Stereo monovision

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Plasmid
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Stereo monovision

#1 Post by Plasmid » Wed Feb 17, 2021 2:41 am

I've noticed that my stereo has a amblyopia problem, so after setting up the diopter , I will start to zoom in with the zoom knob, I've noticed that the more I zoom in the more blurry the image gets, (even when adjusting the focus). Take for example zooming into a moth's eye,whenn the zoom is at max the image on the left eye will become blurry that the one on the right will be clear, ... Back up the focus a bit and is the complete opposite, there is no in-between. Is this normal ? Or does it need some type of adjustment?

Greg Howald
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Re: Stereo monovision

#2 Post by Greg Howald » Wed Feb 17, 2021 3:25 am

Check two things
1. Are Eyepieces the same size.
2. Are both Eyepieces all the way in.
I've had problems with both and the result of my inattention matches your results.
Other than that, the storehouse of my small mind is empty.
Greg

Scarodactyl
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Re: Stereo monovision

#3 Post by Scarodactyl » Wed Feb 17, 2021 1:10 pm

Generally not a good sign, yeah. At max zoom eyepiece position matters the least so usually eyepiece adjustment issues don't show quite this way. I've seen this symptom in some pretty beat up stereos though. I'd definitely go through the whole eyepiece setup ritual again to be sure that isn't it (and definitely check what Greg saiid about the eyepieces as well!).

viktor j nilsson
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Re: Stereo monovision

#4 Post by viktor j nilsson » Wed Feb 17, 2021 1:34 pm

Can you change the diopter setting on both eyepieces? If you can, I would focus on one eyepieces first. Try different diopter settings and see if there is one setting where you maintain parfocality over the entire zoom range, and then adjust the other to match.

Are you using glasses? If I'm not using my glasses and change the diopter setting to compensate I lose parfocality as I zoom.

Plasmid
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Re: Stereo monovision

#5 Post by Plasmid » Wed Feb 17, 2021 4:09 pm

Took the whole diopter apart, regrease it, and put it back together, but that was not the problem...... The problem is cheap manufacturing , it looks like wesco used the cheapest metal available and so the zoom screw like drive had cracked, specially the one that holds the left lens as it moves through the travel. The leg that Im pointing at completely came off, heres hoping some apoxy will do the work. :(
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IMG_20210217_110300300_HDR.jpg
IMG_20210217_110300300_HDR.jpg (68.35 KiB) Viewed 3364 times
Last edited by Plasmid on Wed Feb 17, 2021 6:19 pm, edited 2 times in total.

Plasmid
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Re: Stereo monovision

#6 Post by Plasmid » Wed Feb 17, 2021 4:15 pm

Weird design, this spring holds tension down on the lens carriers, I doubt that that was the cause metal failure, the whole part has become brittle, likely the cause of stress as it travels up and down the screw like adjustment.
Attachments
Rubber bands did the trick they work a lot better than the spring
Rubber bands did the trick they work a lot better than the spring
IMG_20210217_114020191_HDR.jpg (52.5 KiB) Viewed 3355 times
IMG_20210217_111131315_HDR.jpg
IMG_20210217_111131315_HDR.jpg (57.65 KiB) Viewed 3361 times
Last edited by Plasmid on Wed Feb 17, 2021 6:44 pm, edited 1 time in total.

Greg Howald
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Re: Stereo monovision

#7 Post by Greg Howald » Wed Feb 17, 2021 5:04 pm

That's just sad😔. Pot metal I suppose.

Plasmid
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Re: Stereo monovision

#8 Post by Plasmid » Wed Feb 17, 2021 6:17 pm

Greg Howald wrote:
Wed Feb 17, 2021 5:04 pm
That's just sad😔. Pot metal I suppose.
Not even teflon coating for the sake of decency. :lol:
Yeah the metal is flaking all around where you see the apoxy, short term solution until I can find a replacement head or that specific part. Darn shame the optics are very clear when working

Greg Howald
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Re: Stereo monovision

#9 Post by Greg Howald » Wed Feb 17, 2021 9:52 pm

I'm not very smart when it comes to things like this but what if you coated it with some of that silicone spray lubricant?
Greg

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mrsonchus
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Re: Stereo monovision

#10 Post by mrsonchus » Wed Feb 17, 2021 10:04 pm

Just a quick but probably wrong thought. Have you actually set the 'scope to be parfocal in the required way for a stereo-zoom.

