn the screen brightness down to absolute minimum.

 

Rick

[JoeFaz]

Both exit pupils were perfectly round so I doubted that I had a prism misalignment issue caused by shipping.  I put my attention on the objectives. I removed the outer retainer; and then two inner rings with pin holes for the wrench.  The third inner ring is what moved the objective around and it had spanner wrench pin holes.

 

It was a simple process.  I rotated the objective until I was in perfect collimation.  It took all of about a minute and I was done.  No more double vision and these binoculars really perform well.  I couldn't be more pleased with them now that they are collimated.

 

It is better actually to rotate an objective (or both if needed) because a prism adjustment might result in some light loss and you might create a cat's eye pupil trying to collimate that way.  It is a lot more tricky than objective rotation. But if you have to, then you have to I guess.  In my case, I didn't need a prism tweak.

 

Rick

I'm curious, did you attempt to turn the second ring before the third? And did the third ring move the objective itself, or did you have to loosen it and then manually rotate the objectives? My assumption of there being 2 rings after the outside retaining ring would be that the innermost would be an objective retaining ring and the "middle" one would rotate an entire lens cell. The reason there are multiple rings is, presumably, because these binos are nitrogen filled, and loosening the objective retaining ring, whichever one it is, would likely release all of the internal nitrogen. So a nitrogen-filled bino with eccentric objectives most likely requires, at minimum, an objective retaining ring, a means to rotate the objective lens cell without having to loosen the objective retaining ring, and a lens cell retaining ring. The lens cell retaining ring must be the outermost, and I would guess the innermost to be the objective retaining ring and that you would not want to touch that one if you don't want to release all of the internal nitrogen.

 

Of course, there's more that one way to skin a cat, and there's more than one way to design eccentric objectives for nitrogen filled binos, so you may not have released the nitrogen. However, in the design that I've seen before, you probably would have done so if you loosened the innermost retaining ring. If this post gives you pause, you might consider going through with the exchange still. You did, after all, pay for a collimated and nitrogen-filled bino. You didn't receive the former, and may or may not have the latter now.

[revans]

I'm curious, did you attempt to turn the second ring before the third? And did the third ring move the objective itself, or did you have to loosen it and then manually rotate the objectives? My assumption of there being 2 rings after the outside retaining ring would be that the innermost would be an objective retaining ring and the "middle" one would rotate an entire lens cell. The reason there are multiple rings is, presumably, because these binos are nitrogen filled, and loosening the objective retaining ring, whichever one it is, would likely release all of the internal nitrogen. So a nitrogen-filled bino with eccentric objectives most likely requires, at minimum, an objective retaining ring, a means to rotate the objective lens cell without having to loosen the objective retaining ring, and a lens cell retaining ring. The lens cell retaining ring must be the outermost, and I would guess the innermost to be the objective retaining ring and that you would not want to touch that one if you don't want to release all of the internal nitrogen.

 

Of course, there's more that one way to skin a cat, and there's more than one way to design eccentric objectives for nitrogen filled binos, so you may not have released the nitrogen. However, in the design that I've seen before, you probably would have done so if you loosened the innermost retaining ring. If this post gives you pause, you might consider going through with the exchange still. You did, after all, pay for a collimated and nitrogen-filled bino. You didn't receive the former, and may or may not have the latter now.

You've given more deep thought to this than I have

 

Now I'm going to give you a chuckle... you may wonder how it relates, but I have a short haired Lemon English Pointer (see avatar).  Well, I took a single short hair shed by the dog and purposefully put it in the middle of the objective glass that I was working on.  If the hair turned while I was using the adjustable pin spanner wrench, then the objective was turning.  Neat trick huh?  And afterwards I could just blow the hair away and have a pristine objective again.

 

Anyway, after removing the outermost objective casing and exposing the three-ring system, each with 1.5mm holes for a spanner wrench, I found that the initial ring I encountered did not rotate the objective when turned.  Neither did rotation of the second ring after I'd removed the first.  Only upon reaching the third ring did using the spanner wrench also turn the objective.  I don't know if there was another ring under that one or not and I don't know if by turning it I let nitrogen escape. I'd like to think that nitrogen would escape only if I'd removed the objective cell from the barrel, which I didn't come even close to doing.... but then maybe turning the innermost ring could have released the nitrogen.... I'm not expert enough to know one way or the other.

 

But, anyway, it allowed me to achieve collimation.  I had to do something because the binos just couldn't be used at all in the state of collimation they arrived in.  Double vision was fierce and I was even getting eyestrain and the start of a headache looking through the binos.

 

If I let the nitrogen out, then fine.  The learning experience was worth it and at least I can use the binos and they are a dream to use now.  No eye strain at all and a perfect merged FOV. 

