• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

Swift Trilyte MkIII 8X40 collimation (1 Viewer)

Maarten90

Member
Hi all,

I once previously asked on this forum about a badly collimated binocular and ended up buying a new Nikon Aculon 8X42, which was great advice. So here I am again.

Now someone has given me his used, spare binocular: a Swift Trilyte MkIII 8X40 (1982). It is out of collimation, I think, which is regrettable because otherwise my girlfriend and I could watch birds simultaneously.

So, does anyone have any idea if it is doable to collimate it myself? And if so, where I can find how to do so? And if not, if this old model is worth it taking it to a professional repair shop? And what this might cost?

Thanks!
Maarten
 
Hi Maarten.
There is an 8x30 Trilyte on sale for £39 with warranty and an 8x40 maybe £69 or less.
There is/are repair shops near you, but it probably costs as much to fix as it is worth.
Not sure whether you could make it work yourself.

I had one but the image was a bit dull.
 
Maarten,
To get a usable binocular for not much money, say £10 or £20, a tour of charity shops and boot fairs is the way to go.
A bright torch is needed. Shine it into the eyepiece end. Look into the front very carefully and make sure there is no fungus or moisture deposit inside.
Then carefully check mechanical parts and especially the alignment.
Look at a distant car number plate or similar for resolution.

Don't buy something with faults or waste money. Eventually something good will turn up.
But it takes time. If you have that then no problem. If not, then maybe not a good idea to spend much time searching.
 
Hi Binastro,

Thanks for the info!

I had in fact not planned to acquire a second binocular, I don't have the time to go looking for one right now. But when I was given one I thought I might as well try and figure out if I could get it to work properly because that would be conveniant.

But I will keep an eye out for a second good binocular.
 
Hi all,

I once previously asked on this forum about a badly collimated binocular and ended up buying a new Nikon Aculon 8X42, which was great advice. So here I am again.

Now someone has given me his used, spare binocular: a Swift Trilyte MkIII 8X40 (1982). It is out of collimation, I think, which is regrettable because otherwise my girlfriend and I could watch birds simultaneously.

So, does anyone have any idea if it is doable to collimate it myself? And if so, where I can find how to do so? And if not, if this old model is worth it taking it to a professional repair shop? And what this might cost?

Thanks!
Maarten
If you have a bino with rubber armor sleeve, you can remove it to expose prism adjustment screws. I have an older pair of cheapie Bushnell Trophy xlt 10x50. It came brand new, way out of collimation. I dont know how your binos are set up, but mine and many roof prism types have 2 screws on each barrel. Looking at the binos from the bottom, one screw will be on right (vert adjuster) and one on left (horiz) adjuster. I suggest trying only to adjust one barrel. Set binos as solidly as you can, maybe resting on something stable, and if you can, turn the right screw clockwise and watch a vert object such as a street light pole, or a street sign that has both vert and horiz lines, about 100yds away. If double vision gets worse, turn it back counterclockwise and see if that works. After youve got the vert line dialed in, go to the left screw and start on the horiz edges of the street sign.

I got my binos in a hurry for a trip, and didnt even check them before leaving an hour after they arrived. My expensive Leica binos seemed to walk off by themselves, out of my camping supply case. Kids! Bushnell had such a horrible customer service system and warranty (better since 4/17) that I didnt bother with them. I got them for $125.00 on sale. That wont hurt too much if I couldnt adjust them myself. They told me to send them in as there was no way for me to fix the problem. BS!
 
Hi and welcome.

It will be pointed out that you got conditional alignment for your own IPD.

It is much more complicated to get it right for all IPDs.

But you got a working binocular.
 
Hi all,

I once previously asked on this forum about a badly collimated binocular and ended up buying a new Nikon Aculon 8X42, which was great advice. So here I am again.

Now someone has given me his used, spare binocular: a Swift Trilyte MkIII 8X40 (1982). It is out of collimation, I think, which is regrettable because otherwise my girlfriend and I could watch birds simultaneously.

So, does anyone have any idea if it is doable to collimate it myself? And if so, where I can find how to do so? And if not, if this old model is worth it taking it to a professional repair shop? And what this might cost?