1) set both diopter adjustments to zero - i.e. no adjustment applied.
2) zoom to max-zoom and focus as sharply as possible on an object, edge whatever, using both eyepieces in the usual way, not one at a time etc.
3) zoom out to minimum zoom (without moving object of course) then set each eyepiece to best focus with it's own diopter adjuster.
4) zooming in to max-zoom now should stay parfocal over the whole range, i.e. focus should be maintained if set well in above process.
John B

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Re: Stereo monovision

#11 Post by Plasmid » Thu Feb 18, 2021 12:42 am

Greg Howald wrote:
Wed Feb 17, 2021 9:52 pm
I'm not very smart when it comes to things like this but what if you coated it with some of that silicone spray lubricant?
Greg
I used some Nyogel when I first got it two weeks ago, the problem with the spray is that the lens sit just below that linear cam, to be honest Im not sure what could had caused the metal to flake off like that, but seemed very brittle. Im going to attempt to fix it as much as i can, I paid $4.70 plus SH for this particular one so im not too distraught by the failure, it just amazes me how the metal could fail that way. So far the apoxy and the rubber band in place of the spring are working and the image is clear now, I'll have to look for a way to reinforce that part as I doubt Wesco has a replacement.

Plasmid
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Re: Stereo monovision

#12 Post by Plasmid » Thu Feb 18, 2021 12:58 am

mrsonchus wrote:
Wed Feb 17, 2021 10:04 pm
Just a quick but probably wrong thought. Have you actually set the 'scope to be parfocal in the required way for a stereo-zoom.

1) set both diopter adjustments to zero - i.e. no adjustment applied.
2) zoom to max-zoom and focus as sharply as possible on an object, edge whatever, using both eyepieces in the usual way, not one at a time etc.
3) zoom out to minimum zoom (without moving object of course) then set each eyepiece to best focus with it's own diopter adjuster.
4) zooming in to max-zoom now should stay parfocal over the whole range, i.e. focus should be maintained if set well in above process.
Yep, I attempted to see if it was an eyepiece problem, I found that in order to see a clear image on both eyepices, the one that was blurry would have to be lifted completely out of the eyepiece insertion tube and then some 20mm, .....took both biopters apart and no change. I then noticed thet the left sliding cam carrier was brittle and the fork like structure was wider than the right one on the picture.Manually moving the left one with your hand would make the image clear up, the spring that holds both cams linear to each other was pishing the left one further than the right one.When I attempted to bend it back it just snapped, I glued it back in place and the small rubber bands keep the two cams linear in relation to one another. My understanding is that this particular stereo is a cheap knock off of a Olympus or Nikon!
Attachments
How the carrier was prior to snapping off, being wider the cam had more room to be pushed down by the metal spring that was in place
How the carrier was prior to snapping off, being wider the cam had more room to be pushed down by the metal spring that was in place
IMG_20210130_121254.jpg (51.09 KiB) Viewed 3300 times
Last edited by Plasmid on Thu Feb 18, 2021 1:19 am, edited 1 time in total.

Scarodactyl
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Re: Stereo monovision

#13 Post by Scarodactyl » Thu Feb 18, 2021 1:05 am

If you'll show the whole thing we can probably tell you which one it's imitating. Hard to tell from just the base, amd Wesco has sold a lot of stuff over the years.

Plasmid
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Re: Stereo monovision

#14 Post by Plasmid » Thu Feb 18, 2021 1:17 am

Scarodactyl wrote:
Thu Feb 18, 2021 1:05 am
If you'll show the whole thing we can probably tell you which one it's imitating. Hard to tell from just the base, amd Wesco has sold a lot of stuff over the years.
Oh yes I believe you mentioned on a previous post that it was a copy of the Olympus SZ6045
viewtopic.php?f=25&t=11762&p=97085&hilit=Embryo#p97085
Not sure how many components are an exact copy.

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