 

I certainly don't want to put anyone off buying Oberwerk 20x80 Explore binoculars.... quite the opposite.  These are tremendous binoculars for the money and their light weight and ease of use in a ZGC makes them worth their weight in gold.  It is true that the binocular skin does not allow access to the prism collimation screws by the amateur at least, without marring the skin.  But actually, I'd rather not adjust the prisms anyway unless it is absolutely necessary because there is a great chance of achieving collimation but losing light throughput.  I much prefer objective rotation as the mechanism of achieving collimation if possible.... in my case it appeared to me that the prisms were well aligned as the exit pupils looked very normal and symmetrical.  The only thing left to try was objective rotation and it worked for me after buying the adjustable spanner wrench using a pair of 1.5mm pins.

 

The nitrogen was a nice feature, but what caused me to buy these binoculars was their light weight.  I don't think you can find a lighter pair of 20x80s on the market.  And the optics are as good as in the Oberwerk 15x70 Explore, which is to say that they are great.  I would say essentially as good as my Oberwerk 15x70 Deluxe which had been my favorite binoculars for a couple of years.   Now I suspect my two Explore binoculars are going to get most of the use time in my ZGC.

 

Oh... I should add... Oberwerk was not at all remiss in not rushing me a replacement pair of 20x80 Explore.... they couldn't as they were having a stocking issue.... but they would have when they got more stock in place.  I didn't know all that when I decided to take a hands on approach, but everything turned out fine and I am happy as a clam.

 

Rick

[pat in los angeles basin]

One small quibble- probably just "aligned" for you, not collimated, but with your good luck, you have a better chance of being correct. I do the conditional alignment thing all the time, as I am the only user of the bino, what works for me and my particular IPD might not for a wider/ narrower eye set or eyes with prism.  Pat

[revans]

One small quibble- probably just "aligned" for you, not collimated, but with your good luck, you have a better chance of being correct. I do the conditional alignment thing all the time, as I am the only user of the bino, what works for me and my particular IPD might not for a wider/ narrower eye set or eyes with prism.  Pat

Yes Pat, that is very true.  I notice this all the time.  What seems best for my eyes isn't always best for others.  I have some astigmatism, but it isn't too severe, and I don't have a tendency toward double vision.  Most of the handheld binoculars I have purchased from Oberwerk and others have arrived in what seemed to be perfect collimation to me.  This pair of 20x80 Explore was the exception and as I've said the double vision was extreme with one FOV superimposed 10% to 15% above the other. I just couldn't use them that way.  The only other issues I've had with double vision would be with my 45 degree tilt BTs.  Both of these showed some degree of double-vision but it seems related more to slopes or undercuts being present in the eyepieces and possible sagging of eyepieces in the turret structure that was the main cause.  I did manage to get some improvement with objective rotation in my BT-82 about a year or so back.

 

I'll be the only one using the 20x80 Explore and now they are perfectly collimated for me.  I need all of this New England rain to go away so that I can really assess the capability of this pair in my Bortle 6 sky.  

 

Rick

[pat in los angeles basin]

I need all of this New England rain to go away so that I can really assess the capability of this pair in my Bortle 6 sky.

 

So, who is the deity that we should make offerings to for clear skies?? 

[revans]

Here is a quick update...  I checked with Kevin and it looks like for Nitrogen loss to occur then the objective would have to be removed from the barrel.  I guess I'm safe as nothing close to that happened during adjustment. 

 

Rick

[revans]

I need all of this New England rain to go away so that I can really assess the capability of this pair in my Bortle 6 sky.

 

So, who is the deity that we should make offerings to for clear skies?? 

We in New England just have to adjust to our seasons.  The worst thing about the rain here is that it breeds droves of mosquitoes and they are as bad for observing as clouds and rain themselves.  April was relatively dry, but May is turning out wet.

 

Rick

[revans]

I went back this afternoon and mounted the 20x80 Explore and did some observing of my 2-3 mile distant tree lined ridge and also some tree tops about 50 yards away.  The fog/mist cleared up somewhat for a couple of hours this afternoon but now is back again.

 

Anyway, my collimation needed a micro-tweak.  I found that I must have all three rings so close that they are touching now and when I turn the outermost ring the objective turns.  That did not happen when I did my first collimation so I assume there was probably some spacing between them, making them independent such that only the innermost ring would turn the objective.

 

I spent at least an hour perfecting collimation as much as I could this afternoon.  It seems now to be in good collimation for both near and far observation and the focus point for near and far are still within the reach of the focus mechanism.  All to the good.  

 

When I finished up the final result really "blew me away" as the saying goes. The FOV is sharp and color/contrast rich out to 3/4 of the FOV circumferentially.  The last 1/4 is still sharp but the color and contrast diminish just a bit.  But that is perfectly fine with me.  I have some very expensive binoculars that do that as well.

 

Rick

[harpo80]

Rick, this is very good information and I appreciate your posting it.  I have Explore 20x80s as well; my left eye is not quite right due to prior retinal surgeries and I've written off a little intermittent double vision as related to that, but I will check the collimation/alignment carefully and tweak a little if I need to.

 

I'm finding these binoculars to be really, really good and fun to use on doubles, my main use for them at the moment.