Thanks!
Maarten

Hello Maarten,

Is the binocular badly out of aligment or slight? It could be something very simple, the Trilyte MK111 8x40 has screw in front objective barrels, check that one has not moved, undone slightly, sometimes if the aligment issue is slight a little turn of one barrel will get it back. Look at an object, then through the right barrel with left eye closed, get it centered, then open the left eye, close the right eye and you will see the difference, the object slightly higher or to one side, keeping the binocular steady and closing and then opening one eye should help you see if it's badly out or slight. If slight, try a slight turn of one barrel, if this makes it worse, turn it back and slightly the other way, or try the other barrel, dont turn it too much, just a little at a time, a bit of trial and error might get it right.

Ben
 
Hi everyone,

Thanks for the information and tips! I'll try, carefully and subtly, to adjust one of the barrels. The misalignment must be pretty slight because I find it difficult to actually see it, though I think I can. I'll I think it must be misaligned because it gives me headaches. I have already notices I'm rather sensitive to these kinds of issues.

Also, the rubber eyecups were missing and I got two off an old binocular and taped them on, this might mean that my eyes are further away from the lenses then they should be, could this also be a cause of my headaches, if so they might not be misaligned after all.

Maybe someone could help me which screws specifically I need to try. If I Osidesailer correctly then I must try the very little screws under the rubber (and not the bigger ones on the outside on the front and back of the middle part), and the one near the eyecup is the one for the vertical adjustment (see photos). Is this right?

Thanks!
 

Attachments

  • 20170705_171220.jpg
    20170705_171220.jpg
    374.6 KB · Views: 260
  • 20170705_171122.jpg
    20170705_171122.jpg
    74.3 KB · Views: 374
  • 20170705_171135.jpg
    20170705_171135.jpg
    76 KB · Views: 264
I realise this is an old thread, but today I was looking into alignment on a Chinon 10x42 trilyte-alike that I'd acquired as it was slightly out of alignment. Appears to be probably the same OEM given it also has the >S< mark on the focus wheel tho its not multi-coated.

I can't vouch for which prism screw, mine's the painted on leatherette finish and I didn't want to damage that unless I really had to.

Inspecting the objective end, I found that this one has a single eccentric ring to shift each of the objective lenses, accessible by removing the outer lens rim. Note that this isn't threaded nor a double ring arrangement. You adjust by loosening the regular 2-slot lens ring slightly and then you can carefully adjust the eccentric using a jewellers screwdriver in the slot on this inner ring. It'd be very easy to slip and scratch the lens so take great care. Unless you have a suitable jig, I doubt you can't really do this reliably with the 2-slot ring removed as the eccentric and lens are then loose and tilt as you adjust and then check.

Once you have it all aligned you can then tighten the main lens ring to secure, you may need to hold the eccentric in position with the screwdriver while doing this as it can/does rotate a little.

I guess its possible that at some point in its past life one of the lens rings had worked loose and the alignment drifted when it was tightened back up.

Hopefully this info is helpful to someone else in the future.

edit: my bad, the makers mark is a stylised W rather than the >S< - memory failing with age lol
 
Last edited:
Trilyte Collimation

I realise this is an old thread, but today I was looking into alignment on a Chinon 10x42 trilyte-alike that I'd acquired as it was slightly out of alignment. Appears to be probably the same OEM given it also has the >S< mark on the focus wheel tho its not multi-coated.

I can't vouch for which prism screw, mine's the painted on leatherette finish and I didn't want to damage that unless I really had to.

Inspecting the objective end, I found that this one has a single eccentric ring to shift each of the objective lenses, accessible by removing the outer lens rim. Note that this isn't threaded nor a double ring arrangement. You adjust by loosening the regular 2-slot lens ring slightly and then you can carefully adjust the eccentric using a jewellers screwdriver in the slot on this inner ring. It'd be very easy to slip and scratch the lens so take great care. Unless you have a suitable jig, I doubt you can't really do this reliably with the 2-slot ring removed as the eccentric and lens are then loose and tilt as you adjust and then check.

Once you have it all aligned you can then tighten the main lens ring to secure, you may need to hold the eccentric in position with the screwdriver while doing this as it can/does rotate a little.

I guess its possible that at some point in its past life one of the lens rings had worked loose and the alignment drifted when it was tightened back up.

Hopefully this info is helpful to someone else in the future.

edit: my bad, the makers mark is a stylised W rather than the >S< - memory failing with age lol

Since you’ve resurrected this thread, I would like to chime in, I’ve worked on less than a dozen Trilytes. But I THINK they collimate at the eyepiece. Attached are two illustrations of the predominant methods of attacking that problem, at least if that’s the convention.

Three things said earlier cause me a bit of concern.

— First, I think the “single eccentric ring” is really just a retainer for the objective—since real eccentrics come in pairs—and that it actually collimates via one of the methods already addressed.

— Secondly, Osidesailor said, “I suggest trying only to adjust one barrel.” That’s the kind of fuzzy thinking that can make alignment worse or even damage the binocular. Suppose only the right side is out of alignment and the observer chooses to start his willy-nilly work on the left side. Now he has a bino that is doubly out of collimation! If the error is small or the observer’s spatial accommodation is great, that method might lead to a good—often more than adequate—conditional alignment for THAT user or others with his IPD, but clinically it is not collimation.

— For very minor adjustments, following Ben’s advice might do the trick. In so doing, you need three pieces of information. First, you need to know WHICH side needs the adjustment. Secondly, you should know that that unit has a set screw which must be loosened before the objective housing will turn. Finally, before turning an objective housing, you should scribe the objective housing AND the prism housing so that, if necessary, you can get things back to the original position.

While I’ll probably get yelled at for mentioning either of my books, both have the largest treatises on 3-axis collimation in the English language and because of that, I am not shorting anyone. In addition, I have given this information away dozens of times in the last 20 years just trying to be helpful to those who need it. :cat:

Bill

PS Lee, if I have stepped over the line in trying to be helpful here, please just delete or have me delete the post.
 

Attachments

  • Screen Shot 2019-02-15 at 6.00.54 PM.jpg
    Screen Shot 2019-02-15 at 6.00.54 PM.jpg
    239.4 KB · Views: 134
  • Screen Shot 2019-02-15 at 6.01.28 PM.png
    Screen Shot 2019-02-15 at 6.01.28 PM.png
    103.8 KB · Views: 207
Last edited:
hi Bill

yes I agree I thought it was odd there being only one eccentric ring, having researched a lot before starting any works I was surprised. Whats worse, it moves as you loosen/tighten the securing ring that clamps down onto it which makes it fun keeping the alignment. Pics below hopefully show what I was talking about. The red dot gives me a reference mark for when I put it back together after a quick dismantle for the pics.

The other issue with this one was the dioptre didn't adjust well. Seems someone had turned the ring too eagerly in the past and the element carrier had undone and wasn't threading back into the tube. Not hard to sort tho, remove the top ring and slide the dioptre ring off, remove the pin and then you can unscrew the outer slotted tube and re-thread the lens carrier into the inner tube, then reassemble in reverse and test.

So these have now gone from a L-R displacement that looked like % testing against the stars to single points and more relaxed on the eyes viewing. They aren't bad at all, nice clean image but close focus is only around 15+ ft which I gather the trilyte also "suffers" from.

These Chinons are uppendahl prisms so no adjustment that I saw from the eyepiece end. So perhaps they are slightly different to the swift trilyte model?


I definitely bow to your vast experience in this field, I'm very much a beginner at this. Unless I've fully dismantled things for internal cleaning, I do tend to try to make a determination of which side is out by checking for centrality of the exit pupils and work first on the side most non-central. Perhaps not the way a pro would do it, but on the principle that a lens will be sharpest at centre it seems to me a reasonable starting point. I also won't just dive straight onto the tilt screws, prefer to look inside first and make sure the prisms are seated properly and are free to be tilted rather than find they aren't when you hear glass splintering...
 

Attachments

  • Chinon Trilyte-alike.JPG
    Chinon Trilyte-alike.JPG
    41 KB · Views: 109
  • Chinon obj end.JPG
    Chinon obj end.JPG
    30.7 KB · Views: 41
  • Objective ring.JPG
    Objective ring.JPG
    39 KB · Views: 58
  • eccentric ring.JPG
    eccentric ring.JPG
    52.8 KB · Views: 57
  • Dioptre adj.JPG
    Dioptre adj.JPG
    27.4 KB · Views: 61
Last edited:
hi Bill

yes I agree I thought it was odd there being only one eccentric ring, having researched a lot before starting any works I was surprised. Whats worse, it moves as you loosen/tighten the securing ring that clamps down onto it which makes it fun keeping the alignment. Pics below hopefully show what I was talking about. The red dot gives me a reference mark for when I put it back together after a quick dismantle for the pics.

The other issue with this one was the dioptre didn't adjust well. Seems someone had turned the ring too eagerly in the past and the element carrier had undone and wasn't threading back into the tube. Not hard to sort tho, remove the top ring and slide the dioptre ring off, remove the pin and then you can unscrew the outer slotted tube and re-thread the lens carrier into the inner tube, then reassemble in reverse and test.

So these have now gone from a L-R displacement that looked like % testing against the stars to single points and more relaxed on the eyes viewing. They aren't bad at all, nice clean image but close focus is only around 15+ ft which I gather the trilyte also "suffers" from.

These Chinons are uppendahl prisms so no adjustment that I saw from the eyepiece end. So perhaps they are slightly different to the swift trilyte model?


I definitely bow to your vast experience in this field, I'm very much a beginner at this. Unless I've fully dismantled things for internal cleaning, I do tend to try to make a determination of which side is out by checking for centrality of the exit pupils and work first on the side most non-central. Perhaps not the way a pro would do it, but on the principle that a lens will be sharpest at centre it seems to me a reasonable starting point. I also won't just dive straight onto the tilt screws, prefer to look inside first and make sure the prisms are seated properly and are free to be tilted rather than find they aren't when you hear glass splintering...

190216

You wouldn’t see prism adjusting screws from the eyepiece end. If it's the convention I alluded to, the adjustment screws were for the lateral movement of a lens or part of the eyepiece system. :cat:

Bill
 
ah ok, understood Bill. View into the eyepiece end is as attached on these Chinon's.

I've not dismantled to remove the top plate or focus mechanism as I've not needed to do that to sort the dioptre adjust and everything works smoothly, so on the principle of "if it ain't broke..." have restricted myself to sorting the dioptre and alignment only.
 

Attachments

  • Prism top.JPG
    Prism top.JPG
    21.5 KB · Views: 47
ah ok, understood Bill. View into the eyepiece end is as attached on these Chinon's.

I've not dismantled to remove the top plate or focus mechanism as I've not needed to do that to sort the dioptre adjust and everything works smoothly, so on the principle of "if it ain't broke..." have restricted myself to sorting the dioptre and alignment only.

One of the things that breaks a know-it-all’s heart is when he comes upon something which causes him not to have an instant answer. I have worked on that brand of binocular but I am not at all familiar with what is illustrated by the photo. Some roof prism binoculars are collimated at the objective. Are we sure that is not one? :cat:

Bill
 
hi Bill

from what I've found on this one, it does seem to be the objective end with that odd single eccentric ring arrangement. I have got it aligned that way, is just made fiddly when the eccentric moves as you tighten the lens ring since it's free to rotate, a third hand would be handy some days ;-)
 
out of interest, acquired a Binox 9x35 which is a similar trilyte body type also, this one too has a single eccentric ring arrangement for image alignment. I note the external eyepiece moves when focusing on these where the Chinon occulars move internal to the eyepiece.

J-B20 maker stamped on the end cap, would that tally up with the Swift Trilyte also?

Noticeable thing was the very musty smell when I opened the box, oh dear! Some indications of fungus inside behind the objective lenses so have had them off and given them a clean along with the visible prism face which has improved things a lot.

Also gave the inside of the tubes a wipe which left a greeny-blue residue on the lens wipe. Now to me that doesn't seem right, likely mould?

I guess at some stage I'll need to fully strip and clean the entire casing internally as well as the optics, meantime will keep a close eye on them and keep them separate from the rest of the collection.
 
yeah know what you mean, case is toast at this stage I think, leatherette over card so won't be treatable really. Given the low price I'm OK with taking them to bits at some stage and seeing how they'd clean up internally.

My interest was since it is 7.5 degree FoV where the Chinon 10x40 is a narrow 5.5 by comparison. Cosmetically they are almost unmarked from the outside, just a small scratch on LH occular but near the edge and well outside the exit pupil so don't seem to affect the view at all. Oh focus wheel is at the occular not objective lens end on these, so opposite to the Chinon/trilyte.
 
Warning! This thread is more than 5 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Users who are viewing this thread

Back
Top